Viewing a single comment thread. View all comments

slickhedstrong t1_j7t25ke wrote

Reply to comment by bigwavedave000 in New species identified, from 3D models of prehistoric penguins’ humongous humerus, may be the largest penguin ever to have lived. ~350-pound ‘Kumimanu fordycei’ weighed as much as an adult gorilla; waded the waters off New Zealand about 60 million years ago by marketrent

let me throw in gigantism as an evolutionary trait that protects prey animals from predation, and thus escalation where predators needed to be larger to predate on huge prey.

the sheer variety of species back in time is massively scaled compared to today.

eventually things hit a critical mass though, as that size becomes unsupportable with slower reproduction and birthing cycles and strategies. look at pandas that would rather eat than mate, or alpha walrus social structure where most males never get a chance to copulate.

and so being smaller, caring for smaller young, requires much less resources, and allows much faster breeding, and so becomes evolution's dominant form.

add environmental changes like less oxygen, but count that as part of the resources a species needs to thrive, not a cause for gigantism.

14

faern t1_j7tj1h6 wrote

human also put a negative pressure toward size. We shoot big animal as trophy, we compete for land with those animal. Land that used to feed large animal are now soybeans farm feeding us.

1

irago_ t1_j7tlzwh wrote

The soybeans mostly feed the large animals we didn't kill because they're tame enough

4