Evolutionary Ecology

Question 1

Evolutionary ecology

Answer 1

How do interactions between organisms and their biotic and abiotic environments affect the genetic composition of marine population

Question 2

Speciation

Answer 2

Formation of one or more species from an ancestral species
Occurs when populations become reproductively isolated
Different selection pressures drive natural selection and genetic difference.

Question 3

Allopatric speciation

Answer 3

When two or more populations become geographically isolated
Over time genetic and morphological differences accumulate, causing the formation of new species.

Question 4

Peripatric

Answer 4

When small groups of individuals break off from the rest of the geographic range of a species

Question 5

Parapatric

Answer 5

When populations do not become separated by a barrier, but by colonization of a new habitat
Individuals then only mate with those in the same habitat

Question 6

Sympatric

Answer 6

When there is no geographic or habitat barrier to gene flow between populations

Question 7

How to present evo relationships

Answer 7

Clade, group of organisms comprising all the descendants of the MRCA.
Built using morphological characters, genetic characters, characters shared are synamorphies.
Extinct species can also be added to a tree using morphological characters

Question 8

Phylogeography

Answer 8

Study of historical processes influencing the modern distribution of a species using molecular tools.
Phylogeography is also used to understand the process of genetic population divergence and speciation
Location where two or more clades come into contact is called a phylogeographic break.

Question 9

Comparative phylogeography

Answer 9

Low dispersers, juveniles have a poor dispersal range.
Largely affected by geographic barriers.
Terrestrial:
- reptiles, mammals, birds, cacti
marine:
- fish, isopods, copepods, molluscs

Question 10

Microevolution/plasticity

Answer 10

Microevolution is a genetic change within a population/species over time.
Phenotypic plasticity is when a single genome can produce more than one phenotype when exposed to different environments.

Question 11

Range expansion/contraction

Answer 11

Movements of glaciers, changes in climate.
Sea level change, fossil shells as data points.
Populations within recently expanded portion of species have less genetic diversity.
Habitat generalists have higher genetic connectivity.

Question 12

Life History

Answer 12

Age/stage specific patterns in the timing of events in an organsim’s life:
- Growth rate, reproductive maturity, growth, reproductive timing, sex ratio, life span

Question 13

Giant Pacific Octopus

Answer 13

Grow and mature fast
Lots of babies which defend themselves
V few survive
4 year life span
Reproduce once

Question 14

Killer whale

Answer 14

Grow and mature slowly
Protect them until fully grown
Old age

Question 15

Sheephead

Answer 15

All individuals start female
Reach maturity at ~4 years, sex change ~8 years.
Beneficial for male to be large, defends female groups

Question 16

Giant owl limpet

Answer 16

Starts male, matures ~2 years
Sex change when they have territory
No secondary sex characteristics

Question 17

Human impacts on life history

Answer 17

Species that grow slowly and have low reproductive output are more vulnerable
Generation times are longer
Low population sizes
Older/larger mother produce larger, higher quality eggs.

Question 18

Size selecting harvesting

Answer 18

Affects sequential hermaphrodites sex ratios
Once harvesting is stopped, then affected traits don’t return to previous levels
Affected traits go back to normal after harvesting is relaxed