@Olivier5,
Olivier5 wrote:
BillW wrote:
You went from the wrong direction. We would still be a stromolite without enough oxygen to survive as animals for millions of years.
????
Yeah, I understand how that happened.
BJK agrees to evolution being 100,000 and went backwards 100,000 from the current time period and then you wrote, "Those sites can only be far out there... 100,000 yr ago, current consensus is that Homo sapiens had not yet started speaking. The advent of "behavioral modernity" (aka culture, art, language) is dated around 50,000 yr ago, throught art and complex tools etc."
I say we need to start at the beginning of life on earth for the 100,000 year evolution to start - the stromolites:
"Although simple, cyanobacteria were ultimately responsible for one of the most important "global changes" that the Earth has undergone. Being photosynthetic, cyanobacteria produce oxygen as a by-product. Photosynthesis is the only major source of free oxygen gas in the atmosphere. As stromatolites became more common 2.5 billion years ago, they gradually changed the Earth's atmosphere from a carbon dioxide-rich mixture to the present-day oxygen-rich atmosphere. This major change paved the way for the next evolutionary step, the appearance of life based on the eukaryotic cell (cell with a nucleus)."
http://www.indiana.edu/~geol105b/images/gaia_chapter_10/stromatolites.htm
Only from this beginning could homo sapien evolve some 1.9 billion years later. A farther distance from 100,0000 years!