evolution

Question 1

what are Synergistic effects

Answer 1

two or more things have a greater impact combined than the sum of the individual effects

Question 2

what 2 possible things can happen to a species in danger

Answer 2

evolve or go extinct

Question 3

what is genetic diversity

Answer 3

range of genetic variation in a pop

Question 4

what is a phenotype

Answer 4

the observed trait that is based on genetic makeup + env factors

Question 5

what is Heritability

Answer 5

the likelihood a particular trait will undergo directional evolution due to exploitation

Question 6

how does genetic differentiation change with exploitation

Answer 6

genetic diversity decreases with increasing exploitation

Question 7

what is Directional selection

Answer 7

a mode of natural selection - an extreme phenotype is favoured over others , causing the allele freq to shift overtime in the direction of that phenotype

Question 8

Obvious characteristic at risk of directional selection

Answer 8

body size, growth rates, age at sexual maturity, body shape

Question 9

what characteristics does fishing pressure push populations evolutionarily towards

Answer 9

smaller body size, earlier age at repro, higher rates of repro, away from aggregation

Question 10

characteristics that make Species more likely to evolve

Answer 10

Short generation
Large pop sizes
Faster rates of evolution
Large – behavioural changes

Question 11

3 myths of extinction

Answer 11

• myth of immense ranges - what appeared to be a single species was actually multiple distinct species with different genetics but superficially similar
• “millions of eggs” myth - high fecundity will protect from extinction - wrong
• not being a target of a fishery protects species from extinction - wrong

Question 12

Factors that will increase risk of extinction

Answer 12

Slow pop turnover
Low repro potential
Low capacity for recovery
Restricted geo range
Small pop size

Question 13

4 lists that highlight endangered / threatened species

Answer 13

• Endangered species act – ESA (US act) (endangered + threatened)
• Office of protected resources – NOAA
• IUCN – international union for the conservation of nature and natural resources – international (Red list
  + Number of categories - CR, EN, VU)
• CITES – convention on international trade in endangered species (international) (3 appendixes)

Question 14

what are the 3 appendixes in CITES lists

Answer 14

• Appendix 1 – most critically endangered – cannot be traded e.g. turtles, beaked whales
• Appendix 2 – not currently threatened but could be – can be traded with proper management plan e.g. giant clams, stony coral
• Appendix 3 – any country can list a species

Question 15

what 2 gropus do ESA categorize species into

Answer 15

Endangered = in danger of extinction throughout all or a significant part of its range
Threatened = likely to become endangered in the foreseeable future

Question 16

how many Species are listed with an endangered or threatened status

Answer 16

2,270 species listed

Question 17

what are some species listed as endangered or threatened

Answer 17

14 whales
5 dolphins
7 seals
6sp sea turtles
9 sturgeon
10 sharks
1 sp of seahorse
5 salmon

Question 18

what are the 3 types of extinction

Answer 18

• Ecological extinction = pop reduced to such low numbers that species can no longer carry out its role in its native ecosystem
• Economical extinction = pop reduced to such low level that species is not profitable to capture
• Biological extinction = no specimens left

Question 19

why is extinction bad

Answer 19

• less biodiversity
• everything in an ecosystem is interconnected (trophic cascades, habitats, open niche for invasives etc)