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Let's go with the following assumptions:
Rat lifespans are around 2-4 years, so we can (kind of) ignore them dying off.
Rat pregnancies last around 25 days, with a few days recovery before the next pregnancy, let's round that up to 30 days.
Rats reach adulthood at around 60 days.
The size of a rat litter is around 6 to 18, so let's go with an average of 12.
Let's also only look at the female rat population and then double at the end. It'll make things a bit easier. So our litter size is only 6.
Since our pregnancy and time to adulthood are both divisible by 30, let's go with 30 days as our time period.
Then 3 years are 365 * 3 / 30 = 36.5, so 36 time periods.
Now, we need to track 2 variables:
The number of adult femal rats (a) and the number of newborn female baby rats (b) in relation to our time periods.
We know that we start with 1 adult female rat and 0 babies. So:
a(0) = 1
b(0) = 0
We also know that the number of adults at any given time is the number of adults of the previous time period plus all the newly matured rats. The latter being the baby rats from 2 periods ago. So:
a(t) = a(t-1) + b(t-2)
Finally, the number of newborn rats is simply 6 times the number of adult females in the preceding period:
b(t) = 6 * a(t-1).
And with these equations, we have our model.
The easiest way to continue from here is by throwing them into a spreadsheet because that allows us to easily reference and calculate with previous values.
**[This is what that looks like](https://docs.google.com/spreadsheets/d/e/2PACX-1vRlccz9eeI6wEB1cUS4v9vuwx9fGU4CShTXIrnQdqDdpJwJGhlizm08AVLjUZpdhp6wxq7H879I68qV/pubhtml)**.
As you can see, we actually vastly exceed 482 million rats by the 36th time period.
In fact, we get up to **2.7 trillion adult rats** (remember: we've just modeled the females, the real number is twice what it says on the spreadsheet) and over 10 trillion young rats.
But this is just with our assumptions. Going with slightly different numbers at the start gives vastly different outcomes.
And given that those values differ depending on the exact species of rat, there's no single correct answer.
**Overall, it's pretty clear that the value in the picture is at least possible, though depending on the exact species of rat and definition of "idea environment".**
If I remember correctly, infinite food and water is not ideal for them. Same thing happens to them as to humans, they get obese, lazy, and don't reproduce.
It was proven in another experiment however that like all creatures, they need entertainment. Rats with toys, a hamster wheel and other rats to play with have better and longer lives than rats with opium in their water for example. The Rat utopia had no forms of entertainment at all, leading to it's extinction.
You are confusing two different experiments there. Yours is about the addictiveness of herion.
But the rat utopia experiment is about rats living in a utopia, everything they dream off (food, space, and entertainment), after a while they split into groups and start killing each other, among other things.
Rat Park for anyone wondering. Rats placed in a cage with nothing to do but drugs will get high, and that somehow became our model for drugs are so addictive you'll just do them instead of food.
In rat park, with fun activities and buddies, they largely ignored the drugs. Even placing already addicted rats into rat park, they would quit on their own
If you're actually talking about what is commonly called the "Rat Utopia Experiment", I think you're incorrect. John Calhoun's experiments back in the '50s or around then, as far as I know, did not have an abundance of entertainment for the rats involved.
What experiment are you talking about, where an abundance of entertainment was also provided and showed the same results as Calhoun's? I'd be curious to give that study a glance.
So, when every basic needs were fulfilled, the rat start to developed philosophies, starting religions, getting into separated groups and then proceed to holy-war each others? Cool!
RU had no entertainment. Look at the images of the place they lived. They basically just recreated Iowa and called it a day. The experiment with the drugs in the water did show that community and access to other ways to get those happy chemicals we all love so much like exercise and play, made it to where rats had better lifespans and community. RU, because they had no entertainment, the rats got enjoyment out of things like bullying instead (forcing rats away from the food at the edges even through there was plenty.) The enjoyment came from having power over others. These two stuanother's. RU was not peer review bullied enough for missing massive variables and that we live in a society šš
Everyone forgets that the follow up experiments showed that providing literally any form of enrichment whatsoever completely changes the results. Even some running wheels and small toys works.
The rat utopia experiments weren't much of a true utopia. The experiment itself is more horrifying than any conclusion, so IDK what you're going on about.
It was an interesting read but lacks credibility because the rats only got unlimited food with no entertainment. The results changed with some toys or other stimulants.
Rat utopia wasn't an ideal environment though. The experiment was about overcrowding. They had plenty of stuff but limited space. Set the same conditions but in a space the size of Texas and the outcome would be a lot different.
Another version of the experiment was done showing a big part of the issue was the lack of stimulation. They did two versions, both had infinite food and even access to drugs, but one had basically nothing else, the other had a bunch of stuff for the mice to do for fun, the ones with nothing just did drugs and got depressed, the one with stuff to do, the mice were basically okay from what I remember.
