Evolution: Unit 4, Topic 2

Question 1

What is Evolution?

Answer 1

• The change in the genetic composition of a population during successive generations.
• may result in the development of new species.

Question 2

What are the 2 types of evolutions?

Answer 2

• Micro and Macro Evolution

Microevolution:
- small-scale variations of allele frequencies within a species or population
- descendants are of the same taxonomic group as the ancestor
- refers to any change ein the gene pool of a populations
- occurs at the species level
- Occurs due to mutation, selection, gene flow, and genetic drift.

Macroevolution:
- variation of allele frequencies at or above the level of species over geological time, resulting in the divergence of taxonomic groups.
- descendants it is a different taxonomic group to the ancestor
- almost identical to microevolution, but different in time scales
- changes occur between species and through a longer time.

Question 3

What is Evolutionary radiation?

Answer 3

• an increase in taxonomic diversity or morphological disparity
• increase in the diversity of clade
• The diversity of the clade is generally measured by taxonomic value.
• may be slow or rapid.
• usually follows after mass extinction.

Question 4

What is mass extinction?

Answer 4

• the rapid and widespread extinction of a large number (75%) of species, due to a catastrophic global event or rapid, widespread environmental change.
• when the phenotype, viability, or reproductive success of a species fails to change in response to environmental change, a species can die out.

Question 5

What is the evolutionary timescale?

Answer 5

• geological timescale subdivided into eon, eras, periods and epochs

Question 6

what are phylogenetic relationships?

Answer 6

• evolutionary relationship that exists between a group of species
• the closer the relationship between two organisms, the greater the similarities in their DNA.

Phylogenetic tree - shows evolutionary relationships and the point at which lineages diverged

Question 7

What are comparative Genomics?

Answer 7

• involves comparing the structure of living things and fossil evidence of extinct species to infer evolutionary relationships with a focus on DNA sequences.
• identifies similarities and differences in DNA from different sources.

Question 8

What is the theory of Evolution?

Answer 8

Organic life on Earth has changed over long periods of time and continues to change by the process of natural selection.

Question 9

What is the evidence for evolution?

Answer 9

homologous structures - evidence for common ancestry (divergence),
analogous structures - similar selective pressures can produce similar adaptations (convergent)

similarities and difference among biological molecules (DNA sequence) are used to determine species’ relatedness

biological patterns - how species are related to each other

the fossil record provides information about what species existed at particular times of Earth’s history.