Charles darwin developed the theory that explains how new species develop based on evidence from many different kinds of scientific inquiry. darwin’s theory can only be accurate if the earth is very old. the scientists who provided evidence for the earth’s old age were most likely

In the 19th century, the British physicist Lord Kelvin made an estimate of the age of the earth. He said the earth was approximately 100 million years old.

He relied on calculations of the cooling of the earth from its original state of fusion.

However, with new techniques, scientists claim that the age of the earth is 4600 million years.  Actually is used the isotope marking technique

1. a tropical dry forest carries out more rapid nutrient cycling