A timescale for the origin and evolution of all of life on Earth (https://phys.org/news/2018-08-timescale-evolution-life-earth.html)
(https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/2018/atimescalefo.jpg)
QuoteA new study led by scientists from the University of Bristol has used a combination of genomic and fossil data to explain the history of life on Earth, from its origin to the present day.
Palaeontologists have long sought to understand ancient life and the shared evolutionary history of life as a whole.
However, the fossil record of early life is extremely fragmented, and its quality significantly deteriorates further back in time towards the Archaean period, more than 2.5 billion years ago, when the Earth's crust had cooled enough to allow the formation of continents and the only life forms were microbes.
Holly Betts, lead author of the study, from the University of Bristol's School of Earth Sciences, said: "There are few fossils from the Archaean and they generally cannot be unambiguously assigned to the lineages we are familiar with, like the blue-green algae or the salt-loving archaebacteria that colours salt-marshes pink all around the world.
"The problem with the early fossil record of life is that it is so limited and difficult to interpret—careful reanalysis of the some of the very oldest fossils has shown them to be crystals, not fossils at all."...