Milot, E., Mayer, F., Nussey, D., Boisvert, M., Pelletier, F., & Reale, D. (2011). Evidence for evolution in response to natural selection in a contemporary human population. Proceedings of The National Academy of Sciences, 108(41), 17040-17045. http://dx.doi.org/10.1073/pnas.1104210108
Based on the Darwinian biological evolution theory, Milot et al. (2011) deliver a profound study seeking evidence that humans are still evolving. The research is based on a contemporary society whereby it aims to show a contrasting stance against that suggesting evolution of man has already been decimated by highly advanced technologies and civilization. In the publication, Milot et al. (2011) study variations in the life history of a uniquely existing French-Canadian population in Canada. The population under study was as little as 1,585 in the 1950s and settled in an island called Ile aux Coudres along Canada’s St. Lawrence River. The researchers sought to test evolutionary changes in the population based on women’s ages of first reproduction (AFR) that is considered heritable and with strong genetic correlation to proper physical health.
Data on the population was collected from church registers. The data’s long-term analysis would reveal the life history traits (LHTs). The productive scores of women over the years were collected and analyzed. Milot et al. (2011) found that the Ile aux Coudres population showed a continuous furtherance of AFR. The study showed that women who bore their first kid during 1930s were younger by four years than those who bore their first child around 1800s. This shows that there was an increasing trend in lifetime reproductive success as evidenced by declining AFR from about 26 years in a span of about 140 years. The uncovering of the AFR trait changes among the Coudres population points out to a genetic drift. The results thus detect an evolution taking place though there could have been other factors that played a role.
Natural selection was a theory put forward by the British scientist Charles Darwin to explain his assertions of biological evolutions. In his theory, Darwin assumes that organisms scramble for natural resources that are scarce or limited in nature. Organisms that portray strong traits of survival dominate by the ability to leave more progenies hence superseding other generations deemed weaker (Williams, 2008). As such, nature will ‘select’ the stronger organisms to survive while the weaker are easily eliminated from the ecological system. As per Darwin’s idea, natural selection leads to organisms developing adaptation mechanisms in their environments over a particular period. But then, natural selection can happen with or without changes in the environment. While in a changeless environment natural selection is likely to keep up the status quo, in a changing environment natural selection is bound to advantage variations that enhance the fitness in the new surrounding hence leading to evolution. An example of natural selection, as put forward by Darwin, is the unique variations of the same species of a bird known as Galápagos finch from the Galapagos Islands (Williams, 2008). Darwin observed that the Galapagos finches had different sizes and shapes of beaks, and they were also different from those found across the world.
Milot et al. (2011) claim that AFR follows an identical pattern with age of women at marriage whereby they found that the relationship was even stronger on Coudres’ population. The LHT’s of the population ascertain that factors affected the population against the social and cultural advancements in a broader sense. The results make it sure that the observed changes among the population came about, at least partially, from an evolution response to natural selection on age of first reproduction. Consequently, AFR among other populations did not see any significant deviations.
Williams, G. C. (2008). Adaptation and natural selection: A critique of some current evolutionary thought. Princeton university press.