Genetic Diversity Flashcards
What is genetic diversity?
The number of different alleles of genes in a species or population. Allows natural selection to occur because some characteristics are more advantageous than others
How is genetic diversity increased?
Mutations in the DNA- forming new alleles some can be advantageous, whilst others lead to problems
Gene flow- Different alleles being introduced into a population when individuals from another population migrate into it and reproduce
What is natural selection?
Individuals of a population that are best suited (best allele and phenotype) to their environment survive and reproduce more. Beneficial alleles passed on to next generation
What is evolution?
change in allele frequencies in a population over time
Explain the process of evolution
Variation of alleles exist in population
Result of mutations
Selection for individuals with beneficial allele
More likely to survive and reproduce (differential reproductive success)
Changes allele frequency
Over long period of time
What are the three types of adaptations?
Behavioural, physiological and anatomical
What is behavioural adaptations?
Ways an organism acts that increases its chance of survival
What are physiological adaptations?
Processes inside an organisms body that increase its chance of survival
What are anatomical adaptations?
Structural features of an organism’s body that increase its chance of survival.
What is directional selection?
Where individuals with alleles for characteristics of an extreme type are more likely to survive and reproduce. Could be in response to environmental change
What is stabilising selection?
Where individuals with alleles for characteristics towards the middle of the range are more likely to survive and reproduce. Occurs when the environment isn’t changing, reduces range of possible characteristics
