Also, the benefit of 13 and 17 is that both types will rarely emerge at the same time - and so they won't be competing for food amongst themselves. They'll only have a bit of a problem every 221 years.
@@Pereux0 how old are you? because I'd assume anyone over the age of 15 would understand what the 3rd F actually is (assuming you're a native english speaker, anyways)
I did an essay on the cicada's life cycle before. My theory took this into account, but I emphasized the diversity among different broods of cicadas, as 13 year broods will never emerge with other 13 year broods, 17 never with other 17 (given that they're on different starting years), and the two only cross every 13/17 generations. This is ideal for sustaining each brood's own genetic makeup.
@@dielaughing73 exactly Lol I guess this is one of the bigger swarms this year along with the one he notes in the video I had to look it up cuz I was like wtf math
It wasn't a mysterious cicada organisation it was a project by the government to invite intelligent cryptographers to work for the NSA if I recall correctly.
For anyone seeing this comment more recently, be aware that the pronunciation of cicada is correct for the United Kingdom - Google "cicada pronunciation" and switch from American English to uk English and they'll pronounce it as he does in this video. For some reason above commenter isn't aware that languages can have accents meaning multiple different pronunciations can all be perfectly valid.
I hate it when people talk about cicadas. They always make it sound like you only have to deal with them once every 17 years, but that's not the case! There are cicadas every single year in the south, one species only comes up every 17 years, but there are species with annual cycles and with 3 year cycles and whatnot. There are always cicadas.
You hate that, or is it only mildly annoying when it get's mentioned every 17 years? You must lead a life full of hate my friend. Don't use those words lightly, you are poisoning your own mind.
Wouter Carmeliet I don’t think you understand. Every single year there’s some big news thing saying “7 year cicadas are back!!” “3 year cicadas are back” and if it’s an off year you’ll hear “even though the 3/7/17 year cicadas aren’t here the regular batch are back, get ready for a noisy summer”. It’s very annoying, like it’s some big event and it’s made to be a big deal BUT it’s every single year. News sounds surprised every time.
That... actually helps explain something I've never understood about this story: how this unidentified predator that only eats cicadas is surviving and reproducing for several generations with no cicadas. So they still are eating cicadas, they just aren't eating *your* family of cicadas. And when your emergence causes a boom in the predator population, they'll miss your offspring and eat your competitors instead.
@@TheRealHatsune quite. in my area there are only annuals, Neotibicen. Magicicada are the ones capturing all the attention, tho they are not all 17 yr periodicals. 1 sp. are known to have a 13 yr cycle as well as others with 3, and 8-10
The coolest part of this is that for them to evolve this, populations of cicadas also had to mutate life cycles of non-prime numbers up to 16, predators had to adapt to that, and both of those populations had to die out.
Here in the upper central U.S. we have 3, 7, and 13 year cicadas. Thanks to Numberphile, I understand why these cycles are all prime values. Nature certainly does use math.
In the town where I was born in Mexico we have tons of cicadas so I grew up with their sound and boy, are they annoying lol. But the cicadas there come out every single year and it is around this time (May-ish). I was there visiting about two weeks ago and there were already a bunch of them :-)
5:12 thats actually incorrect. Cicadas are actually Hemimetabolous which means that they dont have a larval/pupal state. They spend those years as nymphs and then molt into an adult when they emerge
HOLY CRAP! I had a weird feeling that I knew this guy from somewhere but I couldn't put my finger on it. I just realized he did a maths show about a year ago(?) that I went to where he did the number distribution thing with 1s more common and the shapes of constant width. I can't believe I've met him and hadn't even realized it.
Breaking news: inspired by cicadas, scientists use natural selection to find new prime numbers. They have since discovered a cicada which emerges every (2^77,232,917) − 1 years. (this is a joke, if it wasn't obvious)
The 17-year periodical cicadas will emerge in spring this year (2021) in 15 states: Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Washington, D.C.
A more parsimonious view is that the prime numbered developmental times represent an adaptation to prevent hybridization between broods with different cycles during a period of heavy selection pressure brought on by isolated and lowered populations during Pleistocene glacial stadia. This hypothesis is supported through a series of mathematical models, and stands as the most widely accepted explanation of the unusually lengthy and mathematically precise immature period of these insects.
hey brady, i love your work, i've been following you for a few good years. i've been impressed by your steady expansion, new and more frequent content, and the increase in amount of channels. what i wonder is when you will reach your personal limit, and whether you plan to employ others to pump out content that you could never generate per week as an individual. currently, you generate the right amount of videos to keep a subscriber occupied - don't overdo it, there is a critical mass for this!
Hi Brady, the end of this video teases a video about the Golden Ratio, it doesn't appear on your channel. I'd like to see it. Thanks for all the good math videos.
Good points. I was referring to the general case where someone might ask "why aren't organisms better adapted in area X?". I believe the seasonal variations might fall under trade-offs (if they were on a 17 year cycle then something worse than not being timed with cicada would occur), unless I'm misunderstanding you. Also, there is the idea that there are other, relatively numerous niches more easily filled than cicada predator.
