The Earth is billions of years old and was once a very hostile place. Eventually, a single cell was formed that evolved and reproduced. What conditions produced this first life on Earth?
- Evolutionary Theory suggests that all forms of life evolved from one ancestor - the first cell.
- 4.5 billion years ago, conditions on Earth were similar to that of Venus, with very little oxygen.
- It is thought that hydrogen, methane and ammonia in the Earth's early atmosphere combined with the oceans to form a prebiotic soup.
- Exposed to ultraviolet rays of the Sun, the prebiotic soup reacted to form organic compounds such as DNA - the building blocks of life.
Charles Darwin, The Origin of Species (1859) - "All organic beings have descended from... one primordial form, into which life was breathed."
This theory of evolution - known as "universal common descent" suggests that humans are not simply evolved from an ape like ancestor, our heritage goes much further than that.
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