Genetics, development, and palaeontology in one bite
Interesting commentary in nature genetics reviews by PD Polly.
In this review the author stresses the potential of teeth as a model system to synthesize evolutionary biology in a way that Genetics, Paleontology, and Evolution could be linked altogether.
Theoretically it was thought that one of the main advantages of sexual populations was that it would purge the amount on non-synonymous mutations (Kn) by meiotic and recombinational reshuffling of genes.
This was tested by Paland & Lynch by using sexual and asexual forms of the water flea Daphnia pulex. They compared mitochondrial genes of the two forms for ratios of synonymous and non-synonymous nucleotide substitutions (Kn/Ks). If everything fitted into the theoretical framework, Kn/Ks should be much higher in asexual populations than in sexual ones…. And the results backed up the hypothesis: 17.7% of amino-acid substitutions arising in asexual lineages persist despite being deleterious, just 4.4% in sexual lineages.
So, another advantage for being sexual… some people should learn
