Answer:During pregnancy, red blood cells from the unborn baby can cross into the mother's blood through the placenta. If the mother is Rh-negative, her immune system treats Rh-positive fetal cells as if they were a foreign substance. The mother's body makes antibodies against the fetal blood cells
Explanation:
By intruding mutations, which are the ultimate source of biological diversity. I think this is it.
Rainfall can cause erosion both when the rain hits the surface of the Earth, called splash erosion, and when raindrops accumulate and flow like small streams. Rivers can create a significant amount of erosion over time. They break up particles along the river bottom and carry them downstream. One example of river erosion is the Grand Canyon which was formed by the Colorado River. Ocean waves can cause the coastline to erode. The shear energy and force of the waves causes pieces of rock and coastline to break off changing the coastline over time. Large floods can cause erosion to happen very quickly acting like powerful rivers.
