The Developmental Biology behind Darwin’s Finch Beak Adaptations
Abzhanov, A, Protas, M, Grant, BR, Grant, PR, Tabin, CJ. 2004. Bmp4 and morphological variation of beaks in Darwin’s finches. Science. 305:1462-1465.
Question 01 Movie
Briefly tell us a bit about yourself, your career path over the years, and specifically what led you to begin working in the field of evo-devo and ultimately on beak formation.
Question 02 Movie
How do you explain the fact that Bmp4 expression remains constant in the lower beak despite the differences in shape?
Question 3 Movie
Why might upper and lower beaks differ in their response to Bmp4? Is this seen in other organisms?
Question 4 Movie
Have you learned anything about what regulates BMP4 expression in the beak? Do you think the evolution of beak size in Darwin’s finches occurred due to direct changes to the Bmp4 gene or to the regulators of Bmp4?
Question 5 Movie
Please explain how BMP4 is operating differently in the ectoderm and in the mesenchyme. Specifically, how can more BMP4 in the ectoderm cause a reduction in the beak, while overexpression of BMP4 in the mesenchyme causes beak expansion?
Question 6 Movie
The paper mentions the fact that the researchers “have not ruled out the possibility that genes expressed in other regions of the face are important for directing morphogenesis.” Has any further work been done concerning this subject, and if so, have any genes been found?
Question 7 Movie
If there were no differences in FGF8 and Shh expression in the beaks of Darwin’s finches, then how could these factors differentially control BMP4 levels leading to a variety of beak morphologies among species?
Question 8 Movie
Besides the value of scientific inquiry, what significance do your findings have toward a better understanding the evolution of different morphologies?
Question 9 Movie
In your opinion what are some of the most pressing questions trying to be addressed by the field of Evo-Devo? In what way is your lab trying approach answers to these questions?