This preview shows page 1. Sign up to view the full content.
Unformatted text preview: area without the other species (allopatry).
Geospiza fortis in sympatry SPECIES L W Green heron Cattle egret Snowy egret Black crowned night heron Great egret Great Blue Heron 18 20 24 25 39 46 26 36 41 44 51 72 Geospiza fuliginosa Character displacement in beak size of populations of Galapagos finches The "ghost of competition past"... The following minimum criteria must be met for character displacement to have occurred: 1. 2. 3. 4. 5. 6. Morphological differences between a pair of sympatric species are greater than the difference between allopatric populations of the same species These morphological differences have a genetic basis Variation in the character has a measurable effect on resource use There must be competition for the resource in question and competition must be directly correlated with the character Differences in the character cannot be explained by differences in the resources available to sympatric vs. allopatric populations (habitat differences). Differences must have evolved in place and not be the r...
View Full Document
This note was uploaded on 10/08/2009 for the course BIS 2 taught by Professor Schwartzandkeen during the Spring '09 term at UC Davis.
- Spring '09