Have a nice Christmas – last blogpost of the year 2012

The end of 2012 is almost there and it has been a while ago when I posted my last post. And for sure I want to wich you all wich a happy and blessed Christmas.

In this post I just want to give you the heads up of what I thought were interesting developments in science and especially in the evolutionary kind of science.

First, I want to point out to the post of Todd Wood about gene conversion as a means to get rid of ‘bad’ mutations. Recombination is the method by which cells swap parts of the genome and can get rid of bad mutations.  But it turns out that gene conversion (type of recombination) is occuring more frequently than thought. In diploid organisms gene conversion could ‘delete’ bad fragments, and copy the good ones. So be sure to check  his post about it!

One remark from my side, is that this was demonstrated in Arabidopsis, which is a plant species, and in contrary to this observation in yeast the number of crossing over events is observerd to be larger than the number of gene conversions. This diffference has probably something to do with the differences in repeat content, as the authors of the original article suggest. So the number of crossing-over is correlated with more repeats. Which indeed is logical.

Second, researchers found that the macro-genomic structure of the Pinophyta (conifers), has remained largely the same during the last 100 million years. As everyone knows the seed plants are composed out of the angiosperms (flowering plants)  and the gymnosperms (conifers, and more), which are presumably diverged from each other around 300 million years ago. The remarkable thing here is that the synteny of the genome has remained the same for so many years. The conifers have remained the same from onwards the Early Cretaceous era.

Why fascinating? In a creationist model the Cretaceous period was definitely during or before the flood. So my hypothesis is that after the flood those gymnosperms or at least the conifers did not show a lot of

diversification, which could be due to the already good adaption of those conifers to harsh environments. Indeed, only 600 conifer species are identified, compared with 400000 species of flowering plants.

Finally, just for fun, I want to point out to an video made by the Biologic Institute. Ann Gauger is talking about population genetics and tree building. The relation between those two very distinct topics is not yet clear to me, but she seems utterly serious about it.

It is time to stop and I wish you all a happy Chistmas!

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