The survival of a species depends on 1. An environment that never changes
2. A continuously increasing life span
3. Reproduction within populations
4. A limit of no more than populations

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures