Monday, April 5, 2010
Cultural (R)evolution
During the course of human evolution, there have been two types of evolution that have gone on: physical evolution, which is the topic most discussed in Why Evolution is True, but also cultural evolution. On page 215, Coyne talks about “gene-culture coëvolution”, which is to say that our culture is influencing the way that our genes propagate themselves. Generally, gene-culture coëvolution results from sexual selection, such as the princess who chooses a certain body type for her mate, setting a fashion for everyone else. Is it possible that, due to differing views of beauty, and supposing that humans continue to evolve, separate cultures may evolve independently? If that were to happen long enough for speciation to occur, what might the ramifications be on international and interpersonal relations? In addition, humans have developed genocide and war. Is war a possible deëvolution mechanism, due to the fact that the healthiest and strongest physical specimens are sent to die? If so, why doesn’t culture evolve for the same purpose as physical characteristics, to produce an organism with the highest likelihood of reproduction? If not, why not?
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The idea that "differing views of beauty" comes into question when we speak of human evolution is a very perplex one. "Beauty" to some people maybe very different for others, and in our society today, mere good looks may not cut it. Intelligence, social status, appearance, and even the vaguely defined "love" all become factors in deciding who to mate (even if they may be for the wrong reasons). For this reason, sexual selection in humans is extrememly difficult to think of in terms of human beings. With that out of the way, human speciation could have drastic effects depending on the degree of differences in the now two species. What would the other species need to eat? Would they be more or less intelligent? These questions would present themselves to us during this time. However until then, we will never know the full extent of ramifications.
ReplyDeleteAlthough speciation has not yet occured in humans, different traits in races are being discovered each day. For example, African Americans have unique muscle fibers (different from caucasians) which allow them to be avid sprinters and runners. Theories for this include the African culture as well as the American slave trade which would force African slaves to work out in fields all day long. This process of natural selection gave African Americans these unique muscle fibers http://www.ncbi.nlm.nih.gov/pubmed/16937962.
Even with seperate cultures in different parts of the world, speciation is likely to never occur. This has been seen with plant species existing in both Asia and North America for over 6 million years and still are able to interbreed. From this example we see that even geographic barriers make it difficult for speciation to occur. But now with easy access to transportation and effective traveling, speciation will be near impossible in humans.
In regards to war, it's not always the healthiest and strongest, but more so - the poor and lower class which are sent off to fight. This often increases the gap between the lower and upper class. Thusly, the upperclass will tend to reproduce with each other and vice versa.
We can clearly see the results of cultural effects on sexual selection in our world today; each continent has a general look like “longer noses” for whites and “eye folds” for Asians. Also, it can be argued that each country, which grew out of a group of similar looking people have their own distinct looks. Coyne writes that 10-15% of genetic variation between humans is by race (213) In the case of isolated amazon rainforest tribes, some of whom have never seen or mingled with outsiders, they probably have an even higher percentage of race genes determine their unique body traits. The probability that speciation in humans will occur is basically zero in sympatric speciation conditions. Sympatric speciation would not work for humans because “interbreeding between diverging forms will constantly be pulling them back into the same species.” (184). However, over a very long period of time, geographic speciation can take place with humans but the two populations may be allowed to interact. On a similar note, since the world is becoming an increasingly smaller place, I think it is possible that in several million years in the future, people from culturally different countries will look more similar; however it is doubtful that there will be a greater difference in looks after the same amount of time. If human speciation occurred, the two resulting species, both still presumably intelligent, may wage war for dominance (nationalism/specieism). Interpersonal relations between species may be shunned by both species, but this would depend on the society that they live in.
ReplyDeleteCurrently, healthcare and medicine and a stable society allow people to ‘alter’ the path of natural selection. Ease of access to basic living necessities allows us to pursue comfort, and in terms of reproducing, beauty. In the past, it was important to pass along the family name, causing males to marry and reproduce with whomever he could. Now, society exerts a great deal of influence on what we perceive beauty as, as well as putting a great deal of focus on it. (I don’t think you’ve ever seen a magazine showing the latest reproductive strategies). Also, advances in childbirth techniques have greatly reduced the number of maternal deaths. There are also drugs that allow couples that are having trouble having a baby have 8 kids (octomom!). All these factors greatly reduce our dependence on natural reproductive ability, allowing our focus to drift to other things, like beauty.
In a study done by Stanford scientists, they present a model that shows that in tribal times, warriors who won battles/ wars against other tribes passed along their genes, resulting in even more aggressive sons. (http://www.physorg.com/news140174454.html) This could be one reason we even have war. Genocide however is usually orchestrated or started by a few fanatics. Hitler and his Nazis used propaganda to convince the public that Jews were bad
War, while may not send only the healthiest and strongest, it does send many of those people to war. Since you have to pass basic training, which is quite grueling for most people, there is at least a preference for those who are physically fit. De-evolution can’t really exist because natural selection always chooses the ones that are best fit for reproduction. At the very most, the world wars ‘slowed down’ natural selection, since so many of that generation died and there was a decrease in variation of the gene pool.