Does evolution repeat itself? Could evolution repeat itself? Where do people stand in relation to the thoughts of Gould and Conway Morris?
Gould has a point, everything is in a state of becoming. As Heraclitus would say, all is change. Replay the tape and nothing would be the same. But would or could there be any similar trends? Would life in general proceed in such a radically different way that Gould makes out?
From “Life’s Grandeur”, Gould states:
“…no persuasive or predictable thrust toward progress permeates the history of life…
“Wind the tape of life to the origin of multicellular animals in the Cambrian explosion, let the tape play again from this identical starting point, and the replay will populate the earth (and generate a right tail of life) with a radically different set of creatures. The chance that this alternative set will contain anything remotely like a human being must be effectively nil, while the probability of any kind of creature endowed with self-consciousness must also be extremely small.”
Conway Morris disagrees with Gould’s conclusion. He champions an inevitable path and cites convergent evolution as evidence which suggests this.
In “The Crucible of Creation” he states,
“What we are interested in is not the origin, destiny, or fate of a particular lineage, but the likelihood of the emergence of a particular property, say consciousness. Here the reality of convergence suggests that the tape of life, to use Gould’s metaphor, can run as many times as we like and in principle intelligence will surely emerge.”
I’m interested in what people have to say about this and its relation to topics such as the emergence of bilateral symmetry and differentiation from head to tail, extreme specialization, encephalization, endothermy, caring for young, transitions from aquatic to terrestrial living and other related topics. These processes have occurred multiple times in different lineages over time.