Berná Luisa, Alvarez-Valin Fernando, D'Onofrio Giuseppe
Laboratory of Animal Physiology and Evolution, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy.
Comp Funct Genomics. 2009;2009:875901. doi: 10.1155/2009/875901. Epub 2009 Dec 16.
Genomewide analyses of distances between orthologous gene pairs from the ascidian species Ciona intestinalis and Ciona savignyi were compared with those of vertebrates. Combining this data with a detailed and careful use of vertebrate fossil records, we estimated the time of divergence between the two ascidians nearly 180 My. This estimation was obtained after correcting for the different substitution rates found comparing several groups of chordates; indeed we determine here that on average Ciona species evolve 50% faster than vertebrates.
对海鞘物种肠鳃纲海鞘和萨氏海鞘直系同源基因对之间的距离进行全基因组分析，并与脊椎动物的进行比较。将这些数据与对脊椎动物化石记录的详细且谨慎的运用相结合，我们估计这两种海鞘之间的分化时间约为1.8亿年前。这个估计是在对几组脊索动物比较中发现的不同替换率进行校正后得出的；实际上，我们在此确定，海鞘物种平均进化速度比脊椎动物快50%。
