www.livescience.com/animals/whales/hidden-hybrid-dna-found-in-blue-whales-reveals-theyve-been-mating-with-other-species-and-their-offspring-are-reproducing
Hidden DNA found in blue whales reveals they've been mating with other species — and their hybrid offspring
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3mo
Not much you can do once you go blue. 💙
The only thing not blue about these whales is their balls.
Thing is they can do that in the ocean because we’re not stopping them. But what about bears? Ultimately would polar bear genetics have been carried by other bear genetics at warm times in the past?
Polar bears are a recent species broken off from brown bears.
*Life…uh…finding a way.
FIFY.
We have no evidence that's what happening, though. This might be more of a "last man on earth" scenerio, and we don't know what that's going to do to the populations long term.
I came across the term “braided river” the other day in an article about human evolution and it was like a lightbulb went off.
We have this idea that evolution is a straight simple line but that doesn’t seem to be the case.
There's a species of a bird that has spread around a mountain range (I think it's Andes), and it's a great visual of how it works just by looking at the map. It starts at the top of the range as one species and then as you go down change in two groups (subspecies?) independently, split by the range, who then meet again at the bottom of the range and produce a viable offspring that is a hybrid of the two subspecies. And just like that you got yourself 4 different varieties of the same bird.
So this is really hard to explain, but essentially what we're worried about is something called "Genetic Swamping", especially in animals that are as rare as both of these species of whale, especially becuase these species have a low population directly as a result of human activity.
Basically in a healthy population unaffected by human activity, this hybridization wouldn't matter and would be almost inarguably a positive influence on the genetics of the blue whale population. If whale numbers were what they should be, these hybrid whales would be sexually completing with their full blooded counterparts, essentially winnowing out any major deleterious effects as both populations would be vast enough that a single hybrid male would essentially be a drop in the ocean. Blue Whales would be able to stay Blue Whales and Fin Whales would be able to stay Fin Whales while these hybrids could happily exist blurring the lines between the two and providing an extra dose of generic diversity.
However, we don't have healthy whale populations of either species. If we did, there would be roughly 14 times the number of blue whales there are right now. Possibly more, that's just a guess based on the most accessible records of there currently being spitting distance of 10,000 mature adults now when the low estimate for mature population in 1926 was 140,000. For fin whales, the numbers are similarly dismal. We have done a fucking number on both species.
Becuase of their low populations of both species, the effect of hybridization isn't a drop in the ocean, it's a cup in the bathtub. And unfortunately, combining two incredibly rare species doesn't give you one healthy population, it gives you one incredibly rare species. Additionally, since this particular hybridization seems to be one way (if I am reading this correctly), we aren't even getting that - we're just getting two incredibly rare species that are closer related than they used to be, essentially loosing a ton of genetic variation and the ability for one species to survive where the other might faulter. Having Flue Whales and Fin Whales might mean both those species could die due to an event that the actual blue whale might have survived.
Again, I want to repeat a little louder - The reason this is concerning is becuase we are potentially losing the genetic diversity of Blue Whales. Blue Whales mate with the hybrids, Fin Whales, so far, don't seem to. As a result, Blue Whales are becoming closer to Fin Whales. It is a huge potential loss of genetic diversity and adaptability.
We don't even know enough about the historical frequency of this hybridization to know if this genuinely is normal, to start with. Maybe it is. Or, maybe we've just killed enough whales that they're willing to mate with partners they never would otherwise. Total "last man on earth" scenerio, essentially.
Then you add to it that if this is normal, then the limited population is still in effect. Previously, there would be enough blue whales that one hybrid would mate with a blue whale, producing a 3/4th blue whale, mating with a blue whale, producing a 7/8ths blue whale, etc, etc. Until the only evidence of Fin Whale heritage would just be a few unique genetic markers that could readily add to the genetic diversity if the blue whale population.
Now there is a very real possibility that there aren't enough blue whales left for that to happen. We may ultimately end up with every blue whale only being, say, 31/32ths blue whale... And those blue whales still hybridizing further with fin whales, meaning that ultimately we loose Blue Whales entirely.
