how scientists categorize whale stocks

From: Orca Network (howard@orcanetwork.org)
Date: Wed Jan 15 2003 - 19:29:41 EST

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    Hi. My name is Ashlee. I am doing a project in my animal science class for
    school and i was wondering if you knew how scientists categorize whale
    stocks? Thank you, Ashlee

    There is a scientific field dedicated to categorizing the plants and
    animals and other forms of life on Planet Earth, and whales are categorized
    according to the same methods used for all the rest. Those methods are
    constantly being developed, however, hence the need for scientists to
    figure out the best ways to do it.

    The conventional way is to look at physical characteristics, body type and
    form, and assign relatedness - similarities and differences - that way,
    then describe an evolutionary family tree that they all fit in, and come up
    the names for each animal's species, genus, family, order, class, phylum
    and kingdom. More recently, genetics - the study of DNA - has proven to be
    a shortcut to finding relatedness, often in surprising ways. A few years
    ago DNA studies determined that sperm whales were more related to baleen
    whales than to other toothed whales. That was hard to accept at the time
    because it was believed that all whales were descended from a kind of
    carnivore (the mesonychid condylarth), which would mean that toothed whales
    came first. Then fossils were discovered that showed that the earliest
    whales were descended from large grazing herbivores (artiodactyls), making
    baleen whales at least as ancient as toothed whales, so that explained how
    sperm whales could be more related to baleen whales than to other toothed
    whales.

    The complete cetacean family tree, showing all the classifications, can be
    found at http://www.crru.org.uk/taxonomy.htm.

    Howard Garrett
    Orca Network
    Greenbank WA
    (360) 678-3451
    www.orcanetwork.org
    howard@orcanetwork.org



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