This is because all the individuals where so genetically similar none of them where fit to fight off the virus...

INBREEDING caused by a bottle neck event

cheetah on cheetah skin graphs where barely recognized by the host's immune system because the make up was so similare it was almost recognizable as self

(leukocyte antigen system HLA in humans)

region of the genome that is dense with genes that code for proteins involved in acquired immunity.

(major concern for zoos-reduced genetic diversity=more susceptible to infectious disease=cheetah)

adenine and guanine

(2 rings)

cytosine and thymine

(single rings)

mutations from purine to purine or pyrimidine to pyrimidine

(more common than transverions)

mutations from purine to pyrimidine or vice versa

(less likely to occure)

64 code for 20 amino acids

two-three fold degeneracy (code for the same)

synonymous mutations - silent

non-synonymous - not silent

carrying only one copy of each gene

(mitochondrial DNA/Y-chromosome/gametes)

trading of fragments of genetic material beween chromosomes before the egg and sperm cells are created, usually breaking and regioining of homologous chromosomes

recombination between genes increases with increasing physical separation (how far apart they are)

1% chance milion base pairs

locust single gene

O=absense of proteins

AB universal recipient

O universal donor

Allele frequencies remain constant in a population from generation to generation

ASSUMING

organisms are diploid, only sexual reproduction

generation are non overlapping, mating is random

size of population infinitely large, allele frequencies are equal in the sees, there is no geographic structures or migrations, no mutations, no selection

the study of how things deviate froom the Hardy-Weinberg model

(selection, mutation, migration, geographic subdivisions, allele frequency differences, small populations)

phenotypes determined by many genes (polygenic)

(body size, percentage of oil in maize)

often phenotypes distributed on a continuous scale

class examples

(boy hight at military school, horse coat color)

random changes in the frequency of alleles in a population due to random sampling

(opposite of selection)

effects small populations the most

in small populations can overcome the effects of selection (become fixed) thus no second gene to balance out or change a detramental characteristic

loss of diversity can lead to lack of resistance agianst infections

causes loss of alleles in small populations

not the same however in explaining inbreeding you can include genetic drift or you can exclude it

both reduce heterozygosity

heterozygote deficiency in inbreeding

loss of alleles in genetic drift

Florida panther = genetic drift and inbreeding lead to appearance of rare traits

kinked tails, cowlicks

detrimental traits:

atrial septal defects

cryptorchidism (testis doesnt drop)

genotype changes affect all loci in the genome

effects on genotpe frequencies might be easily reversible if outbreeding is possible

heterozygote deficiency

 ....

affects only genotype AA, Aa, aa, and not allele frequencies A same % and a same % as before

....

recessive GENOTYPES become more common

...

can affect mean fitness of population (inbreeding depression)

decline in fitness due to inbreeding

can lead to reduced resistance to disease

purging of deleterious alleles.

inbreeding decreases Aa and increases AA & aa so that aa individuals may be purged from the population

Asiatic lions-population trapped on island scenario (slow purge)

Speke's gazelle-4 founders to captive population  (fast purge)

captive population from 3 female and 1 male founder

fast purging of deletarious alleles

inbred gazelles with inbred parents had higher survival than inbred gazelles with non-inbred parents (first generation of inbreeding purged some deleterious alleles)

coefficient of relatedness: siblings 50% (had 2 parents)

grandchildren 25% (had 4 grandparents)

(two outbred individuals: what % alleles shared in common)

kinship coefficient

half of coefficient of relatedness

(probability alleles drawn at random between individuals are IBD

change sequence of DNA

rare

most dont affect fitness

new mutations bimodal (two peaks)

lower peak lethal, high peak neutral, small portion advantageous

15

7 million mice

mutation rate at 1/100,000 (coat color)

-probably brough in from wild not developing in captivity

worry because:

most populations already cary many pre-existing rare recessive deleterious mutations (genetic load/mutation load)

in small populations, inbreeding and genetic drift can increase the expression and frequencies, respectively, of deleterious alleles

low population sizes

as population decreases, mutants with larger detrimental effects become effectively neutral and fixed, lowering population fitness

