Evolutionary Topic: "Are Humans Still Evolving?"
It is often argued that because of recent cultural and technological changes, human populations are no longer exposed to forces of natural selection. Medical advancements have drastically reduced mortality rates and culture and technology have granted us near immunity to the threats of the animal world. However, recent studies demonstrate that the existing variation within our population still allows for natural selection to occur, and that not only do cultural and technological changes not eliminate natural selection, but in certain cases they have been the driving forces behind evolutionary processes that have imposed selective pressures on certain traits.
Natural selection occurs as a result of variation in traits within a population. As certain traits tend to increase the survivability of individuals in relation to their environments, the individuals having those traits are more likely to survive to the age of reproduction, and thereby contribute more strongly to the next generation.
Although factors such as predation and disease no longer implement as much pressure on our species, there are still other factors that prevent all individuals from procreating, such as poverty and epidemics (Balter, 2005:234-37). As a result, as long as not every person meets the conditions to properly procreate, certain individuals are surviving more adequately in their environments. For instance, several genes that code for hemoglobin C and an allele of a sub-Saharan blood group in Africa have been found to provide resistance against malaria (Balter, 2005:234-37). To this day, malaria continues to kill many people in Africa (Balter, 2005:234-37). Therefore, individuals who possess such genes are able to more effectively survive the pressures that their environment exerts, and thereby have a better chance of producing offspring.
Furthermore, according to Balter (2005:234-37) certain people with a mutated CCR5 gene have strong resistance to the...