the fossil in the picture is a trilobite that lived about 500 MYA. So, the age of the rock in the picture is

Deer cave cannot support photosynthesis is as not enough sunlight is present. in spite of this, it still has a complex food chain. what is the energy foundation of this food chain?

Scientists discover two populations of mice on either side of a major river. the two populations have almost identical genes but the mice from one side cannot breed with mice from the other. this is most likely because

Nkentucky, intoxicating beverages (beer, whiskey, wine, etc.) are involved to some extent in approximately % of collisions fatal to pedestrians.