Friday, March 28, 2008

Time Is Getting Short

Time Is Getting Short


I mentioned a couple of years ago
the fossil evidence that life existed at least 3.4 billion years ago--and the presence of an oxygen atmosphere suggests photosynthesis was already at work (thus implying life) 3.8 billion years ago. I also mentioned that this creates an interesting problem for evolutionists--how in the heck did this happen so quickly?

Richard Talcott, "Earth's troubled adolescence," Astronomy, May 2008, 32-37, has one of those very nice simplified explanations of early Earth history that Astronomy is good at presenting. The article points out that the Earth had a catastrophic beginning, with a Mars-size impact at about 4.52 billion years ago that stripped away the atmosphere, created the Moon, melted the surface, and generally, would have ruined your whole day, if you had been on Earth at the time. More importantly, after 500 million years or so of relative calm:
That started to change approximately 4.0 billion years ago. For a period of 200 million years, the rate of impacts skyrocketed as the young planets made a final sweep of the inner solar system. Astronomers don't know for sure what caused this "late heavy bombardment" or where the objects came from....

In any case, the number of impacts spiked....

Although the damage visible on the Moon is sobering, what transpired on Earth would have been far worse.... The late heavy bombardment should have created roughly 40 craters with diameters around 600 miles (1,000 km) and several as big as 3,000 miles (5,000 km) across.

Each of these behemoths would have transformed our planet. The energy released by just one big impact would have vaporized the oceans and much of Earth's crust. The temperature at Earth's surface would have climbed higher than the inside of an oven. These effects could have lingered for 1,000 years.
As the article points out, at 3.5 billion years ago, there was life on Earth. So we're talking about as little as 300 million years and a maximum of 500 million years from the end of temperatures that would have sterilized the planet, to fossils. That's amazingly quick for a blind, random, and necessarily slow process.

It turns out that there is considerable argument about when our atmosphere first had substantial oxygen in it. Here's a book by Stephen E. Kesler and Hiroshi Ohmoto, Evolution of Earth's Early Atmosphere, Hydrosphere, and Biosphere--Constraints From Ore Deposits that argues that there is still consider uncertainty as to whether the atmosphere had free oxygen at 3.8 billion years ago, or not until much later.

A 3.8 billion year free oxygen atmosphere almost certainly requires photosynthesis--and therefore life. That would mean that from sterilizing heat to enough photosynthetic life to turn carbon dioxide into oxygen would be a period between 0 and 200 million years. Blind, random, luck, starts to look pretty unlikely.

Frances Westall and Maud Walsh, "Early Life on Earth : 3.5-3.3 Ga microbial remains from South Africa," Geophysical Research Abstracts points to the 3.5 billion year old microfossils, and observes something that should be making shivers run up the spines of those committed to a blind, random process for life:
The latter is a relatively evolved mechanism for obtaining energy to drive cellular processes. Given the fact that these are amongst the oldest microfossils yet discovered, this implies that these oldest probable microfossils are already far evolved from LUCA, the last universal common ancestor, and that traces of the earlier steps in the origin and evolution of life are missing on Earth (rocks older than 3.5 Ga are too badly metamorphosed to be used in microfossil studies).
Hmmm: "far evolved" not just from the first life, but from the last life that was still a common ancestor of all life. And somehow, we go from life-sterilizing heat, through a completely random, blind process that creates life, and is already "far evolved" in 300 to 500 million years.

Those who insist that Intelligent Design is based on religious faith need to start asking why they are so confident that their model doesn't required a bit of faith to hold onto with data like this!

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