The Recent African Genesis of Humans
Genetic studies reveal that an African woman of 200,000 years ago was our common ancestor
The Multiregional Evolution of Humans
Both fossil and genetic evidence argues that various human groups arose where they are found today
Mountain Belts and the Supercontinent Cycle
Every 500 million years the continents assemble into a single landmass. The tectonic interactions associated with the formation and breakup of such supercontinents provide a new way to view the origin of mountain belts...
Superantigens in Human Disease
These proteins cause food poisoning and toxic shock. They may also contribute to arthritis and AIDS. Investigators are learning how superantigens overstimulate the immune system and induce disease...
The International Thermonuclear Experimental Reactor
This tokamak fusion reactor, sponsored by four industrial powers, will be the most powerful ever built. By fusing deuterium and tritium, ITER should generate more energy than it consumes...
Solid Acid Catalysts
Great progress has been made in the design of these important industrial materials. Some novel solid acid catalysts can reduce the emission of environmentally harmful products
People who have lost an arm or a leg often perceive the limb as though it is still there. They can also feel excruciating pain in specific parts of the phantom limb
Hacking the Genome
The masses of information written in human DNA are being translated into the precise ones and zeros of computer code. The choices made now will determine whether the genome project is a font for future discovery or a binary junkyard of data...
50 and 100 Years Ago: April 1992
The Plankton Stalkers
A Census of Stranglers
D2 or not D2
A Second Glance
Fire in Water
Avoiding the Potholes on Optical Highways
Helping the Little Guy Buy a Computer
Letters to the Editors, April 1992
Book Reviews, April 1992
- Mathematical Recreation
All Paths Lead Away from Rome
Compensation Beyond the Call of Duty
Essay: A Case of Dèjà Vu