Summary of “If the World Began Again, Would Life as We Know It Exist?”

“I’ve spent maybe 50 years studying the evolution of tongues in salamanders,” says David Wake, an evolutionary biologist at the University of California, Berkeley, “This is a particularly interesting case because salamanders, who don’t do anything fast, have the fastest vertebrate movement I’m aware of.” Within their lineage, evolution found a better way to accomplish tongue-hunting.
Random mutations and chance extinctions-events Gould called “Historical contingencies”-would build on each other, he suggested, driving the evolution of life down one path or another.
In Gould’s view, the existence of every animal, including humans, was a rare event that would have been unlikely to re-occur if the tape of life were rewound to the Cambrian period and played again.
In Conway Morris’s view, these constraints make it all but inevitable that if the tape of life were replayed, evolution would eventually reproduce organisms similar to what we have today.
Both scholars recognized that convergence and contingency exist in evolution.
The Long-Term Evolution Experiment, as the E. coli project is known, has surpassed 60,000 generations now, giving Lenski a deep data set from which to draw inferences about the interplay of contingency and convergence in evolution.
If extraterrestrial life faces similar evolutionary pressures to life on Earth, future humans may discover aliens that have convergently evolved an intelligence like ours.5 On the other hand, if contingent events build on one another, driving the development of life down unique paths as Gould suggested, extra-terrestrial life may be extraordinarily strange.
Experimental interrogation of the path dependence and stochasticity of protein evolution using phage-assisted continuous evolution.

The orginal article.