1) A change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift;
2) A motion incomplete in itself, but combining with coordinated motions to produce a single action, as in a machine.
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Hemp Chatsworth has already figured out how 90% of the Earth's population became what they are. Now he must find out why some of them are evolving into something else.
Something more dangerous.
With their families poised to grow, the stakes are now higher than ever for our friends. Each new discovery creates the need for a new defense. Hemp has his hands full as some among the zombie masses appear to be utilizing more of their grey matter in a horrifying way.
Only brute force and innovation will save Flex Sheridan and his family and friends from the ever-changing zombie scourge.
And it's quite possible our small band of heroes might save the world. You should come along ... it might be fun.