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+--- Thread: What if the dinosaurs hadn't gone extinct? Why our world might look very different (/thread-13248.html)
What if the dinosaurs hadn't gone extinct? Why our world might look very different - C C - Nov 25, 2022
https://theconversation.com/what-if-the-dinosaurs-hadnt-gone-extinct-why-our-world-might-look-very-different-191599
EXCERPTS: ... Imagine the asteroid had missed, and dinosaurs survived. Picture highly evolved raptors planting their flag on the moon. Dinosaur scientists, discovering relativity, or discussing a hypothetical world in which, incredibly, mammals took over the Earth.
This might sound like bad science fiction, but it gets at some deep, philosophical questions about evolution. Is humanity just here by chance, or is the evolution of intelligent tool-users inevitable?
[...] In the 1980s, palaeontologist Dale Russell proposed a thought experiment in which a carnivorous dinosaur evolved into an intelligent tool user. This “dinosauroid” was big-brained with opposable thumbs and walked upright.
It’s not impossible but it’s unlikely. The biology of an animal constrains the direction of its evolution. Your starting point limits your endpoints.
If you drop out of college, you probably won’t be a brain surgeon, lawyer or Nasa rocket scientist. But you might be an artist, actor or entrepreneur. The paths we take in life open some doors and close others. That’s also true in evolution.
[...] Dinosaurs did big bodies well. Big brains not so much. ... Dinosaurs did enter new niches over time. ... Dinosaurs seem to have had increasingly complex social lives. ... Yet dinosaurs mostly seem to repeat themselves, evolving giant herbivores and carnivores with small brains.
There’s little about 100 million years of dinosaur history to hint they’d have done anything radically different if the asteroid hadn’t intervened...
[...] They may have evolved slightly bigger brains, but there’s little evidence they’d have evolved into geniuses. Neither is it likely that mammals would have displaced them. Dinosaurs monopolised their environments to very end, when the asteroid hit.
Mammals, meanwhile, had different constraints. ... they repeatedly evolved big brains...
[...] So did eliminating the dinosaurs guarantee mammals would evolve intelligence? Well, maybe not. Starting points may limit endpoints, but they don’t guarantee them either... (MORE - missing details)