Stephen Hawking, the renowned physicist who died in March, warns of both rises in advanced artificial intelligence and genetically-enhanced "superhumans" in a book publishing Tuesday.

According to an excerpt of the book "Brief Answers to the Big Questions" published by the U.K.'s Sunday Times, Hawking wrote AI could prove "huge" to humanity so long as restrictions are in place to control how quickly it grows.

"While primitive forms of artificial intelligence developed so far have proved very useful, I fear the consequences of creating something that can match or surpass humans," Hawking wrote. "Humans, who are limited by slow biological evolution, couldn’t compete and would be superseded."

Hawking wrote about a need for serious research to explore what impact AI would have on humanity, from the workplace to the military, where he expressed concerns about sophisticated weapons systems "that can choose and eliminate their own targets."

Hawking also wrote about advances to manipulating DNA, or what he calls "self-designed evolution. Early advances involving the gene-editing tool CRISPR include alerting DNA to create "low-fat" pigs.

Hawking said initially gene-editing technology will be used to correct genes leading to diseases like cystic fibrosis, but people won't resist using the technology to make them stronger or smarter.

"Once such superhumans appear, there are going to be significant political problems with the unimproved humans, who won’t be able to compete," wrote Hawking. "Presumably, they will die out, or become unimportant. Instead, there will be a race of self-designing beings who are improving themselves at an ever-increasing rate."

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