Space News Archive - April 20, 2004
What was the tipping point when microbial life took over for plant life, when bacteria first took the stage?Astrobiology Magazine -- The bacteria family tree may be facing some changes due to the recent work of an evolutionary biologist at Washington University in St. Louis.
- The navel or umbilicus.
- In Greek archaeology: A central boss, as on a shield, a bowl, etc.
- A sacred stone in the temple of Apollo at Delphi, believed by the Greeks to mark the 'navel' or exact center-point of the earth.