What is the evidence of variation when individuals in a population or group differ in some trait of interest

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

Paint and solvents pose no potential hazard to human health. select the best answer from the choices provided t f