We’ve had this discussion before

Scientists have stuck their necks out and decided that the giraffe is not one species, but four.

Until now, only a single species of giraffe made up of several sub-species had been recognised.

But new DNA evidence shows that four distinct species of the animals exist – and they are genetically at least as different as brown and polar bears.

Do they mean brown or grizzlies? For grizzlies and polar bears can (and do) mate and produce fertile offspring. This, by the more archaic standards to which I adhere, means they are one species.

Pygmies and Vikings are distinctly different and yet they’re the one species.

29 thoughts on “We’ve had this discussion before”

  1. So Much For Subtlety

    Conservation efforts tend to kick in at the species level. No one much was willing to save the Northern Spotted Owl so the Greenies tried to get it defined as a different species.

    So it is species-inflation.

    I expect that there is greater genetic diversity between Vikings and pygmies than between most of these new giraffe species.

  2. So Much For Subtlety

    Incidentally, the US government is determined to save the four thousand or so wild tigers by ….. banning private ownership of tigers. There are as many tigers in captivity in the US as there are in the wild. There may be twice as many.

    http://weaponsman.com/?p=34802

    The stupidity of these is beyond words.

  3. According to the BBC article on this topic, the genetic evidence suggests that the four groups haven’t interbred for more than a million years, which makes the polar/grizzly point moot.

  4. Grizzly is the local North American name for the Brown Bear, which is the same species as the European Brown Bear. Grizzlies have more chance of coming into contact with Polar Bears and can mate to produce fertile offspring.

    The modern concept of species has become more fluid as we’ve discovered more about the nature of nature. In Europe, Herring Gulls and Lesser Black-backed Gulls are separate species and are rarely seen to interbreed. But follow them west and east and they become more and more like each other until (somewhere in Northeast Siberia) they become a single species. There are other examples of ‘ring’ species.

  5. You can get Tigons and Ligers – tiger and lion crosses.

    No-one would suggest that lions and tigers are not different species?

  6. Which reminds me that a Danish fertility clinic is offering IVF from anonymous donors to desperate women using the advertising line:

    “CONGRATULATIONS, IT’S A VIKING!”

  7. “I expect that there is greater genetic diversity between Vikings and pygmies than between most of these new giraffe species.”

    You’d be wrong then – the earliest divergence out of Africa was 60,000 years ago while the giraffes have been reproductively separate for over a million years.

  8. Ligers are weird beasts. Something about the growth inhibitors from male/female Lions/Tigers not being compatible.

    Ligers keep growing. Can get as big as a horse. Eventually they die from various growth related problems.

    Tigons are the opposite. Don’t get much bigger than a dog.

  9. 4 species plus a sub species. Hmm, bet they’d interbreed if they were in a zoo.
    A million years of separation…
    It depends whether you believe evolution is done by creeps or jerks (to use the parlance).
    If done by creeps, the mitochondrial “clock”, then you have a good timeline.
    If done by jerks, bursts of rapid DNA changes, then your time calculation can be completely out of whack.

  10. So Much For Subtlety

    Matthew L – “You’d be wrong then – the earliest divergence out of Africa was 60,000 years ago while the giraffes have been reproductively separate for over a million years.”

    I am not sure you can be wrong if you merely expect something. What we have is a Conservation group commissioning research for the specific purpose of protecting the species. It seems reasonable to take their claims with a grain of salt. After all human populations did not interbreed because they were separated by things like the Sahara desert. What kept these giraffe species apart?

    What is more it was a mitochondrial DNA study. So they were only looking at the females. Which doesn’t mean the occasional male didn’t wander past and interbreed.

  11. So humans look completely different despite recent separations, but giraffes look nearly identical despite a million years?

    I call bullshit on that.

  12. So Much For Subtlety

    Chester Draws – “So humans look completely different despite recent separations, but giraffes look nearly identical despite a million years? I call bullshit on that.”

    No, people look mildly different because of recent separations. While we do not know how long giraffes have been separated. But given who is doing this study and for what reasons, we should be cautious.

    Although they do look very similar. But then so a lot of species that have been separated for a long time.

  13. Bloke in Costa Rica

    Because everyone’s a geneticist, it seems. Humans quite famously have a very low genetic diversity: much lower than cats, for example and much, much lower than dogs.

  14. Matthew L,

    “You’d be wrong then – the earliest divergence out of Africa was 60,000 years ago while the giraffes have been reproductively separate for over a million years.”

    Awesome: I hope I’m as lively as you and my memory’s as sharp when I’m over a million.

  15. So Much For Subtlety

    Bloke in Costa Rica – “Humans quite famously have a very low genetic diversity: much lower than cats, for example and much, much lower than dogs.”

    Lewontin famously claimed humans were not that distinct genetically. But he seems to have picked a very few sites for comparison and may have done so deliberately. Certainly he intended to make a political, not a scientific, point.

    As it turns out humans are moderately-to-high in terms of genetic diversity. Enough that in another species races might have been labelled sub-species. Or at least Sewall Wright has claimed so.

  16. You’d be wrong then – the earliest divergence out of Africa was 60,000 years ago while the giraffes have been reproductively separate for over a million years.

    I must have missed the bit where it said these 4 giraffe populations have been separated for a million years. The article just said that they didn’t interbreed in the wild.

    In any case, amount of time separated isn’t the only factor in how much populations can diverge genetically. There’s also selection pressure to consider. Characteristics can evolve pretty quickly if the selection pressure is heavy enough, as in animal or plant breeding. You don’t need a million years to turn a wolf into a chihuahua or to turn teosinte into maize.

  17. Chester Draws – “So humans look completely different despite recent separations, but giraffes look nearly identical despite a million years? I call bullshit on that.”

    No, humans look different and giraffes don’t, because we are human.
    Ask a giraffe and you would get the opposite answer.

  18. For grizzlies and polar bears can (and do) mate and produce fertile offspring. This, by the more archaic standards to which I adhere, means they are one species.

    I don’t think that anyone has ever said that grizzlies and polar bears are the same species. Because it is not what they can do but what they do naturally. And by and large, polar bears do not interbreed with grizzlies.

    Otherwise one or other species would not exist any more.

  19. SMFS,

    Because it is not what they can do but what they do naturally. And by and large, polar bears do not interbreed with grizzlies.

    The same could be said of the English and the French – do you regard them as different species?

  20. So Much For Subtlety

    Nemo – “The same could be said of the English and the French – do you regard them as different species?”

    It could be said of the English and the French. But it would not be true. The fact the British Army was commanded by Sir Peter Edgar de la Cour de la Billière is proof of that. As is the fact that the French Army used to be commanded by someone called Marshal Marie Esme Patrice Maurice, Count of MacMahon, Duke of Magenta who went on to become the President of France.

    Not to mention the entire history of the Royal family. And Guernsey.

    Although common sense would suggest not interbreeding with French people, in fact it is very hard to make the British and the French stop.

  21. SMFS,

    A name alone proves nothing; Thomas Cochrane, 10th Earl Dundonald commanded both the Chilean and Brazilian navies, but I’ve never heard him accused of bigamy, polygamy, etc… For de la Billiere to be relevant you’d have to display it through actual interbreeding.

    And even if you did so, you’d need a lot more examples before you met your own standard of “by and large”. Marshal Marie Esme Patrice Maurice, Count of MacMahon, Duke of Magenta and erstwhile President of France isn’t my idea of “by and large”, but that might just reflect our differing social milieux.

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