Theory of Evolution by Natural Selection (IQ3)

What is the relationship between evolution and biodiversity?

Biodiversity

refers to the variety/variability of all forms of life on Earth. It exists on three levels: Genetic, Species and Ecosystem Diversity

Evolution

refers to the processes that have transformed life on Earth from its earliest forms to vast diversity

Microevolution

the small-scale variation of allele frequencies within the gene pool of a species (does not result in speciation)

What causes allele frequencies to change?

Gene flow, Genetic drift, Mutations, Selection Pressures

Macroevolution

large scale evolution due to multiple events of microevolution (does result in speciation)

Allopatric Speciation

involves the physical separation of populations, occurs when a species seperate in two and become isolated due to a physical barrier

Sympatric Speciation

involves a reproductive or behavioural separation, occurs when there are no physical barriers, become isolated by disassociating each other from mating

Divergent Evolution

organisms closely related developing different traits through natural selection (ie. Red-bellied blacksnakes in QLD have smaller jaws than those in NSW due to cane toad exposures)

Convergent Evolution

organisms not closely related developing similar traits in response to selection pressures (ie. Sharks and Dolphins have streamlined bodies and dorsal fins to help them swim well)

Adaptive Radiation

a type of of divergent evolution where one ancestral species rapidly evolved into multiple species

Sequential Evolution

is the gradual change in a species over time through the accumulation of small genetic variations, resulting in the development of a new form or species.

Gradualism

slow processes of evolutionary change, seeing transitional organisms between these changes (in generations)

Punctuated Equilibrium

Evolution occurs in short bursts of rapid change, followed by long periods of stability (no change at all)