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Origins of....Species (Life Sciences)
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nemesis8


In: byrhfunt
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The typical nature programme starts off with a celebrity, with a so called burning desire in animal x. A bit of travel occurs.

We then learn that animal x, is perfectly adapted to his environment, however.... they can't leave it there... it turns out evil man (normally it's the fault of the viewer not the locals) is destroying animal x's environment and animal x will shortly be no more.....

What I learn from this is animal x... was not perfectly adapted.
In fact animal x's so called adaptations are actually killing it. I am afraid he is over specialised, he can't change with the world, therefore extinction is normal. The world changes.... always has done.

It seems to me we have this on its head.

Perfect adaptation/selection does not explain survival.

Perfect adaption/selection guarantees extinction.


Let's now look at insect y, he ain't perfectly adapted to live somewhere hot or cold, he has just the normal boring features, he
doesn't turn colour, or do any fancy stuff, laying eggs up a giraffe's nostril... he just gets by....

What do you know... survives after Chernobyl.... It ain't fair but his lack of perfection, and all-round boring qualities, means that he is indestructible. His flexibility is the key.

It's obvious... flexibly adapted animals survive, THE REST ARE GONNA DIE.

I am sorry for the use of caps. But thought it an important point to emphasise.
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Ishmael


In: Toronto
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Yes. Very good thinking.

I will only add that the Giraffe's nose can't be exploited by a generalist. It requires a specialist. That is why nature manufactures diversity.
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GrouchoMarxthespot



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It requires a specialist

Attractive though the idea is, that specialisation can lead to an evolutionary cul de sac when the environment alters, I wonder whether the distinction between generalist and specialist creatures isn't a little misleading in itself?

There is an interesting article, (The Archaeology and Genetics of Malaria Resistance), summarising the work of Sarah Tishkoff, (which has appeared in Science).

The naturally occurring process of mutation of the G6PD gene seems to provide resistance to malaria among those populations most likely to become infected.

Would we call those humans with the inherited mutation specialists or generalists?

I suppose it depends on the frame of reference that we import: If we think that what they are 'doing by being alive', (ie surviving), is avoiding infection, then they are certainly specialists. If we think that what they are doing is all of the things that humans get up to then they are generalists.

The phrase 'natural selection' often seems to be mis-used, sometimes as an ideology, sometimes as entertainment masquerading as science, (Life on Earth), but mostly through the statement survival of the fittest. This is just a tautology, meaning survival of the survivors, but it creates a pseudo scientific idea that, in principle, we could predict what will survive.

The bit that really is useful is that everything that we label living on planet earth has a tendency to mutate, and that these mutations are inheritable.

It seems intuitive that any planet with a system of life based on mutation and inheritance is engaged in the most enormous game of chance. Mutation x in species A changes the environment for all the other organisms it comes into contact with. Their mutations do likewise to it. Some of the mutations will alter the non living environment, (trees absorbing Co2). Furthermore some creatures mutate and inherit at a faster rate, (fruitflies), than others, (crocodiles).

The whole thing is inherently unpredictable; it isn't a case that 'one day we will have a computer capable of performing all the multivariate analysis required': There will never be a computer capable of converting this colossal game of chance into a predictive model.

I wonder why the natural world of living creatures isn't more disorderly given the chaos possible from the interaction of chance mutations with a given environment at any one point in time? Could it be that the inheritance of learned behaviour stabilises what would otherwise be a pretty chaotic system?
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N R Scott


In: Middlesbrough
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Earlier in this thread, Mick wrote;
According to the enthusiasts we have hair on our head so that babies have got something to cling on to in the sea.

Aquatic Ape Theory always makes me wonder about calflicks/cowlicks - the tufts of hair that stick up on people's heads. Particularly the ones on the fringe. I have one on the right side of my fringe (something not too dissimilar to Tintin). It means that whereas the hair on the left side of my fringe grows straight down on to my forehead the hair on the right grows back over and away from my face. When I grow my hair long I've noticed that it actually helps keep my hair away from my eyes.

The obvious problem with long hair is that it obscures vision. Maybe calflicks are a genetic throwback that once helped deal with this problem. Maybe they became redundant when the first prehistoric hairdresser came along?

Calflicks are quite common, some people even have hair that grows back over on both sides of their fringe - witness Eddie Munster.

Having hair that grows away from the face would also be quite advantageous when swimming - hence why nowadays people wear swimming caps or tie their hair back when they go swimming.

It's just a shame there isn't an obvious reason for the tufts of hair that stick up at the back of the head.
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Chad


In: Ramsbottom
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Scotty wrote:
I have one on the right side of my fringe (something not too dissimilar to Tintin). It means that whereas the hair on the left side of my fringe grows straight down on to my forehead the hair on the right grows back over and away from my face.

If I had that problem Scotty, I'd take a razor to it.

Sounds almost as bad as being ginger.

Actually, two of my grandsons have this hideous deformity... but I make them put on MUFC hats when they come to visit.
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N R Scott


In: Middlesbrough
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I hate to tell you this Chad, but I'm actually ginger as well...

...well, borderline. My hair's dark, but I've got freckles, which by all accounts seems to push me into the ginger camp.
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N R Scott


In: Middlesbrough
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Speaking of ginger, here's something interesting about red hair I've noticed over the years;

Elizabeth I - red hair
Oliver Cromwell - red hair
Galileo - red hair
Thomas Jefferson - red hair
George Washington - red hair
Robespierre - red/chestnut hair
Martin Luther - there are portraits by Lucas Cranach the Elder that show him with red hair (although no description, sadly)

Was reformation and revolution a redhead thing? Seems odd that so many of the leaders were red-haired given how fractionally small the redhead population is.
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Mick Harper
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In: London
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given how fractionally small the redhead population is.

