4 Animal Breeding Flashcards
Nature vs. nurture
Nurture: nutrition, rearing, handling, training, disease, social interactions
Nature: genetics; inherent in the animals
Factors that domestication affects (5)
1) Shelter
2) Space
3) Food/drink
4) Social
5) Predation
What are random and directional changes (for domestic phenotype)
Random: inbreeding and genetic drift (random fluctuation in the frequencies of genetic variation over time)
Directional: artificial selection, natural selection in captivity, relaxation of natural selection in captivity
Domestication vs tameness
Taming is something you do to an individual animal. It is a matter of learning. Domestication, on the other hand, happens to a whole species or a population of wild animals.
Can tame a wolf but doesn’t make it domesticated
Types of traits influenced by genes (2)
1) Single gene traits (either on/off)
2) Polygenic
Single gene traits
little or no environmental influence
- haemophillia in cats (blood disorder)
- coat color
Polygenic traits
GeneticxEnvironment interactions
-behaviour, growth, hip dysplasia (eg if overexercise/overfeed)
Mutations (4)
- rare but spontaneous
- can be favorable/unfavorable
- can be dependant upon location (albino)
- wellfare problems
Acceptation of mutations and (deleterious) harmful phenotypes
These phenotypes wont allow animals to survive in the wild
By keeping them as pets, we allow them to pass it to the next generation, unlike in the wild where they wouldnt make it to the next step
Punnet Squares
Useful way of predicting breeding outcomes using known genotypes
1) mum across, dad down
2) take all combinations of the genes eg if BbEe, need 4 columns (BE, Be, be, bE)
Heterozygote vs homozygote
Hetero: mixed allele (Bb)
Homo: same allele (BB/bb)
Epistasis
The interaction of genes that are not alleles, in particular the suppression of the effect of one such gene by another.
eg labrador coat color (black, yellow or chocolate)
Lab coat color genes (summary)
B gene for black coat colour
E gene for extension of pigmentation
- color is fixed but pigmentation is varied
Lab coat color genes (full)
BLACK:black and extension dominant (BB,bb) + (EE,Ee)
CHOCOLATE: black recessive and extension dominant (bb)+(EE,Ee)
YELLOW: extension recessive (ee)
- regardless of the recessiveness/dominance of black gene!!
Determining the black gene in a yellow lab
Chocolate and black labs have noses the same color as their coat. Black gene for yellow labs is not expressed but it can be seen from their nose color (black=dominant, brown=recessive)