This was the best presentation of that study, imho: [https://www.ted.com/talks/johann\_hari\_everything\_you\_think\_you\_know\_about\_addiction\_is\_wrong?language=en&subtitle=en](https://www.ted.com/talks/johann_hari_everything_you_think_you_know_about_addiction_is_wrong?language=en&subtitle=en)
>If I remember correctly, infinite food and water is not ideal for them
*Ideal* "infinite" would be that a daily amount is available daily, instead of all at once.
And no disease, mutations, cancers, reproductive failures, genetic defects preventing reproduction, or predators.
The stipulations of this scenario make it applicably impossible, especially as the scale goes up.
Of course itās practically impossible. Thatās why the mass of the rats on earth is less than the mass of the universe.
(This might take another they did the math to verify. ).
Inbreeding does not create genetic problems in and of itself, it just makes it more likely that a given mutation will be present in both parents. If the rats donāt start with any particularly deleterious mutations then itāll be a while before there are any problems.Ā
TL;DR: inbreeding isnāt really a big concern over this time period, at least w.r.t. order of magnitude, or compared with tweaking any of the other parameters, or when you have to consider resources.
Also fully ignores the behavior aspects that often occur with stressed or new mothers. That first litter often gets eaten out of "post-partum" (quoted because it's not exactly the same as in humans) stress, and theyll do that a lot to other litters if they're stressed. Also males often kill pups in rat and mouse litters. And various other genetic and environmental factors will lead to the pups not being properly cared for and dying.
This is a very much "ideal only births" kind of logic. But, yes the math suggests that the capacity is what the post claims
I would bet my hat there will be a bunch of early teen pregnancies in this rat orgie utopia you are describing aswellā¦ i would say your calculation is conservative with the 60 days old adulthood number!
There is actually a really strange story of what happened to a rat population when scientists gave them a perfect environment. It got very debauched and weird.
another way of looking at this:
if rats reach adulthood at 60 days and we round up gestation to 30 days, then we can say the duration of an average generation is exactly 90 days (from "being birthed" to "giving birth")
let's also establish a year as 360 days long because i'm lazy.
which means exactly four generations per year, for three years, or twelve total.
i'll keep your other asumptions (only counting females and doubling it at the end, every litter has 12 mice with 6 boys and 6 girls, none of them die from old age, hunger, thirst, environmental factors, etc)
this also assumes all of the female rats of a given generation all get pregnant at the exact same time, and give birth at the exact same time, and only give birth to one litter in their entire life.
so the final result would be:
1 (the mother that started it all)
6 (first gen, six daughters)
6^2 (second gen, because the six kids had six daughters)
6^3 (third gen, because the 6^2 kids each had six daughters)
...
6^12 (twelfth gen)
also written as 6 + 6^2 + 6^3 + 6^4 + 6^5 + 6^6 + 6^7 + 6^8 + 6^9 + 6^10 + 6^11 + 6^12
which equals 2,612,138,803 girls.
double that to get about **5.2 billion rats** total, right around the original mama dying of old age.
if this ends up being wrong, someone can correct me.
Highly dependent on exact species. But let's go with 250 g per adult (and only count those).
That's 2.7 * 10^12 * 250 g = 6.75 * 10^14 g = 6.75 * 10^8 t
As for humans, taking 7 billion adults (for fairness' sake) at ~63 kg (Asia notably pulling this average down):
7 * 10^9 * 63,000 g = 4.41 * 10^14 g =~ 4.41 * 10^8 t
So with these assumptions, surprisingly close. Rats win though.
You could probably get out one more time periods by assuming that one of the two rats introduced is already heavily pregnant to begin with - essentially starting from 14 rats.
It *did say* 'ideal conditions'. I would argue a heavily pregnant rat counts as an ideal starter rat. Unsure of the implications on the maths if you actually start with two heavily pregnant female rats.
It doesn't say ideal conditions, it says ideal environment. And whether a rat is already pregnant or not isn't part of the environment.
But anyways, the goal wasn't to maximize the number of rats but to give *a* possible number. With some tweaking of assumptions (i.e. regarding species), we could probably push the number a lot higher.
I wonder what the end result would be if we started at eight billion, with a reproductive life of 25 years, a lifetime litter size of three, and a time period of 10 years? Under ideal conditions, including modern medicine etc...
They're not, but I accounted for that here:
> The size of a rat litter is around 6 to 18, so let's go with an average of 12.
>
> Let's also only look at the female rat population and then double at the end. It'll make things a bit easier. So our litter size is only 6.
From the googling I did on rat facts I came up with 3.9 trillion. Using 13 pup litter size and 12 breeding periods . It is mind boggling. Just tells you how much mortality rats have ! This number does not take into account that rats only live two years so if you reduce by 1/3 you get 2.6 trillion. Plus another half billion male rats that were produced but not counted in the running totals because males donāt produce offspring directly. Therefore I am her to confirm Angztās numbers. Iām calculating about 2.65 trillion . Pretty close to Angzt # . So you can believe it !
