miércoles, 14 de octubre de 2009
GENETICA Y EVOLUCION
THE HISTORY OF LIFE ON EARTH
Life started out small perhaps 3.8 billion years ago and stayed that way for a long time. Eventually it exploded into a multitude of forms that came to include human beings.
By manipulating the information contained in DNA, scientists are raising hopes -and some fears- on a grand scale.
COMMON DESCENT WITH MODICATION
One of these principles has been labeled common descent with modification.
It holds that particular groups, or species, of living can undergo modification in successive generations, with such change something resulting in the formation of new, separate species- one species separating further. If you hand o videotape of this "branching" of species and then ran it backward, what you´d eventually see is a reduccion of all these branches into one, meaning that all living things on Earth ultimately are descend from single, ancient ancestor.
Publicado por CASTRO MACHA , GUSTAVO CARLOS. Founder - Principal en 12:55