Stephen Jay Gould (1941 – 2002)
American geologist, paleontologist, evolutionary biologist and popular-science author, who spent most of his career teaching at Harvard University and working at the American Museum of Natural History in New York.
In this crucial sense, the theory of punctuated equilibrium adopts a very conservative position. The theory asserts no novel claim about modes or mechanisms of speciation; punctuated equilibrium merely takes a standard microevolutionary model and elucidates its expected expression when properly scaled into geological time.
The skein of human continuity must often become this tenuous across the centuries (hanging by a thread, in the old cliché), but the circle remains unbroken if I can touch the ink of Lavoisier's own name, written by his own hand. A candle of light, nurtured by the oxygen of his greatest discovery, never burns out if we cherish the intellectual heritage of such unfractured filiation across the ages. We may also wish to contemplate the genuine physical thread of nucleic acid that ties each of us to the common bacterial ancestor of all living creatures, born on Lavoisier's ancienne terre more than 3.5 billion years ago—and never since disrupted, not for one moment, not for one generation. Such a legacy must be worth preserving from all the guillotines of our folly.
Included in this “almost nothing,” as a kind of geological afterthought of the last few million years, is the first development of self-conscious intelligence on this planet—an odd and unpredictable invention of a little twig on the mammalian evolutionary bush. Any definition of this uniqueness, embedded as it is in our possession of language, must involve our ability to frame the world as stories and to transmit these tales to others. If our propensity to grasp nature as story has distorted our perceptions, I shall accept this limit of mentality upon knowledge, for we receive in trade both the joys of literature and the core of our being.
Phenomena unfold on their own appropriate scales of space and time and may be invisible in our myopic world of dimensions assessed by comparison with human height and times metered by human lifespans. So much of accumulating importance at earthly scales […] is invisible by the measuring rod of a human life. So much that matters to particles in the microscopic world of molecules […] either averages out to stability at our scale or simply stands below our limits of perception.
I picture several reviewers of my own books as passing a long future lodged between Brutus and Judas in the jaws of Satan.
I am willing to believe that my unobtainable sixty seconds within a sponge or a flatworm might not reveal any mental acuity that I would care to call consciousness. But I am also confident […] that vultures and sloths, as close evolutionary relatives with the same basic set of organs, lie on our side of any meaningful (and necessarily fuzzy) border—and that we are therefore not mistaken when we look them in the eye and see a glimmer of emotional and conceptual affinity.
If the neck of the giraffe elongates an inch at a time, then the full panoply of supporting structures need not arise at every step. The coordinated adaptation can be built piecemeal. Some animals may slightly elongate the neck, others the legs; still others may develop stronger neck muscles. By sexual reproduction, the favorable features of different organisms may be combined in offspring.
Creative work, in geology and anywhere else, is interaction and synthesis: half-baked ideas from a barroom, rocks in the field, chains of thought from lonely walks, numbers squeezed from rocks in a laboratory, numbers from a calculator riveted to a desk, fancy equipment usually malfunctioning on expensive ships, cheap equipment in the human cranium, arguments before a roadcut.
We do not inhabit a perfected world where natural selection ruthlessly scrutinizes all organic structures and then molds them for optimal utility. Organisms inherit a body form and a style of embryonic development; these impose constraints upon future change and adaptation. In many cases, evolutionary pathways reflect inherited patterns more than current environmental demands. These inheritances constrain, but they also provide opportunity. A potentially minor genetic change […] entails a host of complex, nonadaptive consequences. […] What “play” would evolution have if each structure were built for a restricted purpose and could be used for nothing else? How could humans learn to write if our brain had not evolved for hunting, social cohesion, or whatever, and could not transcend the adaptive boundaries of its original purpose?
South America had been an island continent, far bigger and far more diverse than Australia, for tens of millions of years before the Isthmus of Panama rose just a couple of million years ago. The resulting flood of North American mammals across the new land bridge corresponds in time with the decimation of the native South American fauna. In fact, most large mammals generally considered distinctly South American... are all recent migrants from North America.
The argument of the “long view” may be correct in some meaninglessly abstract sense, but it represents a fundamental mistake in categories and time scales. Our only legitimate long view extends to our children and our children's children's children—hundreds or a few thousands of years down the road. If we let the slaughter continue, they will share a bleak world with rats, dogs, cockroaches, pigeons, and mosquitoes. A potential recovery millions of years later has no meaning at our appropriate scale.
The real tragedy of human existence is not that we are nasty by nature, but that a cruel structural asymmetry grants to rare events of meanness such power to shape our history.
The legends of fieldwork locate all important sites deep in inaccessible jungles inhabited by fierce beasts and restless natives, and surrounded by miasmas of putrefaction and swarms of tsetse flies. (Alternative models include the hundredth dune after the death of all camels, or the thousandth crevasse following the demise of all sled dogs.)
Many similarities of basic design among animal phyla, once so confidently attributed to convergence, and viewed as testimony to the power of natural selection to craft exquisite adaptation, demand the opposite interpretation that Mayr labeled as inconceivable: the similar features are homologies, or products of the same genes, inherited from a common ancestor and never altered enough by subsequent evolution to erase their comparable structure and function. The similarities record the constraining power of conserved history, not the architectural skills of natural selection independently pursuing an optimal design in separate lineages. Vertebrates are, in a certain sense, true brothers (or homologs) - not mere analogs - of worms and insects.
Each of the major sciences has contributed an essential ingredient in our long retreat from an initial belief in our own cosmic importance. Astronomy defined our home as a small planet tucked away in one corner of an average galaxy among millions; biology took away our status as paragons created in the image of God; geology gave us the immensity of time and taught us how little of it our own species has occupied.
I went to the movies to see Independence Day, the outer-space summer blockbuster of 1996. (Even the most committed intellectual can't survive on an unalloyed diet of Jane Austen remakes.)
Biological evolution is a system of constant divergence without subsequent joining of branches. Lineages, once distinct, are separate forever. In human history, transmission across lineages is, perhaps, the major source of cultural change. Europeans learned about corn and potatoes from Native Americans and gave them smallpox in return.
The story of a theory's failure often strikes readers as sad and unsatisfying. Since science thrives on self-correction, we who practice this most challenging of human arts do not share such a feeling. We may be unhappy if a favored hypothesis loses or chagrined if theories that we proposed prove inadequate. But refutation almost always contains positive lessons that overwhelm disappointment, even when […] no new and comprehensive theory has yet filled the void.
If a man dies of cancer in fear and despair, then cry for his pain and celebrate his life. The other man, who fought like hell and laughed in the end, but also died, may have had an easier time in his final months, but took his leave with no more humanity.
Knowledge and wonder are the dyad of our worthy lives as intellectual beings. Voyager did wonders for our knowledge, but performed just as mightily in the service of wonder—and the two elements are complementary, not independent or opposed. The thought fills me with awe—a mechanical contraption that could fit in the back of a pickup truck, traveling through space for twelve years, dodging around four giant bodies and their associated moons, and finally sending exquisite photos across more than four light-hours of space from the farthest planet in our solar system.