I heard of Xenogenesis on the Galactic Suburbia podcast, and I'm very glad of it.

The work is incredibly original for its time. Taking biotech so far that it is indistinguishable from life. Dealing with biological changes that are required to enable space travel and colonization way back in the late 70s.

Butler manages to deal with the complexities of colonization without taking clear sides. Letting the reader draw his conclusions. The only ones that seem to suffer at her hands are Human males.

Really a wonderful trilogy I was unaware of, highly recommended.