"Missing Link" Found!

[Bianca_Sommerland]

Still in process, last I heard. But if there was life, there's no telling how long it's been buried. Plus, some bacterial organisms are incredibly resilient.

So I've heard. Kinda like bugs. They'll outlive us all.

 

[Katyusha]

It's a fact. They tested the moon rock and found the same minerals and other elements present on Earth. NG had a special on a few months ago about it. There was definitive proof establishing it. The speculative part was the theory of the asteroid they knew hit Earth, but was it the rebound off of Mars, that has markings of a hit from a large object on the surface of it. Just the evidence they've gathered so far from the surface of Mars has been leading them to this conclusion. If a species of humanoid people lived on the surface when it hit, could their DNA have come here on it and grown in the primordial soup, to become us. Just speculation still, but the possibilty of us all being alien beings from another planet might be a proven fact someday.

You said, "It's a proven fact that an asteroid of considerable size hit the Earth and what was left, plus pieces of it and the Earth eventually compressed back together because of the slow rotational gravity to form our Moon."

First, we've known for awhile that the Earth and the moon are made up of the same minerals...that isn't news. Neither is the bulge on Mars that's left over from a collision with a large object. But
what's bolded above is not fact, it's still a theory. Models support it, other evidence supports it, but there is not yet proof that a Mars-sized object ever hit the Earth.

 

[Katyusha]

Cool. But I thought they found signs of former life on mars. Small organisms or something.

Still in process, last I heard. But if there was life, there's no telling how long it's been buried. Plus, some bacterial organisms are incredibly resilient.

The last thing I heard about that was the rocks found somewhere around Antarctica (?) with organisms in them that, because of the composition of the rocks, are thought to come from Mars.

 

[maggiemarie]

Wow, so much to reply too. Time to strap on (hah! pun!!) my science geekiness (and just to prove it, I actually am a science teacher!! w00t!)

However, I worry about the dating which appears to have been done by stratographic method which tends to be fairly inaccurate.

Rather than say this is a new direct link between apes and man, I will hold my thoughts. I see this claim every few years.

The stratigraphic method is always used, because the sedimentary rock formation that fossil remains are found in can not themselves be dated using any radiometric means (baring C14 dating of actual remains, but those must be less then about 50,000 years old).

However, volcanic layers both above and below the layer that A. ramicus was found in CAN be dated quite accurately using the potassium-argon method (among others). Once these absolute dating method establish the possible range, stratigraphic (or 'relative dating') methods can be used to nail down the age of the fossil in question with fair accuracy.

That is not a proven fact. It's still just a theory.

Bolded the dangerous bit. While it is indeed a theory concerning a large impact early in earth's history leading to the formation of the moon, you can't say 'just'. That is sloppy thinking.

A scientific theory is an idea that has been tested repeatedly and supported by reasonable amounts of data. In short, it is the best explanation we have that fits observation and experimentation, and has not yet been disproven by any means. It may be disproven in the future, but until then it is the best we have. Essentially, a "theory" in science is as close to claiming 'my idea is right' as any scientist will comfortably get. Its kind of a big deal.

The way you used 'theory', it should be replaced by 'hypothesis'. Even though the earth-moon thing is actually a theory.

Cool. But I thought they found signs of former life on mars. Small organisms or something.

Those findings were inconclusive. The 'fossil bacteria' originally reported are MUCH smaller structures then any known bacteria, and can be formed as the remains of purely chemical processes that and older Mars could well have had the conditions for. As far as planetary science is concerned, no one has found even remotely credible evidence of life every having existed on Mars...yet.

 

[slyc_willie]

The last thing I heard about that was the rocks found somewhere around Antarctica (?) with organisms in them that, because of the composition of the rocks, are thought to come from Mars.

The ALH rocks? Those were proven, disproven, then proven again, and again disproven. There's no consensus there.

 

[Bianca_Sommerland]

Wow, so much to reply too. Time to strap on (hah! pun!!) my science geekiness (and just to prove it, I actually am a science teacher!! w00t!)




The stratigraphic method is always used, because the sedimentary rock formation that fossil remains are found in can not themselves be dated using any radiometric means (baring C14 dating of actual remains, but those must be less then about 50,000 years old).

However, volcanic layers both above and below the layer that A. ramicus was found in CAN be dated quite accurately using the potassium-argon method (among others). Once these absolute dating method establish the possible range, stratigraphic (or 'relative dating') methods can be used to nail down the age of the fossil in question with fair accuracy.



Bolded the dangerous bit. While it is indeed a theory concerning a large impact early in earth's history leading to the formation of the moon, you can't say 'just'. That is sloppy thinking.

