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iayork t1_iu3hj9n wrote

Certainly it’s possible, though not inevitable. Small inbred populations can persist in spite of small founder populations - the classic examples are island foxes, and island populations are the best studied.

Populations can survive inbreeding better if they have a longish history of smallish (but not too small) populations. This leads to long periods of low-level inbreeding, and that leads to purging of deleterious genes. In other words, a long period of mild inbreeding can accidentally prepare a population for a shorter period of severe inbreeding.

Moose are actually good candidates for this, because they arose during periods of glaciation, which presumably led to small populations that would alternate periods of inbreeding and then as the ice allowed intermingling and new gene flow.

Is this what actually happened? I don’t know, but the principles are pretty well understood and if your question is could this happen, certainly it could. Since there obviously are moose on Newfoundland, the alternative is denying reality or positing some clandestine moose-smuggling operation, so this is the simplest answer.

Further reading:


pds314 t1_iu4emak wrote

Keep in mind moose routinely cross water. It isn't totally impossible they can get to Newfoundland from the mainland on their own. The shortest distance between Newfoundland and the mainland is 17.5 km which is not exceptional for the distance moose can swim.


iayork t1_iu4jnqt wrote

Sure, it’s possible there was outside gene flow (the genetics papers I linked address some of that). But the question is is it possible, not how far can moose swim.


spiderfarmer t1_iu4glei wrote

Why would a moose do that though?


DomovoiP t1_iu4kjmi wrote

Moose likes yummy seaweed, swims out some distance to eat some. Crazy current drags the moose out to sea, it gets disoriented. Moose then swims until it Finds a New Land.


jumpmanzero t1_iu4mqno wrote

And two of them, with a length of seaweed between them, could absolutely bring along a coconut.


Isotope_Soap t1_iu4t36c wrote

Are you suggesting that coconuts migrate?


herbdoc2012 t1_iu4uzeq wrote

On the backs of small parrots flying between the fjiords is how coconuts migrate as we all know that!


DragonBank t1_iu5a683 wrote

The hard part is a female and male both doing this in a period they can viably reproduce and meeting eachother on the islands. I'd assume 100s of moose would need to attempt this before a population occurs.


PacoTaco321 t1_iu5zfwk wrote

It is a low probability of happening, but species spreading to a completely different part of the world from floating thousands of miles across an ocean and having a viable population in that new area also happened a lot more often than you'd probably think, so two moose swimming on their own 18 km is not too much of a stretch.


mdielmann t1_iu63iv0 wrote

If a small population was already there, say, introduced by people, every moose that migrated there would be a breeding candidate.


Ihavebadreddit t1_iu4zofr wrote

A deer swam from NB to PEI recently. 12.9 km roughly

Only to be hit by a truck once it reached the island.

There are no deer in PEI

Well.. there was 1 for a few hours.


mattdjamieson t1_iu6v1ec wrote

It’s true they send people over Confederation bridge to make sure no deer are sneaking over on the highway. Lol


GuanoLoopy t1_iu4k3ei wrote

It's not like they are thinking, 'hey let's go for a long swim', but they do go into water to eat and swim and if they got turned around or a current brought them away from land or a storm came upon them, they have no choice but to keep swimming. So some very small percentage could stumble upon it that way. All you need are a couple (or 4) to get a population started, and if some new moose got added to the genepool via a water crossing that would help a genetically bottlenecked population tremendously.

And at first glance 110K from 4 moose seems like a rather large population boom. But they can produce 1-2 offspring per year, so not accounting for deaths and a best case scenario that can grow rather quickly, and if you can sustain 110K moose there are way more resources available than needed for a much smaller population so resource constraints wouldn't be a problem at least. A few decades and some luck is all they needed.


BigZombieKing t1_iu599d5 wrote

In the rut, a bull moose will come from that distance or more to the call of a cow moose. Plowing through the thickest bush, swimming through anything and just generally ignoring the terrain.

Once there were cow moose across the water, I think bull moose crossing would be inevitable.


Kaalmimaibi t1_iu44n7f wrote

So European royalty would have been fine if they’d just persisted with consanguineous relationships just a little longer? How extraordinary.


iayork t1_iu4be82 wrote

European royalty were pretty much the opposite of “a long period of low-level inbreeding”, so no.


Kaalmimaibi t1_iu4e05b wrote

The data here indicates the predominance were second cousins and it’s been going on for a thousand years. What degree of relatedness and timeframe is necessary then?


Alis451 t1_iu4o4ta wrote

> second cousins

these aren't actually any inbreeding, second cousins are functionally strangers.


iayork t1_iu4kjqp wrote

Are you arguing that the royalty of Europe have entirely gone extinct due to inbreeding? Or are you arguing that occasional members showed deleterious recessives, while most (like Charles) have been spared those effects, as you’d see with purging of recessives?

I know you just made a throwaway joke, but if you’re actually going to make an argument of it, you should think through what you’re actually claiming.


PhilistineAu t1_iu4pjo5 wrote

They would have been fine if they had removed the deleterious genes.

