Decola o entendimento sobre a evolução da asa do morcego

quarta-feira, março 11, 2009

Understanding of bat wing evolution takes flight

Kimberly L. Cooper and Clifford J. Tabin1

Author Affiliations


It has long been debated whether the processes and mechanisms responsible for phenotypic variation within a population or between closely related populations can be extrapolated to explain evolutionary trends over longer phylogenetic distances and especially the generation of novel structures. Although there has been great progress in recent years in addressing the genetic basis for microevolutionary changes, for the most part these efforts have done little to address this debate. Evolutionary genetic studies, by their nature, can only be applied to closely related groups. For example, quantitative trait mapping is limited to species with distinct morphological traits that are capable of producing viable progeny when crossed either naturally or artificially. There are only a few cases in which linkage mapping has thus far been applied even at the distance of interspecific hybrids to identify loci responsible for morphological differences between highly related species (Sucena et al. 2003; Shapiro et al. 2004; Colosimo et al. 2005; Kronforst et al. 2006; Protas et al. 2006; McGregor et al. 2007). While the genomes of more distantly related taxa can be compared, the effect of molecular drift over millions of years has generated a large noise of sequence variation that makes the identification of specific and functionally relevant changes analogous to finding a needle in a haystack. In this issue of Genes & Development, Cretekos et al. (2008) have found one such needle—an enhancer of the paired-box homeodomain transcription factor, Prx1, that accounts for at least part of the extension of the long bones in the wings of bats.


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