Content area
Full Text
ABSTRACT
New ideas in science frequently arise from neglected or distorted antecedents. This essay deals with the idea of biochemical unity, encapsulated in Jacques Monod's well-known phrase, dating from 1954: "Anything found to be true of E. coli must also be true of elephants." An earlier version of this phrase,-"From the elephant to butyric acid bacterium-it is all the same!"-was coined in 1926 by the Dutch microbiologist Albert Jan Kluyver. In that year Kluyver and his associate Hendrick Jean Louis Donker published a celebrated paper, "Unity in Biochemistry." The concept of biochemical unity had many antecedents, but these had never caught on. The Kluyver-Donker paper has often been regarded to provide a boost to biochemical and especially to microbiological thinking. Its interpretations and misinterpretations represent an encapsulated history of biochemistry. The present paper examines the history of the concept of biochemical unity from before to beypnd Kluyver, investigates the two "elephant" phrases and their possible relationships, and ends with a discussion of the attractiveness of unifying ideas in science.
Everything of importance has been said before by somebody who did not discover it.
-Alfred North Whitehead (1917, 362)
MANY PRESENT-DAY BIOCHEMISTRY TEXTBOOKS begin with the idea of an underlying biochemical unity: "the molecular logic of living organisms"; "the molecular logic of the living state" (Lehninger 1975, 3-14); "We'll look at strange and unusual reactions, along with those metabolic sequences common to most living things" (Metzler 2001, 1); "Biochemical Unity Underlies Biological Diversity"; "organisms are remarkably uniform at the molecular level" (Berg, Tymoczko, and Stryer 2002, 7-8). In the words of Nobel laureate Arthur Kornberg (2000): "mechanisms and molecules have been preserved in bacteria, fungi, plants, and animals, essentially intact through billions of years of Darwinian evolution. I regard this insight as one of the great revelations of the 20th century."
Biochemical phenomena can be dissected into recurring patterns or archetypes (Pette 1965): (1) prevalence in the biosphere of a few molecular species, e.g. nucleic acids, proteins, carbohydrates, lipids, coenzymes, and metabolic intermediates; (2) classification of enzyme reactions into six basic types (but see Purich 2001); (3) universality of energy-yielding and energy-requiring processes, centered mainly around adenosine triphosphate; (4) protein and carbohydrate homochirality; (5) metabolic turnover; (6) control mechanisms such as allostery, enzyme induction and...