One thing you haven't mentioned is that Patagonia has been settled by humans long before the other island ecosystems you've addressed in past videos. Animals subject to island gigantism famously are targeted by humans and went extinct extremely often shortly after contact. Thus humans might have hunted some species of Patagonian fauna to extinction, leaving only smaller ones. That's one of the big reasons why their is no more large animals in Australia, why not Patagonia too.
I think that's also just humans being good at extincting other animals in general, especially large ones that have not contacted them before. Africa is the only region that still has large numbers of megafauna, and this is probably because they evolved alongside humans and adapted to them, whereas everywhere else had no idea that the funny naked ape was the most dangerous animal around.
Baikal lake is actually really really cool, I stayed there at January. Freezing cold but so beatiful. When standing still without making any noises you can hear the ice moving and cracking. Really unique sound, like really mild thunderstorm... I've never seen so many stars there.... you can also drink from the lake.
@@YoursUntruly I live here and you can drink this water, it’s safe. They said some small animals clean it. Japanese people even come here to find out if those animals could clean their water too
What do you think about abyssal gigantism? Maybe you could apply your method and consider the ocean depths as an island to understand why squids, arthropods or Greenland Sharks adapted to huge sizes when deep underwater
Abyssal Gigantism is believed to be an adaptation to both pressure and temperature. The square cube law states that as an object doubles in size, its internal space increases by 8x, and its surface space only increases by 4x. This reduces the effective surface pressure by reducing the surface compared to the internal structure pushing back. It also reduces the loss of body heat by reducing the surface area through which heat can be lost. That's the working hypothesis anyway.
Abyssal Gigantism is mostly about efficiency. Because they have so much more volume within them, they retain heat better and are far more efficient compared to smaller counterparts. The channel DeepSeaOddities covers strange critters down there and one of the most common traits among them is Deep Sea Gigantism.
I briefly lived near Mt. Ulurugu. It's one of the most beautiful places I've ever been. I don't remember seeing any tiny chameleons there, but I guess that's kind of the point.
@@RATSKETCHES Imagine trying to correct someone he doesn't know and doesn't know where he lived, spelling it wrong and being in the wrong to begin with.
Speaking of islands, I think Southeast Asia would be an interesting topic to explore if you haven't already. I don't see many RUclipsrs talk about the Wallace Line or the Coral Triangle which is a shame because it's such an intriguing region of the world.
And Borneo too! The Bornean sun bears and pygmy elephants are also examples of insular dwarfism :) Not to mention a close cousin of homo sapiens, another human species, found in the region. What a fascinating place!
4:41 The Saimaa ringed seal is endemic to their habitat in Lake Saimaa, Finland. The lake lies between the cities of Lappeenranta in the south and Joensuu in the north, spanning an oval of approximately 180 by 140 km (112 by 87 mi). It consists of numerous larger basins connected by narrower glacier-carved channels, and its geography is maze-like, having 13,710 islands.
I was expecting you to talk about the Tepuis, in Venezuela and Guiana. These rock formations have a flat top and are totally separated from mainland by high cliffs, an thus they are an amazing example of endemic flora and fauna (for example unique carnivorous plants). Back in the days, the speculation about what could be found on these remote plateaus drove Conan Doyle to write 'The Lost World' where he describes dinosaurs still living there.
The theory of island biogeography is a big part of conservation. The idea that small islands that are further away from the mainland see less colonisation etc is really important on a local scale. In revegetation efforts and natural capital management, "islands" are stands of trees or some other natural feature that harbours wildlife. Windbreaks, roadside vegetation and water reserves are all islands that allow animals to traverse an otherwise inhospitable landscape ( such as paddocks or cities). It's amazing how it can be applied under different scopes or magnitude and it's still applicable
Are we all just going to ignore the fact that the Valdivian rainforest of Chile contains miniature pumas that hunt and devour miniature deer. That is so beautifully brutal.
@@Hunter-jx8jl I fkg knew this reply was gonna come as soon as I read the comment. I was gonna write a more annoying, ironic version of the *your thing, but since you already "uhm achtchually'd" this guy I'm just gonna reply to you instead.
I grew up in southern Arizona, the Sonoran desert makes it a semi arid climate with many similar sky island mountains with interesting geography. I also live in Mozambique for two years In the peace corps and hiked many of the mountains their. I found the climates very similar. Might be an interesting line of investigation for your next video.
As a chilean I grew up hearing teachers talk about how the country is similar to an island due to its natural borders with neighboring countries, such as the Atacama in the north, the ocean in the west and south, and the Andes mountains in the East.
You are the only person I have seen talking about island biogeography and I'm loving it. You helped me find a passion that I didn't even know existed and may be starting some research in the field!
The amount of research and thought that goes into your videos is astounding, I absolutely love every video you release and look forward to learning new information each time!
This series is great because it teaches you a lot about evolution, one of my favorite topics. When it comes to suggestions, I am not able to indicate a specific place, but the introduction mentioned desert oases and in the material I did not notice that there was any mention of animals from oases.
I was shocked while watching the deep sea videos to learn of the giant isopod which has a terrestrial cousin - the woodlouse. It’s also fascinating to learn about the small shallow water sharks like the leopard shark and it’s cousins the Greenland shark (poison meat) the basking and whale sharks as well as the similar appearances of the great white snd salmon shark. Nature is magestical and I can spend a lifetime learning and still not learn it all. Good stuff
Loving this series, great to learn so much more about those lesser known animals. Would love to see a video on New Zealand's diverse bird-family, especially talking about the Moa
One thing that didn't seem to be touched on explicitly in this really interesting vid was the impact of humans, whether predatory or changing the environment (eg through slash & burn) - I didn't know if that was because we've simply been too recent to make a significant contribution to such isolated evolutionary processes...? Aotearoa/NZ is (sadly) a great example of how introduction of humans can cause rapid extinctions of both megafauna and miniaturised species, but do you know if there's anywhere in the world where human impact can be specifically linked to changes in species sizes without actual domestication being involved...?
@@orangeoran4020 A lot of caves in the Hill Country have a species of cute (and endemic) axolotls. I’ll also never forget learning that shrimp live on top of Enchanted Rock, that restructured my brain.
I was extremely disappointed at zero mention of caves. Some are actually sealed off from outside life completely, making them more isolated than an island in the middle of the ocean.
A additional facet regarding the Rhampholeon dwarfism is a trend of reptiles to be smaller in cooler regions. These mountaintop forests although tropical are cooler than lowland rainforest due to the considerable higher elevation.
Another island analog is a small hill of grass in Idaho’s Craters of the Moon National Monument. Lava flows surrounded a plain of grasses long before human arrival and left a small “island” where the grasses were separate from the rest of the plains. Human arrival introduced all sorts of invasive species to Idaho and this “island” acts as a step back in time to all of Idaho’s native grasses.
A pleasant surprise to see you here. Maybe a future collaboration of how much geography has affected politics throughout history and still continues to do so.
Australia and New Zealand are of course good examples of how birds became flightless and larger because of isolation and the lack of predators. I live in Mindanao Philippines these days and since the Philippines developed between 60 million and 50 million years ago there have been many endemic species due to the insular conditions, but no instances of gigantism that I can think of. The Philippine Eagle is an exception but its habitat is only restricted by human intervention. Here in Mindanao is where they are found, and usually ranging from the mountains down towards the coast. I have occasionally spotted mated pairs hunting in the uphill area in Lumbia where I live.
I held one of my finals about this topic (not specifically that part but you get it) and i really enjoyed this video. I had wondered before why there were so few videos about this topic, as i found it very interesting! Thank you :)
There are similar montane forests across Southern Africa. And in some of the ones in South Africa you find Ghost Frogs, which are usually only endemic to isolated mountain peaks across the country. One area in particular is in hogsback in the Eastern Cape, which rises out of the dry plains surrounding it into a temperate rainforest. Its in the Amathole mountain range.
weird that ghost frogs are a thing in mountains in South Africa, they're fairly common on some beaches here in the east coast of the US (specifically Assateague Island I'm not as sure if they're common in other places but they probably are)
@@kevincronk7981 think its probably the case of different genus having the same name, every article I check says there are only species in southern africa and have no related species in North America. Also, had a look at a government website, seems none of the frog species there are classified as ghost Frogs, so could also be a local name.
