Image courtesy of Ingo Oeland/Alamy
Joel Kontinen
When did live appear on Earth?
Earth is some 4.5 billion years old. When it formed
from colliding rocks around a dim, young sun, it was presumably lifeless, and
geologists long thought that life didn’t emerge for a billion years or more. This idea came from analysis of moon rocks brought
back from the Apollo landings, which indicated Earth was pummelled by space
rocks between 4 billion and 3.8 billion years ago – appear n event called the Late
Heavy Bombardment. The implication was that the origin of
life as we know it must have begun after that, since any earlier organisms
would have been blitzed.
But science tells that Earth had live at the beginning just as Genesis says.
Fossils and
genetics are starting to point to life emerging surprisingly soon after Earth
formed, when the planet was hellishly hot and seemingly uninhabitable.
“There’s two
issues with that,” says Philip Donoghue at the University of Bristol,
UK. First,
models suggest that some life could have survived deep in the oceans. More
damningly, it now seems that the Late Heavy Bombardment didn’t actually happen.
The Apollo missions only created
the impression of a huge bombardment over a brief period because they all
collected rocks of a similar age.
We now know that, early in Earth’s history, large
impacts occurred sporadically over hundreds of millions of years. However, we also know that a body the size of
Mars collided with Earth just after it was formed, vaporising the planet’s
surface. “If life originated before then, it would have been
wiped out,” says Donoghue.
Life began when
inert matter self-organised into living systems, but, despite decades of
research, how that happened remains a mystery. Figuring
out when it happened is also a big challenge because the fossil record gets
worse the further back.
Those all speaks of creation, as Genesis tells us.
Source:
Michael Marshall
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