The 100 Most Influential Scientists of All Time (42 page)

(b. Jan. 8, 1942, Oxford, Oxfordshire, Eng.)

E
nglish theoretical physicist Stephen William Hawking developed a theory of exploding black holes that drew upon both relativity theory and quantum mechanics. He also worked with space-time singularities.

Hawking studied mathematics and physics at University College, Oxford (B.A., 1962), and Trinity Hall, Cambridge (Ph.D., 1966). He was elected a research fellow at Gonville and Caius College at Cambridge. In the early 1960s Hawking contracted amyotrophic lateral sclerosis, an incurable degenerative neuromuscular disease. He continued to work despite the disease's progressively disabling effects.

Hawking worked primarily in the field of general relativity and particularly on the physics of black holes. In 1971 he suggested the formation, following the big bang, of numerous objects containing as much as 1,000,000,000 tons of mass but occupying only the space of a proton. These objects, called mini black holes, are unique in that their immense mass and gravity require that they be ruled by the laws of relativity, while their minute size requires that the laws of quantum mechanics apply to them also. In 1974 Hawking proposed that, in accordance with the predictions of quantum theory, black holes emit subatomic particles until they exhaust their energy and finally explode. Hawking's work greatly spurred efforts to theoretically delineate the properties of black holes, objects about which it was previously thought that nothing could be known. His work was also important because it showed these properties' relationship to the laws of classical thermodynamics and quantum mechanics.

Hawking's contributions to physics earned him many exceptional honours. In 1974 the Royal Society elected him one of its youngest fellows. He became professor of gravitational physics at Cambridge in 1977, and in 1979 he was appointed to Cambridge's Lucasian professorship of mathematics, a post once held by Isaac Newton. Hawking was made a Commander of the British Empire (CBE) in 1982 and a Companion of Honour in 1989. He received the Copley Medal from the Royal Society in 2006.

His publications include
The Large Scale Structure of Space-Time
(1973; coauthored with G.F.R. Ellis),
Superspace and Supergravity
(1981),
The Very Early Universe
(1983), and the best-sellers
A Brief History of Time: From the Big Bang to Black Holes
(1988),
The Universe in a Nutshell
(2001), and
A Briefer History of Time
(2005).

(b. Oct. 14, 1946, Salt Lake City, Utah, U.S.)

A
merican geneticist, biochemist, and businessman John Craig Venter pioneered new techniques in genetics and genomics research and headed the private-sector
enterprise, Celera Genomics, in the Human Genome Project (HGP).

Soon after Venter was born, his family moved to the San Francisco area, where swimming and surfing occupied his free time. After high school Venter joined the U.S. Naval Medical Corps and served in the Vietnam War. On returning to the U.S., he earned a B.A. in biochemistry (1972) and then a doctorate in physiology and pharmacology (1975) at the University of California, San Diego. In 1976 he joined the faculty of the State University of New York at Buffalo, where he was involved in neurochemistry research. In 1984 Venter moved to the National Institutes of Health (NIH), in Bethesda, Md., and began studying genes involved in signal transmission between neurons.

While at the NIH, Venter became frustrated with traditional methods of gene identification, which were slow and time-consuming. He developed an alternative technique using expressed sequence tags (ESTs), small segments of deoxyribonucleic acid (DNA) found in expressed genes that are used as “tags” to identify unknown genes in other organisms, cells, or tissues. Venter used ESTs to rapidly identify thousands of human genes. Although first received with skepticism, the approach later gained increased acceptance; in 1993 it was used to identify the gene responsible for a type of colon cancer. Venter's attempts to patent the gene fragments that he identified, however, created a furor among those in the scientific community who believed that such information belonged in the public domain.

Venter left the NIH in 1992 and, with the backing of the for-profit company Human Genome Sciences, in Gaithersburg, Md., established a research arm, The Institute for Genomic Research (TIGR). At the institute a team headed by American microbiologist Claire Fraser,
Venter's first wife, sequenced the genome of the microorganism
Mycoplasma genitalium
.

In 1995, in collaboration with American molecular geneticist Hamilton Smith of Johns Hopkins University, in Baltimore, Md., Venter determined the genomic sequence of
Haemophilus influenzae
, a bacterium that causes earaches and meningitis in humans. The achievement marked the first time that the complete sequence of a free-living organism had been deciphered, and it was accomplished in less than a year.

In 1998 Venter founded Celera Genomics and began sequencing the human genome. Celera relied on whole genome “shotgun” sequencing, a rapid sequencing technique that Venter had developed while at TIGR. The shotgun technique is used to decode small sections of DNA (about 2,000–10,000 base pairs [bp] in length) of an organism's genome. These sections are later assembled into a full-length genomic sequence. This is in contrast to older genome sequencing techniques, in which a physical map of an organism's genome is generated by ordering of segments of chromosomes before sequencing begins; sequencing then entails the analysis of long, 150,000 bp sections of DNA. Celera began decoding the human genome at a faster rate than the government-run HGP.