A scientific theory is an idea that has been tested repeatedly and supported by reasonable amounts of data. In short, it is the best explanation we have that fits observation and experimentation, and has not yet been disproven by any means. It may be disproven in the future, but until then it is the best we have. Essentially, a "theory" in science is as close to claiming 'my idea is right' as any scientist will comfortably get. Its kind of a big deal.

The way you used 'theory', it should be replaced by 'hypothesis'. Even though the earth-moon thing is actually a theory.



Those findings were inconclusive. The 'fossil bacteria' originally reported are MUCH smaller structures then any known bacteria, and can be formed as the remains of purely chemical processes that and older Mars could well have had the conditions for. As far as planetary science is concerned, no one has found even remotely credible evidence of life every having existed on Mars...yet.

Okay, I'm not even going to try and argue with a science teacher. I don't spend enough time in the real world to dispute anything you say. I find it all fascinating. I heard there were fossils. That's about it

 

[maggiemarie]

Okay, I'm not even going to try and argue with a science teacher. I don't spend enough time in the real world to dispute anything you say. I find it all fascinating. I heard there were fossils. That's about it

For recognizing my obvious genius (and not laughing at the geeky bits....they are cute geeky bits!!), you are of course forgiven...and show clear good taste

 

[Bianca_Sommerland]

For recognizing my obvious genius (and not laughing at the geeky bits....they are cute geeky bits!!), you are of course forgiven...and show clear good taste

Well naturally. I'm not too shy to admit when someones got me on brains. I'm clear left side (at least I think that's where creativity comes from? ) And by the way, it is adorable. You weren't snarky and I like that

 

[maggiemarie]

Well naturally. I'm not too shy to admit when someones got me on brains. I'm clear left side (at least I think that's where creativity comes from? ) And by the way, it is adorable. You weren't snarky and I like that

:hugs:

 

[xssve]

An interesting leap, but it doesn't pass the razor test - in fact amino acids and their precursors are found all around in interstellar space, just not necessarily Mars specifically - i.e., we did basically come from outer space, or the rather the basic building blocks of life did, it's unlikely that a entire replicating genome landed anywhere, it really isn't necessary, thin films are an adequate explanation.

Second, Ardipithecus isn't a missing link, there is no missing link, Apes and Humans are variations of a common ancestor, that's the whole point of the article - if Ardipithecus is a common ancestor, and there is no way of telling without DNA, then some part of the population went the terrestrial route, continued accruing terrestrial adaptations, and some other percentage of the population became arboreal specialists.

The Terrestrial adaptations themselves argue that Ardipithecus is not the common ancestor, but the terrestrial line of an even more distant hominid, since, if the hypothesizing in the article is robust, Ardipithecus is accruing terrestrial adaptations for the purposes of increasing reproductive fitness at a relatively high cost in terms of short term fitness, i.e., it's not exactly the path of least resistance, it's neither fish nor fowl - them Ardipithecus babes musta had it goin' on.

The terrestrial preadaptations Ardipithecus exhibits however, are the trends toward generalism that make homo Sapiens the successful species it would eventually become, and I have little doubt Ardipithecus made some significant contribution to the modern line.

 

[Bianca_Sommerland]

If evolution is accurate then isn't everything basically evolved from the same thing?

 

[xssve]

Perhaps, but parallelism theory argues that when conditions exist for a thing to occur, it can occur more or less simultaneously in more than one place and that Two or more instances need not be directly related, the Multiregionalism (MR) hypothesis for example.

In fact it happens all the time with research - often different groups of researchers are working on the same problem and they might come up with the same solution at the same time, without having shared their research - it simply reflects the fact that the state of knowledge, personnel, procedure, instrumentation, etc., make a solution to that particular problem likely.

In other words it's not entirely impossible for Two or more instances of a self replicating genome to spontaneously evolve more or less simultaneously - the conditions that led to it happening once would support it happening more than once - it's simply that you don't really need more than one instance for the sake of argument, and there is really no way of proving it either way.

 

[lance gt]

Well, not quite. When the Moon was formed, Earth was still a volcanically active, inhospitable place with no surface water. Panspermia wouldn't have applied then. Also, the impact on Mars that created the Tharsis Bulge on the opposite wasn't a rebound. It was a deep impact. Material was thrown off of Mars, which might have then landed on Earth a few million years later, but the comet/asteroid/whatever that struck Mars didn't go anywhere else. Most likely, this was the event which stopped the rotation of Mars' core, resulting in a truly dead planet.

