In the European roe deer implantation of embryos after breeding is delayed. The deer breed in July or August but do not give birth until the following May or June. From summer to late December, the embryo rests in a state of dormancy as a 30-cell blastocyst. In late December or early January, the embryo sends a signal that causes the female to release hormones, allowing the embryo to continue to develop normally. Why is delayed implantation an advantageous adaptation for the European roe deer?

How do temperature and salinity affect deepwater currents? they create changes in wind direction, moving denser water in the same direction as the wind and causing the deepwater circulation patterns found in the ocean. as temperatures and salinity levels of water increase, the water rises to the surface where it creates currents as it moves to colder regions. they create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them. they equalize the forces on undersea currents caused by the coriolis effect as they replace more dense water with less dense water.