Population growth
The human population is about 6.8 billion (as at May 2010). It may sound implausible for this population to have grown over just thousands of years, but the graph to the right illustrates how this would be possible, showing the estimated population over thousands of years (Ref).
Bishop Ussher estimated that mankind was created about 6,000 years ago according to the Genealogy of the Bible . The exponential growth looks perfectly reasonable over this 6,000 year period.
The Evolutionary model places "modern man" evolving about 50,000 - 200,000 years ago. If a similar growth rate is applied on an evolutionary time scale, then the numbers don't make sense. Starting with one "couple" just 41,000 years ago would give a total population of 2 x 10 89. To put this number in perspective, there are only 1 x 10 80 atoms in the entire Universe.
graphic
Most archaeologists believe that humans started using cremation relatively recently, probably about 3,000 BC, although this depends on how the timeline is interpreted, meaning it may have been more recent. Prior to this, burial was the norm. If mankind has been around for 50,000 - 200,000 years, where are all the graves? There is a distinct lack of human remains / artefacts to support this timescale.
Scientifically, the different people groups are classified on the basis of geographic origin: African (groups indigenous to Africa), Caucasian (European populations), Greater Asian (Mongols, Polynesians, Micronesians), Amerindian (North & South American Indians, Eskimos), and Australoid (Australia, Papua).
Neither the Bible nor scientific evidence give us an absolute picture of how the people groups arose. The Bible contains no explanation of when or how specific people groups came to be, although there are detailed genealogies in the Bible. Science tells us that the genetic differences among the people groups are very small. Such minor genetic differences can be easily explained through selective breeding using microevolutionary processes.
Every human being in the world is classified as Homo sapiens. Scientists today agree that there is really only one biological race of humans. There is one race, or as Bob Marley sang, One Blood.