Best video yet. I REALLY like what you are doing, bringing something unique that no one else is. It's also fantastic that your research doesn't always lead to answers, because you are asking questions that may not have answers yet. With your level of passion, you could be the one going out there studying these island ecosystems. It would be pretty cool to expand the totality of human knowledge. Just a thought, but keep making the videos!
In regard to the chameleons, another factor might be cold-blooded animals would have more drastic effects from growing larger, as volume to surface area ratios change and the ability to warm themselves in the sun becomes impossible. The opposite problem of Whales, where volume to surface area helps them retain heat.
The argument of heat being a factor isn't plausible. Homeothermic animals (not cold-blooded) want to be warmer, and being larger helps them maintain those temperatures longer so being smaller is not advantageous. Also, they are living in tropical and subtropical environments where heat isn't a factor, they are warm enough to do what they need whenever they want. More likely the ancestral chameleon was already small and these are just a result of a isolative evolution where one species becomes multiple distinct species when one or more population is isolated from the main population. There are other dwarf chameleons that inhabit southern Africa which are related to these montane species. Most likely the environment on these mountains hasn't changed relative to what the ancestral species inhabited. Therefore, there's a lack of change in the amount of dietary stress, which is the main factor related to a change in size. However, predatory or sexual selective influences seem to be present which tends to be the main driver for colour changes as we see in the dramatically different colouration between species.
@@Prospector32 Greetings from Finland. We have some lizards here too and they are very tiny. It is also rather cold here usually. This video showed the "one size fits all" expectation to be a problem when comparing very different things because there are more than just few variables.
It's interesting indeed that an island is an island only to some. I recently learned about the New Zealand Kakapo. While a bird, it's flightless and instead the predators, like ferrets, are able to island-hop by swimming.
Possible idea for “Islands that aren’t islands”. I recently learned of several salt water marshes near my home in south central Kansas, hundreds of miles from the nearest ocean. I know of two large area in Kansas and a larger one in Oklahoma, all of which are important stops for migratory birds on their seasonal trips north and south. Little islands of suitable habitat that make their trips possible. Not sure if there are examples of gigantism or dwarfism I just thought it’d make an interesting video!
Marshes would be fascinating to hear more about! There are such weird & wonderful biological things going on in those areas, whether it's critters/plants that bridge both salt & fresh water survival, or species that rely on marsh areas but migrate across enormous distances to complete their reproductive cycles...?
@@anna_in_aotearoa3166 it’s even more fascinating when you consider the lands surrounding them. Wheat, Corn, and soy fields everywhere and right in the middle these little islands of marshlands and one of the few places where native prairie grasses are allowed to flourish
This is one of the best informational series on ecological topics I have ever seen. I love the way you develop your arguments and the details your provide are amazing! Thank you
What about islands under the water? Like areas in the ocean that rise above the surrounding terrain and get more sunlight but are still below the surface? Volcanic vents could also create isolated islands of a sort.
Currents carry eggs, larvae etc very far. I don't think many of these places are in effect isolated even though the distances between them can be huge. But i may be wrong!
@@5kunk157h35h17 that's certainly true for small animals that mass spawn into the currents. There could however be instances of larger species found in isolated pockets. I don't know of any but it at least seems possible.
@Frank B Yes I think it could happen but I don't see how the main things causing gigantism (untapped resources, lack of predation, lack of competition) would occur in something as connected as the sea. But I don't know enough. I'm just guessing. But if it does happen I think the deep sea would be the best candidate. Deep sea currents are much slower than surface currents. Some isolated parts could possibly be impossible to reach for organisms suspended in them. Quote about currents "Whereas speeds of surface currents can reach as high as 250 cm/sec (98 in/sec, or 5.6 mph) a maximum for the Gulf Stream, speeds of deep currents vary from 2 to 10 cm/sec (0.8 to 4 in/sec) or less."
Loving your work dude. Sharing the amazing uniqueness and complexity of different ecosystems and tieing it in with geology,climate etc is just amazing. Wish u'd been my geography teacher at school!
My first thought for why gigantism is rarer in island analogues than on true islands is actually something you already mentioned earlier in the video when talking about why the chameleons got smaller instead of bigger. When islands form in the ocean they start out as bare rock so none of the niches are filled. This means that once plants begin to populate the islands there are abundant resources and little competition for small animals that make it to the islands so they are able to fill niches typically held by larger animals and grow bigger. When an area becomes isolated on land, for example due to a mountain range, the niches are already filled when the ecosystem is cut off from the ‘mainland’. Therefore the species present don’t experience any decrease, or at least very little decrease, in competition, and experience a decrease in available resources instead of an increase, therefore there tends to be no pressure to get larger. It may also explain why the only example of gigantism in this video was the amphipods in baikal. To me lakes seem most like true islands, being isolated from the moment they form meaning they start out with abundant resources and many open niches, meaning any species that are able to get there from the sea/ocean aka the ‘mainland’ in this situation, have little competition and abundant resources allowing them to undergo gigantism much in the same way as island organisms. I rambled on for longer than intended there, and I don’t know if anyone will actually bother reading all this, but I hope I got my point across in a way that made sense
Endhorric lakes also have another resource that increases, dissolved minerals. The catch there is the species need to be able to adapt to those increases. Plants would have the easier time of it, since they are the initial organism in that chain, whereas further up the food chain, those animals require something else to have had evolutionary success, first, which may not always occur.
Yeah especially in the case of large and deep rift lake type environments like lake Baikal you really do see strong parallels between lakes and islands. Though a nuance to account for in discussion of refugia bases island analogs is that prior to the rise of the Andes to their modern towering heights in the Miocene South America was considerably different from today though in some sense it was an island environment of its own in that its fauna ecology were noticeably distinct. Note that in the far south this does not apply to flora the same way specifically for plants which use wind dispersal as the circumpolar jets of the Antarctic have ecologically kept the flora of the far south in genetic contact. The rise of the Andes to their modern towering heights had a profound effect on these South American ecosystems as it occurred fairly suddenly causing the unique species high on the food chain to be unable to adapt leading to the complete extinction of the Sparassodonts(metatherian mammal apex predators) and Sebecids(an ancient lineage of crocodylomorphs that independently survived the K-Pg extinction convergently evolving theropod like jaw anatomy most strongly resembling the tyrannosauridae) and the extinction of the larger lineages of terror birds. AT their prime south American Sebecids reached some of the largest sizes seen among Cenozoic apex predators filling in the niches of the theropods of the Mesozoic so this arguably might be classified as a form of insular gigantism as south America was isolated though ultimately I think this is a poor fit as the larger sizes might be far better explained in terms of the competition among the branches of the South American predator guilds The point is that this meant these and other ecological niches were vacant when the great American interchange happened some ~10 million years later so a resulting key distinction between South America and other refugia island analog environments is that it was primarily a wave of initially generalist species which invaded the continent speciating into these vacant niches effectively trapping those species which specialize into insular dwarfism. In this sense you may have potentially even gotten gigantism but even if that was the case humans kind of ended that when they came to the Americas. At the very least rodents when they arrived in South America by rafting dispersal sometime between 30 to 50 million years ago certainly did
Would love for you to cover the southern spruce fir forests! They’re a unique one because it shows how mountains not only create different environments through catching rainfall, but also by lowering temperature at higher elevations. It may be a little close to home and commonly visited for your channel but that’s part of what makes it so fascinating to me
I like the direction you are going, it's a topic that has always fascinated me. You should make a video on the Madrean Sky Islands. The Channel Islands in California also had insular dwarfism and gigantism during the ice ages and is shown in the fossil record. Hateg Island is a Cretaceous island in modern Hungary with the same.
