New study suggests that it took very long for animals to develop life on earth. The atmosphere on earth lacked oxygen, and hence was not conducive to conceiving or growth of animals. It was only until 800 million years ago that animals can be found trace of on the face of the earth. Research led by Noah Planavsky from the Yale University suggests that, oxygen levels were at 0.1 percent as compared to today’s levels then, that means that the Earth’s atmosphere would have been inhospitable to most creatures.
“Although innovation in genetics and ecology is the key driving force behind animal evolution, low oxygen levels can stunt that growth. We looked for evidence by analyzing chromium isotopes from sediments in the U.S., Canada, Australia, and China. Earth’s continental crust contains chromium, and because chromium oxidation is directly linked to the availability of oxygen,” said Planavsky.
They researched the samples from older settlements, and also from the newer ones and compared the two. That’s when they realized how the oxygen levels were so meager than what they are in the developed world as of today. The team member of the research said, “It was chromium that allowed us to finally crack the code. Previously, scientists estimated that oxygen stood at 40 percent of today’s levels, which would have been more than enough to support animal life. However, the new findings cast that figure into doubt, suggesting oxygen was practically nonexistent in pre-animal times.”