Water Snakes in Lake Erie Water snakes (Nerodia sipedon) in Lake Erie come in two color phases: banded and unbanded This is a two allele system Banded.

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Presentation transcript:

Water Snakes in Lake Erie Water snakes (Nerodia sipedon) in Lake Erie come in two color phases: banded and unbanded This is a two allele system Banded dominant to unbanded The mainland has really only banded The islands may have both King & Lawson, 1995

Lake Erie water snakes It was found that, when basking on islands, the unbanded snakes are more cryptic and thus remain hidden better. Why wouldn’t selection cause the unbanded pattern to go to fixation? Migration. Every year, banded snakes migrate from the mainland and introduce fresh banded alleles Therefore, migration offsets selection

Genetic Drift

Founder Effect small founding populations have less allelic diversity Clegg, et al, 2002 Silvereye ( Zosterops lateralis )

Silvereye colonization Clegg, et al, 2002

Founder Effect on Allelic Diversity of the Silvereye

Alleles Randomly Fixed

Average Heterogosity Decreases

Alleles Randomly fixed in the field Collared Lizard (Crotaphytus collaris) Templeton, et al, 2002

Multilocus Genotyping of Collared Lizards in the Ozarks

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The Vertebrate Mitochondrial Genetic Code

Alcohol Dehydrogenase (ADH) Gene Alignment in Drosophilia

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