[rolph]

the bottleneck was a global ecosystem level of selection.

dinosaurs pressured the mammals to stay small, hide in burrows, and roam at night.

dinosaurs, and a lot of other things came to an abrupt end, the basal mammals survived in thier bunkers with hoards of seed, and were relieved of selective pressure, thus diversified in thier traits this is when mammalian diurnalism made a big comeback so they could now compete among fellow mammals radiate and expand niche into the estate of the late dinosaurs

[FredPret]

What a wild thought that our ancestor was a mousey thing that hid in a hole, terrified of the giant dinosaurs and falling asteroids, and survived only because it had the Jurassic mouse equivalent of a Costco habit while completely failing to suspect that its distant children will one day rule the planet.

[exolymph]

Path dependence is neat!