I think I’ve watched all of your videos in about two weeks… wasn’t at all into geography before but you make it so interesting and easy to listen to. Please MOOOORE ! 😂
Great video (as usual). Would definitely be interesting to see a follow-up on this. Another example of non-island islands might be cities since they can be more or less isolated and are very different from their surrounding areas.
Not completely isolated, however. Even on Manhattan Island in NYC coyotes have been spotted, having presumably crossed via one of the bridges from the Bronx, on the mainland, where they are now more often seen! And before the bridges, maybe some small species floated across, say, the East River on trees branches or debris.
Is it weird that of all things, the part that I found the most interesting was that about the Andes? Idk why,but I just find the fact that mountains can streach to such a vast area and be so large that they can wall off regions from moisture and keep it in others so fascinating. And the fact that is switches the biomes with the change in wind current, leading to effects that cant be only seen in geology but in things like population density makes it even cooler
You see "rain shadow" effects in most regions. A range of mountains, or even hills, often attracts extra rainfall leaving the clouds empty, which means land on the leeward side of the range gets lower rainfalll than it would otherwise have.
Almost every mountain range and even hills do something similar known as the rain shadow effect. Another good example of this is the Himalayas turning Tibet into a cold desert by keeping the monsoon winds within Northern India and Terai region of Nepal.
@@thelakeman2538 OK, but I'd assume the drsasticness of of something like the Andes can only be done by mountain ranges like them or the Himalayas that are vast and tall. Simple hills can't wall off that much moisture and if it's a single mountain that doesn't stretch that far the same is true.
Nice work. I especially like your engagement in thinking through rather than just relying on other's research for answers. Good work with the graphics too. And, yes. I subscribed. Ronn
I like the idea of the Marozi cryptid. A panthera species long gone undiscovered that lives in the Montanes of Kenya. Essentially adapted to its 'island' climate above the hot savannah below and unable to head down to lower elevations. It's probably not a real creature, and if it was, it's extinct now. But it was always a fun idea.
It did exists, the problem was that its consolidation of evolution, as in, when the species started breeding inbetween themselves, was also during the period of extreme hunting during the late 1800s which caused animals to go extint, or in this case, never allowed to settle as species.
When looking at the mountain forests in Africa, my first thought was that being forced to adapt to an "Island" with higher altitude might effect dwarfism through the simple lack of oxygen.
I love this Island series! Some islands I suggest you make videos about are Madagascar, Indonesian Islands Borneo, Sumatra, Sulawesi, Palawan, and the Island of New Guinea the second largest island in the world.
I recently read Henry gee’s the accidental species, about human evolution, where he talks about Homo Floresesnsis, basically a human species subject to island dwarfism. It would be interesting to make make a video about it in this series, cause Homo Floresensis shows that humans are subject to evolution like any other species.
Great video. I always love your work, as I am obsessed with all type of biogeography. This reminds me a bit of Mount Roraima. A pretty interesting place, as I heard the flora is more closely related to that in Africa then the surrounding ecosystems below.
This was nice. Two things, though: 1. You gotta mention tepuis, if you're talking about in-land islands; 2. Aside from new niches, filled with untapped resources, there is another mechanism for gigantism: cold. A larger body is better at keeping warm and so animals tend to get bigger in colder climates than in warm ones, provided they don't lack resources. Examples: Nordic humans, polar bears, emperor penguins, the endemic Antarctic marine species. The Arctic could be your island for the bears and the Antarctic continent and continental shelf could be other islands, the latter in the ocean (isolated by the South circumpolar ocean and current). Sure, they are continent-sized so might not qualify.
A curiosity that I think is relevant to the topic: the Amazon Basin and the Congo Basin also have similar effects to islands along their beds, due to geological variations producing different speeds of currents, and consequently, of oxygenation of the waters and available resources. Some species exist only in certain stretches of rivers, with distinct subspecies according to those stretches (new subspecies of the pink dolphin is a recent example).
Your general excitement about these topics is just amazing! Thank you for all the great work and time you put into every video! Honestly, it inspires me to find my own niche
Please keep talking about Island BioGeography. I love this series. I have actually been watching since you first released the "Dodo | Island BioGeography 1" video, last year.
For an Island Biogeography episode I would be interested in seeing the unique animals of Australia. I would also like to see an episode of the origin of different flowers. You’ve done fruit and Vegetables, you should do flowers next.
4:00 You literally explained the arguments I was having about something similar on a video about these very seals. I had to elaborate on how the sheets during Ice Age may have an impact on how any of those seals got there, how they got isolated, etc.. The other person cannot seem to fathom the possibility of this happening.
There is one example of Patagonian gigantism you missed among birds. It's that of the Burrowing Parrot also commonly known as the Patagonian Conure. Conures are a group of closely related genera of generally small long tailed parrots from South America who average below 100 grams with only a handful reaching up to 150 grams. The Patagonian Conure is massive compared to the rest of them averaging in the 200 and 300 grams. While that might not seem much for it's kind that's a considerable size difference. It has also developed some unique adaptations to tackle the cooler climate, arid conditions and seasonal changes in food availability in the ranges it occupies. A rarity among parrots it can dramatically change its metabolism and increase its weight to deal with seasonal changes. It also prefers to nest in Cliffsides and ravines in cavities they dig themselves than tree hollows like most other parrots. This species also has an interesting evolutionary history in having originated in Chile then a single wave of migrants were able to penetrate past the Andes sometime during the Late Pleistocene to colonize Argentina and parts of south-western South America. While the deers and cats shrank the parrots got big.
Love the videos. Thank you. There might be a video for you off the South West coast of New Zealand. The Lobsters down there are massive and in abundance. I think I read somewhere that the reasons behind this have everything to do with the ocean currents and NZ being on the edge of the "Ring of fire" I could be way off as I know very little about this, but I would love for you to do some videos about the unique oceans in the Southern Hemisphere. Thanks again for the videos. I think I have seen every one of them by now.
That is interesting. At the same latitude lives the Tasmaian giant freshwater crayfish which grow up to 80 cm long. Not surprisingly they are the biggest (and scariest) freshwater invertibrate in the world.
Worth mentioning Sari-Sariñama caves, Churun Meru and Roraima part of Tepuys system in Canaima National Park, among others. Excellent video and amazing channel.
Your enthusiasm is truly contagious, I had a great watch! This makes me curious about caves and underground systems. Probably the most well-known example of evolution in them is fish growing blind. Do you think there are other kinds of evolutionary niches to be found in caverns? Like, subterranean islands?
Love your videos! I would love it if you were to make videos about the different regions of Peru since we have so many different ecosystems given those phenomenons you mentioned here: the Andes Mountain Range, the wind directions, the Humboldt Current, etc
I have all the same interests I swear… and I love exploring random places in the world on google maps. I knew there were other people who did that. Great video!
4:42 Saimaa ringed seals are named as such due to their only habitat being Lake Saimaa, Finland. Thus, their range is restricted only to the FRESH waters of Lake Saimaa and its surrounding banks.
I love plants and always find it interesting how in places like the Andes orchid diversity explodes because of isolation from the mountains they live by and in.
Glad to see you're back with an episode for us. Great examples to prove your point. The constant adaptation of species to their environment is interesting, I think. Beyond the individual, zoomed out and macro, the limitations of Mount Mobu being an island makes a difference for enough many individuals for it to change the whole species, right? You are very good at what you do, you know.
"I had trouble finding examples of island geography, so if you want to see more videos like that be sure to go back in time and isolate some ecosystems and then let me know in the comments" Great video. Really fascinating stuff. Like you said, you cover a lot of cool topics that no one else does.
@@Stevie-J I pulled a quote from the video and modified it to make a joke. If you rewatch the video really carefully you'll notice that Atlas Pro did not actually advocate that people go back and drastically alter the planet to help him to make content. That's the joke and that's why (I assume) people liked my comment. He says in the first 15 seconds that "no one else on youtube is talking about [island biogeography]". The second part of my comment is agreeing with that. Sorry if complimenting someone isn't entertaining enough for you. Definitely a great reason for you to insult a stranger.