That's what they were assuming with their theory that the Earth was knocked off it's orbital tragectory by an asteroid that put it the right distance from the sun for the planet to cool and water to form from massive condensation. The DNA could have survived in fragments long enough to evolve into organisms that we started from originally. Again, so the theory goes. They used a computer simulation of the impact and a PLAUSIBLE example of how it might have happened. It all makes sense and it's all explainable, but the proof is on its way soon, and we'll all know for sure.
"We are from the planet Mars, take us to your leader"

 

[xssve]

As another example, the wings of Bats and Birds are similar in terms of engineering, surface area to body weight, skeletal structure, etc. - these things are dictated by the laws of aerodynamics and vertebrate physiology, and each evolved the ability to fly completely independently.

 

[lance gt]

If evolution is accurate then isn't everything basically evolved from the same thing?

when you get down to the nuts and bolts of everything, there are common elements that everything shares together.

 

[3113]

Second, Ardipithecus isn't a missing link, there is no missing link

True. But it makes for a good thread title.

 

[xssve]

I did notice the quote marks in the thread title, I was responding to comments made in the body of some of the subsequent posts.

 

[dr_mabeuse]

It's a fact. They tested the moon rock and found the same minerals and other elements present on Earth. NG had a special on a few months ago about it. There was definitive proof establishing it. The speculative part was the theory of the asteroid they knew hit Earth, but was it the rebound off of Mars, that has markings of a hit from a large object on the surface of it. Just the evidence they've gathered so far from the surface of Mars has been leading them to this conclusion. If a species of humanoid people lived on the surface when it hit, could their DNA have come here on it and grown in the primordial soup, to become us. Just speculation still, but the possibilty of us all being alien beings from another planet might be a proven fact someday.

Of couse the moon and the earth have the same composition. They coalesced out of the same cloud of cosmic dust.

This is just a goofy-ass wacko theory that has no heuristic value whatsoever. It's Velikofsky, right? He was some hotel manager or something who decided that Venus had been a run-away asteroid that caromed off of mars and earth before settling down in its present orbit. No one but the tinfoil-hat crowd believes this nonsense.

Any organic matter on a meteor or asteroid would be nothing but soot by the time it went through the heat af atmospheric re-entry. Nothing organic can withstand that kind of heat.

There's a slightly more acceptable theory that sees organic molecules "raining from space" on small particles of interplanetary dust, which wouldn't fall as fast. It seems to me, though, that the odds of a DNA-soaked dust particle falling to earth are worse that the odds against life developing on its own right here.

As for explaining the origin of life, the theory is worthless, because, even if life did originate on some other world and come here, you still have to explain how it arose on the other world. At the same time, if it did arise on some other planet, what kept it from arising here as well?

 

[Verdad]

The 'giant impact hypothesis' is indeed the best-supported hypothesis of Moon's formation. As far as I know, though, it hasn't reached the status of theory and, needless to say, cannot become 'fact'.

According to the hypothesis, Earth was hit by a Mars-sized object—not Mars, and not an object that had been in contact with Mars; rather, an unrelated body that would have been of the approximately same size as Mars.

This hypothetical body is thought to have shared the Earth's orbit, which means it would have circled the Sun along the same path as Earth, maintaining the stabile distance from Earth by being located in one of Earth-Sun's Lagrangian points. The lock between Earth's and Sun's gravitational pulls would have kept the body in its stationary orbit, in much the same arrangement we find between Saturn's co-orbital moons or between Jupiter and its Trojan asteroids.

The disaster is speculated to have been set in motion when the hypothetical body accumulated mass, thus tipping the balance and breaking free from its position. Its slide toward the Earth would have begun, resulting eventually in an impact that would have knocked enough material from both bodies to serve for the formation of the Moon.

I'm hazy on the details, but there's more evidence to support this hypothesis than others, but also more than enough unanswered questions to keep it controversial.

As for panspermia, that's a completely different kettle of fish, as is the question of life on Mars. Neither seem to have much to do with Moon's formation; both seem to be highly problematic.

 

[lance gt]

Of couse the moon and the earth have the same composition. They coalesced out of the same cloud of cosmic dust.

This is just a goofy-ass wacko theory that has no heuristic value whatsoever. It's Velikofsky, right? He was some hotel manager or something who decided that Venus had been a run-away asteroid that caromed off of mars and earth before settling down in its present orbit. No one but the tinfoil-hat crowd believes this nonsense.

Any organic matter on a meteor or asteroid would be nothing but soot by the time it went through the heat af atmospheric re-entry. Nothing organic can withstand that kind of heat.

