Which theory would best explain people spreading quickly throughout the Americas? Why?

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. the production of sterile male ligers is an example of 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. the production of sterile male ligers is an example of a postzygotic barrier the founder effect sympatric speciation a prezygotic barrier

In 2016, two-year-old lane graves was wading in the lagoon of an orlando walt disney world resort and watching a family outdoor movie, when an alligator snatched the boy and disappeared. the resort had signs which read "no swimming, deep drop off" posted along the beach area where lane was taken, and his parents were a few feet away when the incident occurred. several hours later, lane's body was discovered about 15 yards from where he was taken by the gator. a disney employee said this was not the first time an alligator had been spotted in the lagoon beach area. if the graves family files a lawsuit against the resort, what theory would best support their claim?

Why are the majority of the world's economies mixed? what may happen to the "pure" types of economies (traditional, socialist/command, market capitalist) when they incorporate elements from other economic models?