What does Hypoventilation cause?

hypercapnia

Yes because hypoventilation causes decreased o2 in the lungs and a build up of co2. That contributes to hypoxemia which is too much co2 in your blood.

Yes . . . both conditions are manifested by too much C02 in the blood because there is not enough oxygen in the blood.

Proximate: What triggered the immediate response of an animal? Ultimate: how did it benefit the species?

The formation of numerous, closely spaced rills due to the uneven removal of surface soil by streamlets of running water. Also known as rilling; rill wash; rillwork.