This is a very interesting concept. It's quite amazing how evolution works out like this. I don't know if this has any direct correlation, but 13 is a Fibonacci number.
many mammals have 2 mating periods, mostly in spring and fall/autumn. However, flying insects are mostly consumed by birds and other insects. because insects are cold blooded, they are mostly inactive in the winter, so having children in fall/autumn would be a bad idea, since they wouldn't be able to procreate etc before winter. so they mostly only reproduce once every integer amount of years. i'm not sure about the birds, but i would guess that birds aren't numerous enough to make a difference.
I love these videos! You inspired me to create my own mathematical puzzles! First one has been uploaded and they will keep coming, every day, forever. Sorry for appearing as spam but I love Numberphile and are thinking you and maybe some others may enjoy solving them. There will be varied difficulties, up to College level!
im coming from the latest video of steve, one thing i dont get is, sure, 13 is a prime number, but it is not like animals live in discrete numbers, time is a continium, a predator could live 6.5 years. etc
I things would be too different for the wasp, having alternating mating during winter and summer. but idk, also how do the wasps survive for 17 years with no food? is there a small group of cicadas that hatch early each year, like the acorns and are just sacrificed.
humans are one of the only animald to disregard seasons when breeding, animals generally breed so that they give birth in spring in order to nurture the young with as much time as possible before winter
When we didn't know that much about the world our account of time was pretty much based on the sun and the moon. Being hugely influenced by both we were able to start measuring time as it passes by. Only when we started recording the events were we able to not just see the flow of time but measure it in absolute terms. Now, the plants and animals don't have that. They can only react to external factors and seasonal changes caused by Earth's changing position in the orbit which happen yearly.
the prime numbered developmental times represent an adaptation to prevent hybridization between broods with different cycles during a period of heavy selection pressure brought on by isolated and lowered populations during Pleistocene glacial stadia, and that predator satiation is a short term maintenance strategy.This hypothesis was subsequently supported through a series of mathematical models. length of the cycle appears to be controlled by a single gene locus, with the 13-year cycle dominant
+Christian Müller You will have have had 16 generations that never saw a cicada, probably would move on to specialize in other food sources, so the cicada wins.
This is another reason why cicadas didn't "choose" a smaller prime number. 3 or 7 years would be easy enough for predators with a one year cycle to adapt to.
great video, as always, but what if a predator's life cycle averages out to a time that is not a whole number of years? in the case of the 17 year cicada cycle, can a group of predators live a lifespan of 8.5 years? or does nature actually 'prefer,' so to speak, whole numbers when it comes to lifespans (presumably for some biological process with which i am not familiar P:)
The seasons prevent that from happening. Take for example a predator which is an insect and depends on the warm temperature to mature. Starting out in winter is not an option then.
Our farming efficiency has increased drastically just since a hundred years ago. And we continue to make improvements. Our crop yield per acre of corn has increased roughly six times since 1960. So we are using less space to produce more food. As for alkaline metals they are not exceedingly common in the first place (as could be said of helium). But there aren't too many applications of these metals which cannot be done through other, less efficient, means. Also there is still plenty of lithium.
Allow me to ask you a question. Would it be better for the earth to be warmer or cooler? Warmer temperatures give us more arable land, not less, from the poles to the equator. Cooler temperatures give us fewer crops and the little ice age. In which direction should we be heading?
Alternatively, "When comes out the video about golden ratio" still sounds weird, but less so. "Come out" is a single verb in English [not a verb-adverb pair], and is rarely broken into two pieces.
I'm 31. I agree, I've always had the same disposition: The oil won't run out as quickyl as they say. However, I'm aware that it most definitely will run out. It replenishes so insanely slow, and only under the right conditions. The reason we have oil now is because of those huge jungles that existed a very long time ago, I believe. Well, in any case, yes, we'll run out for sure at some point fairly soon.
Those cicada killers are supposed to be solitary ground-dwellers, but my parents had a tree in their backyard that filled up with them for about two months. It was very strange, and freaky at first, because they are huge. But after a while, I became comfortable enough with them, that I'd let them bump into my forehead as I walked under it (it's branches hung to where I needed to duck to get under them). They never paid me any mind.
Isn't this assuming the fact that the cicadas and their predators start their life cycle on the exact same year. What if the predator life cycle starts a year or two after the cicadas?
+Ajay Menon That doesn't really matter because they would only meet once and then would be out of phase again until the next multiple of their life cycles times the prime number of the cicada's life cycle.
The cicadas aren't doing anything intentionally. The 17 year cycle emerged as a successful strategy taking all historical events into account. The cicadas that passed on genes related to yearly emergence didn't survive as well as cicadas that remain in the ground for 2 years. Those that mutated and were able to stay in the ground for longer periods tended to survive better than those that didn't. Apparently the prime number of cycles (17) of that particular brood of cicadas has done very well carrying on.
