The game you're describing sounds like Millennium 2.2 (released as Deuteros in North America), a 1989 title where you colonize the solar system and genetically modify colonists for different planetary environments.
teaching you to fish: https://chatgpt.com/share/6855db77-b474-8012-863e-8cf8d6e415...
You even had to genetically engineer your colonists, so they could withstand the environments. Fun game, but I can't find it via Google.
If anyone knows this game, please share. I'd love to play it again.