Humans have a tendency to think of themselves as distinct from all other species, special, unique. Is this thinking correct in respect to Darwinian selection? Are we above other creatures when it comes to selection? Some scientists believe that the Darwinian perspectives of natural and sexual selection don’t apply to us because people are extremely”ecologically flexible”, meaning that we have the capacity to adapt to a number of types and changes of environment in ways that no other creature can. However, genomic data has provided the scientific community with evidence that choice of phenotypic traits does occur in humans. This means that choice does act on humans, even if the extent at which it acts isn’t fully understood. This subject is of repute in the area of human evolution.
Natural selection is the process described as the choice of biological traits depending on the sexual achievement of individuals carrying these traits. In other words, the”passing on” of specific traits is determined by the reproductive success of these individuals.
Scientists have a fantastic grasp on the roles natural and sexual selection play in most animal populations however, because of lack of suitable datasets, selection in human populations has yet to be fully understood. A study, conducted by Alexandre Courtiol and Virpi Lummaa in the University of Sheffield, looks at whether or not natural and sexual selection happened within this human population and extrapolated their findings to modern human populations. The analysis consisted of analyzing the chance for choice based on 4 points in human life: achieving reproductive age, access to opposite gender, successful mating and fertility. They took into account the gap that wealth and gender would have on those points and split the data into two classes: landowners and landless. This was done to exclude social standing as being a cause for higher reproductive success. They found evidence that both natural and sexual selection acted on this population.
Natural selection was seen by the variance in fitness throughout the population in terms of survival into adulthood and fertility. This is to say, people able to survive to maturity and pass on their genes were better adapted than individuals unable to do so, and therefore chosen more often by the opposite sex.
Variance in mating success clarified the higher variance of male reproductive success, in contrast to females. This greater variance of male reproductive success can be explained by the social situation of the moment. Divorce and adultery were highly prohibited and just in the eventuality of a spouse dying would one be able to remarry and continue to have children, continue to reproduce. Men remarried more frequently than women since women were open to marrying men much older than themselves. Reproductive success would be greater for men as a consequence of the fact that men have a longer reproductive life; there’s no age limitation in men for the ability to procreate. This is not typically seen in cases where the spouse is widowed. Once widowed, most females would not procreate again; they’d cease to have reproductive success. The sexual selection observed in this population can be simply explained by the capacity of men to reproduce for longer; this doesn’t give them higher fitness.
At this time it’s been observed that sexual and natural selection acted on this human population. The results of the study further demonstrated that it was sexual choice that offered the greater proportion of opportunity of selection. To put it differently, that sexual selection accounted for a higher percentage of the total selection. Natural selection was still important, but not to the exact same degree.
The novelty of this study is that it reveals higher opportunity of choice than any other research with human inhabitants. Methods such as statistics of death and birth rates, and demographic surveys don’t account for differences such as economic status, biological contrast and social standing. This study does.
Are humans above other animals when it comes to selection? Comparing the information, Courtiol et al. found that the human population followed the same intensity of Darwinian selection as that expected from any other animal inhabitants. This means that humans in this population were subject to the very same forces of selection expected of any other animal population. Extrapolations can be reached from this analysis. This monogamous population showed both natural and sexual selection to the extent of other animal populations; could a more modern people show the same degree of selection? The changes in social behaviour, technology, and culture appear to have not removed the evolutionary pressures of sexual and natural selection.
It is true that a lot of work has to be done in this field; however, new studies are being designed and carried out that promise to bring forth more info. It is exciting to think that scientists are delving into these questions. Are humans unique in the eyes of sexual and natural selection? Does our”environmental flexibility” set us apart from the other animals? It is my opinion that natural and sexual selection definitely play a role in our societies, but to what extent I remain unconvinced. Likewise to all humans, I like being different from the other species.