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Friday, March 18, 2005

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Cuckoldry not that common after all?

Claims that covert non-paternity (the putative father not being the actual father of a child) is as high as 10% in human populations have been common in recent years. Some time ago, I noticed that there was a discrepancy between this claim and studies done on the inheritance of surnames, which seemed to imply a much lower rate of non-paternity. If 10% of births in the typical family in the past were not actually the children of the father, it is easy to see that, after several generations, the relationship between a surname and the y-chromosome (that is, the actual paternal line) will become rapidly more tenuous. If 10% of "sons" of fathers, taking their father's surname, are actually another man's (the result of adultery), after seven generations less than half the surnames will accurately reflect the true male line [0.9 x 0.9 x 0.9 x 0.9 x 0.9 x 0.9 x 0.9 = 0.48 = 48 percent]. And yet there are studies, such as the Sykes surname study (cited here), extending over many past generations (700 years), which imply much lower rates of non-paternity (1.3% per generation in the Sykes case).

This recent study by Kermyt G. Anderson of the Department of Anthropology, University of Oklahoma, seems to imply that the lower figures for non-paternity are more probable:

" The results suggest that men with high paternity confidence are generally correct in their paternity assessment; these men overwhelmingly tend to be the actual genetic fathers of their putative children, with a median nonpaternity rate of only 1.9%. If men with high and unknown levels of paternity confidence are combined, the median nonpaternity increases to only 3.9%. These figures are dramatically less than the “typical” nonpaternity rate of 10% or higher cited by many authors (e.g., Alfred 2002, Cervino and Hill 2000, MacIntyre and Sooman 1991, Stewart 1989), or the median worldwide nonpaternity of 9% reported by Baker and Bellis (1995). These results presented here suggest that men who think they are the fathers of their children actually are the fathers between 96.1 - 98.1% of the time. "

The Sykes surname study has always seemed like powerful supporting evidence for a low rate of human cuckoldry. I have discussed this with various evolutionary psychologists on the Internet, and some have suggested that morals and behaviour have changed rapidly in recent years. That is, they have suggested that, whereas the Sykes study reflects stricter past behaviour, modern cultures around the world are more "free and easy" and 10% non-paternity is likely in their case. However, this new study from the University of Oklahoma implies that modern cultures are not more "free and easy".

To my mind, surname studies like the Sykes study have all along been very hard to explain if one believes in high (10%, for example) rates of cuckoldry (non-paternity) among humans. It is increasingly likely that what the Sykes study implies is accurate: that ordinary Englishmen and Englishwomen were, on the whole, remarkably well-behaved over a remarkably long time: "When all is said and done, there is more said than done." Despite the occasional shenanigans that undoubtedly went on, and that gave us so many colourful English expressions (like "cuckoldry"), the general picture is of a remarkably high standard of behaviour in an ordinary English population.

Julian

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Saturday, March 12, 2005

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Our dog has diabetes

Our dog, a Samoyed, has diabetes. Now I have to inject her twice daily with insulin. Pinch a roll of skin, pop the needle in and squeeze. Not as hard as it looks, actually. One of the reasons I never thought of being a vet is my general lack of manual dexterity, but I find I can do simple things like this OK. Also, when I did my Ph.D., which involved drawing numerous blood samples from sheep and goats for research on red blood cells, I got pretty deft at the task. Occlude the jugular vein with one hand, tap away to find the now swollen vein with the other, pop the needle in and remove the sample. Some of the sheep had the neck area clipped, which made it even easier.

I went to the Hancock library today, at the Australian National University. Three sections tend to interest me most: that on IQ, that on human biology (including medical anthropology, for example), and the zoology area. I found a copy of Smythies' "The Birds of Borneo", a big fat traditional-looking bird guide, written in that leisurely, gentlemanly, discursive, colonial style favoured once by the British. In his "Into the Heart of Borneo", Redmond O'Hanlon writes of his 1983 trip with some post-colonial irony. One of the books he took with him on the trek was Smythies' work. It was pleasing to find the actual work on a library shelf. It was published in 1960.

I didn't borrow "The Birds of Borneo" (It's a big book, and I didn't share O'Hanlon's dedication to lugging it around.) However, I did borrow E. O. Wilson's "Sociobiology". I dipped into this years ago, but never in great detail. I always liked his "The Insect Societies" better. I think some of his books suffer from gigantism. I have his "The Ants" (written, people tend to forget, with Bert Holldobler as senior author), a volume that I think suffers from being just too darn big. It is the size of a mediaeval bible, and about as easy to consult.

I also borrowed books on medical anthropology, parasite biochemistry, nematode systematics, the agronomy of coffee, the retinas of various fishes, Fijian medicinal plants, the evolution and ecology of mites, ESP, and primitive immune systems. That should keep me going for a while.

The book on mites is quite a sumptuous production. Acarology, the study of mites, seems to have become a major area of activity of late, with several significant monographs being published recently. I wonder if this is due to improved techniques for studying such small organisms as well as their being a comparatively fresh taxonomic group. No doubt their range of habits and habitats makes them of evolutionary interest too.

