Lyceum speaker looks at evolutionary science
The second program of the 2013-14 Victoria College Lyceum lecture series is scheduled for the Leo J. Welder Center at 7 p.m. Tuesday. Nicholas Wade is an author and science journalist who, in a long and distinguished career, has elucidated some of the great mysteries of human existence.
In his book "Before The Dawn" (2006), Wade tackles an enduring question - the origins and development of life on Earth. Mankind's story is not known with any degree of certainty until the advent of written communication around 5,000 years ago and, to a lesser extent, from ever-decreasing archaeological evidence back an additional 10,000 years. The book focuses on what preceded this most recent 15,000-year period, a vast expanse of time we call prehistory.
Science tells us that even the oldest recorded historical events are blinks of an eye in the scale of time since the nascent years of our planet. The Earth is about 4.5 billion years old and has been habitable for 3.8 billion years. Mammals are first dated in the fossil record at 225 million years, while the primate lineage showed up at 65 million. Evidence, indistinct though it is, indicates that anatomically modern humans were in Africa by 200,000 years ago while modern behavior (such as speech and clothing) has existed for 50,000 to 70,000 years. Mankind, as we know it, has been around for .00001 percent of the Earth's existence (less than one second relative to a 24-hour day).
Certainly, Wade's conclusions are not incontrovertible. Making reasoned inferences from scant physical evidence is the way of paleontologists, archaeologists and physical anthropologists - practitioners of the historical sciences, who deal in theory rather than indisputable fact. Add in a Biblical or creationist point of view, and there is a measure of controversy on the subject.
Not even creationists espouse a monolithic view. Literal creationists believe that life and the Earth are 5,000 years old, began in the Garden of Eden and were orchestrated by God as revealed in the book of Genesis. Evolutionary creationists see no inherent contradiction between scientific and Biblical explanations, suggesting that the Earth is billions of years old as scientists have posited and that evolution is real but was set in motion by God and directed by Him. Genesis, to this group, is metaphorical.
Wade synthesizes theories from several disciplines to make a compelling case for the scientific version of human prehistory. In addition to the historical sciences, he examines the work of geneticists using DNA to reconstruct ancient man's evolutionary adaptations as well as his migration patterns. Analyzing the DNA of fossils of varying age and found in various places and comparing it to the DNA of living individuals provides tantalizing clues that man first migrated from Africa around 45,000 to 50,000 years ago. In what must have been an exceedingly daunting venture, as few as 150 individuals left the continent via a southern Red Sea route, landing on the Arabian Peninsula. This intrepid group was part of the "ancestral human population," approximately 5,000 people from whom everyone on Earth is descended. In a process taking tens of thousands of years, succeeding generations put a human footprint in all regions of the globe.
Mankind's story, of course, goes back much further. In a compelling series of chapters, Wade traces the fossil record extending back millions of years and describes the evolutionary pathways that ultimately resulted in the emergence of the human species. Archaeological/paleontological discoveries dated on a timeline, like those showing increasingly larger brain cases in fossilized skulls and increasingly sophisticated tool use, are pieces to a complex jigsaw puzzle.
Paleontology tells us that man's ancient ancestors slowly, over many millennia, began exhibiting traits that enhanced survival: bipedalism (walking on two feet), language acquisition and the addition of molars for chewing food (which allowed for better nutrition, consequently promoting brain growth) are a few prominent examples.
The geologic record, another tool, reveals climatological and environmental factors that prehistoric man experienced. It leads to inferences about how events like the Pleistocene Ice Age governed choice of habitat, migration and ways of making a living.
Wade also delves into a more recent period of man's development. He outlines methods used by specialists in historical linguistics to trace the divergence of all world languages from Proto-Indo-European, thought to be the spoken tongue of the ancestral human population. He turns to archaeology for evidence of the growing social bond between individuals and the transition from itinerant hunter/gatherer societies to those that were agriculturally-based. Both gave rise to community living and the family structure that characterize human societies today.
In total, it makes for a fascinating and compelling story and one infused with the wonders of contemporary science. Please plan to attend the Lyceum and hear Wade flesh out the details of our evolutionary past. The lecture is free of charge.
Dave Ticen is the chairman and a longtime member of VC's Lyceum Committee. Ticen works as a librarian in charge of user education at the VC/UHV Library.