The law of original horizontality explains:

The Law of Original Horizontality is a basic law in geology that was first propounded in the mid-17th century by the Danish scientist Nicholas Steno. The Law of Original Horizontality explains that sedimentary rocks were initially deposited horizontally, or nearly horizontally under the influence of gravity, and that great external forces (such as the movement and collisions of tectonic plates) is responsible for rock layers that are folded and tilted. This law provided more understanding of plate tectonics.

no i don't feel that humans have oversubscribed some medications

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.