11.   Otherwise humans would be evolving into land octopuses.

12.   Scientists long assumed that humans evolved melanin, the main determinant of skin color, to absorb or disperse ultraviolet light.

13.   Similarly, we know that humans evolved as the great cooperators.

14.   The DNA analyses may help to choose between three rival theories of how modern humans evolved.

15.   The researchers say this supports the notion that humans evolved from a small group of ancestors, while other great apes are descended from much larger populations.

16.   They are gathering and preserving our disappearing plant and animal species for re-establishing on Earth at a time in the future when humans have evolved into better caretakers.

17.   They contend that humans evolved around the world in different regions about the same time, often living in isolation but not without occasional infusion of outside genes.

18.   When molecular biologists tackle the problem of how modern humans evolved, they do not go on fossil-hunting expeditions as paleoanthropologists do.

19.   Yet the poll also indicates that many people do not believe humans evolved from lower life forms.

20.   Over time, humans evolve new defenses or invent protections like antibiotics and vaccines.