I think that the wasp just stuns the cicada. so the lava eats it alive (eating the least important thinks first, then the organs) keeping it fresher for longer. I could be wrong but I've seen this behaviour before. Great video by the way; Primes in nature, never thought about it before :D
But the big flaw here is that a life cycle is shown only as an integer. If you look at a life cycle with any continous probability function, then the probability of an animal with a life cycle of 4 years (or any real number) is 0. The mean might be 4, but for any given observation, none of them will exactly be 4. The probability that a life cycle can be between 3,9 and 4,1 can be estimated, but thus, an infinite number of real numbers will multiply to a value between 3,9 and 4,1. So I don't see how the 17 years life cycle would be of any relevance. This seems like a simplifying assumption that simplifies too much.
For the 17 year locust (magicicada septendecim) the 17 year cycle is a survival strategy that unfolded naturally, if you hold to the standard approach to evolution. They never studied any form of math, so they have no worries that a given mathematical model doesn't seem to fit their way of life. They don't have this cycle by choice or desire. The strategy emerged from a meeting of genetic mutations and the realities of survival for emerging broods over the course of probably millions of years. So we are left to believe that a large and robust brood of cicadas just happened upon a 17 year strategy for no reason at all, or that survival pressures left them with a workable and beautiful, if strange, way to survive. Remember too that they are not flying around as mature insects for 17 years. They spend almost their entire lives as grubs in the ground living on tree roots. Then after 17 years of this they emerge, mature and mate. There is something in their genetics/physiology that is triggered after 17 years in the ground-- not at all hard to believe.
I'd assume a much better question than "how much food we produce" is "how much space we take to produce it". Have we enhanced our methods of producing said food or have we merely put more land to use? The latter seems to be unsustainable in the long run, seeing as the population shows no sings of declining in the foreseeable future and it needs space as well. As for your latter question, I've heard that lithium and other alkaline metals are being depleted alarmingly.
Interesting thing is that there's species of cicadas that actually follow the other lower primes. They're less notable because they have smaller swarms due to the facts discussed in this video. If I remember correctly they're called Annual Cicadas.
I came to debunk the myth that all cicada sp. are periodical, that any you find year to year are "out of sync". Cicadadoiea are classified in 2 categories, periodical ( the ones described as masting every few years) and annuals. in NE Ohio, we predominantly have the annuals, notably the genus Neotibicen which come every year in consistent #'s. not all cicadas are periodical! A cicada genus directly inland of the eastern seaboard is Magicicada which have 7 sp. usually 13 and 17 yr sp. variants, but they are not in my immediate location. I've only found them in W. Va and eastward where it is much more forested than most of Ohio.
Well, the "lull" as I in-eloquently put it is a bit misleading. There is a lull in the US crop yields however in other parts of the world there is no such lull because such efficient fertilizer and machinery is not yet available for their use. So, really crop yields will continue to increase for the foreseeable future. It seems that it does boil down to a waiting game though, as most things do.
So prime numbers only make sense as long as you're working with whole numbers. For instance, a predator could have a 6.5 year life cycle or a 3.25 year life cycle which coincides with that of the cicada. Is the reason that's not an issue because most animals' life spans are aligned with years because its easier to keep track of years or something?
Those charts you told me to view up there somewhere, yeah, I'm getting my slopes from said charts. If you look at them you'll see a modest increase for the warming have been experiencing lately, and the time frames I specified there is a decidedly steeper increase. Having passed my fifth grade math class, I can tell you that means it was getting warmer faster.
Why is is that the year is treated as some sort of indivisible unit? For example why can predators have 6.5 year life cycles in order to match up with the 13 year cicadas? Is it something like the seasons that necessitates life cycles of entire years?
He reminds me of Dr Malcolm in Jurassic Park. He looks a (little) bit like Jeff Goldblum, and mostly speaks in a similar hesitant manner, about the same kind of stuff. Very nice video by the way!
To rephrase what someone else said in the comments, cicadas will mutate and emerge at different periods, 15, 16, 18, etc.; Since prime numbers don't have any factors other than 1 and themselves, there are these "islands" at prime number years where the cicadas won't end up overlapping with cicadas of different periods. What this means is they don't end up mixing genes with other groups of cicadas too much, helping to preserve their genetics on those little isles.
That's why I tacked on Mendeleev there. He was basically just a data compiler and an observer. Not quite the same thing, but close. And I'm 100% positive that there are other historical examples of non-scientists changing science forever. And, yes there are plenty of legitimate scientists who reject the idea of AGW. And I'm going to split hairs with you and say that science is easy, good science is difficult.
And the reason they have to breed at the same time each year, in case that's not been cleared up, is simply because they can't tell the time. They have to use outside factors to tell when to mate, and this usually means seasonal changes.
Periodic cicadas don't just come out every 13 or 17 years. One theory is that there was once a single synchronized species but because of local conditions some came out a year early or late, splitting them into 21 "broods" that come out in different years. These broods each have their own territory with little overlap. Some split so long ago they have become separate sub-species. Incidentally, the 17 year broods extend from the mid-Atlantic north and the 13 year ones are in the southern states.
Brady, I heard on your channel that the Golden Ratio is the most irrational number, so that (for example) a plant's leaves overlap as little as possible. In this case, prime numbers make life cycles overlap as little as possible. I wonder, is there a relation between the primes and Phi? Just food for thought...
