When I ponder the "births of the sons of Noah, Shem, Ham and Japheth", three in total, and those sons had 16 sons, and the increase continues at least double in the next generation, I cannot think that humanity has been very long upon the earth as the numbers would be astronomic. Even between the 1920's and now, about 100 years, there has been an increase in world population from 2 billion to over 8 billion.

It would seem that the world and everything living in it is not very old, thousands of years but not millions.

The deluge wiped off the face of the earth vast numbers of creatures living on the land and vast numbers of birds. When the flood started to recede as the wind dried it and the dry land appeared separated once more from the sea, vast numbers of creatures would have been deposited where the water receded at the border ...