Evolution by Natural selection Flashcards
What is evolution?
Evolution is the process of change that occurs in living organisms over many generations. It is the result of natural selection by the environment of favourable variations in the organisms
Evolutionary theory states that all organisms have developed from previous organisms that all living things have a common ancestor in some initial form of primitive life
Mechanisms of evolution
- mutation (causes variation)
- Sexual reproduction (lead to variation)
- natural selection
What is natural selection?
process that results in the adaptation of an organism to its environment by means of selectively reproducing changes in its genotype, or genetic constitution
What was Darwin’s Theory
Natural selection by survival of the fittest explains how species evolve over time through the differential survival and reproduction of individuals with advantageous traits.
Explain how natural selection could lead to a change in allele frequency.
When one species with different characteristics have a higher level of survival in a environment (fitness) they are more likely to reproduce and pass their allele to the next generation
Does Natural selection act on a population or individual?
Acts on populations
- Individual organisms cannot evolve, but as certain traits become more common across generations, the population undergoes evolution.
What is fitness in biology?
an organisms ability to survive and reproduce in its environment.
4 key terms in natural selection
Variation
environmental change
reproduction
advantageous trait
What is variation in natural selection?
- there is variation within populations.
What is environmental change in natural selection?
Change in the environment driving differential reproduction
What is reproduction in natural selection?
There is heredity, they pass on their genes/traits
