Genetic diversity and adaptation Flashcards
What is genetic diversity?
The total number of different alleles in a population
Describe what factors influence genetic diversity
Mutations
Increased gene flow (when populations inbreed)
Explain how a difference in its DNA might lead to an organism having a different appearance and hence the species showing greater genetic diversity
Different DNA, different codes for amino acid, different protein shape, different protein function
Change in a feature determined by that protein
Altered appearance
Greater genetic diversity
What is directional selection?
Selection favouring individuals that vary in one direction from the mean of the population
Changes the characteristics of a population
What is stabilising selection?
Selection favouring average individuals
Preserves characteristics of a population
What is a population?
A group of individuals of the same species that live in the same place and are able to breed with one another
What is the niche of a species?
It’s role within the environment
What is natural selection?
The idea that better adapted species survive and pass on the advantageous genes to future generations
What is evolution?
The process by which the frequency of alleles in a gene pool changes over time as a result of natural selection
How does evolution via natural selection occur?
There’s a variety of different phenotypes within a population
An environmental change occurs and as a result of that the selection pressure changes
Some individuals possess advantageous alleles which give them a selective advantage and allow them to survive and reproduce
The advantageous alleles are passed on to their offspring
Over time, the frequency of alleles in a population changed and this leads to evolution
What are the three types of adaptations to an environment?
Anatomical, behavioural, physiological
What are anatomical adaptations?
Either internal or external physical adaptations
What are behavioural adaptations?
Changes in behaviour which improve the organisms chance of survival
What are physiological adaptations?
Processes inside an organisms body that increase its chance of survival
