Segmentation, metamerism and the Cambrian explosion

Couso, Juan (2009) Segmentation, metamerism and the Cambrian explosion. International Journal of Developmental Biology, 53. pp. 1305-1316. ISSN 0214-6282

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Data on the molecular and genetic basis of animal development, and on genome sequences, have been challenging our established assumptions about animal evolution for the last decade. Recent such data in animals of particular phylogenetic importance beg us to take another look at whether similarities in developmental and genetic mechanisms in current animals are the product of a common inheritance (homology) or convergent evolution (analogy). The evolution of segmentation, in particular whether segmentation and metameric bodies have arisen just once or several times in evolution, is a prime concern. Segmentation and metamerism are striking developmental and body organisations that exist, in varying degrees, in many complex animals, but the traditional view holds that this is the result of convergent evolution. Here, I review recent palenotological and developmental information and conclude that a metameric body plan is not only a likely ancestral character of bilaterian animals, but also a possible trigger for the Cambrian explosion in body morphology and complexity. This conclusion is supported by the phylogenetic distribution and prevalence of metameric phyla in the Cambrian, and the similarity of the genomes and segmentation mechanisms across current bilaterian phyla.

Item Type: Article
Additional Information: Issue 8-10
Schools and Departments: School of Life Sciences > Biochemistry
Brighton and Sussex Medical School > Clinical and Experimental Medicine
Depositing User: Juan Couso
Date Deposited: 06 Feb 2012 20:10
Last Modified: 06 Jun 2019 09:08
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