Which is most likely an example of a vestigial structure?

Which of the following is not a benefit of green revolution? a) new crop varieties b) increased crop yields c) cost effective d) new crops may require larger amonts of water than the previous ones.

Read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. applying the biological species concept, the sterility of ligers reveals that a. lions are probably a subspecies of tigers b. tigers and lions are the same species c. a new species called "ligers" is forming d. tigers and lions are separate species

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?