Forgive me if I'm wrong, but I believe that seasons are what determines the life cycle of animals. An animals usually only mate during one season, and having a fraction of a year thrown in wouldn't probably work. For instance, in your scenario the predators would mate at opposite ends of the year and that's just not ideal.
Seasons also greatly effect the cicada's predator's life cycle. So, life cycle must be a full year, not 0.5 or 0.25. Are there any insects mating during winter in the wild?
I have a question. The prime numbered emergence cycle seems like an awesome tactic, but why can't predators have lifecycles of.. say... 4.25 years? Why does it's lifecycle have to be an integer? Does it have something to do with the adult predator only being able to give birth during spring/summer? I suppose it'd be difficult for one generation to rear in winter and the next in summer, but it doesn't seem implausible. A repeating pattern of say... 13, 17, 11 year gaps seems like a better method.
Cicada getting stung by a wasp: "Same goddamn thing every 52 years."
Or 68 years
Lol
Also, the benefit of 13 and 17 is that both types will rarely emerge at the same time - and so they won't be competing for food amongst themselves. They'll only have a bit of a problem every 221 years.
@@cool_bug_facts The noise will be literally infernal.
2024
last time was 1803
happening this year, pretty nuts! (the noise is so weird, feels like a 1950 movie UFO)
@@Retro_simone how do you figure this year?
3 Fs: Feeding, Fighting and Mating
João Victor Pacífico fecundity
Lol yeah, I was sitting confused for a moment before I understood.
He should have said feeding, fighting and fornicating.
(F)mating
Haha it's funny cause you think he's gonna say fu-
I'm here from the oak tree / squirrels video.
i disliked that 1 too lol
Here we all are,🤔
Yes.
Ye
same
"They come out for the 3 F's. Feeding, Fighting and Mating." This guy is brilliant!
i dont get it
@@Pereux0 how old are you?
because I'd assume anyone over the age of 15 would understand what the 3rd F actually is
(assuming you're a native english speaker, anyways)
@@CaptainCuttlefish74 Im 26
@@Pereux0f*cking
fornicating or fecund or family.. many F words fit ;)
They come out for the three F's Feeding fighting and mating.
F*cking
@@EchoHeo Yes, that's the joke, we all got it which is why it's funny.
@@esotericVideos I know you all know what it is. Stop being salty
@@EchoHeo But like why post it? It's funnier if it's unsaid. And by posting it it feels like you are trying to explain it or something.
@@esotericVideos I don't know I don't remember because I left that comment a year ago
I did an essay on the cicada's life cycle before. My theory took this into account, but I emphasized the diversity among different broods of cicadas, as 13 year broods will never emerge with other 13 year broods, 17 never with other 17 (given that they're on different starting years), and the two only cross every 13/17 generations. This is ideal for sustaining each brood's own genetic makeup.
But doesn’t that counter the “predator satiation” benefit?
People in 2020 checking that it hasn’t been 17 years since this video 😂😂😂😂
Though this year is a 13 swarm for us in New England
I thought we have the seventeen year one going on in the US now?
@@nugboy420 different populations on different cycles maybe?
@@dielaughing73 exactly
Lol I guess this is one of the bigger swarms this year along with the one he notes in the video I had to look it up cuz I was like wtf math
what about 3301?
Everett Logan YOU HAVE BEEN SELECTED. YOU WILL BE CONTACTED SOON. STAY ALERT.
Flambo Vulcano no its real
Yes it is a joke. it its is about (i believe) the mysterious cicada organisation that sent puzzles around the web. Look it up.
It wasn't a mysterious cicada organisation it was a project by the government to invite intelligent cryptographers to work for the NSA if I recall correctly.
Dragons!
Wow, not a single argument about the correct pronunciation of 'cicada.' I'm impressed.
@King Pistachion The irony
Do you smell it
Or are you too busy upvoting your own comments
For anyone seeing this comment more recently, be aware that the pronunciation of cicada is correct for the United Kingdom - Google "cicada pronunciation" and switch from American English to uk English and they'll pronounce it as he does in this video. For some reason above commenter isn't aware that languages can have accents meaning multiple different pronunciations can all be perfectly valid.
@@thmnwthnvwls Reading this back I see why it seems that way but I did mean "arguing *about* [what] the correct pronunciation [is]"
He's British, they pronounce everything wrong.
[ducks and runs]
I hate it when people talk about cicadas. They always make it sound like you only have to deal with them once every 17 years, but that's not the case! There are cicadas every single year in the south, one species only comes up every 17 years, but there are species with annual cycles and with 3 year cycles and whatnot. There are always cicadas.
You hate that, or is it only mildly annoying when it get's mentioned every 17 years? You must lead a life full of hate my friend. Don't use those words lightly, you are poisoning your own mind.