P0=1/(2N)

new mutation present in 1 chromosome of a single individual

probability of fixation is also

1/(2N)

time to loss is short (low initial frequency close to 0)

time to fix is long (low initial frequency far from 1) average = 4N generations

not a separate taxon: just Bengal tigers with 2 copies of recessive mutation (selected for by humans)

very inbred

also have kidney problems and skeletal deformities

vision imparment

process by which favorable heritable traits become more common in successive generations of a population

acts upon phenotypic variation

selection for or against a particular detrimental penotype an allele

(glued in Drosophila melanogaster is a homozygote lethal mutation with a phenotype resulting in death)

at high frequencies decline quickly but at low frequencies they persist

detrimental recessive alleles are shielded from selection in the heterozygous state but not in the heterozygous state under full or partial dominance.

maintains multipple alleles (rather than directional)

heterozygote advantage (overdominance)

favors genetic diversity

immune system genes (MHC) tend to favor heterozygote advantage (also toll-like receptor genes TLRs-innate immunity)

populations that are genetically unique or different enough from other populations that they deserve to receive protection as a separate unit for conservation (florida panther)

similar to subspecies but not the same:

nuclear genetic markers support genetic distinctiveness of morphologically identified subspecies

the Malay tiger is distinct other Southeast Asian tigers as recongnized by genetic identification

active or passive movement of organisms from an ancestral origin to a new geographic area

Tigers of China and Southeast Asia follow Silk Road to expand range to India, Northeast and Central Asia (mitocondrial DNA)

the separation of a previously continuous organismal range by past geologicla or environmental events

ice age end = Sunda Islands isolated from Asian mainland = Sumatra tiger becomes genetically/morphologically distinct

when two populations are compared, what proportion of the genetic variablility is accounted for by genetic differences between two populations

0-1 scale

.05 low .2 high

1 conserve separate

0 can interbreed

migration from a large population to a small one, effectively in one direction only

(example: red wolves-becoming more and more coyote like, coyote alleles diluting the redwolf genome)

gene flow occurs in all directions

allele frequencies change over time in all subpopulations toward a common frequency (shows in human migration)

is the short-term basis for adaptive variation and must be maintained to allow the species to adapt in the future

commonly thought of as allelic diversity or heterozygoosity

can be measured by analyzing various genetic markers

generally smaller than census size (N)

idealized theroretical population with males and female numbers are the same and all individuals have equal mating oportunity

genetic diversity is lost at a rate of 1/2N_e

need to maximize number of breeding individuals, equilize sex ration of breeders, and rotate breeding animals among many animals (reproduce same amount)

calculate kinship among individuals and inbreeding coefficients gives us genome-wide estimated or average levels of diversity in individuals relaive to the source or founder population

look at the family tree

analysis of allelic diversity and heteroxygosity provides and empirical or absolute measurement of diversity at given loci

genetic analysis

animal who has no known ancestores either in the wild or in captivity at the time in entering the zoo population and who has living descendants in the zoo population

black footed ferrets

founder genome equivalents

takes into account the number of founders, the contribution of each, and the retention value for each founder (#offspring), esentially a summary of the number of idealized founder genomes still present in the present population

example of high F_g Pan Pan

gene diversity retained

GD_t =Ht/H0

expected heterozygosity in population/ expected heterozygosity in original source population

gene diversity 90% ideal

under 80% is bad

(golden lion tamarine-very good 96%)

of an individual is the average of thekinship coefficients between two an individual and all living individuals in the population

Kinship K has same value as inbreeding coefficient f

3 genetic considerations

mean kinship of individual (want low)

difference in their mean kinship (want low)

kinship to eachother (want low)

mean kinship values should be similar between mates to avoid mixing rare and common alleles

mananging new founders to increase founder geneome equivalents F_g

founder should not be paired with over represented lineages (avoid rare and common allele pairing)

may be necessary to breed to known successful breeder to ensure succession of novel alleles

dispositon of surplus animals could resutl in reentering into population (disclose breeding status)