Gregory T Ryan
Department of Zoology, University of Guelph, ON, Canada.
Genome. 2002 Oct;45(5):833-8. doi: 10.1139/g02-050.
Although unrelated to any intuitive notions of organismal complexity, haploid genome sizes (C values) are correlated with a variety of cellular and organismal parameters in different taxa. In some cases, these relationships are universal--notably, genome size correlates positively with cell size in each of the vertebrate classes. Other relationships are apparently relevant only in particular groups. For example, although genome size is inversely correlated with metabolic rate in both mammals and birds, no such relationship is found in amphibians. More recently, it has been suggested that developmental rate and (or) longevity are related to genome size in birds. In the present study, a large dataset was used to examine possible relationships between genome size and various developmental parameters in both birds and mammals. In neither group does development appear to be of relevance to genome size evolution (except perhaps indirectly in birds through the intermediation of body size and (or) within the rodents), a situation very different from that found in amphibians. These findings make it clear that genome size evolution cannot be understood without reference to the particular biology of the organisms under study.
尽管单倍体基因组大小（C值）与生物体复杂性的任何直观概念无关，但在不同分类群中，它与各种细胞和生物体参数相关。在某些情况下，这些关系是普遍存在的——值得注意的是，在每个脊椎动物类别中，基因组大小与细胞大小呈正相关。其他关系显然只在特定群体中相关。例如，虽然在哺乳动物和鸟类中基因组大小与代谢率呈负相关，但在两栖动物中未发现这种关系。最近，有人提出发育速率和（或）寿命与鸟类的基因组大小有关。在本研究中，使用了一个大型数据集来检验鸟类和哺乳动物基因组大小与各种发育参数之间的可能关系。在这两个类群中，发育似乎都与基因组大小的进化无关（也许除了在鸟类中通过体型的中介作用以及（或者）在啮齿动物内部可能存在间接关系外），这种情况与两栖动物的情况非常不同。这些发现清楚地表明，如果不参考所研究生物体的特定生物学特性，就无法理解基因组大小的进化。
