Behavioral Ecology Blog

Now I’m no Coleoptera systematist, but it’s hard not to say “Holy Shit” when you look- really look at the evolution of the Coleoptera.

There is a new paper in Science: A Comprehensive Phylogeny of Beetles Reveals the Evolutionary Origins of a Superradiation that is really impressive. Here is the abstract:

Beetles represent almost one-fourth of all described species, and knowledge about their relationships and evolution adds to our understanding of biodiversity. We performed a comprehensive phylogenetic analysis of Coleoptera inferred from three genes and nearly 1900 species, representing more than 80% of the world’s recognized beetle families. We defined basal relationships in the Polyphaga supergroup, which contains over 300,000 species, and established five families as the earliest branching lineages. By dating the phylogeny, we found that the success of beetles is explained neither by exceptional net diversification rates nor by a predominant role of herbivory and the Cretaceous rise of angiosperms. Instead, the pre-Cretaceous origin of more than 100 present-day lineages suggests that beetle species richness is due to high survival of lineages and sustained diversification in a variety of niches.

For general wow purposes, Beetles:

1. Predate the dinosaurs having arisen 285 million years ago
2. Have 168 recognized families
3. Are diverse not because of rapid diversification followed by long periods of stasis, but instead by slow and steady diversifcation and high lineage survival
4. Herbivory has played a role in the diversification of some beetle lineages, but the trait per se does not explain why beetles are so diverse
5. shifts from terrestrial to aquatic habits in the evolutionary history of beetles occurred at least 10 times
6. There are more known species of Coleoptera that any other group of organisms.
7. There are 350,000 of them described (and probably 10’s of thousands yet to be described.

OK, the paper….

They sequences 3 genes (~300bp) for ~1900 species, and this was only enough to get them 80% coverage or recognized families. Wow.. Here is the tree:

Reference: Science 21 December 2007:Vol. 318. no. 5858, pp. 1913 - 1916 DOI: 10.1126/science.1146954

See Shalini’s post on the beetles.