Evolution: Zirconium Silicate

 

To understand the basic idea of radiometric dating, consider Uranium-Lead dating of Zircon, a basically impregnable crystalline compound of Zirconium Silicate that forms at very high temperatures. Zircon sometimes incorporates Uranium molecules into its crystalline structure as it grows because the configuration of outer electrons are similar. This results in Zircon samples with Lead (which Zircon strongly rejects) unnaturally bound to the crystalline structure because Uranium decays into Lead at a steady rate not changed in the millions of years that it has taken for light to reach us from distant stars where this same process of decay is playing out. The age of individual samples of Zircon can therefore be calculated from the ratio of Lead to Uranium. Though the estimated age of terrestrial samples varies because not all zircon crystals were formed at the same time, the Zircon found inside meteorites is all roughly 5 billion years old. The earth could be younger than that, but other evidence indicates otherwise.

Evolution: Apocrypta westwoodi

One has good reason to wonder how complex organisms like Apocrypta westwoodi (Fig Wasp) could arise from a gradual accumulation of random changes, especially since (a) random changes are generally disadvantageous and (b) many organisms have elaborate adaptions that are inextricably associated with parallel adaptions in other organisms.

We should first recognize that the complex systems that we observe in nature are typically more efficient than simple systems that we observe in nature as long as the native environment remains stable. Simple systems, however, are typically more adaptable to unstable environments. For example, opportunistic animals like brown rats (which are native to Asia) and house sparrows (which are native to the Middle East) are found worldwide near human settlements but only infrequently in areas relatively untouched by human settlement (except, of course, in their native environments). Highly specialized animals, on the other hand, typically face extinction when their habitats are disturbed. To take another example from nature, the diversity of plant species growing close to ancient settlements in Central American and South Asian jungles is noticeable lower than the diversity of plant species growing in the surrounding area even after the passage of hundreds of years. Even a small amount of change is generally disadvantageous for highly specialized species.

The same pattern is observable in spoken languages, the most elaborate of which are found among forest peoples of New Guinea, Central Africa, and Brazil. Modern English, by contrast, has a relatively simple and flexible grammatical structure but a vast vocabulary compared to Old English from which it derives. The difference between the two languages—and they are indeed different languages—is plainly illustrated by the opening lines of Beowulf: “Hwæt! Wé Gárdena in géardagum þéodcyninga þrym gefrúnon hú ðá æþelingas ellen fremedon!” How exactly did Modern English arise from such an unrecognizable ancestor? Modern English arose from Old English as the result of (a) millions of regional changes in pronunciation, only some of which became widespread, (b) the emergence of striking metaphors and turns of phrase whose gradual sublimation resulted in curious grammatical artifacts and occasionally inverted meanings, and (c) a simplified grammatical structure coupled with a complex vocabulary that naturally arose because the French nobles who ruled England had an outsized influence on how one should speak, and because English was not the native language of those who ruled England for hundreds of years after 1066.

We can infer (a) that extremely complex systems can develop aggressively from a relationship between a limited number of species if environmental conditions are relatively stable—the “arms race” scenario—but (b) that the playing field is reset by the emergence of generalist organisms if conditions suddenly change. We can also infer (c) that generalist organisms will begin to specialize over time and (d) that the cycle will begin all over again. Millions of intersecting cycles of varying timescale and complexity overlap and interact invisibly over the span of a human life, but things change noticeably over millennia. How exactly all this is happens has yet to be reliably worked out, but there’s an astonishing wealth of evidence that it does indeed occur.

Evolution: Rodhocetus kasrani

 

Having been raised by unbelieving parents, it never occurred to me growing up that the world might have been created in only seven days in the not too distant past, but my views on this topic have shifted over the years. On my seventh birthday, I bought a Time/Life book on Evolution with birthday money. In high school, I enjoyed reading about the Leakey’s discoveries of hominid fossils in the Olduvai Gorge, and I even spent a week at the Darwin Research Center on the Galapagos Island of Santa Cruz during my sophomore year of high school. For me, there simply was no other reasonable explanation of origins.

Nothing changed in this regard after I became a Christian until one day I came across the argument in Romans 5 that all people have inherited sin from Adam. I spent a long time studying this and other passages and contemplating the implications. I also began reading books that took issue with the idea of Evolution and that sought to refute the evidence on which it is based. This lead to a period of active skepticism, and I sometimes engaged in debates on the subject. On one occasion, the professor of a course on Evolution & Systematics offered the class an opportunity to express any dissent on the last day of class. I took the opportunity to point out that the micro-evolutionary processes we had studied may explain how dogs might have diverged into such a wide range of types, but it does not explain how a whale might have evolved from a land animal. There things stood for a decade, during which my focus shifted from Aquacultural Engineering to the Anthropology of Language & Literature so that I could better understand the mechanics of scripture. Then one day, I read in the journal Science that the fossil of a four-legged whale had been discovered in Pakistan. That jarred me, and I began to ponder the question of evolution again.

I had long since dismissed the notion that the first ten chapters of Genesis were intended metaphorically—I can assure you that actual days are intended—but I had also come to regard all scripture as essentially a genealogy of the future, and I knew that the ancient world considered genealogies to be statements of legal standing whose relationship with historical events could be complicated. For example, Samuel was born to Elkanah, a Levite, but he was dedicated to the Lord and so became the son of Eli the High Priest and thus a descendent of Aaron, becoming High Priest after the death of Eli. To take another example, John the Baptist warns the Pharisees against relying on their natural descent from Abraham by declaring: “Bear fruit in keeping with repentance. And do not presume to say to yourselves, ‘We have Abraham as our father,’ for I tell you, God is able from these stones to raise up children for Abraham” (Matthew 3:8-9). Because even stories such as those in Leviticus are considered genealogical elements, it is possible that the account in Genesis of a seven-day creation defines the status of things but not necessarily how events transpired.

So what are we to make of the first three chapters of Genesis? The first chapter describes time and space, as well as inanimate celestial bodies and all living terrestrial creatures, as the handiwork of God. Moreover, all things are assigned their proper boundaries, which in turn serves as the basis for distinctions between clean and unclean, etc. Finally, the last day celebrates God (and not our labor) as the source of Life. The second chapter describes Adam (the Hebrew word for Man) as charged with cultivating (protecting and extending) the garden, beyond which lay a vast wilderness. The extension of the Kingdom of God is, in effect, our eternal purpose. The third chapter describes our fraught relationship with God: our wretchedness, his hiddenness, the chaos that now envelopes us, and the hope of peace in the Son of Man. This is the seed of the Gospel.