What a pity you didn't give us the total number of reformation and revolution leaders of all hair colours beforehand. No need to look it up, it was 1,485.
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N R Scott


In: Middlesbrough
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What about this then re Red Hair.

We know that in ancient Egypt there were quite a few redheads on the scene. We have the red-haired mummies to prove it - Rameses II, etc. As well as this testimony from the Golden Bough;

With regard to the ancient Egyptians we have it on the authority of Manetho that they used to burn red-haired men and scatter their ashes with winnowing fans[.]


But these days there are very few native redheads in Egypt.

Likewise in the days ancient Greece, there was, apparently, a lot of red hair in Thrace and Scythia.

The Ethiopians claim that their gods are flat-nosed and black-skinned; the Thracians, that they are blue-eyed and have red hair - Xenophanes.


Herodotus, likewise, mentions that there are redheads in Scythia in his Histories. But again not much red hair in that part of the world today.

And then in the days of ancient Rome - they associated red hair with the Germanic tribes, but again not much red hair amongst the modern day German population (discounting Boris Becker, of course).

So where's all this red hair gone?

You could also maybe even mention the Red Jews of Eastern Europe if you believe the Arabic accounts that they were red-haired. That's if these 'Red Jews' even existed that is.
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Mick Harper
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In: London
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Sorry about my initial reply, it breaks the rule about not being negative about new ideas. Here's my two-pennyworth. If it is true that redheads get discriminated against by other children (not something I've ever witnessed but is true according to South Park so therefore true) then such children might well grow up more often to be reformists and revolutionaries than is the average for their peers. We call it nowadays The Revenge of the Nerds.
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Hatty
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In: Berkshire
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There seems to have always been a widespread prejudice against red-haired wet-nurses, underlining an unconscious or perhaps conscious association between redheads and witchery.

It may be that non-English such as Irish families were more likely to have the trait and so originated or further confirmed the prejudice.
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Chad


In: Ramsbottom
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N R Scott wrote:
I hate to tell you this Chad, but I'm actually ginger as well...

Ever since you mentioned this, I have had a picture of a freckly ginger kid with a cowlick, floating round in my head .

And the majority of cowlicks that I can recall, tend to be atop ginger noggins (though my two cowlicked grandsons are blond)... Every gormless looking ginger kid you ever see on telly has one.

Anyway, I think I may have found something which could explain why cowlickers have a disproportionately high incidence of gingers amongst their number.

The cowlick is caused by a mutation of the Frizzled6 gene (which can also lead to deformed nails).

Another thing that this group of genes is responsible for is retinal development... and an abnormality here can lead to problems with colour perception.

My hypothesis is that, if cowlickers also have problems with colour perception, they may not actually be able to see gingers for what they are... and may mistake them for normal people. They would then not be able to take the usual avoidance measures when it comes to selecting a mate.

Before long they would have a higher incidence of contamination.
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N R Scott


In: Middlesbrough
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Incidentally, I should say that my general theory re "Where's all this red hair gone?" is pretty much this. Red hair's a Neanderthal trait and the slaughter/interbreeding that we're told went on when Humans first met Neanderthals 35,000 years ago or whenever it was, far from being something that happened for a few thousand years after first contact, has actually been going on to some extent or other right into the modern era.

Hence the Egyptians burning red-haired men, hence the variation in hair and eye colour amidst the European population, hence the episode of South Park where Cartman gets his hair dyed red.

I should point out that my theory is just a variation on a theory that's been touted by others before. Most notably Stan Gooch - mind you, he also believed that Neanderthals were left-handed, nocturnal, sexually-promiscuous, moon-worshippers, so his variation was a lot more interesting than mine.
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Rocky



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Hatty wrote:
Crows' ability to pick out particular people in a crowd is astounding, compelling evidence of domestication surely. Along with pigeons and sparrows the crow has adapted superlatively well to urban environments and as with pigeons have come to be regarded as pests; we know what happened to passenger pigeons once they outlived their usefulness (sparrows are apparently far less numerous these days and are suddenly being missed).

Crows are still very much in evidence in populated rural areas; walking through a farm t'other day that for once wasn't derelict I managed to disturb some crows, the suddenness of their eruption from a tree along with their cawing was quite startling. A Sioux legend recounts that a village was pestered by crows all of whom were destroyed except for a single young bird which was given to the chief and acted as his spy, learning to speak many languages and warning him of danger.

Rooks compete with humans in agricultural areas; since they amass in such large numbers they can inflict considerable damage on crops. Ravens and crows prefer woodland whereas rooks thrive in grassland that nowadays tends to be given over to farming. Rooks are the only corvids to have a white patch around their bill which distinguishes them from crows and ravens but it's only visible on adult birds; they used to be the commonest birds in Britain apparently. Since it's harder to eliminate creatures that are considered intelligent, even human-like, it may be that corvids' brain-power was deliberately downplayed.


Check out this video of a crow. It's learnt how to tobaggan down a roof:

http://www.youtube.com/watch?feature=player_embedded&v=YP9RnDp_tms

It's apparently a hooded crow.
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N R Scott


In: Middlesbrough
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Rocky wrote:
Check out this video of a crow.

That's amazing. Is it just having fun?
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