Even on Earth, life forms of widely differing ancestry, arrive at the same solutions to physics problems, leading scientists note:
Famous paleontologist Stephen Jay Gould (1941–2002) was sure that, if the deck were reshuffled, humans would never evolve — even on this planet — again. As Paul Parsons puts it at BBC’s Science Focus Magazine,News, “Exoplanets: The same laws of physics means similar life forms” at Mind Matters News (November 27, 2021)
His reasoning was that evolution is driven by random sets of genetic mutations, modulated by random environmental effects, such as mass extinctions, and that it would be extremely rare for the exact same set of effects to crop up twice.Paul Parsons, “Could humans be the dominant species in the Universe, and we just don’t know it yet?” at Science Focus (November 19, 2021)
As very large telescopes, capable of peering into exoplanets, are under development, current analysts are rethinking that approach. There are good reasons for thinking that extraterrestrial life forms would share basic characteristics with terrestrial ones (convergent evolution). Cambridge palaeobiologist Simon Conway Morris, for example, told Science Focus that
“One can say with reasonable confidence that the likelihood of something analogous to a human evolving is really pretty high. And given the number of potential planets that we now have good reason to think exist, even if the dice only come up the right way every 1 in 100 throws, that still leads to a very large number of intelligences scattered around, that are likely to be similar to us.”Paul Parsons, “Could humans be the dominant species in the Universe, and we just don’t know it yet?” at Science Focus (November 19, 2021)
On that view, life forms that fly on exoplanets will do what birds, bats, and insects do here, they say. Intelligent species may even look roughly like us.
Dorian Abbot noted in the lecture adopted by Princeton after it was Canceled at MIT that telescopes that can provide much better information about climate on exoplanets are planned for the 2030s and 2040s.
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Zoologist: Law of evolution can predict what aliens will be like. Arik Kershenbaum’s new book argues that convergent evolution on Earth helps us understand what to expect from extraterrestrial life. Kershenbaum’s argument fails when he addresses human culture: It just isn’t true that co-operation among humans is governed wholly by genes.
If we find life on exoplanets, some of it might be “crabs”. Over millions of years, many crustaceans gradually grew to look more and more like crabs, a process called convergent evolution. In an environment similar to Earth’s, we might expect life forms to converge on similar solutions. “Crabbiness” might be one of them.