The New York Times has a story up, After the Dinosaurs’ Demise, Many Mammals Seized the Day. It’s a write-up of a new paper that is open access, Temporal niche expansion in mammals from a nocturnal ancestor after dinosaur extinction.
This research illustrates how computational power has changed evolutionary biology. There has long been an intuitive verbal model that mammals were ancestrally night-adapted creatures based on aspects of their biology, as well as the evolutionary reality that for most of the lineages’ existence they were overshadowed by dinosaurs (remember, more than half of our evolutionary history predates the Cenozoic).
But today we do more than posit models which match and predict the fossil (or genetic) data. Computationally intensive phylogenetic frameworks are tested using extant lineages to generate probabilities of given scenarios generating the data we see given particular models. Something like the Reversible-jump Markov chain Monte Carlo (which is used in this paper) could actually be done manually…if a phylogeneticist had thousands of slaves to do all the computations. Obviously, the emergence of powerful computers accessible to all really changed the game in terms of analytic power.
And yet I wonder about the sense of precision that people gain from these methods. Verbal models are necessarily vague. When you give a probability of a given hypothesis being 0.71, that gives understanding a solidity. But is it warranted? Though researchers understand all the individual moving parts of the phylogenetic framework, only a computer can really bring it all together.
It’s something to consider. This is to a great extent the future of evolutionary biology. Positing models, and put it into a calculating machine like Leibniz dreamed of.
Citation: Temporal Niche Expansion In Mammals From A Nocturnal Ancestor After Dinosaur Extinction
Roi Maor, Tamar Dayan, Henry Ferguson-Gow, Kate Jones
Addendum: This is stupid of me, but only after reading the above paper did I reflect that most amniotes are diurnal and that mammals are the exception. Think about it, birds. And reptiles are probably more sluggish at night.