Wouter Carmeliet I don’t think you understand. Every single year there’s some big news thing saying “7 year cicadas are back!!” “3 year cicadas are back” and if it’s an off year you’ll hear “even though the 3/7/17 year cicadas aren’t here the regular batch are back, get ready for a noisy summer”. It’s very annoying, like it’s some big event and it’s made to be a big deal BUT it’s every single year. News sounds surprised every time.
Remember when the full moon was big news every 30 days?
That... actually helps explain something I've never understood about this story: how this unidentified predator that only eats cicadas is surviving and reproducing for several generations with no cicadas.
So they still are eating cicadas, they just aren't eating *your* family of cicadas. And when your emergence causes a boom in the predator population, they'll miss your offspring and eat your competitors instead.
@@TheRealHatsune quite. in my area there are only annuals, Neotibicen. Magicicada are the ones capturing all the attention, tho they are not all 17 yr periodicals. 1 sp. are known to have a 13 yr cycle as well as others with 3, and 8-10
The coolest part of this is that for them to evolve this, populations of cicadas also had to mutate life cycles of non-prime numbers up to 16, predators had to adapt to that, and both of those populations had to die out.
STEVE MOULD IN NUMBERPHILE!!!!
"ummm, I'm no expert but I assume you're heading towards prime numbers?" I thought Brady WAS an expert :D
The F's feeding fighting and mating. Wait a second.. Mating doesn't start with an F. No wonder he does maths. The silly professor can't spell.
+Hollth Well that joke flew right over your head didn't it?
+AshyLarry He's joking about the joke.
he meant fabricating babys
this is so meta
fornicating
Here in the upper central U.S. we have 3, 7, and 13 year cicadas. Thanks to Numberphile, I understand why these cycles are all prime values. Nature certainly does use math.
“Upper central” yeah no one says that
In the town where I was born in Mexico we have tons of cicadas so I grew up with their sound and boy, are they annoying lol. But the cicadas there come out every single year and it is around this time (May-ish). I was there visiting about two weeks ago and there were already a bunch of them :-)
5:12 thats actually incorrect. Cicadas are actually Hemimetabolous which means that they dont have a larval/pupal state. They spend those years as nymphs and then molt into an adult when they emerge
HOLY CRAP! I had a weird feeling that I knew this guy from somewhere but I couldn't put my finger on it. I just realized he did a maths show about a year ago(?) that I went to where he did the number distribution thing with 1s more common and the shapes of constant width. I can't believe I've met him and hadn't even realized it.
'I say ci-cay-dah, and you say ci-cah-dah,
Let's call the whole thing off!'
I do hope the sick otters get better soon.
But oh, if we call the whole thing off then we must part
It's see ka da
@@neftalithekushite4063 And oh, if we ever part
Then that might break my heart
My favorite thing about this video is that RUclips waited seven years to recommend I watch it.
Right. Just think. We could have corrected this gent 7 yrs ago and He wouldn't live in ignorance.
Breaking news: inspired by cicadas, scientists use natural selection to find new prime numbers. They have since discovered a cicada which emerges every (2^77,232,917) − 1 years.
(this is a joke, if it wasn't obvious)
Who else is here from the seed video
I am
Two people that are really into seed... who would have thought
I'm here from the acorn video, but I've been here before anyway.
I am
Me
0:18 I see what you did there.
Food, Fight, F***
@@gayMath Holy Phuck
This video was mating awesome!!! I mating love this channel :)
The 17-year periodical cicadas will emerge in spring this year (2021) in 15 states: Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Washington, D.C.
Dc isn’t a state
I'm no expert either, Brady... but you do make some highly entertaining and informative videos. Keep doing it, please! :) :)
A more parsimonious view is that the prime numbered developmental times represent an adaptation to prevent hybridization between broods with different cycles during a period of heavy selection pressure brought on by isolated and lowered populations during Pleistocene glacial stadia. This hypothesis is supported through a series of mathematical models, and stands as the most widely accepted explanation of the unusually lengthy and mathematically precise immature period of these insects.
hey brady, i love your work, i've been following you for a few good years. i've been impressed by your steady expansion, new and more frequent content, and the increase in amount of channels. what i wonder is when you will reach your personal limit, and whether you plan to employ others to pump out content that you could never generate per week as an individual. currently, you generate the right amount of videos to keep a subscriber occupied - don't overdo it, there is a critical mass for this!
How do yo think he went?
0:19 "...the 3 Fs, feeding fighting and mating" wait
Hi Brady, the end of this video teases a video about the Golden Ratio, it doesn't appear on your channel. I'd like to see it. Thanks for all the good math videos.
+Lucas Kellner I believe that segment came from the numberphile video on flowers and the fibonacci sequence.
I thing it was about what is the most irrational number
@@Houshalter Nope, he never posted Steve Mould talking about the Golden Ratio
@@austinbryan6759 yeah, I don't think "soon" is gonna be worth the wait this time around.
Good points. I was referring to the general case where someone might ask "why aren't organisms better adapted in area X?". I believe the seasonal variations might fall under trade-offs (if they were on a 17 year cycle then something worse than not being timed with cicada would occur), unless I'm misunderstanding you.
Also, there is the idea that there are other, relatively numerous niches more easily filled than cicada predator.
