Dinesh's photos with the keyword: The Diversity of Life

In this rendition of the fossil record for the human family, the known duration of each species is represented by the shadows cast by the figures. The exact relationship between extinct hominid species is a matter of interpretation, and their placement here is not meant to suggest a particular phylogeny. (Design and Graphic by Douglas Beckner. After Richard Hay, Geology of Olduvai Gorge, UC Press, 1976)

The creation of today’s domestic tomato was skilled feat of plant breeding, but one that requires many generations to accomplish. A wild species or race bred into the domestic stock also carries with its baggage of less desirable genes that reduce yield and quality. Breeders must delete these traits through repeated backcrossing, mating the hybrids back to the domestic strains, in a way that preserves only the desirable genes of both domestic and wild forms in the breeding stock. Finally conventional hybridization can be accomplished solely among species and strains similar enough to be bred together, as in the case of multiple parents of ‘Lycopersicon esculentium” Now, however, traditional selective breeding can be shot-circuites. New methods of genetic engineering have made it possible to transfer genes directly, excising them from the chromosomes of one species and placing them into the chromosomes of another species without hybridization of the entire genomes. . . . Page 448