Evo-devo 2 Flashcards
1
Q
Dog Evolution factors:
A
- reproductive separation and limited effective population sizes of established breeds provide extensive opportunity for divergence - genetic drift
- breeds are also under selection for a variety or morphological and behavioural traits - adaptive
- cranial variation with functional consequences, such as breathing
2
Q
Modularity
A
- identified as independence amoung groups of phenotypic traits
- can help organisms avoid trade-offs and likely alters the rate and direction of evolution-modularity may predispose dogs for rapid evolution of jaw length
3
Q
BMP
A
Bone morphogenetic protein
-have known role in craniofacial development
4
Q
Morpholinos
A
molecules we can design to block the activity of specific genes
5
Q
Zebrafish (danio rerio)
A
- model organism for genetic manipulation
- Injection of BMP3 morpholino at the one-cell stage
- Knocks down the function of BMP3 throughout development
6
Q
Loss or reduction of BMP3 function causes..
A
- shorter flatter face
- BMP3 is the reason why pugs, bulldogs, are brachycephalic
- also shows that the effect of BMP3 in a fish is similar to that in a dog - conserved toolkit gene
7
Q
Summary
A
- Divergence among dog breeds appears to be due to standing variation from their common grey wolf ancestors
- The main change in dog skulls involves lengthening and shortening of the jaws
- Modules in the skull may contribute to the evolution of these changes in jaw length by circumventing tradeoffs
- Jaw length in dogs seems fairly simple, being largely explained by five regions of the genome
- BMP3 looks to be especially important for determining jaw length (alleles are fixed between dolichocephalic and brachycephalic breeds, and it effects zebrafish jaw length)