3 ms·

I am missing why this is important or unexpected. Since most mutations are no-ops, and behavior is frequently expressed through combinations, I'd have expected

I am missing why this is important or unexpected. Since most mutations are no-ops, and behavior is frequently expressed through combinations, I'd have expected what they found. For every useful mutation, there were usually other random mutations that prevent simply flipping back the useful one.

btilly 17y ago
Science isn't about collecting reasonable sounding ideas. It is about collecting useful ways of understanding the world that have been stress-tested until we can have great confidence in them. The paper is the first time anyone has been able to provide solid evidence about whether the evolutionary mechanism you outline really happens. It's the difference between a note in Fermat's margin saying that he has a proof but the margin is too small, and Andrew Wiles writing up a several hundred page proof. Now that it has been demonstrated how to show which mutations are irreversible, the door has been opened to using molecular genetics to provide absolutely definitive answers to questions about the evolutionary tree that we don't have good fossil evidence for. Furthermore the ability to test specific questions about the functionality of putative reconstructions of particular prehistoric genes does a lot to improve our confidence that we're reconstructing them correctly. We've now been able to compare versions of a gene from 440 million years ago and 400 million years ago and gotten specific enough answers back that suggest we've got both versions of the gene right. Monkeys and apes split perhaps 30 million years ago. How accurately can we figure out the genetics of that last common ancestor?