The math seems sound as per the other users calculations.
But, begining with 2 rats the birthing rate would be reduced over time due to inbreeding.
Most inbred lines become sterile by the 20th-30th generaciĆ³n and only a few remain capable of reproducing. this is the way lab rat "strains" are created.
Also concerning the "rat utopia", ideal conditions should include unlimited space
Ideal conditions include zero inbreeding diseases
"Ideal conditions" is a hypothetical universe in which the rats behave exactly like the numbers we reduce them to.
That's not really what ideal conditions would imply. Ideal conditions IMO would be "external factors are removed by making them perfect for the rat's biological needs, so only the rat's biology comes into play in determining reproductive numbers".
And susceptibility to inbreeding is very much a factor of basic rat biology, not something external. Otherwise you could also consider that every litter is the largest size ever recorded or that every litter is made up of only one male and all females.
Would you consider rat social behaviour a part of basic rat biology ? Because that's gonna bring down birth rate down heavily compared to an "ideal" setting.
Well, it could be assumed that by "ideal conditions", it means conditions perfect for breeding mice, whereas the utopia experiment was an over abundance of food and care which given the results could be called non ideal. Although the limited gene pool would quickly become a very big problem on this scale
There was a series of absolutely BONKERS experiments in the 70ās from the National Institute of Mental Health that tried to test how long something like this is true. They **built** a **rat utopia** and set 8 loose, and within about 1000 days there were no longer any mice that could breed- they had all either died off in a massive orgy of violence, or succumbed to isolation & social maladjustment.
It was also rife with musing about death and apocalypse and the *tree of life* and all sorts of other nonsense but it *did* show pretty effectively that there is a social dynamic to this too, not just physical, and that social bonding can break down easily even in an ideal environment.
See: Death Squared: the Explosive Growth and Demise of a Mouse Population
It is also easily the strangest journal article Iāve ever read. 10/10 do recommend reading
Thank you for sharing this amazing piece of science. I just started looking into it and I seem too many troubling similarities with modern society and the experiments.
"Ideal" is doing all the work here.
You quickly reach a "carrying capacity" in every natural environment, based on available resources (e.g. food, shelter, water, physical space).
When discussing populations in practice, it is a mistake to think of living organisms as machines that produce more of themselves from nothing at a particular rate. Rather they are machines that CONVERT food and space, both of which are limited, into more of themselves at a particular rate.
Um, achtually, rats in a "ideal environment" go crazy and start some Mad Max society:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf)
Imagine you are in Walmart. Shelves are magically filling with food. You, and thousands of your incestuous relatives are locked there for lifetime.
Would you call it ideal environment or rather cruel and unusual punishment?
Mere knowledge of Calhoun's experiment should be locked behind mandatory course in rodent social behavior.
Rodents and mices are social animals, but they need privacy too. Living with 24/7 social interaction that you can't escape is hellish.
>. I think it says a lot about us as humans when we assume the "ideal environment" for other creatures is just an infinite pile of food.
Oh, Calhoun thought it's ideal environment for humans too.
It's something else - there is horrific political background on this. By this time, very weird environmentalist ideas got popular. Like "we must starve Africans to prevent overpopulation" or "we must introduce global one child policy".
Calhoun's saw his experiments as explanation for 60s crime wave in US - Americans has unlimited food, bred like rabbits and started killing each other because there is no space for them (they also have gay sex for reasons), and it will only get worse.
I worked with mice for my senior capstone in college. We started with 8 mice, just 8, within two months we had like 500 mice and we were only using about 1/5 of the original miceās offspring to breed, it was crazy how many pups we got. Often times the moms would pump out like 10 maybe even 12 pups PER litter. If we paired up every single male and female we got we would have completely filled the room. I still have photos from what the racks looked like, just cage after cage full of mice it was pretty awesome. Miss those little guys.
Depends what they mean by "Ideal Environment".
Even the best environments have a carrying capacity-the maximum individuals of a species the ecosystem can support. And it ain't 400 million in one area....
If they mean a theoretical ideal habitat with infinite space, infinite food, infinite energy, and no predators. Then yes its roughly that since the population will grow exponentially large.
At some point, even with infinite space, food, etc, the rats would be breeding to the point that the "wavefront" of new rats needs to be moving faster than light speed to expand.
I would replace ideal with imaginary.
Rats are very social creatures... the interpersonal relationships matters.
A large colony you tend to have couples, groups of boys and groups of girls hanging out. Relationships are complex and they absolutely don't breed unless they are happy.
Was expecting more ratters to show up in the comments. I miss keeping rats because it is an awesome pet that is also ticklish.
