Three members of the science faculty yesterday chronicled life on earth from its beginnings to the present and looked into the future in an hour and a half for an audience of about 300.

Life on earth is actually older than previously thought, said Professor of Biology Andrew H. Knoll, who began the symposium, "Prospects for Life: Then and Now," with a slide show.

"We run out of geological record to examine before we run out of evidence for life," Knoll said.

After the first four and one-half billion years, Professor of Geology Stephen J. Gould took over, saying, "Geological time is so immense we can only grasp it in metaphor."

Gould challenged accepted theories and said that human existence was not inevitable. If one organism had not been successful, man might not have evolved, he said.

"If we play life's tape again, there's no reason to think the winners wouldn't be different," Gould said.

Gould pointed to the dinosaurs, saying that there was no biological reason for the dinosaur mass extinction, which he said was probably caused by some type of extraterrestrial impact.

Earth and Planetary Sciences Department Chairman Michael B. McElroy then took over the symposium, examining the present and looking toward the future.