(November 27, 2018 at 4:08 pm)Peebo-Thuhlu Wrote: At work.
Just think.
Worlds where spiders, scorpions and the like develope hinged and efficient 'Book' lungs and so are not just limited by amospheric properties.
Or where crustaceans such as the 'Land frab' and such evolve much earlier and become one of the dominant land based competitors.
Amonites learn to chemically crack water. Keeping the hydrogen in their shells to become fierce aerial predators.
The mutation that allows for placentas never happens and so Marsupials continue to dominate the wilds.
I think because we live in the Phanerozoic eon in the history of earth, We tend to think of alien life as some outlandish variation of the Phanerozoic world on earth. But life on earth lived 7 times as long the Proterozoic eon as in our own Phanerozoic eon. So I think it is not more likely, and more interesting to consider, that ancesters of higher life on alien worlds branched off from their equivalent of our main line of evolution way back in mid or even early Proterozoic.