Naked Science Forum

General Science => General Science => Topic started by: Mad Mark on 31/01/2009 23:42:49

Title: Does evolution ever cease?
Post by: Mad Mark on 31/01/2009 23:42:49
Given enough time what in our universe would be considered the end of evolution for a species?
What would that species require of our universe if anything?
Or would such a thing as the end of evolution for a species ever happen in the universe?
Title: Re: Does evolution ever cease?
Post by: blakestyger on 01/02/2009 00:06:45
If you do statistics and do the 'random walk' with a genus of, say, 10 species using random numbers generated by a calculator  - evens and zero for speciation and odds for extinction - eventually you will end up with the genus becoming extinct; it's inevitable, try it. I did one the other day and it took an hour (about 1800 numbers).

The genus Homo has only one species - us. We are so widespread that it's unlikely that a single event could wipe us out - a large impact might though.

For there to be only one species an evolutionary group such as a genus would have to speciate so many times that no other genus could exist and all species in the world would belong to it. Not very likely - the ultimate extinction of the genus is assured.
Title: Re: Does evolution ever cease?
Post by: Vern on 01/02/2009 04:26:15
Given enough time what in our universe would be considered the end of evolution for a species?
What would that species require of our universe if anything?
Or would such a thing as the end of evolution for a species ever happen in the universe?
There would not be an end to evolution of a species; a species may evolve into other species so that one species becomes many as happens any time one group get separated from the main group for a few thousand years. As long as they don't all die out, they must evolve.
Title: Re: Does evolution ever cease?
Post by: _Stefan_ on 01/02/2009 04:35:12
Since genetic change is unstoppable, as long as there are organisms that reproduce, there will always be evolution.
Title: Re: Does evolution ever cease?
Post by: Chemistry4me on 01/02/2009 08:04:23
Why would it suddenly stop?
Title: Does evolution ever cease?
Post by: Don_1 on 01/02/2009 12:01:04
Take a look at these two articles.
http://news.bbc.co.uk/1/hi/sci/tech/7132794.stm (http://news.bbc.co.uk/1/hi/sci/tech/7132794.stm)
http://www.dailymail.co.uk/sciencetech/article-1070671/Evolution-stops-Future-Man-look-says-scientist.html (http://www.dailymail.co.uk/sciencetech/article-1070671/Evolution-stops-Future-Man-look-says-scientist.html)

Take your pick.
Title: Does evolution ever cease?
Post by: graham.d on 01/02/2009 20:09:10
A good discussion on this subject is in this month's Scientific American.
Title: Does evolution ever cease?
Post by: Vern on 01/02/2009 20:09:35
I suspect the second guy is speculating; something I do a lot of [:)]

An issue of AAAA publication Science the other day had an article that showed that there were new genes showing up in humans that originated in other species. Some caused mutations and some didn't. The genes were transported between species via virus infections.
Title: Does evolution ever cease?
Post by: _Stefan_ on 02/02/2009 06:33:14
PZ Myers explains why Steve Jones is wrong about human evolution stopping:
http://scienceblogs.com/pharyngula/2008/10/very_peculiar.php
Title: Does evolution ever cease?
Post by: Mazurka on 02/02/2009 15:04:48
Clearly the mechanism of natural selection affects mankind differently from other species - simply because we can manipulate our environment to a significant extent.  When discussing human evolution, it amuses me that our technology allows more less fitindividuals to procreate (like for e.g. Daily Heil journalists)

There are a number of species in which the rate of evolution has slowed to what can practically be considered a standstill.  A good example of this is the crocodillians.  They are so supremely honed into their niche that further evolution will not make them any fitterfor their ecological purpose.
Title: Does evolution ever cease?
Post by: Don_1 on 04/02/2009 14:06:34
I think the evolution of man has changed because we, unlike other animals, no longer rely on the selection of a mate by the female according to physical attributes. Selection is more a 50/50 choice by both sexes and based more on visual appearance and personality.

With most animals, especially mammals and the great apes in particular, a single male will be dominant and lay claim to the females within his harem/troupe etc. Or males will be sized up by the females and chosen according to strength. This means a single male will sire a number of offspring by a number of females, passing his genes to all those offspring. This results in relatively fast and noticeable evolutionary change.

Homo Sapiens, by and large, are monogamous and have different priorities when it comes to choosing a mate. The male's genes' will therefore not be spread so widely. The result of this could be that no genetic advance will have sufficient dominance for the characteristic to become prevalent.

Evolution does not exactly stop, but rather is too dilute to be effective.

Well, that's the way I see it; doubtless others will disagree.