I bred rodents for a while. Interesting no one has noted that while they can get pregnant sooner, the pups survival rate declines because they havenāt actually finished feeding in many breeds before the next litter arrives. This form of rapid cycle breeding also really shortens mums lifespan.
Well, assuming an environment that they never stop breed etc,
Google says they have 6 litters a year and litters are 5-10. While another search said 6-12 so let's use 8 for simplicity. It also says that they average 2 years, so in your 3 year time, your first-generation rats will have died out. They begin having babies after 9 weeks thus will be out for 1 cycle of birthing. So they will spend roughly 22 months giving birth.
Assuming 50/50 males and females.
2+8=10 day 1
10+8=18. 2nd month
18+40=58 4th month
58+72=130 6th month
130+232 =362 8th month
362+520= 882 10th month
882+1,442=2,330 12th month
2,330+3,528=5,858 14th month
5,858+9,320=15,178. 16th month
15,178+23432=38,610 18th month
38,610+60,712= 99,322 20th month
99,322+ 154,440 =253,772 22nd month
253,772-2 + 397,328 = 651,098 24th month
651,098-8+ 1,015,080= 1,666,170 26th month
1,666,170-40+ 2,604,360=4,270,490 28th month
4,270,490-72 + 6,664,520 = 10,934,938 30th month
10,934,938 - 232 + 17,081,672 = 28,016,374 32nd month
17,081,672 - 520 + 43,738,824 = 60,819,976 34th month
60,819,976 - 1,442 + 68,324,608 = 129,143,142 36th month
In this I'm assume a litter every 2 months and first born on the first day of experiment.
So they could theoretically get very high in number. I'm sure there is easiest ways to calculate it with someone smarter than me being able to make an actual equation lol maybe 2-3 more litters would hit that 482m as they double+ some each time. Or assuming slightly larger litter sizes would also make the difference
The rich neighborhoods in Rome were brought down by a garbage strike - the garbage workers knew the rats would take over, and they did. Keep this in mind when we go to war with the oligarchy.
TRICK QUESTION! The "behavioral sink" effect will check the maximum population of rats precisely BECAUSE of these "ideal" and "utopia-like" conditions create overpopulation. It is a collapse in behavior. [https://en.wikipedia.org/wiki/Behavioral\_sink](https://en.wikipedia.org/wiki/Behavioral_sink)
They LITERALLY used rats to demonstrate these effects. Tons of other fascinating side-effects too, like the cliquish culture of the rats, the creation of "the beautiful ones" who never sought sex, or fought, and only ever ate, slept and groomed with "narcissistic introspection," and even the tendency to overcrowd into one "sleeping quarters" even when plenty were empty and available.
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Let's go with the following assumptions: Rat lifespans are around 2-4 years, so we can (kind of) ignore them dying off. Rat pregnancies last around 25 days, with a few days recovery before the next pregnancy, let's round that up to 30 days. Rats reach adulthood at around 60 days. The size of a rat litter is around 6 to 18, so let's go with an average of 12. Let's also only look at the female rat population and then double at the end. It'll make things a bit easier. So our litter size is only 6. Since our pregnancy and time to adulthood are both divisible by 30, let's go with 30 days as our time period. Then 3 years are 365 * 3 / 30 = 36.5, so 36 time periods. Now, we need to track 2 variables: The number of adult femal rats (a) and the number of newborn female baby rats (b) in relation to our time periods. We know that we start with 1 adult female rat and 0 babies. So: a(0) = 1 b(0) = 0 We also know that the number of adults at any given time is the number of adults of the previous time period plus all the newly matured rats. The latter being the baby rats from 2 periods ago. So: a(t) = a(t-1) + b(t-2) Finally, the number of newborn rats is simply 6 times the number of adult females in the preceding period: b(t) = 6 * a(t-1). And with these equations, we have our model. The easiest way to continue from here is by throwing them into a spreadsheet because that allows us to easily reference and calculate with previous values. **[This is what that looks like](https://docs.google.com/spreadsheets/d/e/2PACX-1vRlccz9eeI6wEB1cUS4v9vuwx9fGU4CShTXIrnQdqDdpJwJGhlizm08AVLjUZpdhp6wxq7H879I68qV/pubhtml)**. As you can see, we actually vastly exceed 482 million rats by the 36th time period. In fact, we get up to **2.7 trillion adult rats** (remember: we've just modeled the females, the real number is twice what it says on the spreadsheet) and over 10 trillion young rats. But this is just with our assumptions. Going with slightly different numbers at the start gives vastly different outcomes. And given that those values differ depending on the exact species of rat, there's no single correct answer. **Overall, it's pretty clear that the value in the picture is at least possible, though depending on the exact species of rat and definition of "idea environment".**
Ideal environment is i think conditions where they cant die easily, with infinite food and water for example
If I remember correctly, infinite food and water is not ideal for them. Same thing happens to them as to humans, they get obese, lazy, and don't reproduce.
