Explain, with examples, how the process of natural selection and sexual selection are thought to have contributed to modern-day human behaviour.
Lifestyle and behaviours of early humans would have been considerably different to that of modern day humans; however this is not an aspect that happened overnight but something that has taken thousands of years to develop. This aim of this essay therefore will be to explain, with examples, how human behaviour has evolved over time through the aspect of natural and sexual selection and how this has contributed to modern-day human behaviour.
Evolution is a “process over time which enables us to adapt to our changing environments”. Charles Darwin was one of the founders of this theory whereby he identified that rather that a species being fixed at creation they gradually evolve from that of their common ancestors (Darwin cited in Clegg 2007) with characteristics and behaviours, that best suit the ever changing environment we live in, being passed down the generations in order to support survival.
The process in which these characteristics are passed down in that of ‘selection’ whereby certain characteristics are either evolved due to them conferring some advantage on the individual or eliminated due to them being disadvantageous within the particular environment (quote). Therefore genes that are less well suited to the environment have a lesser probability of being passed on.
Selection is divided into two parts the first of these is that of ‘Natural selection’. This is a ‘process whereby physical and behavioural characteristics which enable survival are passed on to descendents’ (Clegg, 2007, p.121). It is a process in which genes, that are best suited to the environment we live in to ensure survival, have been passed onto the next generation and those that are successful go through a process of ‘adaptation’ in which the gene evolves by being gradually added to and modified in order to suit the ever changing world in which we live (Clegg 2007). This process is seen as ‘survival of the fittest’ whereby the best suited characteristics are passed down to ensure survival of the related genes. This can be measured through the genes reproductive success whereby copies of genes can be identified by observing behaviours that are comparable in a range of cultures.
One example of a behaviour that has been passed down many generations and can be seen across a range of cultures is that of cooking, a characteristic that arose around 1.9million years ago (University Of Minnesota, 1999) within Homo erectus times whereby food items, rather than being eaten raw, were cooked by roasting them on fires. Cooking is and aspect that has been essential for human survival and something that is seen by a range of researchers such as Wrangham (2009) to have played huge part within “our evolutionary success…as the digestive track shrank and brain grew”.
It is clear that cooking has been passed down through many generations and therefore, in natural selection terms, this gene has excellent reproductive success. However it must be queried as to how much of this is passed through genes and how much of this is taught through social interaction something that has been addressed by psychologists in which they believe that “there is a genetic predisposition underlying transmission across generations” (Clegg, 1999, p.111) therefore they see genetics and social interaction as working hand in hand in which individuals may have been passed genes with a range of characteristics but it is essential for social interaction to unlock these genetic skills and behaviours.
The second type of selection is that of ‘sexual selection’ seen by theorists as “a special type of natural selection that is concerned with an organism’s ability to successfully reproduce” (Walsh 2000). Natural selection and evolution is reliant on this type of selection as “genes survival is not guaranteed unless reproduction...