Ahhh yes, I live in upstate NY as well. That was quite a freaking snowstorm we had, for mid-April. A friend of mine lost power for 5 days. Anyway, great video as always!
I enjoy your island videos, but I also enjoy your other videos. The thing that sets your videos apart is the quality. Anyway, keep having fun and I will keep watching.
This was truly a wonderfull video! About islands in the sky formed by mountains with tropical surroundings, there is the beatiful example of the tepui mountains in Venezuela (en.wikipedia.org/wiki/Tepui) the fauna is scarse and only include a few batracian if I remember well, but the flaura is astonishing, each tepui harboring a fully different flora. These mountains also are perhaps the oldest in the world. The rock itself is precambrian and it is a very hard type of sandstone/quartzite, plus these mountains never experienced frost, so they have been mountains for much longer than any other on earth.
Would some coral reefs or atolls also qualify to being an island in the sense of what you are discussing here? They are almost the same thing as a 'real' island, except they just happen to be barely under the see level.
If you are looking for another island analog, I recommend diving into the relationship between endemic plants and the geology they are found on. A great example of this can be found in California. Serpentinite is a rock type with a lot of heavy metals and is nutrient poor. It only makes up ~1.5% of the available land, but it's harsh conditions have allowed more unique species to develop. Roughly 12% of all endemic plants in the state are specifically adapted to serpentinite, and they usually have some interesting features to deal with the geological challenges. It would also be interesting to hear how this plays into the larger, local ecosystem (since the animals who interact with these plants may not be as directly impacted by the geology).
My uninformed and totally out of the blue hypothesis is that the artic ring seal eventually evolved to withstand brackish water, and then it could tolerate fresh water, IF the river hypothesis were in fact the right direction.
4:26 - Sure, but migrating up the river would not be done over night either and over generations, seals could have adapted the less and less salty waters. In Canada, the St-Laurence river sees many species of marine mammals and ocean dwelling fishes that swim far into it (Whales have been seen all the up to Montreal) even though the waters from the great lakes that flows through it is freshwater. Even more impressive, Ocean Sharks have been witnessed to go up the Saguenay river, another river that flows out of the freshwater Lac St-Jean lake. While many such animals do so to their own peril, most go safely further towards the inland parts of those rivers because the lower depth of said river are partially salty as the fresh water from the lakes is less dense and flows over the denser salt waters from the sea; even forming intermediary layers of mixed waters in between them. So, getting back to the seals of Lake Baikal, it is certainly not inconceivable that over centuries (Perhaps even millennia) of travels and evolution, arctic seals could have journeyed further and further up the river to the lake until they finally reach the lake. By that time, they would have had plenty of time to adapt from saltwater to freshwaters.
To tag onto your point, he seems to forget that bull sharks transition between fresh water and saltwater rather often. Granted, sharks are a giant fish while seals are mammals, but I would think it is easier for a mammal to change habitats than it would for a fish.
What about salmon and some trout and (I think) sturgeon, that are born in fresh water, swim down to the ocean or sea, live to adulthood there, and then swim back upriver to spawn? Okay, they die after mating, but they survive years in the ocean after leaving the rivers of their birth, so adapting from fresh water to salt is a matter of weeks rather than millennia--and they manage the strenuous swim upriver, often or usually leaping up rapids and falls, without succumbing to the lack of salt water; their death after spawning seems to be a part of their life cycle, just as many insects die after mating.
What most curiosity has awake this video is about what are the oldest species of lake Baikal, because if it's that old the first species already there must have change significantly.
I would like to hear more about these Tepuis in the Amazon jungle (table mountains that rise up to nine thousand feet above the rainforest). There was a documentary about large red crickets and carnivorous plants several decades ago, and that was it. They didn't even specify how much the fauna would differ from one of these mountains to the next.
You know how all the reporter in the 1950's sounded the same? Same with today's reporters. Now, we have RUclipsrs and they also have the same way of speaking just like this guy.
It would be interesting to see if there's anything particular about the biogeography of nested islands or lakes, such as the famous island in a lake in an island in a lake in Quebec.
Fantastic video as always! You might want to check out Saimaa ringed seals and Ladoga ringed seals as the 2 other freshwater seals in the world. And the Ancylus Lake as the predecessor to the modern Baltic sea which in itself is kind of and island ecosystem being largely isolated from the North Sea.
One thing you haven't mentioned is that Patagonia has been settled by humans long before the other island ecosystems you've addressed in past videos. Animals subject to island gigantism famously are targeted by humans and went extinct extremely often shortly after contact. Thus humans might have hunted some species of Patagonian fauna to extinction, leaving only smaller ones. That's one of the big reasons why their is no more large animals in Australia, why not Patagonia too.
That makes wonderful sense.
Guess we're the greatest predator in the world
I think that's also just humans being good at extincting other animals in general, especially large ones that have not contacted them before. Africa is the only region that still has large numbers of megafauna, and this is probably because they evolved alongside humans and adapted to them, whereas everywhere else had no idea that the funny naked ape was the most dangerous animal around.
yh i think giant ground sloth coexist with humans in south america
@@heichan8657 I am pretty sure those are extinct.
or alternately the worst.
Baikal lake is actually really really cool, I stayed there at January. Freezing cold but so beatiful. When standing still without making any noises you can hear the ice moving and cracking. Really unique sound, like really mild thunderstorm... I've never seen so many stars there.... you can also drink from the lake.
I wouldn’t drink from anything that’s non moving.
@@YoursUntruly bikal lake is large enough to have currents
@@YoursUntruly , you shouldn't drink even moving water.
In upstream, there can be anything possible like Dead animals, feces, rotten things.
@@Edward4Plantagenet yeah but it’s a way better bet when you’re dehydrated and NEED to drink something, always go for running water.
@@YoursUntruly I live here and you can drink this water, it’s safe. They said some small animals clean it. Japanese people even come here to find out if those animals could clean their water too
What do you think about abyssal gigantism? Maybe you could apply your method and consider the ocean depths as an island to understand why squids, arthropods or Greenland Sharks adapted to huge sizes when deep underwater
Good suggestion. Probably the stronger pressure is lack of predators, I think food is pretty scarce in the abyssal depths.
Abyssal Gigantism is believed to be an adaptation to both pressure and temperature.
The square cube law states that as an object doubles in size, its internal space increases by 8x, and its surface space only increases by 4x. This reduces the effective surface pressure by reducing the surface compared to the internal structure pushing back. It also reduces the loss of body heat by reducing the surface area through which heat can be lost. That's the working hypothesis anyway.
@@wizardtim8573 Thanks for your scholarly input on this question!
Abyssal Gigantism is mostly about efficiency. Because they have so much more volume within them, they retain heat better and are far more efficient compared to smaller counterparts. The channel DeepSeaOddities covers strange critters down there and one of the most common traits among them is Deep Sea Gigantism.
Spider crabs. 😳
I briefly lived near Mt. Ulurugu. It's one of the most beautiful places I've ever been. I don't remember seeing any tiny chameleons there, but I guess that's kind of the point.
Its uluru not ulugru
@@RATSKETCHES Ulurugu is a range in Tanzania, while Uluru is a mountain in Australia
@@RATSKETCHES Imagine trying to correct someone he doesn't know and doesn't know where he lived, spelling it wrong and being in the wrong to begin with.
@@RATSKETCHESIf you know what Uluru Rock is you know where it is, and it’s not Africa.
@@RATSKETCHESdelete this comment it’s wrong
Speaking of islands, I think Southeast Asia would be an interesting topic to explore if you haven't already. I don't see many RUclipsrs talk about the Wallace Line or the Coral Triangle which is a shame because it's such an intriguing region of the world.
And Borneo too! The Bornean sun bears and pygmy elephants are also examples of insular dwarfism :) Not to mention a close cousin of homo sapiens, another human species, found in the region. What a fascinating place!
One of the richest biodiversity regions too
@@fafddzfaf I'm curious, what other human species?