I love it! Can't wait for more! Great job man!
This is a very interesting concept. It's quite amazing how evolution works out like this. I don't know if this has any direct correlation, but 13 is a Fibonacci number.
but what if the predators cycle is 6 and a half years?
AMagicWizard I think it would pose a problem with mating seasons. Reproductive cycles not aligned with the seasons aren't that common in animals.
Is it like most creatures have only integer life spans or something ? This was really confusing to me too.
many mammals have 2 mating periods, mostly in spring and fall/autumn. However, flying insects are mostly consumed by birds and other insects. because insects are cold blooded, they are mostly inactive in the winter, so having children in fall/autumn would be a bad idea, since they wouldn't be able to procreate etc before winter. so they mostly only reproduce once every integer amount of years.
i'm not sure about the birds, but i would guess that birds aren't numerous enough to make a difference.
I love these videos! You inspired me to create my own mathematical puzzles! First one has been uploaded and they will keep coming, every day, forever. Sorry for appearing as spam but I love Numberphile and are thinking you and maybe some others may enjoy solving them. There will be varied difficulties, up to College level!
"The 3 F's, Feeding, Fighting and Mating"
I ROFL'd
the internet is a crazy place.
2013: video uploaded
2020: people thinking it's 17 y/o but it is 7
2024: I am watching it
2026: 13 y/o, GTA VI, WW3 probably 💀
2030: 17 completed ✅
Ww3 happening? Nah that’s fear mongering
@@goldenfiberwheat238 I was referring to a conspiracy which is saying Earth will be destroy in 2026 by something like WW. So I just write it.
@ what
@@goldenfiberwheat238 I mean I just wrote conspiracy.
im coming from the latest video of steve, one thing i dont get is, sure, 13 is a prime number, but it is not like animals live in discrete numbers, time is a continium, a predator could live 6.5 years. etc
I things would be too different for the wasp, having alternating mating during winter and summer.
but idk, also how do the wasps survive for 17 years with no food? is there a small group of cicadas that hatch early each year, like the acorns and are just sacrificed.
@@Nichoalsziv They live on sap.
humans are one of the only animald to disregard seasons when breeding, animals generally breed so that they give birth in spring in order to nurture the young with as much time as possible before winter
When we didn't know that much about the world our account of time was pretty much based on the sun and the moon. Being hugely influenced by both we were able to start measuring time as it passes by. Only when we started recording the events were we able to not just see the flow of time but measure it in absolute terms. Now, the plants and animals don't have that. They can only react to external factors and seasonal changes caused by Earth's changing position in the orbit which happen yearly.
F e e d i n g , f i g h t i n g , a n d f u c k i n g
NO
. . .
the prime numbered developmental times represent an adaptation to prevent hybridization between broods with different cycles during a period of heavy selection pressure brought on by isolated and lowered populations during Pleistocene glacial stadia, and that predator satiation is a short term maintenance strategy.This hypothesis was subsequently supported through a series of mathematical models. length of the cycle appears to be controlled by a single gene locus, with the 13-year cycle dominant
Where is the golden ratio video featuring Steve Mould? Thanks.
in our imaginations 🌈
The three Fs: feeding, fighting, and mating. Classy
So what about a predator lifecycle of 1 year?
+Christian Müller You will have have had 16 generations that never saw a cicada, probably would move on to specialize in other food sources, so the cicada wins.
This is another reason why cicadas didn't "choose" a smaller prime number. 3 or 7 years would be easy enough for predators with a one year cycle to adapt to.
Thanks for finaly makeing sense of the term ”Well dude the golden ratio in Lateralus is the same maths all nature lives under”
great video, as always, but what if a predator's life cycle averages out to a time that is not a whole number of years? in the case of the 17 year cicada cycle, can a group of predators live a lifespan of 8.5 years? or does nature actually 'prefer,' so to speak, whole numbers when it comes to lifespans (presumably for some biological process with which i am not familiar P:)
The seasons prevent that from happening. Take for example a predator which is an insect and depends on the warm temperature to mature. Starting out in winter is not an option then.
Forgive me, there actually IS one I've seemed to overlook.
Numberphile, you continue to exceed my expectations.
No hard feelings :)
Wait, 3 f's. Feeding, fighting, and mating? This math does not add up xD
Whoooooooosh
@@jackdog06 get out
@@jackdog06 Are you sure that's the right use?
Our farming efficiency has increased drastically just since a hundred years ago. And we continue to make improvements. Our crop yield per acre of corn has increased roughly six times since 1960. So we are using less space to produce more food.
As for alkaline metals they are not exceedingly common in the first place (as could be said of helium). But there aren't too many applications of these metals which cannot be done through other, less efficient, means. Also there is still plenty of lithium.
Today I learnt that "Mating" starts with an "F".
Whoooooosh
They Kent F*****g
Allow me to ask you a question. Would it be better for the earth to be warmer or cooler? Warmer temperatures give us more arable land, not less, from the poles to the equator. Cooler temperatures give us fewer crops and the little ice age. In which direction should we be heading?