Venter's work was viewed at first with skepticism by the NIH-funded HGP group, led by geneticist Francis Collins; nevertheless, at a ceremony held in Washington, D.C., in 2000, Venter, Collins, and U.S. Pres. Bill Clinton gathered to announce the completion of a rough draft sequence of the human genome. The announcement emphasized that the sequence had been generated through a concerted effort between Venter's private company and Collins's public research consortium. The HGP was completed in 2003.

In addition to the human genome, Venter contributed to the sequencing of the genomes of the rat, mouse, and fruit fly. In 2006 he founded the J. Craig Venter Research Institute (JCVI), a not-for-profit genomics research support organization. In 2007, researchers funded in part by the JCVI successfully sequenced the genome of the mosquito
Aedes aegypti
, which transmits the infectious agent of yellow fever to humans.

(b. April 14, 1950, Staunton, Va., U.S.)

A
merican geneticist Francis Collins discovered genes causing genetic diseases and led the U.S. National Institutes of Health (NIH) public research consortium in the Human Genome Project (HGP).

Homeschooled by his mother for much of his childhood, Collins took an early interest in science. He received a B.S. from the University of Virginia (1970), went on to Yale University to earn an M.S. and a Ph.D. (1974), and earned an M.D. (1977) at the University of North Carolina at Chapel Hill. In 1984 Collins joined the staff of the University of Michigan at Ann Arbor as an assistant professor. His work at Michigan would earn him a reputation as one of the world's foremost genetics researchers. In 1989 he announced the discovery of the gene that causes cystic fibrosis. The following year a Collins-led team found the gene that causes neurofibromatosis, a genetic disorder that generates the growth of tumours. He also served as a leading researcher in a collaboration of six laboratories that in 1993 uncovered the gene that causes Huntington chorea, a neurological disease.

In 1993 Collins, by then a full professor, left Michigan to take the post as head of the National Human Genome Research Institute (NHGRI) of the NIH, which had
begun work on the HGP three years earlier with a stated goal of completing the sequencing project in 15 years at a cost of $3 billion by coordinating the work of a number of leading academic research centres around the country, in collaboration with the U.S. Department of Energy and the Wellcome Trust of London. Driven by a sincere interest in successful research that could help humanity, Collins was an obvious choice for the job, and he willingly took a sizable pay cut to participate in a historic project.

The necessity of a government effort was questioned when a rival operation, Celera Genomics, emerged in 1998 and appeared to be working even faster than the HGP at deciphering the human deoxyribonucleic acid (DNA) sequence. Headed by American geneticist and businessman J. Craig Venter, a former NIH scientist, Celera had devised its own, quicker method—though some scientists, Collins among them, questioned the accuracy of the work. However, in the end the public and private endeavours came together. On June 26, 2000, Collins, Venter, and U.S. Pres. Bill Clinton gathered in Washington, D.C., to announce that the rough draft sequence of the DNA in the human genetic map had been completed through the combined effort of Collins's public research consortium and Venter's private company.

The breakthrough was hailed as the first step toward helping doctors diagnose, treat, and even prevent thousands of illnesses caused by genetic disorders. In April 2003, following further analysis of the sequence, the HGP came to a close. The announcement of the completion of the HGP coincided with the 50th anniversary of American geneticist and biophysicist James D. Watson and British biophysicist Francis Crick's publication on the structure of DNA.

A practicing Christian, Collins freely expressed the awe he experienced as a leader in the uncloaking of one of
the mysteries of life. As concerns arose about the moral and ethical implications of the research he had conducted, Collins actively cautioned against misuse of genetic information. At congressional hearings in July 2000, Collins urged the passage of federal law to set guidelines on how individuals' genetic information could be handled. “The potential for mischief is quite great,” he said. On Aug. 1, 2008, Collins resigned from his position as director of the NHGRI in order to pursue broader, more flexible research opportunities.

(b. Sept. 18, 1954, Montreal, Can.)

C
anadian-born American experimental psychologist Steven Pinker was known for his evolutionary interpretation of language acquisition in humans. Pinker studied cognitive science at McGill University in Montreal, where he received his B.A. in 1976. He earned a Ph.D. in experimental psychology at Harvard University in 1979. After stints as an assistant professor at Harvard (1980–81) and Stanford University (1981–82), he joined the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology (MIT). In 1989 he was appointed full professor at MIT and became director of the university's Center for Cognitive Neuroscience.

His early studies on the linguistic behaviour of children led him to endorse noted linguist Noam Chomsky's assertion that humans possess an innate facility for understanding language. Eventually Pinker concluded that this facility arose as an evolutionary adaptation. He expressed this conclusion in his first popular book,
The Language Instinct
, which became a runaway best-seller and was rated among the top 10 books of 1994 by the
New York Times
.
The book's best-selling sequel,
How the Mind Works
, earned a nomination for the Pulitzer Prize for general nonfiction. In
How the Mind Works
(1997), Pinker discussed the development of the human brain in terms of natural selection, applying a Darwinian perspective to a wide range of mental faculties. He expounded a scientific method that he termed “reverse engineering.” The method, which involved analyzing human behaviour in an effort to understand how the brain developed through the process of evolution, gave him a way to explain various cognitive phenomena, such as logical thought and three-dimensional vision.