Why do animals that live on earth fertilize eggs differently than those that live in water?

The animals living on land warms the egg to produce its baby where as the animals living on water doesn't makes it warm and most of them leaves the egg all alone. The egg which animals on land give are dry where as animals living in waters egg is unique than the animals which produce on land

the peripheral nervous system or pns contains the nerves, which leave the brain and the spinal cord and travel to certain areas of the body. the peripheral nervous system's main job is to send information gathered by the body's sensory receptors to the cns as quickly as possible.

an adaptation is a change or process by which an organism takes to be better suited for its environment. for example; migration is a behavioral adaptation, this is needed because birds are not built to last extremely cold climates. there are different adaptations because there are different species needing to adjust to different things, bears don't migrate; they hibernate.