You can be fine if your starting gene population doesn't lead to cascading abnormalities or a high level of disease susceptibility.

If those moose are that genetically close, and they lack sufficient diversity to handle a new disease (or environmental) threat, then you are looking at population collapse. Without that challenge, the population looks fine.


viridiformica t1_iu4z4yp wrote

There's not much selective pressure on royalty though - rather the opposite


Cronon33 t1_iu4utzt wrote

Thanks for this insight, I would have assumed at 4 individuals they'd surely be beneath the minimum viable population and destined for inbreeding depression


iayork t1_iu52lpr wrote

Mostly that’s true. But given the right background, and a significant amount of luck, very small founder populations can expand enormously. This is very common in invasive species. The 200 million starlings in North America today arose from a few dozen in the late 1800s. Bull trout in Montana arose from two founders. A million Barbary Ground Squirrels arose from a single female.

Again, this is possible but not inevitable. Most such introductions will collapse due to inbreeding. But occasionally explosions can happen.


Cronon33 t1_iu54o2o wrote

Right of course, there is no guarantee either way, at least with breeding individuals


atomfullerene t1_iub56ki wrote

Minimum viable population is less of a rule and more of a guideline. Specifically speaking, it's usually defined as something like "the minimum population to have a 95% chance of survival for 100 years, in a population that isn't being specifically managed by people."

95% is a pretty high percentage, so there's a lot of "room" below it. Maybe 4 moose only have a (to pull a number out of the air) 25% chance of survival....but that's common enough that it isn't surprising to see it happened.

And furthermore, populations can have big advantages that mean their actual odds of survival are higher than the given percentage. For example, moose introduced onto an island with no competitors and no predators can expect to have a greater fraction of their offspring survive. And that means their population will more rapidly grow out of the danger zone.


Tempest8008 t1_iu654ty wrote

The Colombian Hippo population is another example. One male and three females were released into the wild less than 40yrs ago and that population is over 70 animals now.


[deleted] t1_iu3wg5t wrote



UnamedStreamNumber9 t1_iu44pi6 wrote

The wolves of isle royale in Lake Superior are from a small founder population that is badly inbred. The population suffers from a lot of mutations, poor health and low fertility/breeding success. A new male swam to the island about 10-15 years ago and it was hoped the new genetics would revitalize the population; but it’s my understanding it hasn’t really helped. The population is expected to go extinct. All this is to ask, are similar issues seen in the Newfoundland moose population?


chris84055 t1_iu53ixc wrote

Neither here nor there, but the story I've always heard growing up in Northern MN was regarding occasional ice crossings in years where Superior froze. I've never heard stories about swimming out to the island.

Completely unrelated, my favorite Isle Royale fact is that there is a lake on the island. That lake contains an island. That island is the biggest island on a lake on an island on a lake in the world.


UnamedStreamNumber9 t1_iu74060 wrote

Yeah, crossed the ice not swam. In part because the lake doesn’t freeze solid enough long enough reliably for other wolves to make the crossing


datanaut t1_iu4vrqa wrote

If half of the moose died prematurely, then the population is not doubling every generation, it's staying the same. You can't just divide the final number by two to account for that. Agreed with the main point though that it sounds possible.


I_raped_a_wizard t1_iu44dg8 wrote

And genetic diversity doesn’t enter in to it?


bad_take_ t1_iu45uuk wrote

There is a lot that should still be considered including the effects of limited genetic diversity. This also does not take into account: if this is the appropriate environment for moose, the prevalence of natural predators, the prevalence of disease, how much food is available, human hunters and if the French have decided to wear Moose skin coats or not. Use the math above with caution.


I_raped_a_wizard t1_iu46b9g wrote

Sure, there are countless factors. I was just under the impression that a population of 4 would be wholly insufficient to continue a species.

I’m uneducated on the topic, just asking questions.


Alis451 t1_iu4ot73 wrote

> continue a species.

does not mean without defects, you can definitely continue a species(with defects) for a very long time. Though with proper genetic testing and mating protocol you can restart a human population from just 2 people, but it would take something like 19 generations to provide enough genetic diversity to become strangers again.

The quoted 50 population required is the "safe" number where you don't have to do a lot of genetic testing, nor would you be required to sire ~20ish children per generation.


I_raped_a_wizard t1_iu4qp19 wrote

Oh okay so you could technically repopulate with just two humans if you were to follow certain protocols?

I didn’t know that was possible. Do you know what exactly you would have to do to achieve that diversity again?


HungryHungryHobo2 t1_iu5cxxf wrote

Do you have a source for the "2 people can recreate the population" claim?
Because I've always seen the low range of estimates for human survival saying we need about 5,000 - 10,000 people to have enough genetic diversity to not die out from inbreeding related illnesses.


Alis451 t1_iu5nqqc wrote

50 is the bare minimum to prevent inbreeding related genetic depression naturally. With new genetic technologies and extensive breeding program you can do it with 2, there are MANY thought examples out there where they talk about how bad it would be to try to do this naturally, this video does discuss using genetic mapping to prevent mismatches, there are a few that discuss it being possible naturally but requiring tens or hundreds of thousands of years to work out.

