Hallmarks of a dwindling population

The last of the mammoth population may have experienced high rates of birth defects due to the dwindling numbers and inbreeding, along with prenatal stress.

Last Woolly Mammoths May Have Suffered Birth Defects | LiveScience.

Fossils of mammoths found near the North Sea and dating to the late Pleistocene, about 12,000 years ago, frequently sported extra ribs along their neck vertebrae. Though harmless on their own, these cervical ribs are often signs of development gone awry. A 2006 study of extra cervical ribs in humans published in the journal Evolution found that about 78 percent of fetuses with cervical ribs die before birth; 86 percent of fetuses that develop with these extra ribs won’t make it to their first birthday.

“The high incidence and large size of the cervical ribs indicates a strong vulnerability, given the association of cervical ribs with diseases and congenital abnormalities in mammals,” the researchers wrote. “The vulnerable condition may well have contributed to the eventual extinction of the woolly mammoths.”

But they were already well in decline. This is the inevitable result of decline, the final blow. It’s a hazard that must also be considered when humans intervene to save threatened animals. The genetic variablity is of great importance.

The paper is available here.

Extraordinary incidence of cervical ribs indicates vulnerable condition in Late Pleistocene mammoths [PeerJ].

  4 comments for “Hallmarks of a dwindling population

  1. Lagaya1
    March 26, 2014 at 2:50 PM

    This could pose a problem for those who want to clone one from cells obtained from a frozen mammoth. Unless the mammoth froze before the population decline started- which I suppose is entirely possible. I’ve always hoped they could do that…

    I suppose the same thing happens with all declining populations. So the people who think we can just clone them again when the time is right, may have a false hope.

  2. Anthony
    March 28, 2014 at 9:15 PM

    There are plenty of mammoth bodies still out there. A population could be started from dozens of specimens. Careful breeding and methodical manipulation could produce hundreds of unique individuals for a founding population. Thylacines have a bigger problem with only a handful of specimens from which to draw.

  3. Lagaya1
    March 28, 2014 at 10:54 PM

    That’s good to know. So at least for mammoths there is a possibility Maybe not so for animals in parts of the world where frozen specimens aren’t found.

  4. Chris Howard
    March 30, 2014 at 8:46 AM

    So that’s what’s happening to the Republican Party.

    The GOP should read this… oh, wait. They don’t believe in evolution, or science.

    I kid, of course.

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