In the 1600's the population was a steady 10,000. Then in the 1700's the population was still steady because of natural selection. Then through the 1800's to 1950 the population escalated then decreased again because of overpopulation along with variation of the dolphins and the adaption of the dolphins. Then natural selection took them out over time. I think in the next couple years that the dolphin population will rise to a great number again then slowly over time get smaller just because it looks like every couple century's the population goes drastically up then slowly goes down in numbers. The specific trait that will mostly likely increase will be the size of the dolphin.