Effects of genetic diversity Flashcards
There needs to be some level of genetic diversity within a population for natural selection to occur
Differences in the alleles possessed by individuals within a population result in differences in
phenotype
Environmental factors affect the chance of survival of an organism; they, therefore, act as a
selection pressure
Selection pressures
increase the chance of individuals with a specific phenotype surviving and reproducing over others
The individuals with the favoured phenotypes are described as having a higher fitness
The fitness of an organism is defined as its ability to survive and pass on its alleles to offspring
Organisms with higher fitness posses adaptations that make them better suited to their environment
A population with a large gene pool or high genetic diversity has a strong ability to
adapt to change
If a population has a small gene pool or very low genetic diversity then they are much less able to
adapt to changes in the environment and so can become vulnerable to extinction
example
Cheetahs are an example of a species with a small gene pool
They experienced a very large decline in numbers approximately 10,000 years ago
This left small, fragmented populations of individuals remaining
There was no mixing between populations and large amounts of inbreeding occurred
This is problematic for conservation as low genetic variation means the species are less likely to be able to respond (survive) in the event of any environmental changes