The most ecologically relevant environmental factor is:

Thermoregulation and osmoregulation can be achieved by all:
1. Amniotes
2. Birds and mammals
3. Vertebrates
4. Chordates and insects

When exposed to cold temperatures, which of the following is responsible for maintaining constant body temperature in humans?
1. Vasoconstriction and shivering
2. Vasodilation and shivering
3. Vasodilation and sweating
4. Vasoconstriction and sweating

Evolutionary biologists believe that “success” of mammals is largely due to their ability to:
1. Produce a large number of progeny
2. Live for a longer life span
3. Maintain a constant body temperature
4. Nurture young ones for longer periods