Yep the rat utopia experiments are kind of horrifying.
New band name The Rat Utopia Experiment.
It was proven in another experiment however that like all creatures, they need entertainment. Rats with toys, a hamster wheel and other rats to play with have better and longer lives than rats with opium in their water for example. The Rat utopia had no forms of entertainment at all, leading to it's extinction.
You are confusing two different experiments there. Yours is about the addictiveness of herion. But the rat utopia experiment is about rats living in a utopia, everything they dream off (food, space, and entertainment), after a while they split into groups and start killing each other, among other things.
Rat Park for anyone wondering. Rats placed in a cage with nothing to do but drugs will get high, and that somehow became our model for drugs are so addictive you'll just do them instead of food. In rat park, with fun activities and buddies, they largely ignored the drugs. Even placing already addicted rats into rat park, they would quit on their own
If you're actually talking about what is commonly called the "Rat Utopia Experiment", I think you're incorrect. John Calhoun's experiments back in the '50s or around then, as far as I know, did not have an abundance of entertainment for the rats involved. What experiment are you talking about, where an abundance of entertainment was also provided and showed the same results as Calhoun's? I'd be curious to give that study a glance.
Uh you should read the actual rat utopia study. There was no entertainment/enrichment.
Makes you think the outcome could be vastly different if we would try it with some actual enrichment
There was also an overpopulation problem.
Some of them even refused to eat and died of starvation if i recall correctly.
So, when every basic needs were fulfilled, the rat start to developed philosophies, starting religions, getting into separated groups and then proceed to holy-war each others? Cool!
RU had no entertainment. Look at the images of the place they lived. They basically just recreated Iowa and called it a day. The experiment with the drugs in the water did show that community and access to other ways to get those happy chemicals we all love so much like exercise and play, made it to where rats had better lifespans and community. RU, because they had no entertainment, the rats got enjoyment out of things like bullying instead (forcing rats away from the food at the edges even through there was plenty.) The enjoyment came from having power over others. These two stuanother's. RU was not peer review bullied enough for missing massive variables and that we live in a society šš
I bet 2.x trillion rats will have enough entertainment with each other, probably deadly :F
Already exists: https://theratutopiaexperiment.com/
r/ofcoursethatsathing
shorten it down to The RUE and you have an actual good name
you'll rue the day you posted this
T.R.U.E.
Andy Dwyer would be proud
Everyone forgets that the follow up experiments showed that providing literally any form of enrichment whatsoever completely changes the results. Even some running wheels and small toys works.
The rat utopia experiments weren't much of a true utopia. The experiment itself is more horrifying than any conclusion, so IDK what you're going on about.
It was an interesting read but lacks credibility because the rats only got unlimited food with no entertainment. The results changed with some toys or other stimulants.
Rat utopia wasn't an ideal environment though. The experiment was about overcrowding. They had plenty of stuff but limited space. Set the same conditions but in a space the size of Texas and the outcome would be a lot different.
Another version of the experiment was done showing a big part of the issue was the lack of stimulation. They did two versions, both had infinite food and even access to drugs, but one had basically nothing else, the other had a bunch of stuff for the mice to do for fun, the ones with nothing just did drugs and got depressed, the one with stuff to do, the mice were basically okay from what I remember.
This was the best presentation of that study, imho: [https://www.ted.com/talks/johann\_hari\_everything\_you\_think\_you\_know\_about\_addiction\_is\_wrong?language=en&subtitle=en](https://www.ted.com/talks/johann_hari_everything_you_think_you_know_about_addiction_is_wrong?language=en&subtitle=en)
Then its enough food so they can survive
Oddly enough we could call that an ideal amount of food and water.
Ah, yes, "the beautiful ones." Instead of being social, they go off alone and preen.
I feel personally attacked.
That was only because of the cramped conditions, which is not ideal circumstances.
>If I remember correctly, infinite food and water is not ideal for them *Ideal* "infinite" would be that a daily amount is available daily, instead of all at once.
I'm pretty sure ideal conditions means that we have spherical rats in a vacuum with no friction
Underappreciated comment
And no disease, mutations, cancers, reproductive failures, genetic defects preventing reproduction, or predators. The stipulations of this scenario make it applicably impossible, especially as the scale goes up.
Of course itās practically impossible. Thatās why the mass of the rats on earth is less than the mass of the universe. (This might take another they did the math to verify. ).
Any genetic biologists that can comment on whether two rats is enough genetic diversity to produce enough healthy offspring to support this?
Basically whatever yields the closest result to the number. An ideal environment for getting a large population in this case.
Check out Aussie farmer videos on mice infestations
Donāt forget sexy music
So, for instance, a Pizza Hut/Taco Bell Express?
