Science Friction_ Where the Known Meets the Unknown - Michael Shermer [143]
Spin doctoring [Darwin] centers on two different subjects: the process of evolution as a theory and mechanism; and the pathway of evolution as a description of life’s history. Spin doctoring for the process tries to depict evolution as inherently progressive, and as working toward some “higher” good in acting “for” the benefit of such groups as species or communities (not just for advantages of individual organisms), thereby producing such desired ends as harmonious ecosystems and well-designed organisms. Spin doctoring for the pathway reads the history of life as continuous flux with sensible directionality toward more complex and more brainy beings, thereby allowing us to view the late evolution of Homo sapiens as the highest stage, so far realized, of a predictable progress.34
Adaptationism—Nonadaptationism. In an essay entitled “Wallace’s Fatal Flaw,” Gould highlights the themes of optimality and suboptimality, continuity and discontinuity, by demonstrating how Alfred Russel Wallace erred in insisting (to Darwin’s dismay) that natural selection could not account for the human mind because he could not conceive of an adaptive use for such a large organ during primate evolution. Therefore, Wallace reasoned, a higher intelligence must have intervened in the process, granting us such nonadaptive abilities as mathematics, music appreciation, and spiritual communication. This hyperadaptationism, in Gould’s reading of the historical record, shows just how dangerous a scientific doctrine can become when carried to an extreme (and thus the lesson for today’s hyperadaptationists).
Natural selection may build an organ “for” a specific function or group of functions. But this “purpose” need not fully specify the capacity of that organ. Objects designed for definite purposes can, as a result of their structural complexity, perform many other tasks as well. A factory may install a computer only to issue the monthly pay checks, but such a machine can also analyze the election returns or whip anyone’s ass (or at least perpetually tie them) in tic-tac-toe. Our large brains may have originated “for” some set of necessary skills in gathering food, socializing, or whatever; but these skills do not exhaust the limits of what such a complex machine can do.35
Punctuationism—Gradualism. In an essay entitled “The Interpretation of Diagrams,” Gould considers the long-standing debate in geology over catastrophism versus uniformitarianism in the context of explaining the origins of the Cambrian “explosion” of life, arguing that the history of life from the beginning has been periodically punctuated by sudden and dramatic change (the “log phase” in the passage below) but most of the time remains relatively stable.
The log phase of the Cambrian filled up the earth’s oceans. Since then, evolution has produced endless variation on a limited set of basic designs. Marine life has been copious in its variety, ingenious in its adaptation, and (if I may be permitted an anthropocentric comment) wondrous in its beauty. Yet, in an important sense, evolution since the Cambrian has only recycled the basic products of its own explosive phase.36
Contingency—Necessity In an essay entitled “The Horn of Triton,” Gould uses the findings (and a striking photograph) from the Voyager spacecraft in its flyby of Neptune with its moon Triton, both in their crescent phases (thus the “horn”) relative to the spacecraft, to consider what we can learn about the uniqueness of history versus the repeatability of nature’s law’s.
I offer, as the most important lesson from Voyager, the principle of individuality for moons and planets. This contention should elicit no call for despair or surrender of science to the domain of narrative.