Presentation on theme: "The evolution of beak size and shape in Darwin’s Finches The role of Developmental Genes and Environmental Conditions Lindsey Williams Elisabet Minter."— Presentation transcript:
The evolution of beak size and shape in Darwin’s Finches The role of Developmental Genes and Environmental Conditions Lindsey Williams Elisabet Minter Corita Fields
Smithsonian: Osteology Hall
Examples of Beak Morphology Smithsonian: Osteology Hall
Beak Morphology Beak length, width, and depth – Environmental Parental Diet Food Availability – Developmental Genes BMP4 and Calmodulin
Parental Diet Food Availability – Small beaked finches prefer small seeds – Large beaked finches prefer large seeds but have the ability to consume small seeds Environmental Influence
During drought of 1977 – soft seeds less abundant – Tribulus seeds more abundant Large, difficult to open Larger beaked finches were more fit than their smaller beaked counterparts Larger beaks survived due to their ability to open Tribulus seeds easier.
Genetic Influence Bone morphogenic protein 4 (BMP4) Calmodulin (CaM)
BMP4 Expression Examined BMP4 Expression in distal beak mesenchyme of finches Figure. A. Beak morphologies. B. Stage 26 BMP4 expression C. Stage 29 BMP4 expression
Result – Enhanced cell proliferation – larger beaks due to significant increases in width, and depth Conclusion – Darwin’s finches exhibit different beak morphologies in part due to the expression of BMP4 BMP4 Expression
Calmodulin Expression Embryonic Stage – Injected CaM via a RCAS virus into embryo at stage 24 – Collected specimens at day 10 Result and Conclusion Figure. A shows the wild type specimen without additional presence of calmodulin. B shows the RCAS:CaM infected specimen.
Calmodulin Expression Examined expression and calmodulin in the skull of embryonic finches Conclusion Figure. A. and B. Morphologies from a monophyletic group. C. Skeletal morphological differences. D. CaM expression in distal – ventral domain in the mesenchyme of the upper beak.
BMP4 and CaM Expression
Conclusion and Further Research Beak morphology is influenced by both developmental genes and environmental factors, not just one Expression of CaM and BMP4 in other anatomical structures in both birds and mammals What protein is expressed that increases beak length once CaM is expressed?
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