Why Darwin Matters_ The Case Against Intelligent Design - Michael Shermer [14]
After two long days of exposing nothing but solid rock and my own ineptness at seeing bone within stone, one of the paleontologists pointed out that the rock I was about to toss away was a piece of bone that appeared to be part of a rib. If it was a rib, then the bone should retain its riblike shape as more of the overburden was chipped away. This it did for about a foot, until it suddenly flared to the right. Was it a rib, or something else? Horner moved in to check. “It could be part of the pelvis,” he suggested. If it was part of the pelvis, then it should also flare out to the left when more was uncovered. Sure enough, Horner’s prediction was verified by further digging.
In science, this process is called the hypothetico-deductive method, in which one forms a hypothesis based on existing data, deduces a prediction from the hypothesis, then tests the prediction against further data. For example, in 1981 Horner discovered a site in Montana that contained approximately thirty million fossil fragments of approximately ten thousand Maiasaurs in a bed measuring 1.25 miles by .25 miles. His hypothesizing began with a question: “What could such a deposit represent?”28 There was no evidence that predators had chewed the bones, yet many were broken in half lengthwise. Further, the bones were all arranged from east to west—the long dimension of the bone deposit. Small bones had been separated from bigger bones, and there were no bones of baby Maiasaurs, only those of individuals between nine and twenty-three feet long. What would cause the bones to splinter lengthwise? Why would the small bones be separated from the big bones? Was this one giant herd, all killed at the same time, or was it a dying ground over many years?
An early hypothesis—that a mud flow buried the herd alive—was rejected because “it didn’t make sense that even the most powerful flow of mud could break bones lengthwise. . . nor did it make sense that a herd of living animals buried in mud would end up with all their skeletons disarticulated.” Horner constructed another hypothesis. “It seemed that there had to be a twofold event,” he reasoned, “the dinosaurs dying in one incident and the bones being swept away in another.” Since there was a layer of volcanic ash 1.5 feet above the bone bed, volcanic activity was implicated in the death of the herd. Horner then deduced that only fossil bones would split lengthwise, and therefore the damage to the bones had occurred long after the dying event. His hypothesis and deduction led to his conclusion that the herd was “killed by the gases, smoke and ash of a volcanic eruption. And if a huge eruption killed them all at once, then it might have also killed everything else around.” Then perhaps there was a flood, maybe from a breached lake, carrying the rotting bodies downstream, separating the big bones from the small, lighter bones, and giving the bones a uniform orientation.29
A paleontological dig is a good example of how hypotheticodeductive reasoning and historical sciences can make predictions based on initial data that are then verified or rejected by later historical evidence. Evolutionary theory is rooted in a rich array of data from the past that, while nonreplicable in a laboratory, are nevertheless valid sources of information that can be used to piece together specific events and test general hypotheses. While the specifics of evolution—how quickly it happens, what triggers species change, at which level of the organism it occurs—are still being studied and unraveled, the general theory of evolution is the most tested in science over the past century and a half. Scientists agree: Evolution happened.
WHY PEOPLE DO NOT
ACCEPT EVOLUTION
The real attack of evolution, it will be seen, is not upon orthodox Christianity or even upon Christianity, but upon religion—the most basic fact in man’s existence and the most practical thing in life. If taken seriously and made the basis of a philosophy of life, it would eliminate love and carry man back to a struggle of tooth and claw.