Armed with a clipboard, compass, tape and grid paper, UCLA
professor Craig Manning and a team of geologists mapped the
outcroppings of a peninsula on Akilia Island in West Greenland.
The geologists hoped to find evidence to support their theory
that life existed on Earth far earlier than conventional wisdom
teaches.
By studying rock on the Akilia Island, scientists can look for
certain elements within the layers that would prove the existence
of life at certain points throughout the planet’s history.And
their discovery of evidence that life began 3.8 billion years ago
““ 300 million years earlier than previously thought ““
represents an advancement in their continuing research that began
10 years ago.
A decade ago, two of the scientists mapping Akilia Island and
another UCLA geologist published a small discovery that existence
of life began 3.8 billion years ago, but critics said the study
lacked concrete evidence.
So this year, study authors Stephen Mojzsis, assistant professor
of geological sciences at the University of Colorado at Boulder,
and T. Mark Harrison, professor of geochemistry at UCLA and
director of UCLA’s Institute of Geophysics and Planetary
Physics, joined Manning to return to West Greenland and thoroughly
re-examine their findings ““ for better or worse.
“It could have gone either way. We could have placed the
claim on much firmer footing, or we could have proved ourselves
wrong,” Harrison said.
Manning and the team of geologists worked for three weeks to map
Akilia Island, meticulously taping off the area in grid format and
then copying the measurements onto over 20 sheets of grid
paper.
The area was roughly the size of two football fields. They
camped in tents, used a small motorboat to transport them from
island to island, and weathered one bad storm that delayed their
return home.
After their expedition, Mojzsis, Harrison and Manning published
stronger evidence for the age of the rocks on Akilia Island last
month in the American Journal of Science. The study contained
Manning’s detailed maps, making their claim that life on
Earth originated more than 3.8 billion years ago stronger than
ever.
The scientists were able to deduce that life was present in West
Greenland 3.8 billion years ago by determining the age of ancient
rocks on Akilia Island indirectly, measuring the age of
cross-cutting rocks that had pushed up from the mantle below.
The geologists were able to work backward to get a picture of
what Akilia Island looked like millions of years ago by unfolding
each crease in Manning’s geological maps. The scientists then
looked for evidence for life in carbon isotopic evidence from the
rocks by analyzing carbon areas of the cross-cutting rocks at the
NSF National Microprobe Facility, housed at UCLA.
“Our study strengthens quite significantly the idea that
life was an early phenomenon on Earth,” said Mojzsis, who was
a post-doctorate research fellow at UCLA.
The issue surrounding the date when life emerged on earth comes
from the fact that the age of rocks is questionable. Rocks, which
chart the passage of time with their internal rate of chemical
decay, haven’t stayed the same since they originated. The
minerals in older rocks have changed from their original condition,
said Mojzsis.
“We don’t have a complete geological record for when
life emerged on Earth. … We have little pieces, hints,”
said Kevin McKeegan, co-director of the NSF National Ion Microprobe
Facility, a professor in the Department of Earth and Space Sciences
at UCLA, and an author of the original 1996 study.
“We are trying to answer the questions of the earliest
evidence for life on Earth … and this is as far back as we can
push it.”