I know, Brennen. I am, once again, trying to argue about something I don’t really understand. I agree with you and Barto that trying to define a race in today’s society is probably impossible. And I also agree with you and Balak that the economic status and other sociological factors have probably greater impact on one’s health than race. But still, common sense tells me that new species is not born over night. The little differences we see in the many different ethnic groups must be the initial step in what we call evolution. It might be correct to classify the Kalahari Bushmen as a different race when compared with, I don’t know, the Matsés tribe in Peru. It certainly gets more confusing when comparing the blacks and whites in the US.
George, you are right that species don’t arise in a day. Maybe, if we had not developed the fast comunication method we developed, the groups you mention would have grown into different species, but if the process of diferentiation was talking place, we destroyed it (or we are destroying it), because we are in a process of mixing groups.
Yes, the lack of geographic isolation largely precludes speciation for us now.
I agree there are genetic differences between populations like the ones you identify. And from a medical point of view, some of them might be relevant. So as a doctor, I’d like to know that my patient is a Kalahari Kung tribesman, or a Laplander, or whatever, especially if there is epidemiological evidence that it narrows my list of diagnoses some. However, I wouldn’t care if they were black, white, Asian, and so on because these classes are not sufficiently specific to matter much and full of loopholes. And outside of the medical setting, I’m still not sure there’s much use to talking about groups of people, even with some small average genetic differences, as “races” since it calls up all sorts of overgeneralization that probably swamps by far its utility. I have no objection to scientific study of race based on my ideology, I just think it’s already been studied sufficiently to demonstrate it’s not a useful biological concept.
I agree that “race” is a fuzzy concept and hard to pin down. Howeve, “racism” is a bit different. People often like to have an excuse to discriminate against other groups. Apparently the most easily identified characteristic is level of melanin in one’s skin. For example, the population on the northern islands of Japan are lighter than those on the southern parts of the country, and the lighter citizens are afforded higher status. While there are many individual exceptions, this seems to be the case worldwide.
I wonder if, when we get much more skilled at genetic mutation, parents will go in to have their ova and sperm modified to replace those genes that contribute to deeper skin color. We may all end up looking like Nordic blonds. The next problem then will probably be the increasing incidence of albinos.
I was going to let this topic go, but Brennen’s “humans passed through a genetic bottleneck coming out of Africa” which is supposed to be responsible for the small genetic diversity in our species has been on my mind for sometime now.
Fine. The genes don’t make us all that different. But what about the epigenetics? According to Wiki, “epigenetic changes play a role in the process of cellular differentiation, allowing cells to stably maintain different characteristics despite containing the same genomic material… The spatial distribution of cells [influenced by epigenetics] that arises during the embryonic development of an organism and that give rise to the characteristic forms of tissues, organs, and overall body anatomy.” After the completion of the Human Genome Project, the scientists realized that even though they now have all the sequences of our genes, they don’t have much. We are not any closer to finding a cure for cancer because epigenetics seem to be as important as genetics, and we know very little about epigenetics.
In another thread I mentioned that chimps, even though are genetically closer to us than to gorillas, resemble gorillas closer than us. Doug said than chimps and gorillas are very different, with which I agree. But neither chimps or gorillas are bipedal, they are both hairy, and neither one of them can fly to the moon.
So no, small genetic diversity between human races doesn’t necessarily prove that we are all alike.
Edit: I forgot to mention that epigenetics is greatly influenced by the environment. Lamarck is back…
Well, my point about the lack of genetic diversty was largely in response to your argument that genetic differences were sufficient to justify “race” as a meaningful biological category. Epigenetics is a really interesting, and still poorly developed, field. You’re right, a lot of it has to do with environment, and you can see differences in gene expression between identical twins due to it. These differences get larger the longer such twins live due to environmntal influences. Now, could this be part of the explanation for how environment affects characteristics previously thought to be inherent and even “race-specific?” Probably. It’s hard to separate out the influences of environement on individuals through influence on the phenotype (body and mind) versus influence on gene expression given what we know now. Still, all that means is that differences we assign to membership in supposed racial groups are possibly due to the influence of environment on gene expression rather than on the inherent genetic differences between groups, which makes the idea of such races as biologically useful categories even less likely. We may not be all alike even though our genes are similar, but if true that means that the differences have much to do with environment, which is a lot more modifiable than genes.
As for chimps and gorillas and people, I’ve already made the point that qualitative genetic differences are clearly more important than quantitative differences. I don’t think this general principle sheds much light of the differences between groups of people, though. Exactly how genes influence complex traits like disease susceptibility or intellectual ability has proven remarkably dificult to figure out because the relationship is so complex and contingent on so many genetic, epigenetic, and environmental variables. I wouldn’t say we shouldn’t research it, but I don’t think we have much evidence yet to support the notion that categorizing people in anything like traditional racial groups for the purposes of predicting anything about the characteristics of inividuals is likely to prove useful or reliable.
a lot of it has to do with environment, and you can see differences in gene expression between identical twins due to it. These differences get larger the longer such twins live due to environmntal influences.
Brennen, where can I read more about this? Do you know any book on this subject that I would be able to understand? (BTW, thanks for your response. I am not sure how you made any sense of my mumbo jumbo post. I think you should try teaching. Do you?)
Reminds me of something. Twenty-five years ago I was talking with a chemist and good friend who worked at a So. Calif. aerospace company as the head of their coatings materials development section. He commented that he was having trouble phasing out the many cans of aerosol paint used in their shops. I “innocently” asked why. He explained (as I already knew) that they used Freons, fluorocarbons, that damaged the ozone layer in the upper atmosphere. I asked why he wanted to stop that from happening. He said that the ultraviolet radiation level would go up greately. I asked what was wrong with that. He said, it would cause many problems such a severe skin cancers. I asked “among whom?” He said, catching on, “Oh, among Caucasians. Damn, I’m going to have all the DC-10s painted with aerosol cans.” (He was African-American).
You’re very kind. I did teach formally for a while, loooong ago, ut I also spend much of my day trying to explain medical concepts to my clients, so I still do in a sense.
I saw a Nova segment on epigenetics, and HERE is the link to the segment, which also has a list of online and print resources on the topic. Can’t say as I know much more than that, but I hope it’s useful.
I just though of something else. Not enough melanin does increase the risk of skin cancer, but I wonder what advantages, except for the obvious one where people are able to absorb more sun in the north, low level of melanin offers. Could light colored eyes have played a rôle in helping to create today’s western society? Eye contact is very important in communication. The lighter the colour of an eye, the more visible its pupil in the opening in the center of the iris. And since the size of the pupil reflects how sincere our intentions are, if we are lying, scared, etc., it might have greatly impacted the way we interact with each other. In other words, if we cannot lie, we cannot deceive, and we become more cooperative. What do you think?
Well, the standard explanation for loss of pigment generally is increased ability to produce Vitamin D at lower levels of UV light in Northern latitudes. Obviously, Vit D is essential for calcium absorption, and it has apparent some cancer-prevention role, and in humans production requires a step involving UV absorption in the skin. Once pigment in general is decreased, that would affect the eyes just like any other part of the body. I don’t think any additional explanation is really necessary.
As for eye contact, it is interesting that humans in general, including those more heavily pigmented, have white sclera, whereas chimps and gorillas have pigmented sclera. This makes the eyes more prominent in humans, which some people think may be an advantage for social communication. On the other hand, subtle eye contact interactions among cats and gorillas have been documented, so this plays a big role in these species despite a, to us, less contrasting eye pigmentation. All kinds of stories can be made up, but I’d be reluctant to make any grand historical conclusions based on such tales.