not people like organism
2007-03-22 12:32:22 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Biology
The timetable
3.6-3.7 billion years ago: appearance of life
2.5 billion years ago oxygen-forming photosynthesis
~2.2 billion years ago: aerobic respiration
~1.5 billion years ago: first evidence of fossil eukaryotes
The appearance of Life: anaerobic heterotrophes
3.6-3.7 billion years ago: appearance of life
Most likely first cells were anaerobic, heterotrophic bacteria
anaerobic = does not require free oxygen
heterotrophic = does not make its own food
2007-03-22 13:50:31 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Prokaryotic bacteria - one-celled organisms without a nucleus. They appeared approximately 4 and a half billion years ago.
2007-03-22 12:38:07 · answer #2 · answered by William S 3 · 0⤊ 1⤋
A species of bacteria
2007-03-22 12:58:08 · answer #3 · answered by Anonymous · 0⤊ 1⤋
Blue-green algae.
2007-03-22 12:36:30 · answer #4 · answered by Anonymous · 0⤊ 3⤋
i believe it was bacteria. Archaebacteria.
2007-03-22 12:36:03 · answer #5 · answered by Katie C. 2 · 0⤊ 1⤋