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The edition of Nature published two days ago is a humdinger. It contains the complete euchromatic sequence of the human genome, the first empirical support for the frame dragging prediction of rotating masses of General Relativity, a serious challenge to the accuracy of both of the most common phylogenetic techniques that we have just been talking about (maximum parsimony and maximum likelihood), and a marvellous paper on the comparative genomics of puffer fish and humans:
Jaillon et al,‘Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype, Nature 431; 946 -957’
The paper is too detailed and involved to summarise in any detail here, but the two major conclusions are that sometime in the ancestry of teleost fish about 230 million years ago there occured a complete genome duplication (if you are interested I can post a summary of the evidence for this); and that the common ancestor of humans and puffer fish (which lived about 400 million years ago) had 12 pairs of chromosomes (puffer fish have 21 pairs and humans 23 pairs) - they even determine on which of the 12 chromosomes of our common ancestor (which was an unknown primitive fish) particular genes reside. They also determine the major chromosomal events that occurred in the puffer fish lineage to convert from the 12 ancestral to the extant 21 chromosomes: a whole genome duplication, two ancient fusions, three recent fusions, one ancient and one recent fission and three major translocations). A similar analysis in the human lineage shows a more complicated pattern of chromosomal rearrangements but correctly predicts the well known recent fusion of two primate chromosomes to form human chromosome 2, the different origins of the two arms of the human X-chromosome, and the fission of a single ancestral chromosome to form chromosome 12 and 22 in the primates.
Alec
evolutionpages.com
The edition of Nature published two days ago is a humdinger. It contains the complete euchromatic sequence of the human genome, the first empirical support for the frame dragging prediction of rotating masses of General Relativity, a serious challenge to the accuracy of both of the most common phylogenetic techniques that we have just been talking about (maximum parsimony and maximum likelihood), and a marvellous paper on the comparative genomics of puffer fish and humans:
Jaillon et al,‘Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype, Nature 431; 946 -957’
The paper is too detailed and involved to summarise in any detail here, but the two major conclusions are that sometime in the ancestry of teleost fish about 230 million years ago there occured a complete genome duplication (if you are interested I can post a summary of the evidence for this); and that the common ancestor of humans and puffer fish (which lived about 400 million years ago) had 12 pairs of chromosomes (puffer fish have 21 pairs and humans 23 pairs) - they even determine on which of the 12 chromosomes of our common ancestor (which was an unknown primitive fish) particular genes reside. They also determine the major chromosomal events that occurred in the puffer fish lineage to convert from the 12 ancestral to the extant 21 chromosomes: a whole genome duplication, two ancient fusions, three recent fusions, one ancient and one recent fission and three major translocations). A similar analysis in the human lineage shows a more complicated pattern of chromosomal rearrangements but correctly predicts the well known recent fusion of two primate chromosomes to form human chromosome 2, the different origins of the two arms of the human X-chromosome, and the fission of a single ancestral chromosome to form chromosome 12 and 22 in the primates.
Alec
evolutionpages.com