Darwinism Genetics

So new genes don’t lead to new species?

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bdelloid rotifer

In “Zoologger: Clone army steals genes from other species” (New Scientist, 23 May 2011), Michael Marshall discusses the way clams steal genes from other clams. And how some life forms don’t have sex at all:

The poster children for asexuality are bdelloid rotifers, tiny animals that have gone without sex for 80 million years. But they cheat: they steal swathes of genes from bacteria, fungi and plants.

So … what about the assured results of scientific evolution theory?

What can we certainly predict, other than that bdelloid rotifers will not become anything else, no matter whose genes they steal? But what would that mean for Darwinian evolution? For the theory of genes?

Warning: Clam sex (or maybe not) discussed.

2 Replies to “So new genes don’t lead to new species?

  1. 1
    ellazimm says:

    From Wikipedia:

    “Bdelloids have been of interest to those interested in the evolutionary role of sexual reproduction, because it has disappeared entirely from the group: males are not present within the species, and females reproduce exclusively by parthenogenesis. Each individual has paired gonads. Despite the fact that they have been asexual for millions of years, they have diversified into more than 300 species and are fairly similar to other sexually-reproducting rotifer species.”

    And from the BBC:

    “The animal is a tiny invertebrate known as a bdelloid rotifer. It lives in freshwater pools. If deprived of water, it survives in a desiccated state until water becomes available again.

    The secret to this novel survival mechanism lies in a twist of asexual reproduction, whereby the animal is able to make two separate proteins from two different copies of a key gene.

    Dr Alan Tunnacliffe, from the Institute of Biotechnology at the University of Cambridge, who led the research, said his team had been able to show for the first time that gene copies in asexual animals can have different functions.

    “It’s particularly exciting that we’ve found different, but complementary, functions in genes which help bdelloid rotifers survive desiccation,” he explained.

    “Evolution of gene function in this way can’t happen in sexual organisms, which means there could be some benefit to millions of years without sex after all.”

    The researchers discovered that two copies of a particular gene, known as LEA, in the asexual pond-dweller are different – giving rise to proteins with separate functions that protect the animal during dehydration.”

    It would be interesting to find out how different the two copies of LEA are. A really fascinating area for research! I wonder how they define ‘specie’ in non-sexually reproducing creatures?

  2. 2
    Mung says:

    How do they know which genes they need?

    And how do they avoid stealing junk?

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