Another Dawkins Row

[Griffin NoName]

Dawkins v. EO Wilson (of the Ants) - actual review is in Prospect magazine

All very silly. But still, genetic imprinting continues to puzzle me.

[Sibling Zono (anon1mat0)]

There is an article in this month's Scientific American about the evolution of cooperation, that mentions how simulations have shown that cooperation doesn't have to help the immediate genetic pool or even kin to be beneficial. I don't know the details of Dawkins' argument but perhaps not all genes have to be selfish...

[Griffin NoName]

Objections to Dawkins seem to be about defining "fitness".

"To use a simple human example, someone with the perfect set of genes for walking with two legs might die early because they jump off a cliff," said Koentges.

Delay jumping off cliffs until you have had children?

[Sibling Zono (anon1mat0)]

That makes me think on roadkill, the butterfly/badger/doe that avoids the highway should be more successful having their genes passed on, the problem is that it takes a number of generations to create both the selective pressure and the right mutation.

[Griffin NoName]

Yes, I don't really see how they could achieve natural selection visa v. roadkill

[Swatopluk]

Now I feel reminded of Discworld swamp dragons

[Aggie]

[untaddy] Dawkins was certainly a formative influence on me, but the older we both get, the more I sometimes feel that he needs a daily cup of STFU with breakfast. He's far too fond of stirring up trouble, and seems to think he's done enough for his field that his word should be dogma, even in areas where he doesn't have expertise. [/untaddy]

Yes, I don't really see how they could achieve natural selection visa v. roadkill

It's a selective pressure, with a very specific stimulus attached to it (which is all it takes to evolve; mutations which result in an aversion to the sound of traffic or smell of asphalt, for example, would help).  Over a long enough timescale, I'm sure the numbers of roadkill for say, deer will decrease.  Mind you, some of the best feeding at certain times of the year (with reduced presence of predators) occurs along the roadsides, so there are selective pressures to stay near the roads but not on them.

For species like amphibians and turtles who must cross roadways in order to get to breeding areas (ponds, etc), the reproductive imperative is probably a bigger driving force than the roadkill effect. However, you could also presume that at least some of the ones who make it successfully across have a better strategy for doing so.  With squirrels, most seem to have the right instinct for dashing across before the vehicle comes, but tend to double back in panic when they hit the far shoulder. That bit might be easy enough to modify over a few hundred thousand generations.

The trouble with cars is that they haven't been around long enough to generate selection over many generations (even for many insects, it's been n<100 since the automobile has been going fast to splatter them on a windshield), and they don't act like a proper predator.  Because they stick to roadways and for the most part try to avoid collisions with wildlife, automobiles are hard for animals to read as sources of mortality, even though they are extremely easy to see, hear and smell.  For an animal that spends its time around roadways, these large, loud, fast objects are probably imposing, but because they don't stalk and pursue like a predator would, they seem relatively harmless.



What might be as interesting would be to look at whether the automobile is a significant selective pressure on human beings.  Why are us conducting a War on Drugs (17,000 deaths/year, data from 2000) but not a War on Automobiles (43,000 deaths) or a War on Tobacco for that matter (435,000 deaths)?

I suppose that the taxes on tobacco are helping to pay for the War on Terror^TM, which was more or less justified due to the 3,000 deaths of the WTC attacks (for the record, the US has lost twice that number in military personnel in the response; civilian and military casualties in Afghanistan and Iraq combined are likely in the hundreds of thousands, possibly over a million).

Where's that pot of STFU? Looks like I need a cuppa this morning, too.

[Swatopluk]

The question is, how much can be put into the genes?  Apart from that, although we have an innate fear of heights, there are still many cases of people falling off cliffs etc.

[Griffin NoName]

The question is, how much can be put into the genes?  Apart from that, although we have an innate fear of heights, there are still many cases of people falling off cliffs etc.

Depends which cliff. In England, if it is Beachy Head it's a suicide. Similar with bridges. The Clifton Suspension Bridge and the Archway bridge in London - it's suicide....... suppose your average bridge might be accidental?? 

