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19 de set. de 2022 · Learn about the mysteries and challenges of understanding how life emerged on Earth 4.3 billion years ago. Explore the possible scenarios, evidence and experiments conducted by UChicago scientists and others.
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. The similarities among all known present-day species indicate that they have diverged through the process of evolution from a common ancestor.
Structures of communities of microorganisms, layered rocks called stromatolites, are found from more than three billion years ago. Since Earth is about 4.6 billion years old, these finds suggest that the origin of life must have occurred within a few hundred million years of that time.
8 de mar. de 2024 · Learn about the possible origins of life on Earth, from lightning strikes to outer space to deep sea vents. Find out how scientists test these hypotheses and what challenges they face.
14 de jul. de 2009 · Timeline of the evolution of life on Earth | New Scientist. Life. Timeline: The evolution of life. The story of evolution spans over 3 billion years and shows how microscopic single-celled...
When did life on Earth begin? Scientists have dug down through the geologic record, and the deeper they look, the more it seems that biology appeared early in our planet's 4.5-billion-year history. So far, geologists have uncovered possible traces of life as far back as 3.8 billion years.
