| 1950 |
First successful freezing of bull semen at -79°C for later insemination
of cows. |
| 1952 |
First animal cloning: Robert Briggs and Thomas King create frogs from
tadpole cells. |
| 1953 |
British scientists James Watson and Francis Crick discover the "double
helix" structure of DNA and are awarded the Nobel Prize in Physiology in
1962. |
| 1962 |
John Gurdon clones frogs, this time using cells from older tadpoles. |
| 1978 |
The birth of baby Louise, the first child conceived through invitro
fertilization. Midwives are Patrick Steptoe and R.G. Edwards of England. |
| 1978 |
David Rorvik's book, In His Image alleges a human cloning. |
| 1983 |
First human mother-to-mother embryo transfer. |
| 1985 |
Ralph Brinster's lab creates the first transgenic livestock; pigs that
produce human growth hormone. |
| 1986 |
Artificially inseminated, surrogate mother Mary Beth Whitehead carries
Baby M to full term, then tries to keep her. She fails. |
| 1993 |
Human embryos cloned. |
| 1997 |
First adult mammal cloned: a sheep, by British scientists. |