February 27 – GRB 970228, a highly luminous flash of gamma rays, strikes the Earth for 80 seconds, providing early evidence that gamma-ray bursts occur well beyond the Milky Way.
February 22 – In Roslin, Scotland, scientists announce that an adult sheep named Dolly has been successfully cloned and was born in July 1996.[1]
March 4 – United States President Bill Clinton bars federal funding for any research on human cloning.
March 14 – The widely cited 1973 John/Joan study of gender reassignment of a twin boy who lost his penis to a botched circumcision is exposed as fraudulent. The supposedly successful outcome for "Joan" reported by John Money had been cited as proof that gender was determined by nurture, yet the patient (later revealed as David Reimer) was in fact deeply unhappy and had returned to his original gender by the age of 15, thus indicating the exact opposite thesis.[2]
July 10 – In London, scientists report their DNA analysis findings from a Neandertal skeleton which support the out of Africa theory of human evolution placing an "African Eve" at 100,000 to 200,000 years ago.
August – Suzanne Simard and colleagues publish their discovery of carbon transfer between trees.[4]
November 6 – The discovery of klotho, a gene involved in human aging, is reported.[5][6]
November 19 – In Des Moines, Iowa, Bobbi McCaughey gives birth to septuplets in the second known case where all seven babies are born alive, and the first in which all survive infancy.
February 7 – Steve Jobs returns to Apple Inc. as a consultant after the company purchases his software startup NeXT.
May 11 – IBM's Deep Blue defeats Garry Kasparov, the first time a computer defeats a chess grand master in a match. Deep Blue has defeated Kasparov before, but has never previously won a match against him.
^Harrington, J. J.; et al. (1997). "Formation of de novo centromeres and construction of first-generation human artificial microchromosomes". Nature Genetics. 15 (4): 345–55. doi:10.1038/ng0497-345. PMID9090378. S2CID9150827.