Julian

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Friday, March 11, 2005

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More worm-blogging

Another episode last night of the TV series on parasites (see below). Some gruesome stuff, including guinea worms being pulled slowly out of peoples' feet in West Africa, a girl who got Leishmaniasis on a holiday in South America, more than I really wanted to know about Ascaris worms, and so on.

Scientific theorising and data were presented by one Dr Roberts, who had a theory that women would be able to detect immunologically superior (and presumably parasite-resistant) men from a peek at only a small amount of their facial skin. A practical test went the way he predicted. This suggests that women can detect - and find attractive - skin with features that somehow, subtly, indicate immune fitness. The men and women involved were young white Britons. But I was reminded of my theory, written up here and titled "African Lips as Health Signals", that the pink, everted lips of many Africans serve the same function: to signify health. Bright red or pink lips would imply health (including the absence of anaemia due to parasites like malaria); pale lips would suggest poor health and an undesirable mate.

Julian

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Monday, March 07, 2005

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Further musings on Hobbits (Homo floresiensis)

Now that their Indonesian captivity is over, the world can look forward to more science being done on the Hobbit bones. In the meantime, here are some results:

" 'Hobbit was a smart little human` say scientists "

" The overall shape of the hominid’s brain is very similar to that of Homo erectus (an earlier ancestor of modern humans). It also has some very advanced features that compare well with the modern human’s brain. Particularly, the frontal lobe, the temporal lobes at the sides and at the back of the brain are very similar to a modern human brain’s features. "

When I was at the Australasian Society for Human Biology meeting last December, I made two remarks in a comment from the floor. One was that I thought the Hobbit could be an extreme form of pygmoid Homo sapiens, associated with rainforest palaeoenvironment. I discuss this further here. The other was that bird brains are very small but some birds (crows, parrots) are being found to be remarkably intelligent. I speculated that a small, well-packed human brain could likewise be intelligent. It seems I was on the right track. (I saw a small flock of sulphur-crested cockatoos feeding on pinecones today. Some were eating them in the tree; some were eating them on the ground. The latter had them upright on the ground and were munching away contentedly. Beautiful big birds - quite "confiding" as birdlovers say - and behaving as intelligently as any monkey with a piece of fruit.)

An interesting thing about the Hobbit find is that two developments have been typical of the aftermath of a major new find of ancient man. One is the bitter dispute over ownership of the material. The second is the claim that the bones are really just from a diseased individual (a microcephalic in this case).

I am constantly surprised by the claim that Homo floresiensis must have been a result of "small island dwarfing". Get out the atlas, and check the island of Flores. It is over two hundred miles long. A "small island"?? Moreover, if islands tend to cause human dwarfing, someone should tell that to the Samoans, the biggest people in the world. (I borrowed this last point from Steve Sailer, but I think he borrowed one of my ideas recently, so that's alright. He has more ideas than me, though. A very smart man.)

Julian

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Friday, March 04, 2005

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Man's oldest enemy

Parasites that is. As I prepare to treat my four-year-old son with head lice mousse, I can't help but reflect on parasites, including this program on Australia's ABC TV, entitled "Body Snatchers". I have only seen one episode, and I gather it is a series. It is a bit sensationalist, but it is a remarkable "first". I certainly can't remember a documentary on parasites before.

I did parasitology at university; it was one of my favourite subjects. I still remember the last lecture, given by Dr Nicholas in 1976, the last lecture of my university career actually, which was on onchocerciasis or "river blindness". I remember Dr Nicholas stressing that river blindness was a case in point that showed that the ancient infections were still with us. Nothing has changed since then. Certainly, the "Body Snatchers" program confirms that parasites continue to be a problem.

I was stunned by the case of the woman aid worker in the documentary who had spent time in Kenya and managed to get sufficiently mosquito-bitten that she had contracted elephantiasis, a serious and disfiguring disease of the lymphatics, which is caused by a filarial worm carried by mosquitoes. She first noticed the problem on a flight home, which makes sense, perhaps, because sitting in a aeroplane would help make lymph pool in her feet. In any case, she had elephantiasis, and apparently the curative drugs are only experimental. Here is an article on the disease, and here are some pictures of what it can lead to. Very ugly.

Mosquito nets are still a good idea in the Tropics.

Then there was the man who came back from Nepal with a tapeworm cyst in his brain that led to fits. His story ended happily enough. This led on to a discussion of the amazing story of an outbreak of tapeworm cysts in the brain (causing fits) in a Jewish area of Brooklyn, New York, ten years ago. It is touched on in this very interesting article on "immigrant medicine". I thought how well this story would have gone as a chapter in a book by Berton Roueche on public health detection. Another man came back from Greece with an infection by Acanthamoebae in the cornea of his right eye, from amoebae in tap water getting onto his contact lens.

It all makes me glad that we live in a temperate zone, here in Canberra, Australia, although I had to kill one of these redback spiders on my daughter's bed last night. They are relatives of the American "black widow" and can be deadly. I have seen them in the garden, but it is a bit unusual to find one inside the house.

Julian

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