Some species of finches have more robust beaks in order
to crush seeds available in their environment. Recent data show
that their BMP4 expression in the developing beak is
initiated sooner than other species, resulting in more tissue
growth during embryogenesis.
First, indicate whether this is an example of heterotopy,
heterochrony, heterometry, or heterotypy, defining your chosen
term. Second, describe how you might use the chicken embryo as a
model system to test the hypothesis that this earlier timing of...