Cladogenesis
An evolutionary splitting event where a parent species splits into two distinct species to form a clade
Adaptive radiation
The burst of divergence from a single lineage to give rise to many new species from a single ancestor
Gradualism
Hypothesis that species evolve gradually by small changes over long periods of time
Punctuated equilibrium
Refers to the speed at which evolution takes place. It is not gradual
What were Darwin’s four observations
- More offspring are produced than are required
- Natural Variation
- A change in the environment leads to differential reproduction
- Characteristics were heritable
Natural selection
The process by which those best adapted to the environmental conditions are more likely to survive and will produce the most offspring
What causes genetic variation
- Germ-line point mutations
- Duplication of genes or swapping their positions
- Whole chromosomes may be deleted or duplicated; the entire set of chromosomes can multiply
- Sexual reproduction
Polyploidy
The doubling or trebling of the two basic sets of chromosomes
Gene flow
The movement of genes between populations. Happens through the migration of organisms or movement of gametes (pollen)
Genetic drift
A process that produces random changes in the frequency of characteristics in a population
Artificial selection
The process of selecting and breeding organisms with desirable characteristics to produce offspring with those characteristics that will be of some use to humans
Inbreeding
The mating of closely related individuals
Outbreeding
The mating of individuals not closely related
Gene pool
The total of all alleles of genes carried by all individuals in an interbreeding population
