Late Heavy Bombardment

Surviving the Late Heavy Bombardment: We find that the “last universal common ancestor” – a hypothetical very early single cell from which all life on Earth descended – existed prior to the “late heavy bombardment”. This was a period of intense meteor bombardment sustained by our planet about 3.9 billion years ago. This is significantly earlier than the currently accepted oldest fossil evidence would suggest (estimating 3.5-3.8 billion years ago). The oldest confirmed fossils are from about 3.4 billion years ago, while the oldest potential fossils have been found on Greenland and date back to about 3.8 billion years ago. There’s also a suggestion that carbon found in a 4.1 billion-year-old mineral called zircon could be biological in nature. However, Read More ›