Alone, not necessarily an issue. But we don't know if the Flue Whales are healthy, adaptable animals yet. We don't know if they actuall fill the same niche and have similar behavior to blue whales. If they don't, then we have no idea how the loss of blue whales might effect the ecosystem as a whole.
I again want to stress, if this was happening under different circumstances, it wouldn't be concerning at all. If two species of animal were interbreeding and merging into one species without it being directly our fault, it wouldn't be any issue. I mean, hell - everyone I've ever talked to thinks the unisexual Ambystoma salamanders and Heliconius butterflies are dope as fuck! It's just that the circumstances humanity has places whales under has made this normally healthy process something that could be dramatically maladaptive.
Human activity is the sixth great extinction. Unlike the other triggers, though, humans are a sapient biotic factor, capable of looking around at everything dying around us and going "Wait. What the fuck?" and trying to stop it. We love whales, we want to protect them, and while there are Blue Whales and Fin Whales we want to preserve both species to the best of our abilities. If that becomes impossible, then I am absolutely certain we will love and try to protect our future population of Flue Whales, but the potential loss of two species that we're facing right now?
Yes, that's alarming. Note that alarming isn't a statement that something is bad, it's a statement that we don't know if it's bad or not. But traditionally the loss of genetic diversity has always been bad, and that is almost certainly what we're facing here.
Also to be clear, this is incredibly oversimplified. If you read the article, there are two distinct populations of blue whales that clearly handle the interbreeding differently. I just was already writing a damn book, so I kinda shorthanded a lot of stuff becuase I ain't getting paid to do this, you know? I'll see if I can come back later to leave some good links, though.
This was helpful, thanks
Very interesting, thank you!
Most all hybrid species are born sterile, like ligers and mules. For a hybrid to be reproductively viable it means the parent species are much more closely related as species than previously thought.
Cause they're gonna start dating the sexy monkeys, their kids will have thumbs and legs, and then they wipe out humanity
Fine by me. Let’s welcome our aquatic overlords. Anything is better than what we’re doing.
Genetic replacement, like pigeons.
Fin whales! Critically endangered blue whales are interbreeding with fin whales. Hope it works!
Fascinating. I wonder how it works with the massive size differences. Blue whales can be almost twice the size of fin whales.
Many species have far larger size difference when it comes sexual dimorphism and it works just fine.
Chihuahua’s somehow interbreed with all other dogs. It works, at least if the mom is the big one or a bet does a c-section.
One summer, I'd frequently hear whimpers of pain and my mom would shout at me to go grab the pickle jar. I filled it up with cold water and ran outside to the whimpers and threw the water between the German Shepard and my female Chihuahua. That'd get them unstuck, but my Chihuahua was bow-legged that summer. Some of the ugliest puppies I've ever seen, but she lived.
In a new study, published Jan. 6 in the journal Conservation Genetics, researchers analyzed the genomes of B. m. musculus in the North Atlantic for signs of inbreeding, which could impede the recovery of this group.
'Impede' is generally not a hopeful term.
“Could impede” is not “will impede”. Hope it works, since they are doing it anyway and there is no stopping it now.
...I mean, I guess it depends on what you mean by "hope it works". I also wish the whales well, and you're correct that we can't exactly stop it, but from my background and ecology I am not particularly optimistic about this development.
think of the "You vs. the Guy she tells you not to worry about" memes whales must have when they get cucked by a Blue Whale
I was thinking it might be the reverse. This could be the result of a male fin whale that likes his ladies on the large side.
BBW (big beautiful whales)
BBBW (big beautiful blue whales)
Dolphins will get their freak on with anything willing or unwilling. Why would whales be any different?
We have killed so many of them that they can't find a mate of their own species anymore.
What a dork!
It’s just nature’s way must survive and it’s fun
Somefin fishy is going on here....
But seriously, this statement:
...if introgression continues, it could reduce the amount of blue whale DNA across the population, which could make these whales less resilient to adapting to new challenges, such as human-caused climate change.
doesn't make sense to me. I read the non-technical sections of the paper. There are several statements about the of reducing the species "genetic integrity," but nothing about that is quantitatively bad for the whales themselves. Whether or not "genetic integrity" is a scientific quality, by what logic should one assume that a species gaining diversity through hybridization makes that species less resilient to adaptation?
