Just ran across an article worth quoting. While none of this is news to anyone who follows this blog, consider how seamlessly it fits the front-loading message of this blog (minus the “surprising” nature of the results, that is):
Environmental factors aside, the genetic make-ups of the unicellular ancestors of multicellular lineages must also have been pivotal in facilitating the repeated emergence of the trait. But until recently, the sources and ancestral function of genes fundamental to the multicellular lifestyle were completely unknown, as such genes were thought to be present only within the multicellular lineages to which they were first identified and studied. Emerging data from comparative and functional genomics studies in several multicellular lineages and comparisons with their unicellular relatives, as well as experimental studies of ‘multicellular’ genes in a unicellular context, have begun to provide an increasingly clearer snapshot of the molecular foundations upon which multicellular lineages were founded.
One of the most surprising results generated by the comparative analysis of several unicellular eukaryotic genomes has been the extent to which their genomes contain proteins which were previously only known from multicellular organisms. Their presence in the unicellular relatives of multicellular lineages suggests that these proteins were likely present in their last common unicellular ancestor, immediately before the emergence of multicellularity.
– Rokas, A. 2009. The molecular origins of multicellular transitions. Current Opinion in Genetics & Development 18:472–478