Rewrite the second sentence in each pair, providing an effective transition and clarifying any cross-references.

Modern biologists have tried for decades to explore the relationship between ancient humans and Neanderthals, but analyzing DNA from prehistoric hominids has until recently proven very difficult.

The “clean room” at the Max Planck Institute in Germany is like those used in the manufacturing of computer chips or space telescopes, solving the issue by preventing contamination from dust particles so that biologists can extract and examine minute bits of DNA from 400,000-year-old hominid bones.