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The wikipedia article opens with "Neanderthals (Homo neanderthalensis or H. sapiens neanderthalensis) are an extinct group of archaic humans (generally regarde

The wikipedia article opens with "Neanderthals (Homo neanderthalensis or H. sapiens neanderthalensis) are an extinct group of archaic humans (generally regarded as a distinct species, though some regard it as a subspecies of Homo sapiens) who lived in Eurasia until about 40,000 years ago" https://en.wikipedia.org/wiki/Neanderthal https://en.wikipedia.org/wiki/Neanderthal If Neanderthals and Homo sapiens could interbreed and produce offspring that could reproduce, doesn't that clear up any confusion about them possibly being a distinct species?

Tor3 2y ago
A species isn't defined by if it can interbreed with other species or not. Horses and donkeys can produce offspring (although they are mule - and there's some discussion about how certain Neanderthal/Sapiens combinations could possibly also be mule, but that's not important). And Darwin's finches (https://en.wikipedia.org/wiki/Darwin%27s_finches https://en.wikipedia.org/wiki/Darwin%27s_finches) are defined as different species, but can technically interbreed.
beloch 2y ago
By calling them "H. sapiens neanderthalensis", the authors are tipping their hand. They view Neanderthal's as a subspecies. There are those who disagree. The definition of what a species is seems to depend on who you talk to. There are examples of animals, currently classified as different species, being able to interbreed and produce fertile offspring. e.g. Polar bears (Ursus Maritimus) and Grizzlies (Ursus arctos horribilis) can breed to produce fertile Grolar bears[1]. TL;DR: Although Polar bears and Grizzlies appear to be very different, they diverged relatively recently and have remained distinct mainly through geographic separation. They don't interbreed much because they generally aren't in the same places during mating season. Although their physical traits have changed considerably, genetic differences haven't yet built up to the point where their offspring are infertile. It's conceivable that the different subspecies of humans were isolated from each other in very different environments and evolved along very different lines. However, they weren't isolated from each other so long that genetic changes made it impossible for them to produce fertile offspring. [1]https://slate.com/news-and-politics/2010/05/when-polar-bears-and-grizzlies-breed-they-can-produce-fertile-offspring-why-can-t-other-species.html https://slate.com/news-and-politics/2010/05/when-polar-bears...
- compressedgas 2y ago
  Consider https://med.stanford.edu/news/all-news/2016/04/modern-men-lack-y-chromosome-genes-from-neanderthals.html https://med.stanford.edu/news/all-news/2016/04/modern-men-la...
- rvense 2y ago
  https://en.wikipedia.org/wiki/Liger https://en.wikipedia.org/wiki/Liger
throw839393 2y ago
It is more like a race. There are people with Neanderthal heretige living today. It is even used as a slur.
dan-robertson 2y ago
The classic elementary school definition of species is something like “x and y are different species if they cannot produce fertile offspring” which is obviously already incomplete (it causes eg two males of one species to be different species, for example) but could be made a bit more precise. But the actual definition is much more “a species is a group of reasonably closely related and similar organisms, capable of reproducing fertile offspring given sufficiently many individuals, and the grouping is useful for scientists to talk about”. Obviously that definition isn’t useful for a layperson to decide how to taxonomize things, but I think it’s a useful definition to have when reading about classifications of things into species.
- woleium 2y ago
  also see “ring species”. there are types of co-habiting gulls who cannot interbreed, but if you follow breeding pairs round the world you can go from one type to the other.
meheleventyone 2y ago
Species is a human taxonomy which doesn't strictly relate well to the variety of organisms in the living world. There are lots of different definitions and ways to approach it depending on context.
throwanem 2y ago
The term of art here is "species concept", of which there are several, well covered in [1]. Interfertility is a feature of some, but not all. [1] https://bio.libretexts.org/Courses/University_of_California_Davis/BIS_2B%3A_Introduction_to_Biology_-_Ecology_and_Evolution/02%3A_Biodiversity/2.01%3A_Species_Concepts https://bio.libretexts.org/Courses/University_of_California_...
adrian_b 2y ago
In general, in biology species are not defined by the impossibility of having viable hybrids between them, but by the fact that in natural conditions they do not normally interbreed, which allows their genes to drift away, becoming more and more different with the passing of time. For a species to exist, interbreeding must be both possible and frequent, which ensures that the entire population of the species remains uniform genetically for as long as the species exists, even when its genes may become more and more different from those of other species. The most frequent way for a new species to appear is when there is geographic isolation between two populations, which prevents interbreeding. Then, after many generations, the genetic differences may become so great that even when the populations are reunited interbreeding will fail, resulting in hybrids that are either non-viable, or sterile, like mules. With Neanderthals and Denisovans, the geographic separation has started the process of development of new species and they have become clearly differentiated from a genetic point of view. Nevertheless, not enough generations had passed so that the differences would become so great as to make interbreeding impossible. Even if we know that successful interbreeding has existed, we do not know which was the percentage of success for such interbreeding, i.e. how many of the hybrids were both viable and non-sterile. So it is a rather arbitrary choice to decide whether to call Neanderthals and modern humans as different subspecies or different species. In any case, they were easy to distinguish. There are many closely related species between which interbreeding is easily performed in captivity, e.g. in zoos, but it almost never happens in natural conditions, where wild animals may choose partners according to their preferences, so those species are easily distinguishable, due to their genetic differences that are preserved by the lack of interbreeding.
- pcthrowaway 2y ago
  To add to this, an example of 2 species which are easily distinguishable but can produce viable offspring (though the males are usually infertile) are Ligers (Lion + Tiger hybrids) Lions and Tigers are distinct enough that I don't believe anyone has made the argument that they're the same species. Though I do now wonder if they're really as distinct from one another as different breeds of house-cats