@@DesertsOfHighfleet it’s something like “homo florensus” they’re related to the dovicidans species of asia
@@DesertsOfHighfleet Homo floresiensis en.m.wikipedia.org/wiki/Homo_floresiensis
4:41 The Saimaa ringed seal is endemic to their habitat in Lake Saimaa, Finland. The lake lies between the cities of Lappeenranta in the south and Joensuu in the north, spanning an oval of approximately 180 by 140 km (112 by 87 mi). It consists of numerous larger basins connected by narrower glacier-carved channels, and its geography is maze-like, having 13,710 islands.
That is another exclusively freshwater seal.
I was expecting you to talk about the Tepuis, in Venezuela and Guiana. These rock formations have a flat top and are totally separated from mainland by high cliffs, an thus they are an amazing example of endemic flora and fauna (for example unique carnivorous plants).
Back in the days, the speculation about what could be found on these remote plateaus drove Conan Doyle to write 'The Lost World' where he describes dinosaurs still living there.
Came to the comments to say this, though I couldn't remember the name, and only the general area.
Is that where Mount Roraima is?
At the top of this tepui, the borders of guiana, venezuela and brazil meet. They have different names depending on the side you are.
@@AntonioZL guyana*
@@hoseasylvester2596 It's guiana in portuguese, which is my native language.
The theory of island biogeography is a big part of conservation.
The idea that small islands that are further away from the mainland see less colonisation etc is really important on a local scale.
In revegetation efforts and natural capital management, "islands" are stands of trees or some other natural feature that harbours wildlife.
Windbreaks, roadside vegetation and water reserves are all islands that allow animals to traverse an otherwise inhospitable landscape ( such as paddocks or cities).
It's amazing how it can be applied under different scopes or magnitude and it's still applicable
Correction! There is another fresh water seal in a lake in Finland called Saimaa Ringed Seal!
I had decided to shut up about it until he said that baikal seal is the only freshwater seal... xD
Can confirm.
Wait but aren't the Saimaa and the Ladoga just subspecies of the ringed seal? The Baikal seal is a species of its own.
@@TheWoollyFrog He never said species of seal though, he just said seal
@@TheWoollyFrog it's still a seal living purely in fresh water.
Are we all just going to ignore the fact that the Valdivian rainforest of Chile contains miniature pumas that hunt and devour miniature deer. That is so beautifully brutal.
That's sick
Dude you’re channel is like a public service, thank you for teaching such interesting content.
Your*
@@Hunter-jx8jl I fkg knew this reply was gonna come as soon as I read the comment. I was gonna write a more annoying, ironic version of the *your thing, but since you already "uhm achtchually'd" this guy I'm just gonna reply to you instead.
I grew up in southern Arizona, the Sonoran desert makes it a semi arid climate with many similar sky island mountains with interesting geography. I also live in Mozambique for two years In the peace corps and hiked many of the mountains their. I found the climates very similar. Might be an interesting line of investigation for your next video.
As a chilean I grew up hearing teachers talk about how the country is similar to an island due to its natural borders with neighboring countries, such as the Atacama in the north, the ocean in the west and south, and the Andes mountains in the East.
Your teacher isn't wrong. Countries are islands too in many perspectives.
en.wikipedia.org/wiki/Island_mentality
Vale la pena mencionar que los animales gigantes se extinguieron en Chile, como en todo América
@@Nickferal e en australia tambien
You are the only person I have seen talking about island biogeography and I'm loving it. You helped me find a passion that I didn't even know existed and may be starting some research in the field!
Love your content man, it is so consistently of the highest quality.
The amount of research and thought that goes into your videos is astounding, I absolutely love every video you release and look forward to learning new information each time!
This series is great because it teaches you a lot about evolution, one of my favorite topics. When it comes to suggestions, I am not able to indicate a specific place, but the introduction mentioned desert oases and in the material I did not notice that there was any mention of animals from oases.
I was shocked while watching the deep sea videos to learn of the giant isopod which has a terrestrial cousin - the woodlouse. It’s also fascinating to learn about the small shallow water sharks like the leopard shark and it’s cousins the Greenland shark (poison meat) the basking and whale sharks as well as the similar appearances of the great white snd salmon shark. Nature is magestical and I can spend a lifetime learning and still not learn it all. Good stuff
Loving this series, great to learn so much more about those lesser known animals. Would love to see a video on New Zealand's diverse bird-family, especially talking about the Moa
One thing that didn't seem to be touched on explicitly in this really interesting vid was the impact of humans, whether predatory or changing the environment (eg through slash & burn) - I didn't know if that was because we've simply been too recent to make a significant contribution to such isolated evolutionary processes...?
Aotearoa/NZ is (sadly) a great example of how introduction of humans can cause rapid extinctions of both megafauna and miniaturised species, but do you know if there's anywhere in the world where human impact can be specifically linked to changes in species sizes without actual domestication being involved...?
I am thrilled to have come across this RUclips connection. I think your content, production quality and enthusiasm are well above par. Thank you.
I'd love to see your thoughts on cave "island" populations! This series is great, please keep it up! :)
In spain there is a cabe were albino scorpions live and you cant find em in another place of the world
In Texas there's a group of caves where each one has a some different completely endemic species of spider.
@@orangeoran4020 A lot of caves in the Hill Country have a species of cute (and endemic) axolotls. I’ll also never forget learning that shrimp live on top of Enchanted Rock, that restructured my brain.
I was extremely disappointed at zero mention of caves. Some are actually sealed off from outside life completely, making them more isolated than an island in the middle of the ocean.
Not to mention "Culex pipiens molestus", in the London Underground!
A additional facet regarding the Rhampholeon dwarfism is a trend of reptiles to be smaller in cooler regions. These mountaintop forests although tropical are cooler than lowland rainforest due to the considerable higher elevation.
Another island analog is a small hill of grass in Idaho’s Craters of the Moon National Monument. Lava flows surrounded a plain of grasses long before human arrival and left a small “island” where the grasses were separate from the rest of the plains. Human arrival introduced all sorts of invasive species to Idaho and this “island” acts as a step back in time to all of Idaho’s native grasses.
Cool!
Good call.
As you mentioned though, invasive species have made it appear like the rest of the area unless you know what you are looking for.
@@norml.hugh-mann yeah, it’s pretty neat! 🪨
I live in eastern Wa and have always wanted to see the craters of the moon, I geuss that is one thing I will have to look out for.
"Lakes are small bodies of water"
Great Lakes: "Am I a joke to you?"
As far as bodies of water go, even the great lakes are pretty small compared to oceans and seas
Very interesting, I never thought of lakes and caves consciously as islands before with the same evolutionary pressures.
A pleasant surprise to see you here. Maybe a future collaboration of how much geography has affected politics throughout history and still continues to do so.
@@OptimisticNihilist15 A collab from Politics with Paint and Atlaspro would be amazingg!
Evolutionary and literal pressure
Australia and New Zealand are of course good examples of how birds became flightless and larger because of isolation and the lack of predators. I live in Mindanao Philippines these days and since the Philippines developed between 60 million and 50 million years ago there have been many endemic species due to the insular conditions, but no instances of gigantism that I can think of. The Philippine Eagle is an exception but its habitat is only restricted by human intervention. Here in Mindanao is where they are found, and usually ranging from the mountains down towards the coast. I have occasionally spotted mated pairs hunting in the uphill area in Lumbia where I live.
The Congo River could be a good one to look at. It's a very deep river and separates some recent speciations, like the chimpazee/bonobo split.
@@cruz7579 Yeah and the incredible current separates some too.
I held one of my finals about this topic (not specifically that part but you get it) and i really enjoyed this video. I had wondered before why there were so few videos about this topic, as i found it very interesting!
Thank you
:)
There are similar montane forests across Southern Africa. And in some of the ones in South Africa you find Ghost Frogs, which are usually only endemic to isolated mountain peaks across the country. One area in particular is in hogsback in the Eastern Cape, which rises out of the dry plains surrounding it into a temperate rainforest. Its in the Amathole mountain range.