When comes the video about golden ratio out? :D
+Highle Welt You must be German ;)
*When will you release a video about the golden ratio?
True, cant be more Kartoffel than me :D
Alternatively, "When comes out the video about golden ratio" still sounds weird, but less so. "Come out" is a single verb in English [not a verb-adverb pair], and is rarely broken into two pieces.
I'm 31. I agree, I've always had the same disposition: The oil won't run out as quickyl as they say.
However, I'm aware that it most definitely will run out. It replenishes so insanely slow, and only under the right conditions. The reason we have oil now is because of those huge jungles that existed a very long time ago, I believe. Well, in any case, yes, we'll run out for sure at some point fairly soon.
if you wanna go down a rabbit hole look up conspiracy theories about abiotic petroleum
I see 13 and 11. How odd!
Those cicada killers are supposed to be solitary ground-dwellers, but my parents had a tree in their backyard that filled up with them for about two months. It was very strange, and freaky at first, because they are huge. But after a while, I became comfortable enough with them, that I'd let them bump into my forehead as I walked under it (it's branches hung to where I needed to duck to get under them). They never paid me any mind.
they're too busy worrying about the 3 F's
Isn't this assuming the fact that the cicadas and their predators start their life cycle on the exact same year. What if the predator life cycle starts a year or two after the cicadas?
+Ajay Menon That doesn't really matter because they would only meet once and then would be out of phase again until the next multiple of their life cycles times the prime number of the cicada's life cycle.
The cicadas aren't doing anything intentionally. The 17 year cycle emerged as a successful strategy taking all historical events into account. The cicadas that passed on genes related to yearly emergence didn't survive as well as cicadas that remain in the ground for 2 years. Those that mutated and were able to stay in the ground for longer periods tended to survive better than those that didn't. Apparently the prime number of cycles (17) of that particular brood of cicadas has done very well carrying on.
I think that the wasp just stuns the cicada. so the lava eats it alive (eating the least important thinks first, then the organs) keeping it fresher for longer. I could be wrong but I've seen this behaviour before. Great video by the way; Primes in nature, never thought about it before :D
But the big flaw here is that a life cycle is shown only as an integer. If you look at a life cycle with any continous probability function, then the probability of an animal with a life cycle of 4 years (or any real number) is 0. The mean might be 4, but for any given observation, none of them will exactly be 4. The probability that a life cycle can be between 3,9 and 4,1 can be estimated, but thus, an infinite number of real numbers will multiply to a value between 3,9 and 4,1. So I don't see how the 17 years life cycle would be of any relevance. This seems like a simplifying assumption that simplifies too much.
For the 17 year locust (magicicada septendecim) the 17 year cycle is a survival strategy that unfolded naturally, if you hold to the standard approach to evolution. They never studied any form of math, so they have no worries that a given mathematical model doesn't seem to fit their way of life. They don't have this cycle by choice or desire. The strategy emerged from a meeting of genetic mutations and the realities of survival for emerging broods over the course of probably millions of years. So we are left to believe that a large and robust brood of cicadas just happened upon a 17 year strategy for no reason at all, or that survival pressures left them with a workable and beautiful, if strange, way to survive. Remember too that they are not flying around as mature insects for 17 years. They spend almost their entire lives as grubs in the ground living on tree roots. Then after 17 years of this they emerge, mature and mate. There is something in their genetics/physiology that is triggered after 17 years in the ground-- not at all hard to believe.
Life cycles depend on the season of the year, therefore they can't be other things than an integer number of years.
I'd assume a much better question than "how much food we produce" is "how much space we take to produce it". Have we enhanced our methods of producing said food or have we merely put more land to use? The latter seems to be unsustainable in the long run, seeing as the population shows no sings of declining in the foreseeable future and it needs space as well. As for your latter question, I've heard that lithium and other alkaline metals are being depleted alarmingly.
Ah yes the three Fs of nature. Feeding fighting and mating
This is an amazing video. Thank you brady/numberphile.
3 F's? Half-Life 3 Confirmed
Interesting thing is that there's species of cicadas that actually follow the other lower primes. They're less notable because they have smaller swarms due to the facts discussed in this video. If I remember correctly they're called Annual Cicadas.
Thumbs up for the three Fs.
It’s been 7 years, the 7 year ones are back
I came to debunk the myth that all cicada sp. are periodical, that any you find year to year are "out of sync". Cicadadoiea are classified in 2 categories, periodical ( the ones described as masting every few years) and annuals. in NE Ohio, we predominantly have the annuals, notably the genus Neotibicen which come every year in consistent #'s. not all cicadas are periodical!
A cicada genus directly inland of the eastern seaboard is Magicicada which have 7 sp. usually 13 and 17 yr sp. variants, but they are not in my immediate location. I've only found them in W. Va and eastward where it is much more forested than most of Ohio.
Well, the "lull" as I in-eloquently put it is a bit misleading. There is a lull in the US crop yields however in other parts of the world there is no such lull because such efficient fertilizer and machinery is not yet available for their use. So, really crop yields will continue to increase for the foreseeable future.
