Black-bellied seedcrackers are a species of bird found in central africa. they live in various habitats where individuals eat either hard, large seeds or small soft seeds. individuals with thick, shorter beaks can eat the harder seeds. individuals with thin, longer beaks can eat softer seeds. individuals with beaks of intermediate thickness and length cannot really eat either type of seed very well. if you measured beak width and length in populations of black-bellied seedcrackers, what type of selection would you expect to find?

the transfer of energy between two molecules spaced just nanometers apart plays a key role in many technologies, including photovoltaics, quantum information systems, lighting, and sensors, as well as in biophysics to measure nanometer distances and in photosynthesis. but an open question in this area is what effect, if any, the surrounding photonic environment has on this nanoscale energy transfer. by designing and performing a carefully controlled experiment to answer this question, scientists have settled the debate and found clues to improving the efficiency of many of the technologies that rely on this process.

explanation:

answer; i believe the correct answer to the above question is ( friction)