1. declined due to habitat loss, poaching, road kills
Florida panther:
declined due to habitat loss, poaching, road kills
evidence of inbreeding:
low fertility, sperm abnormalities, cowlicks, kinked tails,
cardiac defects, undescended testicles, high disease rate
1989 PVA – high probability of extinction in short time

2. Genetic studies indicated low variability:
Florida panther:
Genetic studies indicated low variability:
P H DNA H
Florida
Western US
Other felids
Found to have hybridized with S. American sub-
species; introgressed animals with higher P
1989 PVA – high probability of extinction in short time

3. Outbred with sub-species from Texas - added 8 females in 1995
Florida panther:
Outbred with sub-species from Texas - added 8 females in 1995
F1 hybrid kittens do not have cowlinks or kinked tails
Texas genes are now 15-29% of total
1989 PVA – high probability of extinction in short time

4. Variation: Variation is present within individuals
among individuals within populations
among populations

5. metapopulations - regular extinction and recolonization events
- networks of populations that have some degree of gene flow among geographically separate populations
- regular extinction and recolonization events

6. Populations that are spatially isolated will tend to diverge genetically
each population is representative of the species, but may not contain all of the species’ variation
many populations may disappear before the species is endangered

7. Metapopulations
endangered Glanville fritillary butterfly (Finland) – occupies meadows
1600 meadows, of which were occupied in
approx 200 extinctions and 114 colonizations per year
Alan Barnes

8. Populations that are spatially isolated will tend to diverge genetically
how many subpopulations can we afford to lose?
which ones do we choose to save? how many?
how many do we have habitat for?
how different is different enough to warrant isolation/preservation?

9. Populations that are spatially isolated will tend to diverge genetically
how many subpopulations can we afford to lose?
which ones do we choose to save? how many?
how many do we have habitat for?
how different is different enough to warrant isolation/preservation?
how well can we describe differences among populations?

10. Measurement of genetic differentiation among populations: genetic distance (D)
Quantitative measure of genetic divergence between two sequences, individuals, or taxa
Relative estimate of the time that has passed since two populations existed as a single, panmictic population

11. Three most commonly used distance measures
Nei’s genetic distance (Nei, 1972)
Cavalli-Sforza chord measure (Cavalli-Sforza and Edwards, 1967)
Reynolds, Weir, and Cockerham’s genetic distance (1983)
Nei’s assumes that differences arise due to mutation and genetic drift, C-S and RWC assume genetic drift only

12. Genetic distance
Nei’s genetic distance surveyed over wide variety of taxa:
geographic populations
subspecies
species
genera
Avise and Smith 1977, Davis 1983

13. Dendrogram of genetic distances:
(clustered using UPGMA, Unweighted Pair-Group Method with Arithmetic Mean:
each new unit has a distance to the cluster = average of the distance from unit to each
species in the cluster)
Genetic distance (D)

14. Lampsilis cardium
(pocketbook mussel)
Lampsilis ovata
(pocketbook mussel)

15. Nei’s genetic distance
Lampsilis cardium
(pocketbook mussel)
WV L. ovata
IL L. cardium
WV L. cardium
VT L. “ovata”
MO L. cardium
WV L. fasciola
Nei’s genetic distance
Lampsilis ovata
(pocketbook mussel)

16. Tuatara – New Zealand
Of three remaining populations considered to be same species, one was different species – nearly neglected as simply third popn.

17. dusky seaside sparrow Habitat loss (mosquito control)
Spraying for mosquitoes added pesticides to food web
Reserve established; highway constructed through it
(to connect Kennedy Space Center w. Disney World)
Marsh drained
Last 7 males cross-bred with related sub-species –
unsuccessful
Last sparrow died in 1987
Melanistic subspecies, extinct in 1987; posthumus genetic analysis revealed close relationship with Atlantic coast seaside sparrows, but large distance between At. and Gulf coast popns. – conservation emphasis in wrong place
dusky seaside
sparrow

19. Genetic distance (D)

20. Genetic distance (D)

21. Issues with genetic diversity among populations
outbreeding depression/hybridization
local adaptation
example: ibex extirpated from Czechoslovakia (Capra ibex ibex)
- transplanted from Austria successfully (Capra ibex ibex)
- then added bezoars (C. i. aegagrus) and Nubian ibex (C. i. nubiana)
- fertile hybrids rutted in early fall instead of winter (as natives did)
- kids of hybrids born in February, coldest
month of year, entire population
went extinct
David Hall

22. Issues with genetic diversity among populations
outbreeding depression/hybridization
local adaptation
co-adapted gene complexes

23. inbreeding
depression
outbreeding
depression
Reproductive success
inbreeding random mating inter-breeding

24. Loss of fitness due to - Inbreeding:
accumulation of homozygous recessives
loss of superior heterozygotes
Outbreeding:
reduced fitness of F1 generation
- disruption of local adaptation
- epistatic interactions
reduced fitness of F2 generation
- breakup of co-adapted gene complexes
More empirical studies on inbreeding than outbreeding….
Two hypotheses for effects of both inbreeding and outbreeding
not just an academic argument – if second, then not possible to improve fitness with inbred lines and purging of deleterious alleles

25. Populations that are spatially isolated will tend to diverge genetically
q = .2
p = .5
q = .5
p = .7
q = .3
p = .55
q = .45
p = .5
q = .5

26. Genetic diversity among populations
Increases due to isolation, followed by
genetic drift
inbreeding
selection
local adaptation
Decreases due to gene flow (migration)
as migrants move between populations, they homogenize
allele frequencies among populations

27. Genetic diversity among populations
Increases due to isolation, followed by
genetic drift
inbreeding
selection
local adaptation
Decreases due to gene flow (migration)
as migrants move between populations, they homogenize
allele frequencies among populations
larger populations diverge slowly through drift
– few migrants needed to counteract
small populations diverge rapidly through drift
– more migrants needed to counteract

28. Changes in genetic diversity among populations
m = proportion of population that migrates
Nm = number of migrants randomly exchanged per generation
Ne = 1,000, m = 0.01, Nm = 10
Ne = , m = 0.01, Nm = 1
approx 1 migrant/generation will maintain same alleles among populations (= qualitative similarity)
but 10 migrants per generation may still permit significant differences in allelic frequencies ( = quantitative dissimilarity)

29. Changes in genetic diversity among populations
m = proportion of population that migrates
Nm = number of migrants randomly exchanged per generation
Ne = 1,000, m = 0.01, Nm = 10
Ne = , m = 0.01, Nm = 1
“in the absence of natural selection, the amount of genetic divergence among demes is a function of the absolute number of migrants exchanged (Nm), not the proportion of exchange (m)” (Allendorf 1983)

30. Isolation by distance p = 0.65 q = 0.35 p = 0.75 p = 0.55 q = 0.25

31. Isolation by distance

32. Isolation by distance
Mussel ‘lures’ with glochidia

33. Genetic distance between populations
Elliptio dilatata