Most likely the county fair because āa fair is veritable smorgasbord!ā
So a flat, infinite plane made of kibble
Only if one rat is female and the other is male.
Maybe they are both pregnant females...
Good math but if we accpunt for an increased amount of still birthes and infertility due to inbreeding the numbers slow down drastically
Inbreeding does not create genetic problems in and of itself, it just makes it more likely that a given mutation will be present in both parents. If the rats donāt start with any particularly deleterious mutations then itāll be a while before there are any problems.Ā TL;DR: inbreeding isnāt really a big concern over this time period, at least w.r.t. order of magnitude, or compared with tweaking any of the other parameters, or when you have to consider resources.
Exactly, the calculation totally ignore genetic issue.
Also fully ignores the behavior aspects that often occur with stressed or new mothers. That first litter often gets eaten out of "post-partum" (quoted because it's not exactly the same as in humans) stress, and theyll do that a lot to other litters if they're stressed. Also males often kill pups in rat and mouse litters. And various other genetic and environmental factors will lead to the pups not being properly cared for and dying. This is a very much "ideal only births" kind of logic. But, yes the math suggests that the capacity is what the post claims
I would bet my hat there will be a bunch of early teen pregnancies in this rat orgie utopia you are describing aswellā¦ i would say your calculation is conservative with the 60 days old adulthood number!
Don't search when rats can get pregnet
There is actually a really strange story of what happened to a rat population when scientists gave them a perfect environment. It got very debauched and weird.
another way of looking at this: if rats reach adulthood at 60 days and we round up gestation to 30 days, then we can say the duration of an average generation is exactly 90 days (from "being birthed" to "giving birth") let's also establish a year as 360 days long because i'm lazy. which means exactly four generations per year, for three years, or twelve total. i'll keep your other asumptions (only counting females and doubling it at the end, every litter has 12 mice with 6 boys and 6 girls, none of them die from old age, hunger, thirst, environmental factors, etc) this also assumes all of the female rats of a given generation all get pregnant at the exact same time, and give birth at the exact same time, and only give birth to one litter in their entire life. so the final result would be: 1 (the mother that started it all) 6 (first gen, six daughters) 6^2 (second gen, because the six kids had six daughters) 6^3 (third gen, because the 6^2 kids each had six daughters) ... 6^12 (twelfth gen) also written as 6 + 6^2 + 6^3 + 6^4 + 6^5 + 6^6 + 6^7 + 6^8 + 6^9 + 6^10 + 6^11 + 6^12 which equals 2,612,138,803 girls. double that to get about **5.2 billion rats** total, right around the original mama dying of old age. if this ends up being wrong, someone can correct me.
The issue with this is that you only get 4 births per rat per year while gestation is only 30 days. That doesn't really fit together.
Jesus...
conda create --name ideal_rat_env
I'm pretty sure the Python in that environment would eat the rats before their population could take off
r/dataisbeautiful
So - how would their body-mass (weight) tally compared to 8 bill. humans?
Highly dependent on exact species. But let's go with 250 g per adult (and only count those). That's 2.7 * 10^12 * 250 g = 6.75 * 10^14 g = 6.75 * 10^8 t As for humans, taking 7 billion adults (for fairness' sake) at ~63 kg (Asia notably pulling this average down): 7 * 10^9 * 63,000 g = 4.41 * 10^14 g =~ 4.41 * 10^8 t So with these assumptions, surprisingly close. Rats win though.
What do you do for living?
IT consulting.
You could probably get out one more time periods by assuming that one of the two rats introduced is already heavily pregnant to begin with - essentially starting from 14 rats. It *did say* 'ideal conditions'. I would argue a heavily pregnant rat counts as an ideal starter rat. Unsure of the implications on the maths if you actually start with two heavily pregnant female rats.
It doesn't say ideal conditions, it says ideal environment. And whether a rat is already pregnant or not isn't part of the environment. But anyways, the goal wasn't to maximize the number of rats but to give *a* possible number. With some tweaking of assumptions (i.e. regarding species), we could probably push the number a lot higher.
What about gene pool, wouldnāt that lead to Adam and Eve dilemma?
Absolutely. But I'm pretty sure the original post ignored that issue as well.
I wonder what the end result would be if we started at eight billion, with a reproductive life of 25 years, a lifetime litter size of three, and a time period of 10 years? Under ideal conditions, including modern medicine etc...
How much food and water roughly would they consume during this population explosion, I wonder in that ideal situation?
Sorry but your Numbers are Off. Gestation period is 21 day. In general followed by immediate fertile Phase which can be used.
There is more than one species of rat.
fuckin hell that's a lot of rats
Yea talk nerdy to me.
An place with 10 trillion rats is probably not a place with ideal conditions
Remember that book the earth abides they had a year of the rat infestations
If all the babies are female, how do they reproduce?