Very interesting, thanks.
weird that ghost frogs are a thing in mountains in South Africa, they're fairly common on some beaches here in the east coast of the US (specifically Assateague Island I'm not as sure if they're common in other places but they probably are)
@@kevincronk7981 think its probably the case of different genus having the same name, every article I check says there are only species in southern africa and have no related species in North America. Also, had a look at a government website, seems none of the frog species there are classified as ghost Frogs, so could also be a local name.
Best video yet. I REALLY like what you are doing, bringing something unique that no one else is. It's also fantastic that your research doesn't always lead to answers, because you are asking questions that may not have answers yet. With your level of passion, you could be the one going out there studying these island ecosystems. It would be pretty cool to expand the totality of human knowledge. Just a thought, but keep making the videos!
In regard to the chameleons, another factor might be cold-blooded animals would have more drastic effects from growing larger, as volume to surface area ratios change and the ability to warm themselves in the sun becomes impossible. The opposite problem of Whales, where volume to surface area helps them retain heat.
It’s probably both.
Need i remind you of Pliosaurs, and Plesiosaurs, Crocodilians Varanids etc.
The argument of heat being a factor isn't plausible. Homeothermic animals (not cold-blooded) want to be warmer, and being larger helps them maintain those temperatures longer so being smaller is not advantageous. Also, they are living in tropical and subtropical environments where heat isn't a factor, they are warm enough to do what they need whenever they want.
More likely the ancestral chameleon was already small and these are just a result of a isolative evolution where one species becomes multiple distinct species when one or more population is isolated from the main population. There are other dwarf chameleons that inhabit southern Africa which are related to these montane species. Most likely the environment on these mountains hasn't changed relative to what the ancestral species inhabited. Therefore, there's a lack of change in the amount of dietary stress, which is the main factor related to a change in size. However, predatory or sexual selective influences seem to be present which tends to be the main driver for colour changes as we see in the dramatically different colouration between species.
@@Prospector32 Greetings from Finland. We have some lizards here too and they are very tiny. It is also rather cold here usually.
This video showed the "one size fits all" expectation to be a problem when comparing very different things because there are more than just few variables.
It's interesting indeed that an island is an island only to some. I recently learned about the New Zealand Kakapo. While a bird, it's flightless and instead the predators, like ferrets, are able to island-hop by swimming.
Possible idea for “Islands that aren’t islands”. I recently learned of several salt water marshes near my home in south central Kansas, hundreds of miles from the nearest ocean. I know of two large area in Kansas and a larger one in Oklahoma, all of which are important stops for migratory birds on their seasonal trips north and south. Little islands of suitable habitat that make their trips possible. Not sure if there are examples of gigantism or dwarfism I just thought it’d make an interesting video!
Marshes would be fascinating to hear more about! There are such weird & wonderful biological things going on in those areas, whether it's critters/plants that bridge both salt & fresh water survival, or species that rely on marsh areas but migrate across enormous distances to complete their reproductive cycles...?
OMG this sounds dope af!
@@anna_in_aotearoa3166 it’s even more fascinating when you consider the lands surrounding them. Wheat, Corn, and soy fields everywhere and right in the middle these little islands of marshlands and one of the few places where native prairie grasses are allowed to flourish
en.m.wikipedia.org/wiki/Quivira_National_Wildlife_Refuge
en.m.wikipedia.org/wiki/Salt_Plains_National_Wildlife_Refuge
This is one of the best informational series on ecological topics I have ever seen. I love the way you develop your arguments and the details your provide are amazing! Thank you
What about islands under the water? Like areas in the ocean that rise above the surrounding terrain and get more sunlight but are still below the surface? Volcanic vents could also create isolated islands of a sort.
Taal Volcano is a “Vulcan Point island within a crater lake on the volcano island within a lake on Luzon island.”
Currents carry eggs, larvae etc very far. I don't think many of these places are in effect isolated even though the distances between them can be huge. But i may be wrong!
@@5kunk157h35h17 that's certainly true for small animals that mass spawn into the currents. There could however be instances of larger species found in isolated pockets. I don't know of any but it at least seems possible.
@Frank B Yes I think it could happen but I don't see how the main things causing gigantism (untapped resources, lack of predation, lack of competition) would occur in something as connected as the sea. But I don't know enough. I'm just guessing. But if it does happen I think the deep sea would be the best candidate. Deep sea currents are much slower than surface currents. Some isolated parts could possibly be impossible to reach for organisms suspended in them.
Quote about currents "Whereas speeds of surface currents can reach as high as 250 cm/sec (98 in/sec, or 5.6 mph) a maximum for the Gulf Stream, speeds of deep currents vary from 2 to 10 cm/sec (0.8 to 4 in/sec) or less."
@@5kunk157h35h17 They can be isolated if the water has a higher salinity.
Loving your work dude.
Sharing the amazing uniqueness and complexity of different ecosystems and tieing it in with geology,climate etc is just amazing.
Wish u'd been my geography teacher at school!
My first thought for why gigantism is rarer in island analogues than on true islands is actually something you already mentioned earlier in the video when talking about why the chameleons got smaller instead of bigger. When islands form in the ocean they start out as bare rock so none of the niches are filled. This means that once plants begin to populate the islands there are abundant resources and little competition for small animals that make it to the islands so they are able to fill niches typically held by larger animals and grow bigger. When an area becomes isolated on land, for example due to a mountain range, the niches are already filled when the ecosystem is cut off from the ‘mainland’. Therefore the species present don’t experience any decrease, or at least very little decrease, in competition, and experience a decrease in available resources instead of an increase, therefore there tends to be no pressure to get larger. It may also explain why the only example of gigantism in this video was the amphipods in baikal. To me lakes seem most like true islands, being isolated from the moment they form meaning they start out with abundant resources and many open niches, meaning any species that are able to get there from the sea/ocean aka the ‘mainland’ in this situation, have little competition and abundant resources allowing them to undergo gigantism much in the same way as island organisms.
I rambled on for longer than intended there, and I don’t know if anyone will actually bother reading all this, but I hope I got my point across in a way that made sense
Endhorric lakes also have another resource that increases, dissolved minerals. The catch there is the species need to be able to adapt to those increases. Plants would have the easier time of it, since they are the initial organism in that chain, whereas further up the food chain, those animals require something else to have had evolutionary success, first, which may not always occur.
Yeah especially in the case of large and deep rift lake type environments like lake Baikal you really do see strong parallels between lakes and islands.
Though a nuance to account for in discussion of refugia bases island analogs is that prior to the rise of the Andes to their modern towering heights in the Miocene South America was considerably different from today though in some sense it was an island environment of its own in that its fauna ecology were noticeably distinct. Note that in the far south this does not apply to flora the same way specifically for plants which use wind dispersal as the circumpolar jets of the Antarctic have ecologically kept the flora of the far south in genetic contact.
The rise of the Andes to their modern towering heights had a profound effect on these South American ecosystems as it occurred fairly suddenly causing the unique species high on the food chain to be unable to adapt leading to the complete extinction of the Sparassodonts(metatherian mammal apex predators) and Sebecids(an ancient lineage of crocodylomorphs that independently survived the K-Pg extinction convergently evolving theropod like jaw anatomy most strongly resembling the tyrannosauridae) and the extinction of the larger lineages of terror birds. AT their prime south American Sebecids reached some of the largest sizes seen among Cenozoic apex predators filling in the niches of the theropods of the Mesozoic so this arguably might be classified as a form of insular gigantism as south America was isolated though ultimately I think this is a poor fit as the larger sizes might be far better explained in terms of the competition among the branches of the South American predator guilds
The point is that this meant these and other ecological niches were vacant when the great American interchange happened some ~10 million years later so a resulting key distinction between South America and other refugia island analog environments is that it was primarily a wave of initially generalist species which invaded the continent speciating into these vacant niches effectively trapping those species which specialize into insular dwarfism. In this sense you may have potentially even gotten gigantism but even if that was the case humans kind of ended that when they came to the Americas. At the very least rodents when they arrived in South America by rafting dispersal sometime between 30 to 50 million years ago certainly did
This is one of the best channels on youtube.
