Two things. We are not the top of the food chain. Ask anyone who's come up against a shark, tiger or bear. Secondly, unlike other species, we tend to kill others of our kind.
And, don't discount diseases, famine or parasites. The Black Death claimed a third of the European population in the 1300s and a 19th century famine in China claimed millions.
Hell, people are one of the biggest hindrances to population growth. Even if you discount the 100 million or so who perished in the last century, you've still got the millions slaughtered by the Huns, the Mongols, the Saracens, the Crusaders. Then you have the tens of millions of Native Americans who didn't survive contact with the Europeans and their diseases.
Like I said, don't let reality interfere with your calculations.
One on one without tools, maybe. But it's safe to say that man has killed far more sharks, tigers and bears than they have killed man. And sharks can't even survive in our natural habitat. Man has to go swimming in the ocear or seafaring for them to be a threat.
"Secondly, unlike other species, we tend to kill others of our kind."
Certainly man is a threat. But I'm supposed to believe man had 300,000 years of constant war that kept his population from growing to a point beyond where records of his existence are almost impossible to find?
"you've still got the millions slaughtered by the Huns, the Mongols, the Saracens, the Crusaders. Then you have the tens of millions of Native Americans who didn't survive contact with the Europeans and their diseases."
Look at that site on population statistics. Reality is that human population kept growing despite all those things. We had all those things and we still grew.
I'm supposed to believe that in a much more sparsely populated earth, man was even more limited in growth by those things. I would think he would be less limited due to the lower population. And in no case would I think he would stagnate for 300,000 years.
2000 years of growth followed by a global flood reducing the population to 8 followed by 4000 years of growth is much more believable.