There's a slightly more acceptable theory that sees organic molecules "raining from space" on small particles of interplanetary dust, which wouldn't fall as fast. It seems to me, though, that the odds of a DNA-soaked dust particle falling to earth are worse that the odds against life developing on its own right here.

As for explaining the origin of life, the theory is worthless, because, even if life did originate on some other world and come here, you still have to explain how it arose on the other world. At the same time, if it did arise on some other planet, what kept it from arising here as well?

Well Doc, even though I'm not a science major, I have studied enough and seen enough evidence to know DNA can be carried by an asteroid and surviv an entry to our atmosphere. The asteroid that hit Earth, wasn't planet sized, it was a few hundred miles across. Still one big fucking hunk of rock to hit us. Mars has shown signs that it could have been inhabited, not sure of what, but millions of years have past and the planet is out of its original orbit. A species could very well have lived and developed there hundreds of millions of years before we started out. Remembering that this is a theory presented and not fact, the Big Bang was a theory too and now it's fact.

 

[Tio_Narratore]

What I find amazing is the found essentially complete skeletons after 4 million years. Leaky's original austrolopithicus africansus was on a hard pallet and part of the skull cap. Even Lucy was not nearly as complete.

However, I worry about the dating which appears to have been done by stratographic method which tends to be fairly inaccurate.

Rather than say this is a new direct link between apes and man, I will hold my thoughts. I see this claim every few years.


Not really stratigraphic, Jenny, but Potassium-Argon Radioactive decay. The Ardipithecus fossil was sandwiched between two undisturbed volcanic layers that can be very accurately dated using that method. The fossil is younger than the layer below and older than the one above, and that puts it at approximately 4.4 million years old.

 

[xssve]

The real significance of this find is that it abrogates the whole Savannah hypothesis and proposes a new selection stressor: it suggest that bipedalism may have been selected for because women are hard to please.

4 million years later, and nothing's changed, lol.

 

[3113]

The real significance of this find is that it abrogates the whole Savannah hypothesis and proposes a new selection stressor: it suggest that bipedalism may have been selected for because women are hard to please.

4 million years later, and nothing's changed, lol.

We're easy to please. Men just have a hard time figuring such things out. 4 million years later, and nothing's changed

For the record, though, I don't agree with the premise that we went bipedal because the men needed to haul food in their arms to get the females to have sex with them. Granted, humans are scavengers and being able to haul food helps us survive better than if we were hanging from trees (that's the deal here right? The hands aren't good for hanging from trees, but they are good for carrying food if bipedal). First, I don't see that sex has to be the reason why we hauled in food--shouldn't it be the other way around evolutionarily speaking? This mutation happens and the animals with it can haul more food so they produce more kids because they're better nourished.

Next, if the "ape" with this mutation can run with a baby in its arms faster from predators, then why wouldn't that be reason enough for it to succeed?

 

[Jenny_Jackson]

Well Doc, even though I'm not a science major, I have studied enough and seen enough evidence to know DNA can be carried by an asteroid and surviv an entry to our atmosphere. The asteroid that hit Earth, wasn't planet sized, it was a few hundred miles across. Still one big fucking hunk of rock to hit us. Mars has shown signs that it could have been inhabited, not sure of what, but millions of years have past and the planet is out of its original orbit. A species could very well have lived and developed there hundreds of millions of years before we started out. Remembering that this is a theory presented and not fact, the Big Bang was a theory too and now it's fact.

There's a problem here, Lance. This theory has the same problem that arrises with the meteor that killed off the great lizards of the Cretatious. That theory says the meteor landed to form the Gulf of Mexico. Oops! When Pangia broke apart it created the Gulf of Mexico from hump on the West side of Africa. You can't have it both ways.

Supposibly, if I remember, this meteor that created the moon struck some 3 or 4 billion years ago. Erosion from water, wind, subsequent earth quakes and additon meteor strikes have wiped out any evendence of this meteoric occurance.

 

[lance gt]

There's a problem here, Lance. This theory has the same problem that arrises with the meteor that killed off the great lizards of the Cretatious. That theory says the meteor landed to form the Gulf of Mexico. Oops! When Pangia broke apart it created the Gulf of Mexico from hump on the West side of Africa. You can't have it both ways.

Supposibly, if I remember, this meteor that created the moon struck some 3 or 4 billion years ago. Erosion from water, wind, subsequent earth quakes and additon meteor strikes have wiped out any evendence of this meteoric occurance.

I guess we'll have to talk to the nice folks at the astro-physics labs and get their opinion here. It's their theory after all, not mine. I'm just the boob in front of the tube, sucking all this shit up.