In the Hershey/Chase experiment phage proteins and DNA were radioactively labeled and allowed to inject coding material into bacteria. It was found that only radioactively labeled DNA was present in the bacterial cells which had been transformed. If radioactively labeled protein had been discovered in the transformed cells, what would this have told us about the molecules acting in genetics

A virus is made of two main components. A proteic capsid and genetic material. The Hershey/Chase experiment demonstrated that the virus introduces it's genetic material(DNA) inside the host cell to force it to make more viruses. This proved that genetic information is stored in DNA. If the marked proteins were found in the host cell that would have meant that proteins carry genetic information which they don't.

not only is it colder, it also becomes darker, less salty, and more dense.

the fossil record provides evidence of a common ancestor to many species.