natural selection Flashcards
Natural selection (def.)
a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are individuals with other characteristics
Evolution (def.)
development of new types of living organisms from pre-existing types by the accumulation of genetic differences over long periods of time (works on entire population, not individuals)
role of natural selection in evolution
Natural selection leads to evolutionary adaptation, a population’s increase in the frequency of traits suited to the environment → so natural selection leads to evolution, seen either as:
- A change in the genetic composition of a population over time or
- The entire biological history, from the earliest microbes to the enormous diversity of organisms that live on earth today
variation and competition lead to differential survival of, and reproduction by, those organisms best fitted to the environment (answering technique)
examples of environmental factors that act as forces of natural selection (answering technique)
Different environmental conditions exert differential selection pressures on the two populations. In absence of mating between the two populations, they are unable to (recognise the mating song) and cannot mate when they were put together. Mutations result in the change in characteristics in the two populations of __.
examples of artificial selection such as in the production of economically important plants and animals (answering technique)
Selective breeding is a selection caused by humans and is a deliberate and planned process, selecting for characteristic. The best of the progeny showing these particular characteristics are used as the next generation of parents. Over generations, continuous removal of progeny showing less desired features leads to deliberate genetic change, where the population of __ carrying characteristic becomes more common.
