October 29, 2004 | David F. Coppedge

Platypus Has 10 Sex Chromosomes

The duck-billed platypus has thrown another curveball at evolutionary theory.  Long puzzling to phylogenists for its mosaic of features that make it seem part mammal, bird and reptile, it has now revealed a genome with 10 sex chromosomes – 10 X in the female, and 5 X plus 5 Y in the male.  Moreover, the sequence of the X chromosomes differs in length and makeup.  The purpose of this arrangement is unclear, but observations by Australian scientists showed that the chromosomes segregate faithfully during meiosis.  “It’s hard to speculate on how that could have evolved,” said one researcher, according to Nature Science Update.    Whatever the reason, it works.  Science Now says, “the platypus manages to keep its reproduction from going awry.”
For a creationist view on how this is problematic for evolution, see Brad Harrub’s analysis on Apologetics Press.

Nature Science Update relates the Darwinian tale as, “Monotremes were the first group to branch off after mammals evolved 210 million years ago.  Their egg-laying shares a common origin with birds and reptiles, although the bill is thought to have evolved independently.”  Any proof?  No.  Any transitional forms?  No.
    One researcher said, “Mammals are pretty boring when it comes to sex chromosomes.  The platypus is a huge exception.”  Who said sex was boring?  It keeps the Darwin theorists awake at night, but with more pain than pleasure.

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Categories: Biology, Mammals

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