1.Why do some traits, such as thicker fur or flowers of different colors, evolve over time within a population of organisms?

Of seawater increases with decrease in the temperature. therefore, the cold water sinks to the deeper layers at the bottom

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels

Which would be the most useful source of evidence to support mcneill's contention?