Tuesday, March 9, 2010

Why Choose?

Charles Darwin believed mate selection in sexually dimorphic species of animals was based on "pure aesthetics" (161). On the next few pages (162-167), Jerry Coyne gives several reasons for which animals may prefer the appearance of certain mates to others, but never completely disregards Darwin's hypothesis. Do you believe there is any reason that humans are attracted to certain mates besides aesthetics, as Darwin believes?


  1. Sexual selection in humans is the subject of much controversy. Coyne, on pages 162 - 167, talks about female in other species after establishing that "yes, females do choose, and that choice seems to explain sexual dimorphisms". But if you take a look at humans, you see a very high emphasis on female attractiveness...and you see male choosiness.

    Humans are attracted to their mates based on direct and indirect benefits, and also based on personal happiness. Humans have lots of extra-aesthetic factors that they take into consideration consciously while thinking about a mate but also subconsciously when they are attracted to one.

    In his book, Coyne gives very brief mention to the fact that human females ornament themselves. In his paper, Jonathan Gottschall suggests a solution to the riddle of "Greater Emphasis on Female Attractiveness in Homo Sapiens". This greater emphasis on females could be because of the "unsually high variability and detectability of women's reproductive value, especially aspects of reproductive value that are can be accurately assessed on the basis of age", moreso than for a male.

    But why are indicators of female reproductive value so much more visible than those of males? And why can we see choosiness from both sides? Gottschall suggests that humans are a "partially sex-role reversed species". Males have a very high level of parental investment - in a typical case, the male stays with his mate, caters to her during pregnancy, provides for his family during nursing, and supports his children until they grow up. (There is the exception of those that impregnate and run away, but this is clearly disadvantageous to everyone involved). Thus, he would want to choose a mate with the best possible genes that would give him the best reproductive success. Thus, his mate must be as healthy and fertile as possible.

    Something similar applies to females. Since parental investment is a lot more equal in humans (though still greater in females), the females still get to choose and the males still get to ornament. For example, most females exhibit a strong preference for buff men because they can protect them and beat up antagonists. The aesthetics are there, but they are also an indicator of the male's usefulness to the female - the direct benefit (p. 162) she gets from choosing this male. Muscularity and strength can also be good indicators of health. Genetic diseases can also be evident in the male's body or mind. So if a male is not aesthetically pleasing, that usually means that he is unhealthy, weak, or has some sort of disease that could be indirectly disadvantageous to the female if she chose him.
    Males are attracted to the same ideals. Female beauty can be a good indicator of healthy and fertility. This is probably why males prefer curvier figures, higher voices, shinier hair, etc.

    Society also has a large say in what humans are attracted to. On page 215, Coyne shows the power of a cultural fad to determine evolution in "gene-culture coevolution". One person's preferences spread to all the rest. In the same way, pale skin used to be "in", and the ideal woman was pale, delicate, and had a tiny waist. Now, generally, males see paleness as negative and associate it with either being sick or spending too much time inside. They don't like frail women because they look like they need taking care of. Instead of tiny waists, they look for leanness and athleticism. The definition of beauty changes over time, so in general, aesthetics not associated with health and reproductive value should not really matter.


    Why Evolution is True

  2. The way humans are attracted to other humans, in my opinion, follows does not follow Darwin's original belief that is was based purely on aesthetics, but is more complicated because of cultural influences. Coyne describes the benefits of a female choosing a mate on page 162 on his novel when he says, "She can benefit directly- that is, by picking a male who will help her produce more or healthier young during the act of child care. Or she can benefit indirectly, by choosing a male who has better genes than those of other males (that is, genes that will give her offspring a leg up in the next generation)." The real question concerning this issue though is, what is attractive to humans?

    Different times call for different measures and style changes from generation to generation. This is usually apparent when I visit my grandparents' houses and we (as a family) go through the old photo album. It is always a good time because the outfits that they wore as children look prim and proper compared to the outfits of the average teens of the new millenium. Along with the non-biological theme of clothes, the way people behave and look (phylogeny) change with time and culture. According to the CDC, in 2008, there were 2,162,000 marriages with a marriage rate of 7.1% per 1,000 people in the total population. However, for every 1,000 people (population) 3.5 individuals filed for divorce and went through with it. Why does divorce occur one may ask? Although there are thousands of reasons behind divorce, when all is said and done the way humans feel around each other is the deciding factor (protection, support, physical attractiveness, and behavior).

    Humans are a different case of sexual dimorphisms because instead of just one sex (male or female) evolving to find mates such as in peacocks, both sexes of humans are changing their looks and behaviors to "meet the standards" of the other and find the right partner for them. Today, with all the information about being healthy, many Americans want to stay in shape because it shows the other sex that you have the ability to raise a happy and healthy family with the "good genes" that are associated with your looks. In older days, obesity was associated with wealth and power for kings and queens, but society today has dramatically changed the way people view obese individuals because as of 2010, 65% of people in the U.S. are considered overweight or obese (CDC). When males or females are considering who "is in their league," they consider all the consequences that physical attributes can apply. Being smart and responsible can be observed through actions, but before meeting someone (in most cases) you see them first, which is usually the deciding factor. This topic, all in all, is very complicated to explain because every human is genetically different and beauty is more than just what is on the outside.