from Computing the Organism; Natural History 4/2000
Environmental Variation

Richard Lewontin


Clones of seven Achillea plants showing striking differences when grown in different environments.
"...an organism is the unique outcome of a process that is also contingent on the sequence of environments in which it develops. This can be illustrated by the famous experiments of Jens Clausen, David Keck, and William Hiesey. Taking advantage of the fact that certain plants, simply by being cut in pieces, can be cloned into genetically identical individuals, the researchers divided each of several Achillea millefolium plants into three segments. One was planted at about 100 feet above sea level; one in the foothills of the Sierra Nevada, at about 4,600 feet; and one high in the mountains, at about 10,000 feet. The resulting variation among genetically identical organisms can be seen in the illustration at left. Moreover, recent animal cloning experiments have repeatedly shown striking variations among individuals with the same DNA. Although this has apparently surprised the cloners, it should not have."