DNA analysis reveals there are four distinct giraffe species, not one
1–10 of 107 posts
Re: DNA analysis reveals there are four distinct giraffe species, not one
#2> The findings suggest that genetic exchange among the four species is rare, maybe even nonexistent. This genetic isolation defines them as distinct species, as opposed to subspecies.
A bold, up-front assertion that Native Americans were in fact a distinct species from Europeans.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#3> The findings suggest that genetic exchange among the four species is rare, maybe even nonexistent. This genetic isolation defines them as distinct species, as opposed to subspecies. A bold, up-front assertion that Native Americans were in fact a distinct species from Europeans.
The quoted statement should be interpreted in the context of the study. Specifically, in the context that "species’ current ranges are not always delineated by geography".
The genetic isolation of Native Americans was clearly a result of a geography.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#4> The findings suggest that genetic exchange among the four species is rare, maybe even nonexistent. This genetic isolation defines them as distinct species, as opposed to subspecies. A bold, up-front assertion that Native Americans were in fact a distinct species from Europeans.
The quoted statement should be interpreted in the context of the study. Specifically, in the context that "species’ current ranges are not always delineated by geography". The genetic isolation of Native Americans was clearly a result of a geography.
The context does not contradict that statement. Every single measure used on every other animal would at minimum place humans in several subspecies. But we do not apply the same standards to ourselves for political reasons.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#5Earlier quoted context omitted.
The quoted statement should be interpreted in the context of the study. Specifically, in the context that "species’ current ranges are not always delineated by geography". The genetic isolation of Native Americans was clearly a result of a geography.
The context does not contradict that statement. Every single measure used on every other animal would at minimum place humans in several subspecies. But we do not apply the same standards to ourselves for political reasons.
Humans have not really had enough time as independent populations to diverge much. The north american land bridge disappeared ~14,500 years ago so only ~14,000 years as separate populations. African > Eurasia had regular exchanges as they where within relatively short walking distances.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#6Earlier quoted context omitted.
The context does not contradict that statement. Every single measure used on every other animal would at minimum place humans in several subspecies. But we do not apply the same standards to ourselves for political reasons.
Humans have not really had enough time as independent populations to diverge much. The north american land bridge disappeared ~14,500 years ago so only ~14,000 years as separate populations. African > Eurasia had regular exchanges as they where within relatively short walking distances.
>Humans have not really had enough time as independent populations to diverge much
There is no scientific basis for that claim. Many other animals have diverged less, in less time and are still separate subspecies.
>African > Eurasia had regular exchanges as they where within relatively short walking distances.
Interbreeding does not mean subspecies don't exist. Coyotes and wolves are totally separate species and they interbreed. This does not make them the same species, much less the same subspecies. Or the very example given in the article: polar bears and brown bears. Separate species, overlapping geographical regions, crossbreeding occurs in the overlap. Or again from the article example: giraffes.
Also note they talk about the genetic distance, but the genetic distance between a west african and an australian aboriginal is greater than the difference between wolves and dogs, which are subspecies. Again, by all measures we use for wild animals, humans consist of several subspecies at least.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#7Earlier quoted context omitted.
The context does not contradict that statement. Every single measure used on every other animal would at minimum place humans in several subspecies. But we do not apply the same standards to ourselves for political reasons.
Humans have not really had enough time as independent populations to diverge much. The north american land bridge disappeared ~14,500 years ago so only ~14,000 years as separate populations. African > Eurasia had regular exchanges as they where within relatively short walking distances.
That's not true we've seen speciation happening in front of our eyes with some species.
While time is a factor 14,000 is more than enough for humans to speciate, the reason why this hasn't happened to humans is something that is actually a subject of research today.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#8> The findings suggest that genetic exchange among the four species is rare, maybe even nonexistent. This genetic isolation defines them as distinct species, as opposed to subspecies. A bold, up-front assertion that Native Americans were in fact a distinct species from Europeans.
https://en.wikipedia.org/wiki/Species_problem
The word "Species" is mixed up in all manner of biological and sociological turmoil. I was even of the impression that becuase of DNA sequencing the term is falling out of favour amongst researchers.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#9Earlier quoted context omitted.
Humans have not really had enough time as independent populations to diverge much. The north american land bridge disappeared ~14,500 years ago so only ~14,000 years as separate populations. African > Eurasia had regular exchanges as they where within relatively short walking distances.
>Humans have not really had enough time as independent populations to diverge much There is no scientific basis for that claim. Many other animals have diverged less, in less time and are still separate subspecies. >African > Eurasia had regular exchanges as they where within relatively short walking distances. Interbreeding does not mean subspecies don't exist. Coyotes and wolves are totally separate species and the…
The thing is we're talking about species here, not subspecies.
Re: DNA analysis reveals there are four distinct giraffe species, not one
#10Earlier quoted context omitted.
Humans have not really had enough time as independent populations to diverge much. The north american land bridge disappeared ~14,500 years ago so only ~14,000 years as separate populations. African > Eurasia had regular exchanges as they where within relatively short walking distances.
That's not true we've seen speciation happening in front of our eyes with some species. While time is a factor 14,000 is more than enough for humans to speciate, the reason why this hasn't happened to humans is something that is actually a subject of research today.
Humans have a long reproductive cycle, so that's under 1,000 generations. For comparison bacteria can reach 1,000 generations in ideal conditions in less than 1 year.