Mankind quantity...?

Question

if we were to work backwards with simple math when would the first modern man have been born. meaning, the earth just passed 6 billion people and several years ago it surpassed 5 billion. working backwards in general numbers when would the first man/woman have walked earth. and do not read to much into this, it is not religous or evolutionary in nature.

Answer 1

All right, we have one little problem here.  The inner workings of evolution are not such that one day an archaic Homo sapien (either Homo ergaster or Homo heidelbergensis depending on what phylogeny you believe in?) is in birth and then, voila, out pops the first true anatomically modern Homo sapien.  Irregardless of the fact that evolution is a rather slow process, however, the earliest sites of anatomically modern Homo sapiens date back to around 100,000 years ago.  Qufzeh and Skhul, in the middle east, are the oldest sites to have be dated definitively at 90,000 years ago, but there are also sites at Klasies River Mouth in South Africa and Omo-Kibish in Ethiopia where anatomically modern Homo sapiens have been found.  The S. African site has been dated with electron spin resonance and resulted in being classified as between 134,000 and 74,000 years ago and the Ethiopian site was dated to 130,000 years ago, but the finding of a much more primitive skull in the same soil formation has led some to believe that the site had been disrupted and the finding may have come from a higher soil layer, so again this site is not with certainty.

Anyways, 100,000 years ago is curently the accepted date for the beginning of anatomically modern Homo sapiens, but given the fact that the change would have been gradual you could easily put +/- 5000 behind that to account for this evolutionary change to have occured in full.  So if the earth's history were put into a large book with each page representing 1 million years (making the book 6000 pages long) then that gradual change and the first fully anatomically modern Homo sapien would be written down as taking his first step and walking on the face of the earth at the bottom of the last page.  A couple sentances later, the last sentence would say "man then released all the carbon that had been stored into the earth over the previous 5 billion years back into the atmosphere."... turn the page!

Now that we have pegged the date at 100,000 years ago, you also want to "estimate" a head count for all mankind it seems?  Truly, this is not possible.  Looking at mitrochondrial DNA for instance, it is evident that there was a bottle neck in the human population 70,000 years ago such that the reproductively involved individuals (assumingly all that were present?) would have been no greater then 14,000 individuals.  One hypothesis to account for this is the eruption of the Toba supervolcano in Sumatra, Indonesia who's impending ash cloud and sulphuric acid rain had a catastrophic effect on the african continent thus reducing the number of humans present at that point and also resulted in a 12,000 year long ice age.  At that one squeezed point on human development it is possible to estimate our population because of the extreme restriction that was put on our DNA pool, but other less destructive events can not be estimated.  The 70,000 years since were also marked with an ice age between 13,000 and 24,000 years ago and even a "mini ice age" that started in 1250 AD resulted in famine and death throughout medival europe.  So considering that our population was truly not a linear progression, the numbers can not truly be estimated accurately.

I hope all of this helps.

Answer 2

there is no definit answer since man evolved over millions of years not just a single time

Answer 3

If you're going to "do the math", when are you going to interject the plagues of history, such as the Black Plague, etc., or genocidal events like the Holocaust?

My point is that with population didn't grow in a direct exponential curve; it went up and down according to war, disease, and famine.

Answer 4

OOOOO girl!  This is a very complicated question.

After much introspection, data provided to me from an assortment of diciplines has given me no additional insight which, would, helpfully provide an accurate postulation which might assist your search for an accurate response.  Sorry.

Answer 5

THE PRIMATES(FROM WHICH WE EVOLVED) HAVE APPEARED 7 MILLION YEARS AGO SOMEWHERE IN AFRICA