G. Ledyard Stebbins

"Lucy" - Australopithecus

Tomoko Ohtaexternal image ohta.jpg


Tomoko Ohta is a Japanese scientist who works on molecular evolution. In 1973, she developed a model of mutations that are slightly deleterious. Slightly deleterious mutations are mutations that have a small negative effect on an organism. In the 1960's and 1970's she worked on the neutral theory of molecular evolution with Motoo Kimura. Neutral mutations are mutations that don't really affect an organism.

Ohta's work is important from an evolutionary science perspective because it helps explain how negative mutations help change an organism or species or population.Her work on neutral mutations is important because it shows that mutations don't necessarily affect the health or fitness of an organism or population. Her work with mutations affects work on evolution that comes after because it shows that mutations don't necessarily affect an organism or the offspring of an organism. Her work also affects population genetics,which is the study of how populations change and evolve.
external image neutral_scales.gif
Sources
http://en.wikipedia.org/wiki/Neutral_theory_of_evolution
http://en.wikipedia.org/wiki/Tomoko_Ohta
http://en.wikipedia.org/wiki/Population_genetics
http://authors.library.caltech.edu/5456/1/hrst.mit.edu/hrs/evolution/public/images/ohta.jpg
http://evolution.berkeley.edu/evosite/evo101/images/neutral_scales.gif