When Humans lost their Hair (evolution, science, anthropology, Zen)

[Victor]

Beyond Stones & Bones

By Sharon Begley
Newsweek

March 19, 2007 issue - Unlike teeth and skulls and other bones, hair is no match for the pitiless ravages of weather, geologic upheaval and time. So although skulls from millions of years ago testify to the increase in brain size as one species of human ancestor evolved into the next, and although the architecture of spine and hips shows when our ancestors first stood erect, the fossil record is silent on when they fully lost their body hair and replaced it with clothing. Which makes it fortunate that Mark Stoneking thought of lice.

Head lice live in the hair on the head. But body lice, a larger variety, are misnamed: they live in clothing. Head lice, as a species, go back millions of years, while body lice are a more recent arrival. Stoneking, an evolutionary anthropologist, had a hunch that he could calculate when body lice evolved from head lice by comparing the two varieties' DNA, which accumulates changes at a regular rate. (It's like calculating how long it took a typist to produce a document if you know he makes six typos per minute.) That fork in the louse's family tree, he and colleagues at Germany's Max Planck Institute for Evolutionary Anthropology concluded, occurred no more than 114,000 years ago. Since new kinds of creatures tend to appear when a new habitat does, that's when human ancestors must have lost their body hair for good—and made up for it with clothing that, besides keeping them warm, provided a home for the newly evolved louse.

http://www.msnbc.msn.com/id/17542627...week/?GT1=9145

I figured this would be a good discussion.

Is it just me, or does this new finding sound bizzare?

[MdmSzdWhtGuy]

Victor,

I think it kind of makes sense, don't you? If a new species of lice evolved, or hybridized or whatever term you want to use around 114,000 years ago, and that species lives only in clothing, then I think that might be a pretty strong indicator that this was around the same time when clothing for humans became the norm. Very interesting thought tho.

Makes me think why can't we get lucky enough to find some cave men frozen in ice the way we always see in such classic films as "Encino Man"?

B.

[Victor]

Originally Posted by MdmSzdWhtGuy

Victor,

I think it kind of makes sense, don't you? If a new species of lice evolved, or hybridized or whatever term you want to use around 114,000 years ago, and that species lives only in clothing, then I think that might be a pretty strong indicator that this was around the same time when clothing for humans became the norm. Very interesting thought tho.

Makes me think why can't we get lucky enough to find some cave men frozen in ice the way we always see in such classic films as "Encino Man"?

B.

Well, I've always thought that cavemen generally congregated in a small clan or family. These lice are attracted to low standards of hygiene...surprise, suprise. But here is the deal, these little bugs are a nasty bunch. It killed thousands in the concetration camps and I can't imagine a small clan of poor hygenic cavemen being a problem for these bugs. So what's the deal? What did the cavemen do differently to survive? It certainly wasn't their hygene, because that's exactly what gave them lice to begin with.

Also, if the cavemen were smart enough to clothe themselves, make tools, etc. then I highly doubt they continued to be as poorly hygenic as it takes for these bugs to live in. You're only talking about 114,000 years.

[religion-science]

ahha yeah it is bizzare, but there is lots of bizzare science. It dosn't make it wrong.

[Runlikethewind]

Originally Posted by Victor

Stoneking, an evolutionary anthropologist, had a hunch that he could calculate when body lice evolved from head lice by comparing the two varieties' DNA, which accumulates changes at a regular rate. (It's like calculating how long it took a typist to produce a document if you know he makes six typos per minute.)

I have a dificult time accepting this. I am no scientist but I have studied evolution and as far as I know the debate over gradualism and punctuated equilibrium (PE) has not been settled. If PE is going on then I don't think that genetic change would accumulate at such a regular rate. I could be wrong but to continue with the anaolgy of the typist what if the typist was writting perfectly for hours then just got tired and started making all kinds of mistakes. If this is interpreted under gradualism then the average is taken and it only looks like 6 typos per min when in reality it was no typos for 10 min and 60 typos in 2 min or something like that. Anyway I am just not sure how accurate that calculation can even be. It seem to assume the rate of genetic chang which I am not so sure is very constant at all. But then again I am no scientist...