It seems that it does boil down to a waiting game though, as most things do.
Anybody agree Brady should get some applause for guessing 17 is a prime number?
So prime numbers only make sense as long as you're working with whole numbers. For instance, a predator could have a 6.5 year life cycle or a 3.25 year life cycle which coincides with that of the cicada. Is the reason that's not an issue because most animals' life spans are aligned with years because its easier to keep track of years or something?
I'm waiting for a predator with a one-year cycle
Most animals can only really have whole number life cycles. There are a few exceptions, but most of those are on the equator
Those charts you told me to view up there somewhere, yeah, I'm getting my slopes from said charts. If you look at them you'll see a modest increase for the warming have been experiencing lately, and the time frames I specified there is a decidedly steeper increase. Having passed my fifth grade math class, I can tell you that means it was getting warmer faster.
I got the joke roughly 5 seconds later and almost spat my tea out.
Why is is that the year is treated as some sort of indivisible unit? For example why can predators have 6.5 year life cycles in order to match up with the 13 year cicadas? Is it something like the seasons that necessitates life cycles of entire years?
yep. Can't make a new wasp in the wrong season it will die out if it can't find its food
In answer to 1: Only in areas where seasonal changes don't matter. Most animals rely on a specific season for mating
He reminds me of Dr Malcolm in Jurassic Park. He looks a (little) bit like Jeff Goldblum, and mostly speaks in a similar hesitant manner, about the same kind of stuff.
Very nice video by the way!
We have annual, three, and seven year broods of cicadas here also.
00:16 "The three F's: Feeding, Fighting, and.....Mating" LOL
It is also worth noting, cicadas have a prime number life cycle so there is less competition for food.
To rephrase what someone else said in the comments, cicadas will mutate and emerge at different periods, 15, 16, 18, etc.; Since prime numbers don't have any factors other than 1 and themselves, there are these "islands" at prime number years where the cicadas won't end up overlapping with cicadas of different periods. What this means is they don't end up mixing genes with other groups of cicadas too much, helping to preserve their genetics on those little isles.
The most effective way to kill a joke is to spell it out.
The final "F" is for FANTASTIC!
The "crappy doodle" was surprisingly close to the real thing xD
I love evolution. It's terribly inefficient, but it's still awesome.
Seasonal changes affect basically everywhere on the planet, if to a lesser degree in some areas.
That's why I tacked on Mendeleev there. He was basically just a data compiler and an observer. Not quite the same thing, but close. And I'm 100% positive that there are other historical examples of non-scientists changing science forever.
And, yes there are plenty of legitimate scientists who reject the idea of AGW. And I'm going to split hairs with you and say that science is easy, good science is difficult.
For a brief moment, my brain autoadjusted that title to "City 17".
And the reason they have to breed at the same time each year, in case that's not been cleared up, is simply because they can't tell the time. They have to use outside factors to tell when to mate, and this usually means seasonal changes.
Old video but I remember the Cicada year 7 years ago in New Jersey. Great explanation.
Periodic cicadas don't just come out every 13 or 17 years. One theory is that there was once a single synchronized species but because of local conditions some came out a year early or late, splitting them into 21 "broods" that come out in different years. These broods each have their own territory with little overlap. Some split so long ago they have become separate sub-species. Incidentally, the 17 year broods extend from the mid-Atlantic north and the 13 year ones are in the southern states.
Brady, I heard on your channel that the Golden Ratio is the most irrational number, so that (for example) a plant's leaves overlap as little as possible. In this case, prime numbers make life cycles overlap as little as possible. I wonder, is there a relation between the primes and Phi? Just food for thought...
The easy oil reserves are pretty well gone, yes, but it is now becoming profitable to get at the difficult oil and those reserves are simply massive.
Forgive me if I'm wrong, but I believe that seasons are what determines the life cycle of animals. An animals usually only mate during one season, and having a fraction of a year thrown in wouldn't probably work. For instance, in your scenario the predators would mate at opposite ends of the year and that's just not ideal.
Seasons also greatly effect the cicada's predator's life cycle. So, life cycle must be a full year, not 0.5 or 0.25. Are there any insects mating during winter in the wild?
3 Fs... feeding, fighting and mating. Steve, you haven't changed at all.
It's like the three R's: Reading, Riting and Rithmatic, which was obviously coined by someone who failed at least one.
Boy, people here sure do love that "3 F's" joke.
I have a question. The prime numbered emergence cycle seems like an awesome tactic, but why can't predators have lifecycles of.. say... 4.25 years? Why does it's lifecycle have to be an integer? Does it have something to do with the adult predator only being able to give birth during spring/summer? I suppose it'd be difficult for one generation to rear in winter and the next in summer, but it doesn't seem implausible. A repeating pattern of say... 13, 17, 11 year gaps seems like a better method.
21 seconds in and I'm already dying of laughter
Excellent segment at the Maths Inspiration show this week!
They are not a small flying insect. They are in fact one of the largest insects on the planet.
yeah they're beefy. I strangely find the noise they make soothing. It's a nice background sound to hear as the sun goes down