The Scientist - Complex genomes evolved by chance

[iansmith]

The question of whether the evolution of large and complex genomes in complex multicellular organisms is due to natural selection or simply a function of chance has been the subject of considerable debate. In November 21 Science, Michael Lynch and John Conery at Indiana University argue that the inclusion of intragenic spacers—introns—and transposons, coupled with the increase in gene number associated with genomes of multicellular animals and plants, were not essential for adaptive phenotypic diversification during eukaryotic evolution, but are the result of orders-of-magnitude reductions in population size. This process magnified random genetic drift and prevented “purifying” natural selection from removing them (Science, 302:1401-1404, November 21, 2003).

http://www.biomedcentral.com/news/20031124/03

 

[Monique]

We have introns, but small eukaryotes do not, not because they are good for us but because our population size is too small for us to stop them accumulating.

Interesting statement..

 

[iansmith]

I just read the paper and the were some mistake. First , they assume that prokaryotes gave rise to eucaryotes. They also group bacteria and archea into prokaryotes. These two statements goes against the new theory of cell evolution.

Bacteria and Archeae also exhibit group II introns in their genes
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=1899138
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=11755525&dopt=Abstract
http://www.blackwell-synergy.com/links/doi/10.1046/j.1462-2920.2003.00398.x/full/

Their idea is interresting but the I am doubtfull about some details

 

[Monique]

They just published in Science.. you'd think that the journal has a very strict peer reviewing policy..