- Genes are made up of DNA which provides the blueprint for the structure and function of the human body. This could include behaviour.
- An individual’s genome refers to all the genes that individual possesses.
- The link between genes and behaviour can be studied using one or more examples.
Genes are switched on and off by signals from inside and outside the body.
Internal signals include the presence of hormones or other chemicals, or indeed other genes.
Hormones are frequently produced as a result of environmental events and work by altering gene expression.
There are countless environmental events that also affect gene expression.
The signal activates special proteins that can promote or block the expression of a gene. Genes are constantly being switched on and off.
Sometimes genes are permanently switched off. This is mostly achieved by methylation of the DNA molecule as part of the developmental process.
This effect on genes is sometimes referred to as epigenetics as there is no alteration in the actual structure of the DNA.
Mutations occur when there is an actual alteration of the DNA.
- Competition for scarce resources, like food or mates, leads to the promotion of favourable traits; physical or behavioural.
- Whatever their nature, they are regarded as favourable traits as they allow the individual to acquire sufficient resources in order to survive and reproduce.
- When the individual reproduces, it passes these traits on to the next generation; the more they reproduce, the more individuals will have the trait in the next generation; survival of the fittest by natural selection
- Genetics and environmental challenges are therefore both important in the success of specific traits and behaviour
- Evolutionary explanations for behaviour can be studied using one or more examples.