[Swatopluk]

I think there a many accidental falls (balconies and open windows probably #1, natural steep places far behind).
It's often actually the vertigo that gives the final 'push' despite having evolved to keep people away from places where a fall is likely to be lethal.

[Sibling DavidH]

I've always wondered about that fear of heights, since we are not all that far from ancestors which used to live in the trees.

[Swatopluk]

I read that some peoples e.g. in South America in the Andes lack the fear of heights (mutation). They were at least in the past much sought after as construction workers fro skyscrapers (and afterwards window cleaners for the same).

[Sibling DavidH]

Yes, North American Indians too, I believe.

The fear gets counterproductive once you're high up.  Most people will easily walk along a twelve-inch-wide plank a foot above the ground, but if they tried it a hundred feet up, many would fall off from sheer terror.  That must kill a lot of the people it's meant to save.

[Bob in a quantum-state-of-faith]

Skunks.

Why skunks?  Because prior to human's invading the North American wilderness, skunks pretty much had it easy-- few predators would bother them.  The few that did, the skunks' rapid breeding strategy more than compensated for.

So most skunks were rather bold in their habits-- mostly moving about at night, but pretty much completely unafraid of what could happen to them.

Along comes humans-- who continued to ignore skunks.

Then:  the automobile.   Traveling in excess of 40mph, on roadways.  

Now, the building of roadways did not bother the skunk-- he boldly crossed these whenever it suited his needs, and without a second's thought.

Unfortunately, the skunk's primary mode of defense was useless to a 2-ton, speeding car--  **squash**.     With an ordinary predator, once they tangled with a single skunk, they typically left the species (and all that skunk's relatives) strictly alone-- lesson learned.

Cars?  Not so much-- cars cannot "learn", as it turns out-- cars are not really bothered by the smell, unfortunately for the boldly going skunks.

So, what happened?  Obviously, within any given population of skunks, there are the boldly-go ones, and then, there are some timidly go ones.   If the boldly-go skunks are being squashed in a greater proportion to the timidly-go skunks?  After a few generations, the timidly-go skunks will outnumber the boldly-go skunks.

In short?*

We are selectively breeding for timid skunks.


_______

*  (too late, right?)

[Griffin NoName]

Is there any evidence of unusually fearful skunks?

The car/vehicle angle can be applied to many species. eg. a toitorse is so slow the are bound to be hit crossing the road whether they shrink inside their shell or not. Would that lead to shell-less toitorses?

[Bob in a quantum-state-of-faith]

Is there any evidence of unusually fearful skunks?

The car/vehicle angle can be applied to many species. eg. a toitorse is so slow the are bound to be hit crossing the road whether they shrink inside their shell or not. Would that lead to shell-less toitorses?

Yes-- there is some evidence of timid skunks, post-modern highways.

In fact, it's become rather a tell-tale, if a skunk is not acting rather timid around humans?  That skunk is likely infested with rabies.

As for the shell-less turtles?  I don't see that.  I would presume that in any given population of skunks, there would normally be a distribution of timid to bold.   Pre-automobile, the bolder skunks would likely get more to eat than their timid counterparts, and likely have more babies, weighting any given population in favor of the bold.  

Post-auto, boldness gets you squashed sooner or later, so the population would shift to the more timid members, weighting it that way.  

It's a really rough hypothesis, but one thing I noticed-- the number of dead skunks (by the road) has diminished from when I was small.   Then, if we drove anywhere out of town in summer, we'd encounter at least one dead skunk by the road-- more likely more than one.

These days?  It's become pretty rare to see a dead'un.    Mostly, I hear about skunks from reports of rabid ones getting trapped by authorities.  

[Aggie]

It's a really rough hypothesis, but one thing I noticed-- the number of dead skunks (by the road) has diminished from when I was small.   Then, if we drove anywhere out of town in summer, we'd encounter at least one dead skunk by the road-- more likely more than one.

These days?  It's become pretty rare to see a dead'un.    Mostly, I hear about skunks from reports of rabid ones getting trapped by authorities.   

