The thick mass of grass roots that hold prairie soil in place is called

What came first egg or chicken? and is tomato a vegetable or a fruit?

What two fields of study provide the core information that is used to classify organisms?

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