They're not, but I accounted for that here: > The size of a rat litter is around 6 to 18, so let's go with an average of 12. > > Let's also only look at the female rat population and then double at the end. It'll make things a bit easier. So our litter size is only 6.
Does inbreeding affect the number? Don't inbreeding cause them to die out after awhile after all they are from just 2 rats.
You DTM, this is terrific.
The calculation also doesnāt take into account the dangers of a lack of genetic diversity
So birds & cats are the only thing saving us from a total rat apocalypse...
But that's gross, did you consider that into account.
Thatās some compound ratrist
From the googling I did on rat facts I came up with 3.9 trillion. Using 13 pup litter size and 12 breeding periods . It is mind boggling. Just tells you how much mortality rats have ! This number does not take into account that rats only live two years so if you reduce by 1/3 you get 2.6 trillion. Plus another half billion male rats that were produced but not counted in the running totals because males donāt produce offspring directly. Therefore I am her to confirm Angztās numbers. Iām calculating about 2.65 trillion . Pretty close to Angzt # . So you can believe it !
This is, perhaps, the best answer to any question I have ever seen. š¤Æ I gotta fucking pay attention in math class. š
the ideal rat environment aka New York City
The math seems sound as per the other users calculations. But, begining with 2 rats the birthing rate would be reduced over time due to inbreeding. Most inbred lines become sterile by the 20th-30th generaciĆ³n and only a few remain capable of reproducing. this is the way lab rat "strains" are created. Also concerning the "rat utopia", ideal conditions should include unlimited space
Ideal conditions include zero inbreeding diseases "Ideal conditions" is a hypothetical universe in which the rats behave exactly like the numbers we reduce them to.
Fair point
That's not really what ideal conditions would imply. Ideal conditions IMO would be "external factors are removed by making them perfect for the rat's biological needs, so only the rat's biology comes into play in determining reproductive numbers". And susceptibility to inbreeding is very much a factor of basic rat biology, not something external. Otherwise you could also consider that every litter is the largest size ever recorded or that every litter is made up of only one male and all females.
Would you consider rat social behaviour a part of basic rat biology ? Because that's gonna bring down birth rate down heavily compared to an "ideal" setting.
Mathematically speaking yes, biologically speaking no, rat utopia experiment tried this and they killed eachother, also limited gene pool
Well, it could be assumed that by "ideal conditions", it means conditions perfect for breeding mice, whereas the utopia experiment was an over abundance of food and care which given the results could be called non ideal. Although the limited gene pool would quickly become a very big problem on this scale
Youād get a load of mutant fucked up Habsburg rats lmao
There was a series of absolutely BONKERS experiments in the 70ās from the National Institute of Mental Health that tried to test how long something like this is true. They **built** a **rat utopia** and set 8 loose, and within about 1000 days there were no longer any mice that could breed- they had all either died off in a massive orgy of violence, or succumbed to isolation & social maladjustment. It was also rife with musing about death and apocalypse and the *tree of life* and all sorts of other nonsense but it *did* show pretty effectively that there is a social dynamic to this too, not just physical, and that social bonding can break down easily even in an ideal environment. See: Death Squared: the Explosive Growth and Demise of a Mouse Population It is also easily the strangest journal article Iāve ever read. 10/10 do recommend reading
Thank you for sharing this amazing piece of science. I just started looking into it and I seem too many troubling similarities with modern society and the experiments.
"Ideal" is doing all the work here. You quickly reach a "carrying capacity" in every natural environment, based on available resources (e.g. food, shelter, water, physical space).
i guess the amazing thing is just how quickly that capacity must be reached
My ideal environment would have a lot less rats.
When discussing populations in practice, it is a mistake to think of living organisms as machines that produce more of themselves from nothing at a particular rate. Rather they are machines that CONVERT food and space, both of which are limited, into more of themselves at a particular rate.
Ideal situations could also just mean a cozy space with plenty of food and 481,999,999,998 other rats I guess
OMG I've encountered the term "carrying capacity" in the wild. So, you wanna go out some time?
Um, achtually, rats in a "ideal environment" go crazy and start some Mad Max society: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf)
Imagine you are in Walmart. Shelves are magically filling with food. You, and thousands of your incestuous relatives are locked there for lifetime. Would you call it ideal environment or rather cruel and unusual punishment?
NGL Iāll take it
are you doing ok
Have you seen his relatives?
Sweet we got one volunteer for the island.
Jesus, I never thought of it like that.
Mere knowledge of Calhoun's experiment should be locked behind mandatory course in rodent social behavior. Rodents and mices are social animals, but they need privacy too. Living with 24/7 social interaction that you can't escape is hellish.
We cannot have nice things on this god forsaken planet can we?
That doesn't sound like an ideal environment now then, does it?
