Re:Evolution Runs Faster on Short Timescales
by veddox on Saturday June 17, 2017 @08:24AM
(#14575589)
I'm sorry, I really can't follow your line of reasoning here. Could you elucidate?
Re:Evolution Runs Faster on Short Timescales
by Retric on Saturday June 17, 2017 @08:45AM
(#14575655)
Sure, a fox is not the size of a wolf because both are useful sizes to be. If you follow the evolution of foxes getting slightly larger or slightly smaller both provide advantages so it's really a balance which may change over time that determines what happens.
AKA, fox sizes might drift up and down some over time, the average is going to stay near their current size unless say wolves died out. At which point they may quickly get larger and replace wolves, but they would not keep growing indefinitely and end up the size of great whales as they are now constrained by the 'wolf' niche. Further, foxes may end up spiting, you have foxes that look about the same, and foxes that look a lot like wolves.
Now if you chart sizes as say 10,11,12,11,10,9 then the transition between those stages is a 'fast' + or - 1, but the net result is only -1 over 6 steps or -1/6th.
The same thing is likely going on with less obvious features, but they are less intuitive.
Beyond that, what worked for trilobites largely works for horseshoe crabs.
Consider if something is getting larger by say 1% per thousand years, well over 1 million years that's simply unsustainable without becoming ~21,000x as large and thus a very different organism. Further conditions may change promoting periods of shrinking which means the average is going to trend to ever smaller changes per period of time.