Interstellar used this thought experiment, though instead with 1 women and 5,000 frozen embryos, with strict genetic selection as well, i think to ensure only daughters were born for the first few generations.

Basically a lot of stuff to dig through that just talks about dangers, but not many that actually discuss the actual possibility, and with modern gene editing, the answer is "yes, but..." and depends on the access one would have to said technology. I think I saw somewhere strict genetic control and breeding control for 19 generations(~400 years) to get suitable genetic drift to be strangers again, of which you could get 50 from that would be able to satisfy the bare minimum of stable natural population.


KnoWanUKnow2 t1_iu4go5a wrote

There were no predators on the island for the moose (outside of the brown black bear, which isn't particularly good at taking down a moose). That helped them to quickly reproduce and spread.

The annual quota for moose hunting in Newfoundland is 27,667 animals, and that quote is about 60% met, which means 16-17 thousand are removed every year. Of note they weren't hunted at all (legally) before 1930.


LiquorEmittingDiode t1_iu4iaft wrote

There's actually no brown bears here in Newfoundland either, just black bears and coyotes. Neither of which are particularly good at taking down an adult. There used to be wolves, but Wikipedia tells me they went extinct in 1911 which doesn't leave much room for interaction between the species.


KnoWanUKnow2 t1_iu4j5jo wrote

And coyotes only came over in the 1980's, so they didn't affect the founder population at all.


LiquorEmittingDiode t1_iu51w0t wrote

I always found that pretty amazing. Coyotes have existed in north america for over a million years and they happened to finally make it to this island just a few decades ago.


[deleted] t1_iu4pky5 wrote



Brandon432 t1_iu4ry5w wrote

Ursus arctos is a species properly known as the brown bear. It includes a bunch of subspecies: Himalayan Brown Bear, Atlas Bear (extinct), North American Brown Bear (aka “grizzly”), Kodiak Bear, Eurasian Brown Bear, and others.

“Grizzly” is a colloquial name for two subspecies (if you count the extinct California Grizzly). The species is brown bear. “Brown bears” definitely exist.


Brandon432 t1_iu4srkv wrote

This is a perfect answer to OP’s question “is it possible?” The back of envelope exponential population model above gives an estimate that is the same order of magnitude as and also exceeds OP’s datapoint before accounting for drag factors.

“Did it produce?” is a different question


SuppiluliumaX t1_iu3e6en wrote

Possible, yes, likely, no. It would be technically possible to get a viable population out of four, especially since the four could be entirely unrelated and very genetically diverse. However, it's likely that they were not as genetically diverse as possible and that there would be a risk of inbreeding. In order to assess this you ideally would analyse the genome of a sample of, say 1000 moose in order to get an idea of the diversity in the group.


perta1234 t1_iu3nxrh wrote

1000 is not needed. Well sampled 50 is very good already, if the idea is to know about past and influential things. And even no genome is needed. Maybe couple of thousands of SNPs is enough.

So you are sure noone studied it yet? Check the case for Swedish wolves if you want to know of a similar thing.


perta1234 t1_iu3q63l wrote

Suggests it could be

Inbreeding quicker than in recent past increases the RISK of deleterious genetic syndromes. Moreover, adaptive potential might be lower.

Species can adapt to inbreeding to some extent. More outbred the species is, more damaging the inbreeding is.


Loose_Ad8430 t1_iu4pdll wrote

I mean you say that but this is exactly what happened. Originally 2 were brought over but that didn’t work so they brought 4 over and now there is thousands.


TedW t1_iu5gwj2 wrote

Do we know that the original 2 died, and that exactly 0 have immigrated since then?


DrBarry_McCockiner t1_iu4c7ed wrote

What it comes down to is how "clean" the genes of the original four were. The fewer genetic defects (and by defects, I mean genetic anomalies that are directly responsible for disease or disability, either dominant or recessive) that exist in the genome, the more viable the population is.


Tinchotesk t1_iu6ueka wrote

Here is an answer from a mathematical and not biological point of view. It seems like moose cows breed more or less annually annualy from age 3 to 11. So I assumed that each female produces 2 females during her life, that is has calfs every other year and half are female; I assume they die at age 11. I'm ignoring all other factors, but just trying to give a perspective on how these things work.

With the above parameters, here is the female population every 10 years:

Year 1: 2

Year 11: 20

Year 21: 164

Year 31: 1277

Year 41: 9931

Year 51: 77181

Year 61: 599847

The point is that these processes are exponential, that is they grow pretty fast.


FriedMule t1_iu3edvs wrote

Yes and no, it is technically possible, but they would be so inbred that the chance of survival is low and the chance of brain damage and deformities is really high. I do not know the minimum number to start up a healthy population, but is definitely more than 4.

EDIT: Article that says 50/500 where 50 is to avoid inbreed and 500 is to avoid genetic problems, meaning more than 4 is clearly needed.


m_Pony t1_iu46168 wrote

And yet there is a thriving population of 110,000 moose on an island which previously had none.