being_interesting0 t1_j8gtbeo wrote

No. 2 reasons.

  1. Life is a winner take all phenomenon. Once life has overtaken and adapted to an ecological niche, it would be very hard for something new to evolve there that was better adapted

  2. There is a hypothesis that the first chemical steps in abiogenesis required an earth with no or low oxygen. Nick Lane talks about this in some of his books (highly recommend)


being_interesting0 t1_j4tyanf wrote

Here is a paper that suggests epigenetics plays a large role.

It is true that mammal size is correlated to heart rate, and both are correlated to lifespan. Most mammals get about 1 billion heart beats. Humans have managed to beat this by being more social (supporting our elders in pre-medicine societies) and then using medical technology to really overcome natural entropy.