Thursday, October 20, 2016

Glaciers and Humanity

Our post title suggests a relationship between cycles of global climate and their effects on humanity. This proposal is true in a powerful way. Long term earth temperatures cycle between warmer and cooler. On a short time scale, daily and seasonal temperature changes impact what we wear, what activities we enjoy, when we take vacations, and dozens of other choices. On a longer scale some observers may notice that winters are warmer than they were in our youth. Truly long term cycles are more difficult for our contemporary population to identify and appreciate. For example, Earth experienced the Medieval Warm Period from 950-1250 AD and the Little Ice Age from 1300-1850 AD. Even more fascinating are exceedingly long term glacial events and ice ages of earth’s history. People are more immediately impacted by short term changes in temperature, falling short of an in-depth understanding of how changing dynamics of climate—temperature and precipitation—have impacted humanity over thousands of years.    

One example of lack of understanding of climate dynamics relates to the rise of civilization about 10,000 BC. Glacial episodes on Earth in the past 2.5 million years have been ubiquitous. Widespread continental glaciers have covered broad regions that are ice free today. Northern North America and Northern Europe have been overlain by thick ice sheets periodically during the Pleistocence—the last 2.5 million years until 11,000 years ago. Following glacial advances, our planet experiences warmer interglacials during which glacial ice melts and retreats. Presently we live in an interglacial epoch called the Holocene. Essentially, the major effects of the most recent Wisconsin glacial stage are behind us even with the presence of current ice caps at the North and South Poles and in Greenland. Therefore, Earth is still considered to be in the last stages of an Ice Age. Another major glacial advance is possible at some point in the distant future.

The rise of civilization owes more to the demise of the Wisconsin glacial event than any other factor. In terms of the history of humanity, civilization arose following the Wisconsin with surprising rapidity. Our recent blogs describe a more urban, sedentary culture and the rise of farming in association with civilization’s emergence around 10,000 BC. In the many tens of thousands of preceding years, progress of human achievement as we comprehend it, was glacially slow. Some believe true humanity would have progressed beyond the hunter/gatherer stage long before.

We quote from the 10-year update of Who Was Adam, an RTB Press 2015 volume co-written by Reasons to Believe scholars Fazale Rana and Hugh Ross: “The descriptions of the Garden of Eden (Genesis 2-3) and of Noah’s flood (Genesis 7-9) imply that both events occurred during an ice age. The last ice age event took place 13,000—112,000 years ago, so it is reasonable to assume both Noah and Adam might have lived within this period, or Noah only during the last ice age but Adam and Eve during the preceding one…” The preceding one refers to the Illinoisan glacial stage within our current ice age. It occurred 140,000—235,000 years ago, the third of four glacial stages during the 2.5 million year Pleistocene geological epoch.

Hugh Ross and Fazale Rana in their Who Was Adam 10-year update cite several trustworthy researchers who place the well-publicized “mitochondrial Eve” (the mother of all living, either one individual or a small group of individuals) at about 150,000 years ago. Likewise, they cite reliable researchers who have proposed dates for Y-chromosomal Adam (the father of all living, either one individual or a small group of individuals) at between 100,000 and 200,000 years ago. Thus, dates for both mitochondrial Eve and Y-chromosomal Adam converge at around 150,000 years ago. This resolves the RTB problem in their 2005 volume where projected dates for mitochondrial Eve and Y-chromosomal Adam were very different from each other. Some recent work indicates that “while not conclusive, a number of studies suggest that modern human behavior emerged earlier than 70,000 to 80,000 years ago.” 

Many questions recur as we study the issue of dates for the origin of humanity. We wonder why these fully human men and women did not advance beyond a primitive culture for tens of thousands of years. We may also wonder about the existence of primitive cultures in our modern time. There exist a number of uncontacted indigenous peoples in various countries, mainly in jungles of South America, Africa, and Indonesia. They are fully human but resist contact with the outside world. Their lives have not advanced far beyond Paleolithic cultures of humans long before the human embrace of agriculture about 10,000 BC. Uncivilized and uncontacted does not diminish their full humanity. This phenomenon may help us understand that fully human men and women existed and survived during the harsh and changing conditions of the ice age prevailing during most of the lengthy human habitation on this planet. They survived but did not thrive. 

In our youth we learned from Scripture about the creation of the universe, Earth, and living things including humanity in the Image of God. The Bible contains minimal information about timelines and details of creation and the events leading to Noah’s flood. The human authors of the Old Testament chose mainly to detail the calling and events of the Chosen People about 2,000 BC beginning with the patriarch Abraham in Genesis 11. Accurate interpretation of Scripture is a responsibility we share with trusted scholars. Skilled scientists help us discover historical geological and archeological facts. We are thankful to our Creator for the skills of both theologians and scientists.