4 ms·
>How do we draw the line between species, exactly? Similar to this, you can distinguish between races and genders with skeletal tendencies now, but we're all on
by ummonk 7y ago
>How do we draw the line between species, exactly? Similar to this, you can distinguish between races and genders with skeletal tendencies now, but we're all one species. So when they are compatible enough to bone each other and said boning yields offspring, what exactly determines the line between 2 species and 2 distinct populations of 1 species?
You can't. In practice, extinct branches of humans are classified as separate species, and animals are classified as a bunch of species because biologists get credit for discovering new species. In contrast, living branches of humans (e.g. bushmen vs. pygmies vs. everyone else) ar classified as a single species even if they have evolved largely in isolation for hundreds of thousands of years and rarely interbreed, because classifying them separately could give ammo to racists and worse.
>I'm also always intrigued by statements like this: "Interestingly, they suggest that 6%-7% of the genomes of West Africans is archaic in origin". I know it's over-simplifying for the lay-person, but 6-7% is the high end of what people claim is the genetic difference between us and chimpanzees, and we can't even reproduce with chimpanzees and don't even have the same number of chromosomes. So there's a lot more than that we have in common with some archaic species, and a lot less that we'd expect to have with closer relatives.
It usually means 6-7% of genes that vary between humans.
- danans 7y ago> In practice, extinct branches of humans are classified as separate species They were classified that way, until the presence of Neanderthal & Denisovan DNA was discovered in modern humans. > In contrast, living branches of humans (e.g. bushmen vs. pygmies vs. everyone else) ar classified as a single species even if they have evolved largely in isolation for hundreds of thousands of years and rarely interbreed They are classified as a single species with the rest of humans because they can interbreed with other humans, not for political reasons. We couldn't draw the same conclusion about extinct branches until recently because we don't have living groups of them that we can observe interbreeding. Now that we see the genetic evidence of that the classification has changed.
- xeeeeeeeeeeenu 7y ago>They are classified as a single species with the rest of humans because they can interbreed with other humans https://en.wikipedia.org/wiki/List_of_genetic_hybrids https://en.wikipedia.org/wiki/List_of_genetic_hybrids
- wnoise 7y ago> They are classified as a single species with the rest of humans because they can interbreed with other humans This is not the standard for, e.g. birds, however. Consider the mallard. It's happy to breed (with fertile offspring) with just about any duck. However the ornithology community does not say "great, they're all ducks, maybe with separate subspecies". Instead they complain about "genetic pollution" wiping out species of ducks through genetic drift. Myself, I think it would be perfectly reasonable to call these subspecies and keep the Biological Species Concept[1], but in actual usage the Biological Species concept is dead. [1] https://en.wikipedia.org/wiki/Species_concept#Mayr.27s_Biological_Species_Concept https://en.wikipedia.org/wiki/Species_concept#Mayr.27s_Biolo...
- lazyier 7y agoIn the past the rules for 'species' was not whether or not they will interbreed, but whether or not their offspring would be fertile. A horse and a donkey can breed just fine, but a mule cannot. This makes sense because we know that species eventually differentiate and whether or not they can recombine is a good indication of how far apart that separation is. But nowadays all that stuff is thrown out of the window. I don't really understand why it is no longer considered a useful distinction.
- catalogia 7y ago> A mule cannot [breed]. That's almost always true, but isn't an absolute. There are documented cases of fertile mare mules: https://en.wikipedia.org/wiki/Mule#Fertility https://en.wikipedia.org/wiki/Mule#Fertility
- ummonk 7y agoThe Hawaiian duck isn't racist enough in choosing mates so now conservationists want to bring back more genetically pure Hawaiian ducks through selective breeding. It's rather ridiculous.
- danieltillett 7y agoAre lions and tigers different species?
- danans 7y agoMale ligers are sterile, so it's more plausible to call the parents different species. I've seen no evidence to support the proposition that the children of San and Pygmies with outside human populations are sterile. Given that, the question is what would the motivation possibly be to call them a separate species from the rest of humanity?
- danieltillett 7y agoThere is evidence that the male offspring of the Neanderthal/African Homo spp. were infertile.
- danans 7y agoEven if that were true, what does that have to do with the Pygmies or the San?
- danieltillett 7y agoNothing as Pygmies and the San are not different species of the homo genus.
- ummonk 7y agoFirst, many organisms reproduce asexually and are thus classified into species on other grounds. Second, animals that have the ability to produce fertile offspring with each other are still often classified as separate species or at least subspecies (depending on whose definition you use) if they don't customarily interbreed and have differing appearances / characteristics.