Tor3 2y ago

A species isn't defined by if it can interbreed with other species or not. Horses and donkeys can produce offspring (although they are mule - and there's some discussion about how certain Neanderthal/Sapiens combinations could possibly also be mule, but that's not important). And Darwin's finches (https://en.wikipedia.org/wiki/Darwin%27s_finches https://en.wikipedia.org/wiki/Darwin%27s_finches) are defined as different species, but can technically interbreed.

beloch 2y ago

By calling them "H. sapiens neanderthalensis", the authors are tipping their hand. They view Neanderthal's as a subspecies. There are those who disagree. The definition of what a species is seems to depend on who you talk to. There are examples of animals, currently classified as different species, being able to interbreed and produce fertile offspring. e.g. Polar bears (Ursus Maritimus) and Grizzlies (Ursus arctos horribilis) can breed to produce fertile Grolar bears[1]. TL;DR: Although Polar bears and Grizzlies appear to be very different, they diverged relatively recently and have remained distinct mainly through geographic separation. They don't interbreed much because they generally aren't in the same places during mating season. Although their physical traits have changed considerably, genetic differences haven't yet built up to the point where their offspring are infertile. It's conceivable that the different subspecies of humans were isolated from each other in very different environments and evolved along very different lines. However, they weren't isolated from each other so long that genetic changes made it impossible for them to produce fertile offspring. [1]https://slate.com/news-and-politics/2010/05/when-polar-bears-and-grizzlies-breed-they-can-produce-fertile-offspring-why-can-t-other-species.html https://slate.com/news-and-politics/2010/05/when-polar-bears...

compressedgas 2y ago
Consider https://med.stanford.edu/news/all-news/2016/04/modern-men-lack-y-chromosome-genes-from-neanderthals.html https://med.stanford.edu/news/all-news/2016/04/modern-men-la...
rvense 2y ago
https://en.wikipedia.org/wiki/Liger https://en.wikipedia.org/wiki/Liger

throw839393 2y ago

It is more like a race. There are people with Neanderthal heretige living today. It is even used as a slur.

dan-robertson 2y ago

The classic elementary school definition of species is something like “x and y are different species if they cannot produce fertile offspring” which is obviously already incomplete (it causes eg two males of one species to be different species, for example) but could be made a bit more precise. But the actual definition is much more “a species is a group of reasonably closely related and similar organisms, capable of reproducing fertile offspring given sufficiently many individuals, and the grouping is useful for scientists to talk about”. Obviously that definition isn’t useful for a layperson to decide how to taxonomize things, but I think it’s a useful definition to have when reading about classifications of things into species.

woleium 2y ago
also see “ring species”. there are types of co-habiting gulls who cannot interbreed, but if you follow breeding pairs round the world you can go from one type to the other.

meheleventyone 2y ago

Species is a human taxonomy which doesn't strictly relate well to the variety of organisms in the living world. There are lots of different definitions and ways to approach it depending on context.

throwanem 2y ago

The term of art here is "species concept", of which there are several, well covered in [1]. Interfertility is a feature of some, but not all. [1] https://bio.libretexts.org/Courses/University_of_California_Davis/BIS_2B%3A_Introduction_to_Biology_-_Ecology_and_Evolution/02%3A_Biodiversity/2.01%3A_Species_Concepts https://bio.libretexts.org/Courses/University_of_California_...

adrian_b 2y ago

In general, in biology species are not defined by the impossibility of having viable hybrids between them, but by the fact that in natural conditions they do not normally interbreed, which allows their genes to drift away, becoming more and more different with the passing of time. For a species to exist, interbreeding must be both possible and frequent, which ensures that the entire population of the species remains uniform genetically for as long as the species exists, even when its genes may become more and more different from those of other species. The most frequent way for a new species to appear is when there is geographic isolation between two populations, which prevents interbreeding. Then, after many generations, the genetic differences may become so great that even when the populations are reunited interbreeding will fail, resulting in hybrids that are either non-viable, or sterile, like mules. With Neanderthals and Denisovans, the geographic separation has started the process of development of new species and they have become clearly differentiated from a genetic point of view. Nevertheless, not enough generations had passed so that the differences would become so great as to make interbreeding impossible. Even if we know that successful interbreeding has existed, we do not know which was the percentage of success for such interbreeding, i.e. how many of the hybrids were both viable and non-sterile. So it is a rather arbitrary choice to decide whether to call Neanderthals and modern humans as different subspecies or different species. In any case, they were easy to distinguish. There are many closely related species between which interbreeding is easily performed in captivity, e.g. in zoos, but it almost never happens in natural conditions, where wild animals may choose partners according to their preferences, so those species are easily distinguishable, due to their genetic differences that are preserved by the lack of interbreeding.

pcthrowaway 2y ago
To add to this, an example of 2 species which are easily distinguishable but can produce viable offspring (though the males are usually infertile) are Ligers (Lion + Tiger hybrids) Lions and Tigers are distinct enough that I don't believe anyone has made the argument that they're the same species. Though I do now wonder if they're really as distinct from one another as different breeds of house-cats