by the discovery that many genes involved in pattern formation, morphogenesis and differentiation have been remarkably conserved through evolution. To what extent are the roles of these genes also conserved? Geneduplication is a major factor complicating comparison of developmental genes between
early stages of development, become different. At a higher level of integration we see that the chordate body plan or phylotype can be recognized in a much more complex form in vertebrates. Geneduplication seems to provide a mechanism which allows functional divergence. Evidence for such processes to
was previously suggested that all main classes of monoamine receptors already existed in the Precambrian, before the separation between vertebrates and invertebrates. A period of intense geneduplication and divergence probably occurred about 400 million years ago (MYA), closely before the explosive
., Fritsch, R. M., Blattner, F. R. Species level phylogeny of Allium subgenus Melanocrommyum—incomplete lineage sorting, hybridization and trnF geneduplication. Taxon (in press).
Hanelt, P., Schultze-Motel, J., Fritsch, R., Kruse, J., Maaß, H. I., Ohle, H., Pistrick, K. 1992. Infrageneric grouping
. 2009. Correcting estimators of θ and Tajima's D for ascertainment biases caused by the single-nucleotide polymorphism discovery process. Genetics 181: 701-710.
Rodin, S. N., Riggs, A. D. 2003. Epigenetic silencing may aid evolution by geneduplication. J. Mol. Evol. 56: 718-729.
mutations, with a consistency index of 0.91, a homoplasy index of 0.087, a retention index of 0.86 and a rescaled consistency index of 0.79. Bootstrap values are shown on the branches of the tree. Also indicated are the two geneduplication events which occurred indepentently in ancestral Acanthopterygii
. The lack of amplification with the eel material is due to degradation of genomic DNA. The present results show the existence of PTHrp-like DNA in sub- mammalian vertebrates and of PTHrp-likc proteins in fish. It is now accepted that PTH and PTHrp genes arc the result of geneduplication (MANGIN et al
hexamerin receptor (Burmester, 2004 ; Immesberger & Burmester, 2004 ).
Phenoloxidase and its inactive form prophenoloxidase are the most basal group in the arthropod haemocyanin superfamily, and gain and loss of functions have occurred across the superfamily with time and geneduplications (Burmester
Lynch, M., Conery, J. S. 2000. The evolutionary fate and consequences of duplicate genes. Science 290: 1151-1155.
Lynch, M., Force, A.G. 2000. The origin of interspecific genomic incompatibility via geneduplication. Am. Nat. 156: 590-605.
Machado, C.A., Hey, J. 2003. The causes of