Submitted by insink2300 t3_11drr8s in askscience
aartadventure t1_jabnn6o wrote
Reply to comment by atred in Why does temperature determine the sex of certain egg laying animals like crocodiles? by insink2300
Most mutations are not good, or downright lethal, leading to miscarriage, cancer and other awful outcomes. Especially in multicellular organisms, advantageous mutations occur quite rarely. That organism also has to be lucky enough to survive long enough to reproduce (you might have an incredibly advantageous mutation but just be unlucky and get struck by lightning before you reproduce for example). It may be something more akin to flipping 50 or 100 heads in a row.
zakabog t1_jabpr91 wrote
> Most mutations are not good...
Based on what exactly? A single mutation isn't likely going to do much unless it happens in the correct place.
> It may be something more akin to flipping 50 or 100 heads in a row.
Which is rather easy if you've got millions of years to do it.
aartadventure t1_jac3zfp wrote
It could be that most mutations do nothing bad, or that they end up being harmful in time, such as cancer. Here is one paper on the topic:
https://www.sciencedaily.com/releases/2022/06/220608112504.htm
And yes, that was my point. Evolution tends to work slowly, over millions of years, due to the low chance of a beneficial mutation occurring, and then also being selected for in a given environment. And, since environments change, what was once beneficial, may end up becoming harmful over time.
owiseone23 t1_jac29v1 wrote
it's not uncommon for traits to evolve across "fitness valleys". That is, a trait with positive fitness that requires multiple generations to evolve with intermediate generations having negative fitness.
With a large population and a lot of time, random variation makes it possible to evolve across fitness valleys.
atred t1_jacj4vp wrote
> It may be something more akin to flipping 50 or 100 heads in a row.
50 heads in a row has a chance of 1 in a quintillion. Are you sure that's the chance to get an advantageous mutation?
Viewing a single comment thread. View all comments