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Article: Rocks reflect existence of life 2.7 billion years ago Discovery pushes trail of complex life forms back as much as a billion years
- Article from:
- The Milwaukee Journal Sentinel (Milwaukee, WI)
- Article date:
- August 13, 1999
- Author:
CopyrightCopyright 1999 The Milwaukee Journal Sentinel. Provided by ProQuest LLC. (Hide copyright information)
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Australian scientists say they have found evidence that complex
forms of life existed on the Earth 2.7 billion years ago, 500 million
to 1 billion years earlier than previously thought.
The life forms are single-celled creatures called eukaryotes, the
first known cells to have nuclei and specialized internal structures
for processing energy. Present-day descendants of this group include
all the higher kingdoms of life, like plants, animals and fungi, as
well as many single-celled creatures like amoebas.
The first life, simple bacteria with no nuclei, is believed on the
basis of fossils to have appeared by 3.5 billion years ago, and
possibly as long ago as 3.8 billion years ago. The Earth is ...