Evolution and aggression

• Genotype

  Instruction from our genes which occurs at conception and provides the genetic code for how an individual develops. We inherit 50% of our genes from our mother and 50% from our father. It determines characteristics such as eye colour, and natural hair colour. In MZ twins this is identical.
• Evolution

  The changes in inherited characteristics (genotype) in a biological population over successive generations.
• Natural selection

  The major process that explains evolution whereby inherited traits that enhance an animal's reproductive success are passed on to the next generation and thus

  'selected', whereas animals without such traits are less successful at reproduction and their traits are not selected.
• Sexual selection

  An evolutionary explanation of partner preference. Attributes or behaviours that increase reproductive success are passed on and may become exaggerated over succeeding generations of offspring.
• in a species genetic differences cause variation.->variation arises when parents ,genes are combined producing offspring, and spontaneous genetic mutations in DNA->Members of same species are competitive with each other for resources ->individuals who possess characteristics that are advantageous for survival pass on genes to next generation, individuals who cannot survive/fail to reproduce dont pass on gene—>means 'only the fittest survive', ->genes that are responsible for advantageous traits are passed to offspring, over time become more frequent in future generations.