A superlative science fiction author with a penchant for sweeping, all-encompassing plotlines and a talent for writing sympathetic, human characters.
Most at home with the biological sciences, but he's also well versed in astronomy and physics. His books cover more intellectual ground than your average university philosophy text, but still manage to be spellbinding. His writing is sometimes quite sensual.
His works include Queen of Angels, Slant and Moving Mars, which all occur in the same future world, and collectively span a period of time from the mid 21st century, straight through to the end of the 22nd century. Although the books' plots are largely unrelated, they share some characters and are similar in tone and in the ideas they present.
He also wrote Forge of God and Anvil of Stars, a two-book cycle about Earth's first (and last) encounter with intelligent aliens, and the aftermath.
His latest offering is Darwin's Radio, a biological thriller chock-full of hard sf to suit the pickiest microbiologist, with a truly epic ending. It is similar to Blood Music, one of his first novels.