Okay, so currently we have two species: The Fin Whale and The Blue Whale. Both of these species have really tiny populations compared to what they should have, like literally 1/10th of the number of mature animals we would hope to see. Becuase of thos low low population, hybridization has a disproportionate high effect on the species as a whole.
Fin Whales and Blue Whales will mate. This produces a Flue Whale. It is healthy and happy, etc, etc. The Flue Whale can mate with Blue Whales but can't mate with Fin Whales, as near as we can tell.
Eventually, it would be very arguable to say we don't have any Blue Whales, only Flue Whales. That means we are losing blue whale genetics. We aren't gaining diversity, we're losing it. There is less blue whale in the ocean.
This alone isn't necessarily a problem, but we have no evidence that Blue Whales becoming Flue Whales won't effect their ecological roll and cause problems downstream for the rest of the relevant ecology.
Additionally, if an event happens that would harm Fin Whale populations but leave Blue Whale populations largely unaffected, odds are very high that event would also harm Flue Whale populations. Essentially, it makes it more likely that an event that would negatively effect one species would negatively effect both species.
The individual animals seem to be thriving, but that doesn't mean anything for the overall population hardiness. It also doesn't mean that the many species that in some way rely on blue whales will be able to survive with only Flue Whales.
The term for this is "Genetic Swamping". I am sure there are papers and YouTube videos that explain it better than I do.
Thanks for that context. Do you know if genetic swamping is specific to groups with low effective population sizes? Or is it considered inherently harmful to parent populations of any size?
You know, I am not entirely certain. My instinct is to say that Genetic Swamping is a term specifically reserved for when overall genetic variation is reduced by hybrids, but I could be dead wrong about that.
Sorry, I am a microbiologist professionally so my knowledge on this is very much dictated by my personal interests rather then a formal education. You've found a big hole in my knowledge that I'll have to try to fill sometime.
There's also a concept called "de-extinction" through the process of "back breeding", which is kind of genetic swamping in reverse? It would involve using the preserved gametes of one extinct species to inpregnate an extant species, and then continue to use the preserved gametes to fertilize each generation afterwards.
As far as I am aware, this is a massively controversial idea, espcially when it comes to species that are functionally extinct instead of entirely extinct. That is, species that only have known specimens of one sex surviving.
Examples include the Yangtze Giant Softshell Turtles (the last known female died in 2023) and the Northern White Rhino (the last known male died in 2018). The Northern White Rhino gets even more complicated as we have viable embryos preserved - 14 of them, in fact - so we could potentially use a surrogate Southern White Rhino to revive the species without true hybridization.
Underwater orgy time. Guess when you’re the biggest boy on the block, dem ladies ain’t saying no.
Or blue whale ladies are really into short kings.
Nature is kinky. And that's a scientific fact. 😎
Amateur Big blue whale in action POV
Go on and get it big dawg.
So they get fertile offspring? Not really different species then...
“Species” by definition is a blurry line. What makes a separate? Is it reproductive isolation? Is it distinct morphology? Is it genetic? There are multiple lenses through which to define species. In fact, there are many examples of two sister taxa (or closely related species) which can produce fertile offspring. When fertile hybrids reproduce, this is an example of reticulate evolution, and it has famously occurred in many different Homo species, playing a critical role into the rapid evolution of Homo sapiens.
I'm well familiar with Mayr and the definition of species 😅.
I would also btw, not call neanderthals a distinct species. Subspecies or variant is more appropriate, seeing as to how similar we were and how much we interbred.
Any hole is a goal!
There’s a joke here somewhere about sperm whales, but I don’t know what it is…
That’s why my neighbor looks like a whale.
Ocean Orgy
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“Blue whales in the Atlantic Ocean are harboring a previously unknown and potentially alarming level of hybrid DNA, a new study shows. The findings hint that whale hybrids are much more reproductively viable than previously realized.”
Why is this alarming if the offspring are viable?