Depends on whether population numbers are constant, I suppose.  This could indicate a population drop in general.  I do agree with your general hypothesis.

[Bob in a quantum-state-of-faith]

It's a really rough hypothesis, but one thing I noticed-- the number of dead skunks (by the road) has diminished from when I was small.   Then, if we drove anywhere out of town in summer, we'd encounter at least one dead skunk by the road-- more likely more than one.

These days?  It's become pretty rare to see a dead'un.    Mostly, I hear about skunks from reports of rabid ones getting trapped by authorities.   

Depends on whether population numbers are constant, I suppose.  This could indicate a population drop in general.  I do agree with your general hypothesis.

It could simply be a drop in population, I agree-- but I've never seen that discussed anywhere, by anyone.  I would think such a sharp decline would have gone noticed, and alarmist noises would be about the place.

[Roland Deschain]

Maybe the people involved are becoming a little too set in their ways, but essentially this is nothing unexpected. We've been arguing over the fine print of evolutionary theory for a long time now, and only time will show whose hypothesis is correct. Both have merit, and both seem logical, so maybe there's a little of each at play here, making both just two parts of the whole picture. What will become important in the future is which one is more important. Maybe it will be found that each hypothesis is more important for each different domain/kingdom/phylum/class/order/family/genus/species.

Selective pressure, and how important various pressures are, will either show in our lifetimes, or not. With enough deaths, as in the case of roadkill of skunks, then this is most likely showing, although one could also say that there are just less skunks alive, and hence less available to kill. Maybe it could also be that the ones who live in areas near roads have been killed off, and it is mainly the ones living in more isolated areas that have taken over, although i'd favour the timidity hypothesis on available evidence within this thread, with an emphasis on the species being removed from certain habitats from previous evidence of what we've done in other places. If the skunks start moving back into the road areas, you'll know.

In the case of giant tortoises, it's different. Skunks breed far quicker for one thing, and as a consequence, genetic changes will occur more readily. With the tortoise, if it's getting killed by car that does it, it's going to take a lot longer for any change to be noticed due to its slower life cycle. I don't know what it would take for it to lose its shell, but i'm very sure that being run over (trying to imagine a car hitting a tortoise weighing 1/4 of a metric tonne) would not select for that.

[Sibling Zono (anon1mat0)]

You would imagine it would select the cars not hitting them to avoid the repair costs.

[Sibling DavidH]

^

[Griffin NoName]

In the case of giant tortoises, it's different. Skunks breed far quicker for one thing, and as a consequence, genetic changes will occur more readily. With the tortoise, if it's getting killed by car that does it, it's going to take a lot longer for any change to be noticed due to its slower life cycle. I don't know what it would take for it to lose its shell, but i'm very sure that being run over (trying to imagine a car hitting a tortoise weighing 1/4 of a metric tonne) would not select for that.

I was meaning the domestic tortoise, usually belonging to children as a pet.

[Bob in a quantum-state-of-faith]

You would imagine it would select the cars not hitting them to avoid the repair costs.

Brilliant!

Just as we humans are unwittingly performing an intelligence test on ourselves, with respect to seat belts....

... there are two kinds of people who ride in cars:

1) those who wear seat belts
2) and those who are seriously injured or dead

[Roland Deschain]

Zono, that was brilliant!

The domestic tortoise? It would be one thing if they were in the wild, but the ones being kept as pets are bred away from those sorts of dangers, so evolution will select them for other pressures.

[nefyuBB]

Yes, North American Indians too, I believe.

The fear gets counterproductive once you're high up.  Most people will easily walk along a twelve-inch-wide plank a foot above the ground, but if they tried it a hundred feet up, many would fall off from sheer terror.  That must kill a lot of the people it's meant to save.

Not all tribes unca Daybid , juss the Mohawk tribe . rrrrrrrrr

[Sibling DavidH]

Hello, nefyu!  Good to see you.  Now you come to mention it, you're right.

[Griffin NoName]

Hey! Neffu!