For more than two decades, international teams of paleoanthropologists have been discovering human-like fossils from a medieval archaeological site in the former Soviet Republic of Georgia known as Dmanisi.
A new human Georgian skull fuels the dilemma further. In 1991, David Lordkipanidze of the Georgian National Museum in Tbilisi discovered the first four human-like fossils.
Increased archaeological interest in this Georgian site began in 1936 following the discovery of ancient and medieval artifacts.
Scientists have long known that extremely low levels of free-oxygen [< 10-5] atmosphere on early Earth are critical for any viable origin of life model of evolution.
The controversy surrounding the atmospheric concentration of oxygen in the origin of life stems from the laws of organic chemistry.
The autonomous assembly of complex organic molecules has only been observed in an oxygen-free atmosphere.
However, the evidence for an oxygen-free Earth atmosphere has a checkered history.
Darwin, Then and Now, the Most Amazing Story in the History of Science, chronicles Darwin's life, how he developed his hypothesis, specifically what he said, and what scientists have discovered since the publication of The Origin of Species in 1859.
The book traces the rise and fall of evolution's popularity as a scientifically valid theory. With over 1,000 references from Darwin and scientists, Darwin Then and Now retraces developments in the most amazing story in the history of science.
Darwin Then and Now is an educational resource focusing on understanding the intersection of evolution and science to develop basic skills for analyzing and assessing the theory of biological evolution.