sentences:  She then finished her Ph.D. in Zoology from the University of Arkansas in 1970 at the age of 40 after raising a family of three daughters with her then husband ornithologist Douglas A. James.Her dissertation involved observing patterns of intraspecific size variation in 12 species of birds found in areas of the United States.James looked specifically at Bergmann’s rule hypothesizing that temperature may not be the most important factor determining body size patterns across gradients.