RT Journal Article SR Electronic T1 Divergent evolution and the Darwinian theory JF American Journal of Science JO Am J Sci FD American Journal of Science SP 21 OP 30 DO 10.2475/ajs.s3-39.229.21 VO s3-39 IS 229 A1 J. T. Gulick YR 1890 UL http://www.ajsonline.org/content/s3-39/229/21.abstract AB