Watching your videos are seriously the highlight of my month it’s literally an experience
Brilliant! I like the vibe and the flow and the the overall intellectuality of you videos! Good work!
Would love for you to cover the southern spruce fir forests! They’re a unique one because it shows how mountains not only create different environments through catching rainfall, but also by lowering temperature at higher elevations. It may be a little close to home and commonly visited for your channel but that’s part of what makes it so fascinating to me
No other channel holding my attention like this one lately
Top tier content, no filler, relevant pics/images, great narration... nice job bro
Just noticed you have over a million subscribers. Been watching since that number was in the low thousands. Congratulations and keep up the great work
I like the direction you are going, it's a topic that has always fascinated me. You should make a video on the Madrean Sky Islands. The Channel Islands in California also had insular dwarfism and gigantism during the ice ages and is shown in the fossil record. Hateg Island is a Cretaceous island in modern Hungary with the same.
I think I’ve watched all of your videos in about two weeks… wasn’t at all into geography before but you make it so interesting and easy to listen to. Please MOOOORE ! 😂
Great video (as usual).
Would definitely be interesting to see a follow-up on this.
Another example of non-island islands might be cities since they can be more or less isolated and are very different from their surrounding areas.
Not completely isolated, however. Even on Manhattan Island in NYC coyotes have been spotted, having presumably crossed via one of the bridges from the Bronx, on the mainland, where they are now more often seen! And before the bridges, maybe some small species floated across, say, the East River on trees branches or debris.
This concept is a thing called allopatry. Its what happens when animals are separated. Not only by sea but by basically anything
Is it weird that of all things, the part that I found the most interesting was that about the Andes? Idk why,but I just find the fact that mountains can streach to such a vast area and be so large that they can wall off regions from moisture and keep it in others so fascinating. And the fact that is switches the biomes with the change in wind current, leading to effects that cant be only seen in geology but in things like population density makes it even cooler
You see "rain shadow" effects in most regions. A range of mountains, or even hills, often attracts extra rainfall leaving the clouds empty, which means land on the leeward side of the range gets lower rainfalll than it would otherwise have.
Almost every mountain range and even hills do something similar known as the rain shadow effect. Another good example of this is the Himalayas turning Tibet into a cold desert by keeping the monsoon winds within Northern India and Terai region of Nepal.
@@Dave_Sisson Hey atleast that way you also get rivers, right?
@@thelakeman2538 OK, but I'd assume the drsasticness of of something like the Andes can only be done by mountain ranges like them or the Himalayas that are vast and tall. Simple hills can't wall off that much moisture and if it's a single mountain that doesn't stretch that far the same is true.
yet, there's also the antartandes if they had any opportunity to do so aswell when there was no ice on the continent.
Nice work. I especially like your engagement in thinking through rather than just relying on other's research for answers. Good work with the graphics too. And, yes. I subscribed. Ronn
I like the idea of the Marozi cryptid.
A panthera species long gone undiscovered that lives in the Montanes of Kenya.
Essentially adapted to its 'island' climate above the hot savannah below and unable to head down to lower elevations.
It's probably not a real creature, and if it was, it's extinct now.
But it was always a fun idea.
It did exists, the problem was that its consolidation of evolution, as in, when the species started breeding inbetween themselves, was also during the period of extreme hunting during the late 1800s which caused animals to go extint, or in this case, never allowed to settle as species.
I LOVE this channel. No politics/war , all Geography/science. Thank you for this respite from the world.
When looking at the mountain forests in Africa, my first thought was that being forced to adapt to an "Island" with higher altitude might effect dwarfism through the simple lack of oxygen.
I love this Island series! Some islands I suggest you make videos about are Madagascar, Indonesian Islands Borneo, Sumatra, Sulawesi, Palawan, and the Island of New Guinea the second largest island in the world.
I recently read Henry gee’s the accidental species, about human evolution, where he talks about Homo Floresesnsis, basically a human species subject to island dwarfism. It would be interesting to make make a video about it in this series, cause Homo Floresensis shows that humans are subject to evolution like any other species.
I second that! More documentaries about the real life "hobbits" and the related "orang pendak" myths of Indonesia.
Watching videos like yours reminds me of how much beauty and mystery we still have left in the world…I really hope we don’t lose it
Great video. I always love your work, as I am obsessed with all type of biogeography. This reminds me a bit of Mount Roraima. A pretty interesting place, as I heard the flora is more closely related to that in Africa then the surrounding ecosystems below.
This was nice. Two things, though:
1. You gotta mention tepuis, if you're talking about in-land islands;
2. Aside from new niches, filled with untapped resources, there is another mechanism for gigantism: cold. A larger body is better at keeping warm and so animals tend to get bigger in colder climates than in warm ones, provided they don't lack resources. Examples: Nordic humans, polar bears, emperor penguins, the endemic Antarctic marine species.
The Arctic could be your island for the bears and the Antarctic continent and continental shelf could be other islands, the latter in the ocean (isolated by the South circumpolar ocean and current). Sure, they are continent-sized so might not qualify.
A curiosity that I think is relevant to the topic: the Amazon Basin and the Congo Basin also have similar effects to islands along their beds, due to geological variations producing different speeds of currents, and consequently, of oxygenation of the waters and available resources.
Some species exist only in certain stretches of rivers, with distinct subspecies according to those stretches (new subspecies of the pink dolphin is a recent example).
The seals simply walked
…2000 km….
Ikr
I absolutely freaking love this channel. And island isolation is such a fascinating biogeography topic!
As an environmental history MA student and biogeography nerd, your channel is awesome
Your content inspires me
You and Bibliariadon are the only two youtubers who I have heard mention these principles. Thank you for broadening our horizons.
PBS Eons have also covered - a channel worth checking out if you haven’t seen it
@@absolutetucker9198 thanks, I've subbed to them, but haven't watched them too much in the past. Will give them another look nowm
Greetings from the shores of Lake Baikal! It's cool to see a mention of it
Your general excitement about these topics is just amazing! Thank you for all the great work and time you put into every video! Honestly, it inspires me to find my own niche
This video has way more info packed inside it than the title would suggest. You do amazing work! Keep it comimg!
This channel is really something to be proud of, congrats on all the hard work paying off!
Please keep talking about Island BioGeography. I love this series. I have actually been watching since you first released the "Dodo | Island BioGeography 1" video, last year.
For an Island Biogeography episode I would be interested in seeing the unique animals of Australia.
I would also like to see an episode of the origin of different flowers. You’ve done fruit and Vegetables, you should do flowers next.
4:00 You literally explained the arguments I was having about something similar on a video about these very seals. I had to elaborate on how the sheets during Ice Age may have an impact on how any of those seals got there, how they got isolated, etc.. The other person cannot seem to fathom the possibility of this happening.
It was on the video by Moth Light Media: How did a seal get to a lake in the middle of Siberia ruclips.net/video/7GUnQsnLVGo/видео.html
Ice in land?? Impossible!
There is one example of Patagonian gigantism you missed among birds. It's that of the Burrowing Parrot also commonly known as the Patagonian Conure. Conures are a group of closely related genera of generally small long tailed parrots from South America who average below 100 grams with only a handful reaching up to 150 grams. The Patagonian Conure is massive compared to the rest of them averaging in the 200 and 300 grams. While that might not seem much for it's kind that's a considerable size difference. It has also developed some unique adaptations to tackle the cooler climate, arid conditions and seasonal changes in food availability in the ranges it occupies. A rarity among parrots it can dramatically change its metabolism and increase its weight to deal with seasonal changes. It also prefers to nest in Cliffsides and ravines in cavities they dig themselves than tree hollows like most other parrots. This species also has an interesting evolutionary history in having originated in Chile then a single wave of migrants were able to penetrate past the Andes sometime during the Late Pleistocene to colonize Argentina and parts of south-western South America. While the deers and cats shrank the parrots got big.
Love the videos. Thank you.
