Darwin had argued that the Earth was immensely old which gave his gradual process of evolution plenty of time to unfold.
The great physicist Lord Kelvin had countered that the planet was actually relatively young perhaps 20 million years old.
Ar (98.1%), with a combined half-life of 308,000 years.
The half-life of this hydrophilic nonreactive isotope makes it suitable for geologic dating in the range of 60,000 to 1 million years.
Where are the data and age calculations that result in a consistent set of ages for all rocks on earth, as well as those from the moon and the meteorites, no greater than 10 000 years? Second, it is an approach doomed to failure at the outset.
Life is well over 3.5 billion years old, and until about 600 million years ago, the planet was dominated by microbes.
Radioactive clocks have shown that evolution can change its pace the Cambrian Explosion of about 535 million years ago saw the relatively rapid emergence of many major lineages of animals in just a few million years.
C was mostly incorporated into the seawater from the atmosphere.
If the oceans that the plankton live in are stratified (meaning that there are layers of warm water near the top, and colder water deeper down), then the surface water does not mix very much with the deeper waters, so that when the plankton dies, it sinks and takes away Grasses in temperate climates (barley, rice, wheat, rye and oats, plus sunflower, potato, tomatoes, peanuts, cotton, sugar beet, and most trees and their nuts/fruits, roses and Kentucky bluegrass) follow a C3 photosynthetic pathway that will yield δ In contrast, C4 feeders will have bone collagen with a value of −7.5‰ and hydroxylapatite value of −0.5‰.
Darwin had finally gotten the luxury of time he had craved.