1990
		1990
		1991
		1992
	Richard J. Roberts, and Phillip A. Sharp share a Nobel Prize in Medicine for for their discoveries of split genes. Kary Mullis and Michael Smith share a Nobel Prize in Chemistry, with Mullis cited for his contributions to the developments of methods within DNA-based chemistry and Smith for his fundamental contributions to the establishment of oligonucleiotide-based, site-directed mutagenesis and its development for protein studies.	1993	William (Bill) Clinton becomes forty-second president of the United States.
		1994
	Edward B. Lewis, Christiane Nüsslein-Volhard, and Eric F. Wieschaus share a Nobel Prize in Medicine for for their discoveries concerning the genetic control of early embryonic development.	1995
		1996
		1997
		1998
		1999
		2000