These finches have merely adjusted built-in genetic settings. They have not created anything new.
The differences in finch beaks is due to the timing and amount of BMP4 (a bone morphogenetic protein) during embryonic development and to the protein calmodulin. 1 This modification of genetic “switches and knobs” is hardly the type of evolution required to turn molecules into man, or one type of animal into another. For changes like this, we would need brand new knobs, switches, and features that were not there before.
Site Under Construction
This site is still under construction. It needs more references, citations, and debate arguments. If you would like to help, please view the community page.
Cotner, S., & Moore, R. (2011). Arguing for Evolution: An Encyclopedia for Understanding Science. Santa Barbara, Calif.: Greenwood.
- Cotner and Moore, 2011, p. 132: ” … another bone morphogenetic protein–BMP4–explains much of the variation in beak sizes that characterizes these finches. BMP4 is a key signaling molecule that activates other genes, which in turn regulate bone mineralization. Finches with larger, ticker beaks show earlier and more pronounced BMP4 activity during embryonic development. Adding BMP4 to developing chick tissues results in birds with ticker and wider beaks, and blocking BMP4 with an antagonizing protein produces chicks with smaller beaks. Another protein, calmodulin (or calcium-modulated protein, CaM), is a calcium-binding regulatory protein that plays a role in beak variability. Specifically, higher levels of CaM are associated with the longer beaks of the cactus finches. Apparently, fundamental differences between these species is not due to any dramatic genetic alterations, but rather is the result of small changes in the timing and extent of expression of these two proteins.” ↩