Everything comes from the ground so soil or water
Keratin is responsible for skin color. The more the melanin in the skin, the darker the skin color of the person. Collagen and keratin makes up nails and hairs. Elastin is a connective tissue that connects the epidermis and the dermis. The dermal papillae nourishes the root hairs.
This is where species split off to form new species. It represents a common ancestor shared between those species.
Answer: common ancestor
It was used by Hubble to measure velocities of galaxies
Because radiation goes a long way. Radiation itself isn't visable but if it's from a nearby star you'll be able to see the star. Radiation keeps moving outwards forever. Things that can sense radiation that you can't see will help you have an idea how far away the source of that radiation is from
