How could something as complex as the human eye or the octopus eye have evolved by natural selection?

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

In two sentences explain the differences of neutrophil and macrophage

Which promotes sustainability? o a. using more landfills o b. finding new sources of coal o c. increasing consumption o d. encouraging recycling programs