The evolutionary history of muscle development in the paired fins of teleost fish and the limbs of tetrapod vertebrates is still, to a large extent, uncertain. There has been a consensus, however, that in the vertebrate clade the ancestral mechanism of fin and limb muscle development involves the extension of epithelial tissues from the somite into the fin/limb bud. This mechanism has been docu...

The fossil record indicates that crinoids have exhibited remarkable regenerative abilities since their origin in the Ordovician, abilities that they likely inherited from stem-group echinoderms. Regeneration in extant and fossil crinoids is recognized by abrupt differences in the size of abutting plates, aberrant branching patterns, and discontinuities in carbon isotopes. While recovery is comm...

The evolutionary study of the mind in the twentieth century has been marked by three self-conscious movements: classical ethology, sociobiology and Evolutionary Psychology (capitalized to indicate that it functions here as a proper name). Classical ethology was established in the years immediately before the Second World War, primarily by Konrad Lorenz and Niko Tinbergen (Burckhardt, 1983). Int...

Compositional genomics is an approach to the problem of the organization of eukaryotic genomes. Initially this approach consisted of analysing the base composition of complex eukaryotic genomes (such as the nuclear genomes of vertebrates) by using density gradient centrifugation in the presence of sequence-specific ligands. This approach revealed that vertebrate genomes are mosaics of very long...

R eading the French version of Journey to the Ants by Bert Hölldobler and Edward O. Wilson (1996) during the course of my graduate studies, I remember being amazed by the description of circular mills formed by an isolated group of army ants. This phenomenon occurs when a group of foragers is separated from the main column of the raiding swarm by a perturbation of their pheromonal communication...

The enzyme enolase [EC 4.2.1.11] is found in all organisms, with vertebrates exhibiting tissue-specific isozymes encoded by three genes: alpha (alpha), beta (beta), and gamma (gamma) enolase. Limited taxonomic sampling of enolase has obscured the timing of gene duplication events. To help clarify the evolutionary history of the gene family, cDNAs were sequenced from six taxa representing major ...

Dog domestication was probably started very early during the Upper paleolithic period (~35,000 BP), thus well before any other animal or plant domestication. This early process, probably unconscious, is called proto-domestication to distinguish it from the real domestication process that has been dated around 14,000 BC. Genomic DNA analyses have shown recently that domestication started in the ...

Genomes conceal a vast intricate record of their carriers' descent and evolution. To disclose this information, biologists need phylogenetic models that integrate various levels of organization, ranging from nucleotide sequences to ecological interactions. Rates of duplication and horizontal gene transfer, organism trees and ancestral population sizes can all be inferred through statistical mod...

Evolutionary psychologists have emphasized the importance of natural selection in shaping cognitive functions, but historical contingency has not received direct study. This is crucial because in response to selection, complex traits tend to be fine-tuned or jury-rigged rather than totally reconstructed. We hypothesize that the neural and cognitive strategies an animal employs in signal recogni...

BACKGROUND The universality of marriage in human societies around the world suggests a deep evolutionary history of institutionalized pair-bonding that stems back at least to early modern humans. However, marriage practices vary considerably from culture to culture, ranging from strict prescriptions and arranged marriages in some societies to mostly unregulated courtship in others, presence to ...