NCTimes covers a new paper by Richard Lenski on the “Evolution Of A Beneficial Mutation”:
In other words, the other 11 populations may have evolved through different beneficial mutations to the same outcome, in terms of increased survival. If that is true, then there would be no evolutionary pressure in the 11 populations to evolve a mutation that would be superfluous or perhaps even harmful.
From the paper itself:
The latter explanation adds historical contingency, such that the likelihood of a particular outcome is conditional on whether some other event has already occurred.
This is essentially what Neil Shubin says in Your Inner Fish concerning the evolution of bodies: that organisms had the DNA to evolve them but weren’t able to until the advent of significant amounts of oxygen in the atmosphere.
When I get a chance to read the paper itself, I’ll try to post my impressions.
