What did darwin observe about finches in the gal�pagos islands?
a. their feathers were adapted to match their environment.
b. their beaks were adaptations related to the foods the finches ate.
c. they had homologous body structures with other flying vertebrates.
d. they were unrelated to mainland bird species.

Explain why in any given geographical region, women tend to have lighter skins( by 3-4% on average) than men?

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

When analyzing tree rings, what do scientists assume a thin ring indicates?