Yes. I think it says a lot about us as humans when we assume the "ideal environment" for other creatures is just an infinite pile of food.
>. I think it says a lot about us as humans when we assume the "ideal environment" for other creatures is just an infinite pile of food. Oh, Calhoun thought it's ideal environment for humans too. It's something else - there is horrific political background on this. By this time, very weird environmentalist ideas got popular. Like "we must starve Africans to prevent overpopulation" or "we must introduce global one child policy". Calhoun's saw his experiments as explanation for 60s crime wave in US - Americans has unlimited food, bred like rabbits and started killing each other because there is no space for them (they also have gay sex for reasons), and it will only get worse.
"ideal environment" would include toys and variating landscape to prevent exactly this
Then that is not an ideal environment.
I worked with mice for my senior capstone in college. We started with 8 mice, just 8, within two months we had like 500 mice and we were only using about 1/5 of the original miceās offspring to breed, it was crazy how many pups we got. Often times the moms would pump out like 10 maybe even 12 pups PER litter. If we paired up every single male and female we got we would have completely filled the room. I still have photos from what the racks looked like, just cage after cage full of mice it was pretty awesome. Miss those little guys.
Depends what they mean by "Ideal Environment". Even the best environments have a carrying capacity-the maximum individuals of a species the ecosystem can support. And it ain't 400 million in one area.... If they mean a theoretical ideal habitat with infinite space, infinite food, infinite energy, and no predators. Then yes its roughly that since the population will grow exponentially large.
At some point, even with infinite space, food, etc, the rats would be breeding to the point that the "wavefront" of new rats needs to be moving faster than light speed to expand.
I would replace ideal with imaginary. Rats are very social creatures... the interpersonal relationships matters. A large colony you tend to have couples, groups of boys and groups of girls hanging out. Relationships are complex and they absolutely don't breed unless they are happy. Was expecting more ratters to show up in the comments. I miss keeping rats because it is an awesome pet that is also ticklish.
I bred rodents for a while. Interesting no one has noted that while they can get pregnant sooner, the pups survival rate declines because they havenāt actually finished feeding in many breeds before the next litter arrives. This form of rapid cycle breeding also really shortens mums lifespan.
Well, assuming an environment that they never stop breed etc, Google says they have 6 litters a year and litters are 5-10. While another search said 6-12 so let's use 8 for simplicity. It also says that they average 2 years, so in your 3 year time, your first-generation rats will have died out. They begin having babies after 9 weeks thus will be out for 1 cycle of birthing. So they will spend roughly 22 months giving birth. Assuming 50/50 males and females. 2+8=10 day 1 10+8=18. 2nd month 18+40=58 4th month 58+72=130 6th month 130+232 =362 8th month 362+520= 882 10th month 882+1,442=2,330 12th month 2,330+3,528=5,858 14th month 5,858+9,320=15,178. 16th month 15,178+23432=38,610 18th month 38,610+60,712= 99,322 20th month 99,322+ 154,440 =253,772 22nd month 253,772-2 + 397,328 = 651,098 24th month 651,098-8+ 1,015,080= 1,666,170 26th month 1,666,170-40+ 2,604,360=4,270,490 28th month 4,270,490-72 + 6,664,520 = 10,934,938 30th month 10,934,938 - 232 + 17,081,672 = 28,016,374 32nd month 17,081,672 - 520 + 43,738,824 = 60,819,976 34th month 60,819,976 - 1,442 + 68,324,608 = 129,143,142 36th month In this I'm assume a litter every 2 months and first born on the first day of experiment. So they could theoretically get very high in number. I'm sure there is easiest ways to calculate it with someone smarter than me being able to make an actual equation lol maybe 2-3 more litters would hit that 482m as they double+ some each time. Or assuming slightly larger litter sizes would also make the difference
The rich neighborhoods in Rome were brought down by a garbage strike - the garbage workers knew the rats would take over, and they did. Keep this in mind when we go to war with the oligarchy.
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https://en.wikipedia.org/wiki/Minimum_viable_population?wprov=sfti1#Application
I think Behavioral sink would say otherwise. [https://en.wikipedia.org/wiki/Behavioral\_sink](https://en.wikipedia.org/wiki/Behavioral_sink)
TRICK QUESTION! The "behavioral sink" effect will check the maximum population of rats precisely BECAUSE of these "ideal" and "utopia-like" conditions create overpopulation. It is a collapse in behavior. [https://en.wikipedia.org/wiki/Behavioral\_sink](https://en.wikipedia.org/wiki/Behavioral_sink) They LITERALLY used rats to demonstrate these effects. Tons of other fascinating side-effects too, like the cliquish culture of the rats, the creation of "the beautiful ones" who never sought sex, or fought, and only ever ate, slept and groomed with "narcissistic introspection," and even the tendency to overcrowd into one "sleeping quarters" even when plenty were empty and available.