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Human karyogram. Neurogenetics studies the role of genetics in the development and function of the nervous system.It considers neural characteristics as phenotypes (i.e. manifestations, measurable or not, of the genetic make-up of an individual), and is mainly based on the observation that the nervous systems of individuals, even of those belonging to the same species, may not be identical.
James Mark Baldwin and others suggested that an organism's ability to learn new behaviours (e.g. to acclimatise to a new stressor) will affect its reproductive success and will therefore have an effect on the genetic makeup of its species through natural selection. It posits that subsequent selection might reinforce the originally learned ...
When mutations affect the mating habits of species, different traits that would otherwise benefit the species procreating are compromised. A couple chemicals that are altered from mutation and have a great impact on mating, are dopamine and serotonin. Each of these chemicals either has a reaction to how the animal acts, or how the species body ...
Behavioural genetics, also referred to as behaviour genetics, is a field of scientific research that uses genetic methods to investigate the nature and origins of individual differences in behaviour.
Some nonlethal regulatory mutations occur in HOX genes in humans, which can result in a cervical rib [95] or polydactyly, an increase in the number of fingers or toes. [96] When such mutations result in a higher fitness, natural selection favours these phenotypes and the novel trait spreads in the population.
One study on the comparison of genes between different species of Drosophila suggests that if a mutation does change a protein, the mutation will most likely be harmful, with an estimated 70 per cent of amino acid polymorphisms having damaging effects, and the remainder being either neutral or weakly beneficial. [8]
Social behavior is regulated by neurotransmitters, such as dopamine and serotonin, in the emotional centers of the brain – primarily the amygdala and the hypothalamus, and although parasites may be capable of stimulating specific neurochemical pathways to induce behavioral changes, evidence suggests that they alter neurochemical communication ...
Since mutation rate is relatively constant, roughly one half of these changes occurred in the human lineage. Only a very tiny fraction of those fixed differences gave rise to the different phenotypes of humans and chimpanzees and finding those is a great challenge. The vast majority of the differences are neutral and do not affect the phenotype.