Extended response Flashcards
What is the theory of evolution
The theory of evolution is that all species come from a common ancestor and all species are distantly related. This has happened through genetic changes in a population cause by recombination, mutations, and selection pressures.
What are mutations
Mutations – Mutation is a random process in that the change can occur anywhere in a length of DNA. Some mutations can be a disadvantage, and others can be an advantage.
What is genetic drift
Genetic drift – Genetic drift produces random changes in allele frequencies in a population over time. This happens through purely random events like natural disaster or a group leaving a population. The genetic variation, or allele frequency, in these individuals differs from that in the original population, where some alleles are eliminated and some become very common.
What is natural selection
Natural selection - Natural selection is the process where individuals with traits best suited to their environment are more likely to survive and reproduce, passing those traits on to their offspring
What is sexual reproduction
The offspring gains unique combination of genes from their parents increasing genetic diversity in the gene pool
Describe how natural selection acts on a population
- It all starts with genetic variation this naturally exist through sexual reproduction, crossing over, mutations and gene flow.
- This genetic variation means that some individuals within the population have traits better suited to their environment.
- Individuals with favourable traits are more likely to survive and reproduce than others of their species and pass on those traits to the next generation.
- Over time, the individuals with the favourable traits become more numerous in the population. That is the process of evolution by natural selection
What is gene flow
Gene flow – The movement in genetic material the individuals carry from one population to another. However, gene flow can only occur between separate populations that are still part of the same species, because they must be able to reproduce
What is speciation
The process by which new species of living things develop from existing ones by evolution
What are the steps of speciation
- A population is split up (geographic isolation)
- The two isolated populations experience different selection pressures
- The individuals with the favorable traits become more common as we know in natural selection
- Over time the populations will accumulate enough genetic changes that they cannot interbreed and produce fertile offspring