There might be a video for you off the South West coast of New Zealand. The Lobsters down there are massive and in abundance. I think I read somewhere that the reasons behind this have everything to do with the ocean currents and NZ being on the edge of the "Ring of fire"
I could be way off as I know very little about this, but I would love for you to do some videos about the unique oceans in the Southern Hemisphere.
Thanks again for the videos. I think I have seen every one of them by now.
That is interesting. At the same latitude lives the Tasmaian giant freshwater crayfish which grow up to 80 cm long. Not surprisingly they are the biggest (and scariest) freshwater invertibrate in the world.
Recently found this channel - it's so nerdy and wholesome and I love it 😭
Ah but you are mistaken, Ladoga ringed seal and Saimaa ringed seals are fresh water seals aswell
Worth mentioning Sari-Sariñama caves, Churun Meru and Roraima part of Tepuys system in Canaima National Park, among others. Excellent video and amazing channel.
Your enthusiasm is truly contagious, I had a great watch!
This makes me curious about caves and underground systems. Probably the most well-known example of evolution in them is fish growing blind. Do you think there are other kinds of evolutionary niches to be found in caverns? Like, subterranean islands?
Love your videos! I would love it if you were to make videos about the different regions of Peru since we have so many different ecosystems given those phenomenons you mentioned here: the Andes Mountain Range, the wind directions, the Humboldt Current, etc
I have all the same interests I swear… and I love exploring random places in the world on google maps. I knew there were other people who did that. Great video!
i love your biogeography videos, i also liked a lot the "where foods/spices/whatever came from"
4:42 Saimaa ringed seals are named as such due to their only habitat being Lake Saimaa, Finland. Thus, their range is restricted only to the FRESH waters of Lake Saimaa and its surrounding banks.
I love plants and always find it interesting how in places like the Andes orchid diversity explodes because of isolation from the mountains they live by and in.
Glad to see you're back with an episode for us.
Great examples to prove your point.
The constant adaptation of species to their environment is interesting, I think.
Beyond the individual, zoomed out and macro, the limitations of Mount Mobu being an island makes a difference for enough many individuals for it to change the whole species, right?
You are very good at what you do, you know.
"I had trouble finding examples of island geography, so if you want to see more videos like that be sure to go back in time and isolate some ecosystems and then let me know in the comments"
Great video. Really fascinating stuff. Like you said, you cover a lot of cool topics that no one else does.
@@Stevie-J I pulled a quote from the video and modified it to make a joke. If you rewatch the video really carefully you'll notice that Atlas Pro did not actually advocate that people go back and drastically alter the planet to help him to make content. That's the joke and that's why (I assume) people liked my comment.
He says in the first 15 seconds that "no one else on youtube is talking about [island biogeography]". The second part of my comment is agreeing with that. Sorry if complimenting someone isn't entertaining enough for you. Definitely a great reason for you to insult a stranger.
@@Stevie-J You haven't been on the internet long enough if you think pulling a quote from a video is a sign of a bot.
All your videos are awesome, keep posting as always!!! Great efforts 👍
Ahhh yes, I live in upstate NY as well. That was quite a freaking snowstorm we had, for mid-April. A friend of mine lost power for 5 days.
Anyway, great video as always!
I enjoy your island videos, but I also enjoy your other videos. The thing that sets your videos apart is the quality. Anyway, keep having fun and I will keep watching.
Great video! There is also something cool going on with the evolution of cichlids in lake malawi.
I thought he was going to mention the Cichlids in this video, but maybe he'll do a future video on them
Evolution is a powerful force. It doesn’t always work intuitively but it always works logically. These were some really great examples.
This was truly a wonderfull video!
About islands in the sky formed by mountains with tropical surroundings, there is the beatiful example of the tepui mountains in Venezuela (en.wikipedia.org/wiki/Tepui) the fauna is scarse and only include a few batracian if I remember well, but the flaura is astonishing, each tepui harboring a fully different flora. These mountains also are perhaps the oldest in the world. The rock itself is precambrian and it is a very hard type of sandstone/quartzite, plus these mountains never experienced frost, so they have been mountains for much longer than any other on earth.
Would some coral reefs or atolls also qualify to being an island in the sense of what you are discussing here? They are almost the same thing as a 'real' island, except they just happen to be barely under the see level.
Yes, I have been enjoying this. Thanks for your research and presenting it in an easily-absorbed way.
If you are looking for another island analog, I recommend diving into the relationship between endemic plants and the geology they are found on.
A great example of this can be found in California. Serpentinite is a rock type with a lot of heavy metals and is nutrient poor. It only makes up ~1.5% of the available land, but it's harsh conditions have allowed more unique species to develop. Roughly 12% of all endemic plants in the state are specifically adapted to serpentinite, and they usually have some interesting features to deal with the geological challenges.
It would also be interesting to hear how this plays into the larger, local ecosystem (since the animals who interact with these plants may not be as directly impacted by the geology).
That's a really awesome topic, I'd never heard about that before
Yes, this would be cool to learn about.
I'd be curious to see which animals spread these plants' seeds.
My uninformed and totally out of the blue hypothesis is that the artic ring seal eventually evolved to withstand brackish water, and then it could tolerate fresh water, IF the river hypothesis were in fact the right direction.
4:26 - Sure, but migrating up the river would not be done over night either and over generations, seals could have adapted the less and less salty waters. In Canada, the St-Laurence river sees many species of marine mammals and ocean dwelling fishes that swim far into it (Whales have been seen all the up to Montreal) even though the waters from the great lakes that flows through it is freshwater. Even more impressive, Ocean Sharks have been witnessed to go up the Saguenay river, another river that flows out of the freshwater Lac St-Jean lake. While many such animals do so to their own peril, most go safely further towards the inland parts of those rivers because the lower depth of said river are partially salty as the fresh water from the lakes is less dense and flows over the denser salt waters from the sea; even forming intermediary layers of mixed waters in between them. So, getting back to the seals of Lake Baikal, it is certainly not inconceivable that over centuries (Perhaps even millennia) of travels and evolution, arctic seals could have journeyed further and further up the river to the lake until they finally reach the lake. By that time, they would have had plenty of time to adapt from saltwater to freshwaters.
To tag onto your point, he seems to forget that bull sharks transition between fresh water and saltwater rather often. Granted, sharks are a giant fish while seals are mammals, but I would think it is easier for a mammal to change habitats than it would for a fish.
Yes, and there are othe freshwater seals in Lake Lagoda an some Finish lakes.
What about salmon and some trout and (I think) sturgeon, that are born in fresh water, swim down to the ocean or sea, live to adulthood there, and then swim back upriver to spawn? Okay, they die after mating, but they survive years in the ocean after leaving the rivers of their birth, so adapting from fresh water to salt is a matter of weeks rather than millennia--and they manage the strenuous swim upriver, often or usually leaping up rapids and falls, without succumbing to the lack of salt water; their death after spawning seems to be a part of their life cycle, just as many insects die after mating.
What most curiosity has awake this video is about what are the oldest species of lake Baikal, because if it's that old the first species already there must have change significantly.
Bacteria.. algae? If animal maybe fish or frogs? The seals needed food.
I would like to hear more about these Tepuis in the Amazon jungle (table mountains that rise up to nine thousand feet above the rainforest). There was a documentary about large red crickets and carnivorous plants several decades ago, and that was it. They didn't even specify how much the fauna would differ from one of these mountains to the next.
Those are some of the coolest landforms in the world, he should definitely do a video on their biology
You know how all the reporter in the 1950's sounded the same? Same with today's reporters. Now, we have RUclipsrs and they also have the same way of speaking just like this guy.
Yeah they fuckin suck
It would be interesting to see if there's anything particular about the biogeography of nested islands or lakes, such as the famous island in a lake in an island in a lake in Quebec.
Rhode Island
Fantastic video as always! You might want to check out Saimaa ringed seals and Ladoga ringed seals as the 2 other freshwater seals in the world. And the Ancylus Lake as the predecessor to the modern Baltic sea which in itself is kind of and island ecosystem being largely isolated from the North Sea.