Sahiwal

Tharparkar

Genotypic Frequencies of Indian Dairy Cattle

AA = 0.031AB = 0.276BB = 0.693

AA = 0.023AB = 0.733BB = 0.244

What are the allelic frequencies of each breed?

Allelic Frequencies of Indian Dairy Cattle

A = 0.17B = 0.83

A = 0.15B = 0.49

What are the expected genotypic frequencies of each breed?

Expected Genotypic Frequencies of Indian Dairy Cattle

ExpectedAA = 0.029AB = 0.282BB = 0.689

How do you interpret these results?

ExpectedAA = 0.023AB = 0.150BB = 0.244

ObservedAA = 0.031AB = 0.276BB = 0.693

ObservedAA = 0.023AB = 0.733BB = 0.244

Cavener & Clegg, 1981

Elena/Lenski experiment

• Science, 1996

-Elena , Cooper & Lenski, Science, 1996

14

Modes of SelectionModes of Selection

Mukai & Burdick, 1959

Kuru - a prion disease

Pr(normal)

Pc(misfolded)

Kuru - a prion diseaseObserved Genotypic Freq. in South Fore’

MM = 0.221MV = 0.514VV = 0.264

Obs. Genotypic Frq. in

South Fore’ Cannibals

MM = 0.133MV = 0.767VV = 0.1

• Hedrick, Science, 2003

Other overdominance examples

• Sickle cell anemia• Warfarin resistance in rats• Transferrin genotypes in pigeons• MHC class II

Modes of SelectionModes of Selection

Modes of SelectionModes of Selection

Campanula americana(Tall Bellflower)

• Galloway & Etterson, J. Evol. Biol. 2003

Diopsids - Stalk-eyed Flies (Cyrtodiopsis dalmanni)

•Wilkinson, Amitin & Johns Integr. Comp. Biol., 2005

Negative Frequency-dependent Selection

Frequency of yellow morph