Dr. Frank Brown presented impressive information of his careful geologic dating of the East African strata that has produced the most complete sequence of fossil hominids o an overflow crowd of approximately 165 attendees at our Darwin Day Celebration. Dean of the College of Mines and Earth Sciences and Distinguished Professor of Geology & Geophysics at the University of Utah, Brown, along with several U. scientists, have advanced our understanding of human evolution from tree-dwelling primates to omnivores.

While Utah is known as a great fossil resource, East Africa is the place for human fossils. Evidence for human evolution of 6-million years can be traced. For 42 summers, Brown has labored in a low arid basin around Kenya's Turkana Lake where volcanic sediments have yielded a trove of fossilized human remains.

Brown has been able to accurately date these specimens by mapping the ages of geologic layers where the bones were found. Techniques he used included measuring ratios of potassium to calcium and identifying the volcanic source of benchmark layers of volcanic ash.

The archeological tool that Brown used, known as potassium-argon ratio dating, can very accurately determine the ages of layers of sedimentary soils. These soil layers may be volcanic ash deposits, ancient lake or sea sediment, or other source materials. Obviously, the uppermost sediment layers are quantifiably younger than the lower layers.

Other methods such as cyclical movements of earth's magnetic poles also corroborate and complement the potassium-argon dating results; Brown studied the rich sediment deposits on the Mediterranean floor associated with wet cycles in the Nile-drained East Africa.

Brown continued on with some discussion of recent human development and the evidence of Homo erectus and associated stone tools in the Pleistocene epoch some 1.3 to 1.5 million years ago--which is quite "recent" considering that the age of earth is now thought to be 4.5 to 4.6 billion years.

Not surprising to humanists, this type of investigation dates the earth and seas several orders of magnitude greater than the age developed by early clerics who seem to have simply added up the ages of Old Testament genealogical families back to Adam.

When Charles Darwin was forming his ideas about evolution; the term "dinosaur" was new. Also there was no method for dating fossils, and connections between microbes and disease were poorly understood. Darwin who wrote On the Origin of Species, the 1859 book that changed the course of science, knew little about geology, fossils, time, and genetics, said Brown. The only bones of ancient man known to science then were pieces of a Neanderthal skull mistakenly attributed to a "microcephalic idiot."

Darwin's great insight was not about evolution, which had been advanced long before his voyage on the HMS Beagle, but identifying the mechanism that directed it. From his observations of Galapagos birds and other animals, Darwin extrapolated that the creation of new life forms resulted from "natural selection" or environmental and behavioral factors that gave a competitive advantage to individuals whose traits were best suited to exploit ecological niches.

Brown pointed out that two or more versions of man coexisted throughout the history of Homo genus.

"People like to think we're different than the rest of creation, that we're special," Brown said. "We have tools being used 2.6 million years before the appearance of any Homo species, so maybe we're not so special after all."

Lee Siegel, in a glowing article about Brown in magazine Continuum, wrote that Brown usually spoke the appropriate native language--Swahili, Kikuyu, Amharic, or Turkana--when working in Africa. Once he sent a list of about 1,000 words in Dassanetch--a language spoken by a tribe in Ethiopia--to a linguist who had written that the language contained only 300 words.

"When Arthur Smith was president of the U, Brown objected to racial and gender categories in a diversity report he was asked to write. Instead, he listed every individual in his college by personal characteristics, including foreign languages spoken, religion, war experience, and left- or right-handedness. He had the report translated into 20 languages."

--Sarah Smith