Evolution terminology Flashcards
What is evolution?
changes in allele frequency in a population over generations
What are the 4 mechanisms of evolution?
- mutation
- genetic drift
- gene flow
- Natural selection
What is biological fitness?
capability of an organism to produce viable offspring relative to others in a population
What is genetic drift?
process of random changes in allele frequency due to sampling error (i.e bottlenecks and founder effect)
What is a population bottle neck?
an existing population decreases in size and the allele frequencies in the remaining population differ from the original (same habitat, different points of time)
What is the founder effect?
new isolated population is founded in a different location, and the allele frequencies are different (new habitat)
Can genetic drift introduce new alleles?
no
What is gene flow?
the movement of alleles into or out of a population due to the movement of individuals between populations or the movement of gametes (tends to homogenize allele frequencies between populations)
Can gene flow introduce new alleles into a population?
yes
What happens if there is a lack of gene flow between populations?
increases genetic divergence, can result in speciation
What is an adaptation?
A heritable trait that increases the ability of an individual to survive and reproduce compared to individuals without the trait
What are the three kinds of adaptations?
- structural
- physiological
- behavioural
What is natural selection?
occurs when individuals with certain heritable traits produce more surviving offspring than individuals that don’t have those traits
What is the result of variation in traits?
differences in fitness
What is sexual selection?
traits are selected even if they have no obvious survival advantage, can even be maladaptive
