Natural selection Flashcards
Why may organisms not survive and reproduce?
natural selection
Predation, disease and competition
What is intraspecific
competition?
competition within a population caused by Genetic variation
What is the principle of evolution by natural selection?
organisms with phenotypes that provides a selective advantage are more likely to survive and reproduce and
thus pass on their favourable alleles to the next generation.
This means that the proportion of individuals with the favourable
allele will increase in the next generation (increase the allele frequency) within the population
Define evolution
the change in allele frequencies in a population over time.
Define an adaptation
a trait that enhances survival in a habitat
Describe the types of adaptation
Anatomical adaptations are structural features
Behavioural adaptations e.g. hibernation
Physiological adaptations are changes to cellular processes e.g. fight or flight adrenaline response
What is convergent evolution?
organisms that live in similar
conditions are subject to the same selection pressures, resulting in similar adaptations
Evidence for the theory of natural selection
the fossil record and biological molecules, including mDNA
antibiotic resistance
bacteria and pesticide resistance in insects are examples of…
Evolution by natural selection
