Are you suggesting that there is a link between evolutionary biology and this dude with the pink banana hammock? Maybe he's an evolutionary biologist out for a typical weekend on the town!
Posted on 11/04/2005 5:00:06 AM PST by PatrickHenry
Minerals help molecules thought to have been essential for early life to form.
A team of US scientists may have found the 'primordial womb' in which the first life on Earth was incubated.
Lynda Williams and colleagues at Arizona State University in Tempe have discovered that certain types of clay mineral convert simple carbon-based molecules to complex ones in conditions mimicking those of hot, wet hydrothermal vents (mini-volcanoes on the sea bed). Such complex molecules would have been essential components of the first cell-like systems on Earth.
Having helped such delicate molecules to form, the clays can also protect them from getting broken down in the piping hot water issuing from the vents, the researchers report in the journal Geology [Williams L. B., et al. Geology, 33. 913 - 916 (2005).].
"It's very interesting that the clays preserve them," says James Ferris, a specialist on the chemical origins of life at Rensselaer Polytechnic Institute in Troy, New York. "It shows that this could be an environment where complex organic molecules can be formed."
Some like it hot
Hydrothermal vents are created when seawater that has seeped through cracks in the seafloor is heated by magma just below the surface. The water streams back out of the rock in a plume that can reach temperatures of around 400 °C.
Vents are a favourite candidate for the site where life first appeared. Their heat provides an energy source; the minerals provide nutrients; and the deep-sea setting would have protected primitive organisms from the destructive meteorite impacts that scoured the planet's surface early in its history.
But researchers have long wondered how, if early life did form in this environment, it escaped being boiled and fried by the harsh conditions.
The Arizona State team has shown that clay minerals commonly found at vents can encase organic molecules, keeping them intact.
Between the sheets
The group simulated the vent environment in the laboratory, immersing various types of clay in pressurized water at 300 °C for several weeks and looking at the fate of a simple organic compound, methanol, in this stew. They chose methanol because their earlier work had shown that the compound could be formed in a vent environment from simple gases such as carbon dioxide and hydrogen.
Clays generally consist of sheets made of aluminium, silicon and oxygen atoms, which are stacked on top of one another. In some of these materials, such as the clays saponite and montmorillonite, there is room for other atoms and molecules to slip between the layers.
Spouting soup
The researchers found that the methanol in their artificial vent system was converted to various large organic molecules over six weeks or so, so long as the clay's layers were spaced widely enough to hold the compounds.
"The clay provides a safe haven for the organic molecules, essentially like a 'primordial womb'," the team reports. Eventually, changes in the clay's mineral structure caused by heat, pressure and time may cause the sheets to close up and expel the molecules inside. But they think that some of these could spout out from the clay into less hostile environments than the hottest part of the vent, creating an organic soup in which life might arise.
These findings add weight to the idea that clays were the key to the origin of life. Previous research has shown that clays act as catalysts for the formation of polymer molecules such as the precursors of proteins and DNA. They can also encourage lipid molecules to arrange themselves into cell-like compartments called vesicles.
So you're saying we should skip Medicine Hat and head straight to glamorous, glitzy Yellowknife...
If all individuals are equally fit, then selection doesn't take place and allele frequencies don't change. So hypothetically, if that were the rule, that all individuals in any population survive to pass on their genes, then that would invalidate natural selection.
Now there's a thought... Nope. To cold for me.
If the manifestation of that goal, or purpose, is realized, why should it now falsify the mechanism. How is the predicted conclusion of a premise, grounds for falsification, or disqualification.
The "goal" of evolution is the same as the "goal" of a snowflake.
Evolution is a result of the differential reproduction by less vs more fit individuals in a given environment (natural selection) combined with non-identical replication of DNA (mutation).
The no-identical replication makes variation, changes in the environment make selection.
Pile up enough changes and there is a new species.
Why do you have a problem with this?
Almost:
Genesis 2:7
the LORD God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.
Here's something else similar:
John 9:5-7
5 While I am in the world, I am the light of the world."
6 Having said this, he spit on the ground, made some mud with the saliva, and put it on the man's eyes. 7"Go," he told him, "wash in the Pool of Siloam" (this word means Sent). So the man went and washed, and came home seeing.
Mud: not clay.
How does one KNOW this?
What 'changes' faster?
the environment or critters who live in it?
Depends.
In a generally benign environment, there'll be lots of variation among the critters.
If the environment tightens up, many of the variants will be killed off.
Benign menas benign for the critter (which includes plants, bacteria etc).
YEC INTREP
Thanks for the ping!
Are you suggesting that there is a link between evolutionary biology and this dude with the pink banana hammock? Maybe he's an evolutionary biologist out for a typical weekend on the town!
Why?
I've heard that the changes in environment 'force' changes in the critters.
If not, then there would be lots of 'variation' in all KINDS of critters: humans included.
Noticed any wierd ones among us lately?
;^)
(Other than the check-out tabliods, that is....)
to here:
Since DNA doesn't replicate perfectly, offspring don't perfectly match parents. Slightly bluer feathers on a Blue Jay, or longer wings on a dragonfly, bigger teeth on a tiger...
all kinds of stuff.
If the environment is benign, none of this matters and most of the variants get to reproduce at the same rate as the rest of the population. Plus the variations don't show much, they tend to jitter around a norm.
Taking the Blue Jays...some are bluer, some are greyer, some fly a bit faster, all sorts of stuff.
Environment changes:
more rain consistently for several years: equals more clouds so the greyer jays survive better than the bluer or the normal ones (who, being easier prey for the hawks help to fuel a population explosion among the hawks). The normal poulation begins to look a bit different, despite the fact that female jays prefer to mate with bluer males (things are never neat in biological systems)
Eventually the "normal" jay looks greyer and flies faster than earlier jays did. The rest have been turned into hawk dinner so their genes have mostly disappeared from the population.
Now change the environment a bit.
We now have a normal population of slightly greyer, faster flying jays.
Does it stop there?
No.
You see, the climate didn't change all over so, over the mountain, there are still slower flying, bluer jays. But, of course, there's still that mountain. Some jays fly over, some don't, so the edges of the populations are still pretty variable.
But the population centers are more stable. Gradually on the grey side, those females who will tolerate greyer males reproduce more successfully.
More grey males and more grey tolerating females. We're on our way to speciation.
It's called paleontology - you can get a lot of info from a fossil. Much like forensics, a lot of information in a fossil is invisible to the unaided eye. If you'd really like to see all the steps it takes to get from the raw fossil to the reconstructed image, and aren't just being flippant about it, I'd suggest reading more about paleontology and possibly looking up the actual journal where this find was recorded. Me, I'm not an expert at paleontology, so I can't help a whole lot.
Vetustovermis is potentially one of the most important fossil finds of all time, if it indeed is what it is thought to be. Hopefully more fossils from its era will be found in the future.
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