antifreeze in fishes

[wigginhall]

Reading around about evolution, as I like to do, I came across this topic, and the interesting point that antifreeze could not evolve in fish in freezing waters, as previously such fish could not have survived.   So the antifreeze evolved in fish outside freezing waters, and then they could move into freezing waters.   It's an argument against 'purpose', since the antifreeze outside freezing waters was superfluous for the prevention of freezing, but maybe had another function. 

It's just an interesting point about 'purpose' and teleology, since the development of antifreeze was obviously not planned.   In fact, there are fish with antifreeze who live away from the polar areas. 

[Shaker]

It's a good point about evolutionary co-opting of a thing previously evolved for purpose A for new purpose B - waste not want not!

Of course this revives the still far from settled debate between the panadaptationists - where every feature is an adaptation for something, even if uncountable ages ago - and the others for whom randomness (sometimes things just exist for no adaptive reason in particular) is more prominent.

[Udayana]

Not wanting to support any idea of purpose or direction for evolution, however even those that do would surely accept that random mutations are an essential aspect of the mechanism of evolution?

[Shaker]

Not wanting to support any idea of purpose or direction for evolution, however even those that do would surely accept that random mutations are an essential aspect of the mechanism of evolution?

Absolutely - no question.

But the main take-home message in What Evolution Is by Ernst Mayr - one of the great architects of modern evolutionary theory - is that evolution is a two-step process: the raw material is entirely random genetic variation which is then sieved by non-random natural selection (non-random because dependent upon a specific set of environmental conditions).

Those that take a teleological view of evolution must presumably think that even within the randomness of genetic variation there's some guiding force at work nudging things towards a desired end. In Finding Darwin's God Ken Miller (a very good cell biologist, keen science communicator, ardent proponent of evolution and a Catholic) latches onto randomness at the quantum level as a gap to hide God in. Simon Conway Morris takes much the same line. It's a philosophical stance, a religious belief even, which is fine, but it isn't science.

[Gonnagle]

Dear Shaker,

But the main take-home message in What Evolution Is by Ernst Mayr - one of the great architects of modern evolutionary theory - is that evolution is a two-step process: the raw material is entirely random genetic variation which is then sieved by non-random natural selection (non-random because dependent upon a specific set of environmental conditions).

Nope, gobblydegook to me, see I get it, evolution, even natural selection, but the terminology is wrong, this evolution stuff is to important, we need simpler explanations, something a world wide audience can latch on to, everyone should be discussing this, your basic man ( me ) in the street should have at least a simple. understanding of evolution, a building block that they can use to take it further.

This is one of the jobs I think scientists should be looking at, make it interesting, make it as simple as possible so the whole world can join in the discussion.

But I know that is a tough ask, making it simple without dumbing it down.

Gonnagle.

[Nearly Sane]

The quantum defence drives me up the wall as I have expressed before


http://www.religionethics.co.uk/index.php?topic=9431.25

[wigginhall]

It's a good point about evolutionary co-opting of a thing previously evolved for purpose A for new purpose B - waste not want not!

Of course this revives the still far from settled debate between the panadaptationists - where every feature is an adaptation for something, even if uncountable ages ago - and the others for whom randomness (sometimes things just exist for no adaptive reason in particular) is more prominent.

Well, you've expressed that better than I did.  I think the notion of co-opting is what I was searching for.   I think that 'exaptation' means the same thing.   The classic example is feathers, which may have evolved for warmth, but then became co-opted for flight.

Anti-freeze is such an amazing development in animals.

[torridon]

I agree.  What evolution produces in the seas in particular is awesome.  Like fish that swim in dark waters so they have evolved their own personal head torch :

http://www.telegraph.co.uk/content/dam/london-culture/deep_sea_anglerfish-large.jpg

Fish in Florida that live in trees :

http://www.dailymail.co.uk/news/article-488193/The-fish-survive-months-tree.html

You couldn't make it up could you ?

[Hope]

I agree.  What evolution produces in the seas in particular is awesome.  Like fish that swim in dark waters so they have evolved their own personal head torch :

http://www.telegraph.co.uk/content/dam/london-culture/deep_sea_anglerfish-large.jpg

Fish in Florida that live in trees :

http://www.dailymail.co.uk/news/article-488193/The-fish-survive-months-tree.html

You couldn't make it up could you ?

Don't forget the species that live and thrive around the superheated water that erupts from funnels that exist near the areas of the sea-bed that are actively creating new material.