BIO220 Lecture 15

Question 1

Summarize what Wilson said about biodiversity

Answer 1

loss of biodiversity:

• irreversible
• least predictable consequences
• earth is largely unstudied & unappricated

Question 2

define: biodiversity

Answer 2

number & kinds of living organisms in a given area

Question 3

interspecific variation is also known as…

Answer 3

species diversity

Question 4

intraspecies variation is also known as…

Answer 4

genetic diversity

Question 5

interspecies variation is studied by…

Answer 5

ecologists

Question 6

intraspecies variation is studied by…

Answer 6

evolutionary geneticists

Question 7

3 levels of genetic diversity

Answer 7

1. within individuals (heterozygosity)
2. between individuals of the same population
3. between individuals of the same species

Question 8

CONSERVATION GENETICS

Answer 8

applying genetic methods to conservation, restoration, and endangered species management

Question 9

What happens genetically to declining populations?

Answer 9

• genetic drift
• inbreeding
• allee affects
• demographic stochasticity

= loss of genetic variation

Question 10

Allee effect

Answer 10

positive correlation between population size or density and the mean individual fitness
- reproduction rate depends on pop’n density

Question 11

demographic stochasticity

Answer 11

random differences among individuals in survivorship and reproduction -> variable pop’n growth rate

“random bad events”

Question 12

does demographic stochasticity happen if individuals have the same average survival reproduction?

Answer 12

Yes

• doesn’t have to do with phenotype
• RANDOM

Question 13

demographic stochasticity is most important in ___ populations

Answer 13

small

Question 14

What matters more for small populations: genetics or demographics?

Answer 14

• Genetics: population decline => decreased Ne => extinction
• Demography: demographic stochasticiy => extinction before effects of genetics can manifest

Both have effect

• inbreeding affect demographics
• demographic stochasticity exacerbate lower Ne

Question 15

what are the problem with cheetahs (genetically)?

Answer 15

very, very similar genetically

• MHC locus: can accept each other’s skin grafts
• low polymorphism
• low heterozygousity

Question 16

problem with captive cheetas

Answer 16

• low sperm counts

- high disease load

Question 17

How did genetic variation in cheetahs get so bad?

Answer 17

• historical bottleneck lowered Ne

- inbreeding when Ne was low lowered it even more

Question 18

In the wild, most cheetah deaths are due to…

Answer 18

cubs die because mom goes hunting (75%)

- deaths are not related to genetics

Question 19

Genetic diversity of wild cheetah

Answer 19

• MHC allele number: low compared to other mammals
• Nucleotide diversity: similar to other cats, high compared to dogs
• AA variation at MHC: similar to other cats

Question 20

how do we measure genetic diversity?

Answer 20

• allele number
• nucleotide diversity
• AA sequence diversity

Question 21

Florida panthers are a sub-species of…

Answer 21

mountain lion found in Florida

Question 22

Problem with Florida panthers

Answer 22

Inbreeding depression:

• low sperm count
• 1 testicle
• 90* bend in tail

Question 23

“Genetic rescue” of Florida panther goals

Answer 23

Translocation of 8 female pumas from Texas:

• increase genetic diversity
• improve population numbers
• reverse inbreeding depression

Question 24

“Genetic rescue” of Florida panthers results

Answer 24

• more genetic variation w/in individuals
• N increase (4x)
• Ne increase (2x)
• increased heterozygosity = increased survivalship

Question 25

WT vs. admixed panthers vs. backcross F1 panthers in terms of survival. Explain.

Answer 25

Backcross F1 has higher survival because higher heterozygousity. Admix was the first generation, so lower heterozygosity, but still higher than WT.

Question 26

What was done to rescue genetic diversity of Swedish adders? What effect did this have?

Answer 26

20 male adders introduced to the isolated population in Sweden - increase in population density & recruits (young -> adult) - more variation at MHC locus

Question 27

What happened to Prairie Chickens?

Answer 27

Fragmentation & elimination of prairie habitat caused pockets of very small populations -> low genetic diversity within each fragmented group - egg hatching & male population size declining

Question 28

What was done to rescue diversity of Prairie Chickens?

Answer 28

Translocation: put the isolated groups together | - more egg hatching & more males

Question 29

What happened to the wolves in Scandinavia?

Answer 29

Hunted to near extinction

Question 30

How was genetic diversity rescued in wolves?

Answer 30

Single immigrant wolf arrived: - increase population size - increase Ne

Question 31

Inbreeding coefficient

Answer 31

How inbred a species is - high = low genetic diversity - low = high genetic diversity

Question 32

Within ___ generations, the immigrant male wolf became related to every individual in the population

Answer 32

2.5

Question 33

What happened to the wolf population long-term?

Answer 33

inbreding coefficient is starting to go up again, because male wolf has fathered every unique pup possible. Future matings are all between siblings/half-siblings.

Question 34

Examples of human induced mortality

Answer 34

- hunting - fragmentation - road accidents

Question 35

introduction/translocation has ___-term benefits

Answer 35

short

Question 36

Are genetic rescues effective?

Answer 36

Yes, but only short-term

Question 37

Genetic rescue is a ____ strategy

Answer 37

time-buying

Question 38

How should we properly use genetic rescue strategies?

Answer 38

- Use it to temporarily increase population size and reduce likelihood of extinction - Use gained time to fix underlying problem - Eliminate/reduce factors that are causing endangerment

Question 39

What is needed for long-term genetic health of endangered species?

Answer 39

Eliminate/reduce factors that are causing endangerment