[MdmSzdWhtGuy]

Originally Posted by Victor

Well, I've always thought that cavemen generally congregated in a small clan or family. These lice are attracted to low standards of hygiene...surprise, suprise. But here is the deal, these little bugs are a nasty bunch. It killed thousands in the concetration camps and I can't imagine a small clan of poor hygenic cavemen being a problem for these bugs. So what's the deal? What did the cavemen do differently to survive? It certainly wasn't their hygene, because that's exactly what gave them lice to begin with.

Also, if the cavemen were smart enough to clothe themselves, make tools, etc. then I highly doubt they continued to be as poorly hygenic as it takes for these bugs to live in. You're only talking about 114,000 years.

I am not saying you are incorrect in what is in bold letters above, but I was wondering where you got that bit of information. I have been told (and I honestly don't know if this is an "old teacher's tale") that lice (at least head lice) only live where it is relatively clean. It could be that body or clothing lice don't need the same conditions to thrive, I don't know, but I was curious where the statement bolded above came from.

If that statement is true, and again, I have no strong reason to think it is not, then I think you have a pretty strong argument there, tho, there continues to be tons of different parasites and pathogens in our current population, and the species continues to thrive.

I guess tho, that this is just the best indicator we have, thus far, to try and calculate when humans or pre-humans might have lost their hair, tho I would not say it is definitive by a long stretch.

B.

[Victor]

Originally Posted by MdmSzdWhtGuy

I am not saying you are incorrect in what is in bold letters above, but I was wondering where you got that bit of information. I have been told (and I honestly don't know if this is an "old teacher's tale") that lice (at least head lice) only live where it is relatively clean. It could be that body or clothing lice don't need the same conditions to thrive, I don't know, but I was curious where the statement bolded above came from.

If that statement is true, and again, I have no strong reason to think it is not, then I think you have a pretty strong argument there, tho, there continues to be tons of different parasites and pathogens in our current population, and the species continues to thrive.

I guess tho, that this is just the best indicator we have, thus far, to try and calculate when humans or pre-humans might have lost their hair, tho I would not say it is definitive by a long stretch.

Perhaps it's a good start, but I just wasn't impressed by it.

I got my information from wiki. Just type in lice and you should get several hits. Try this one:
http://en.wikipedia.org/wiki/Body_louse

[michel]

This is strange; I had always understood the louse to be the "vacuum cleaner" of our skin and hair. Head lice go for clean hair; the same goes for bed mites - they aren't bothered by cleanliness (from http://www.headliceprevention.com/faqs.htm#mychild )

How come we get head lice?Head lice are a normal part of Nature, a living creature that needs food and shelter. Human blood is it's food supply and human hair their perfect shelter. In other words they belong on us. Trouble is we don't like that very much and want to get rid of them. Don't ever be surprised when they show up in class, they are actually normal companions to us humans.


Is it due to dirty hair?No absolutely not, it's more to do with skin chemistry. Some heads are just nice places to be if you are a head louse. If your child's head is an attractive head they will be plagued while their brother, sister or even twin may never have a visitor.

[Victor]

Originally Posted by michel

This is strange; I had always understood the louse to be the "vacuum cleaner" of our skin and hair. Head lice go for clean hair; the same goes for bed mites - they aren't bothered by cleanliness (from http://www.headliceprevention.com/faqs.htm#mychild )

How come we get head lice?Head lice are a normal part of Nature, a living creature that needs food and shelter. Human blood is it's food supply and human hair their perfect shelter. In other words they belong on us. Trouble is we don't like that very much and want to get rid of them. Don't ever be surprised when they show up in class, they are actually normal companions to us humans.


Is it due to dirty hair?No absolutely not, it's more to do with skin chemistry. Some heads are just nice places to be if you are a head louse. If your child's head is an attractive head they will be plagued while their brother, sister or even twin may never have a visitor.

You are the second person that metions this. Perhaps it's Boby lice that are the "dirty ones"?