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Is Evolution Still Just A "theory"?

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If natural selection were obvious, why did it take Darwin and Malthus to point it out?
You're referring to statement #2 in JRS's proposed Law of Evolution, the one which I say cannot be a Law since it is a prescientificic tautology, that it is self-evident. A self evident idea is one which contains the evidence for its truth within the idea itself. It is self-evident that, once grasped, #2 is true. But ideas do not spring into the mind sui generis (created by pigs).
Natural selection says a lot more than "things which are capable of surviving survive".
We are not talking about natural selection, we are talking about clause #2.
Its semantically impossible, since if a male ever gave birth we would probably stop referring to him as a male.
Did you notice that you said it is impossible and improbable (which implies possible)? If it's impossible (on whatever grounds), then it would be impossible for us to refer to a male who gave birth as a male. There would be no "probably" about it. I personally don't accept your claim, but it's a theoretically testable one. When radically new existents come into play, their place relative to other existents has to be sorted out, and indeed what would happen is a new concept would be forms (probably something like a "girly man").
Appeals to nature here is just a refusual to give a more detailed explanation. "Everything acts according to its nature". Great. But this doesnt move us forward, and it has no explanatory value in this context.
I didn't think you were arguing my side, but now apparently you've decided to. Let's take this just a bit further: clause #2 reduces to the scientifically uninteresting claim "Everything acts according to its nature", and is not part of a supposed Law of Evolution.

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I actually think in biology that we have a little too much certainty, even without the laws. Perhaps this is not a problem with laws or theories, per se, but with people just not thinking. For example, the Central Dogma, which states the DNA is transcribed into RNA which is translated into protein, has around since the 70s, and unfortunately, it really it got in the way of peoples' thinking when it came to prions (those protein things that cause mad cow disease), which somehow reverse-translate into DNA (I think, I'm not totally sure on this but it's something like that - either that or RNA).

Sorry to jump in on this thread several months after this post, but I have to correct this. It has now been shown that prions are probably misfolded proteins that are able to induce the same misfolding on healthy versions of the protein. In this way, they "propagate" their misfolded state without any requirement to invoke DNA or RNA in any way. Here is a link to the nature news article describing the evidence: Nature News

I am not sure if you have to pay to see this content so I will summarize just in case. Basically the authors first showed that a prion protein in yeast was infectious; that is, transfer of only the protein could induce prion disease. Then they showed that this occurred even if they damaged the cells DNA and RNA synthesis ability. Then they showed that two different prion "strains" (same protein, different disease characteristics) could be distinguished based on structural features of the protein, suggesting that the difference between the disease characteristics was due to differences in the structural folding of the proteins.

This is now the strongest theory as to how proteins themselves can be infectious. It is far from proven.

So basically this example does not contradict the "central dogma". Nonetheless, science students are constantly taught models that are incomplete or incorrect. Teaching these models-as-fact definitely decreases the chances of a student identifying a different, equally plausible model.

Alice

PhD Student in Genetics

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Sorry to jump in on this thread several months after this post, but I have to correct this. It has now been shown that prions are probably misfolded proteins that are able to induce the same misfolding on healthy versions of the protein. In this way, they "propagate" their misfolded state without any requirement to invoke DNA or RNA in any way. Here is a link to the nature news article describing the evidence: Nature News

That is fascinating; I had not heard about this before. Thanks for the reference!

I should have given a better example of a very obvious example of violation of the central dogma: the activity of reverse transcriptase. I also should have said that the central dogma states that the information flow is only one-way. (Alice, I know you know this, but there might be some other people here who are a little confused about what I was saying before.)

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they simply call these 'theroies' because it's a title. These 'theroies' and 'cells' are words given to things people can prove correctly (most of them ). Except some astrological ones. We are still not really, really, sure if our universe is exploded from a dot. :glare: But so far its good.

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I think because biology is not of the form P1V1 = P2V2,V1 / T1 = V2 / T2, PV=NRT or

    Helmholtz7.GIF

The implication is that these equations give you the whole answer. You can compute reality from these simple rules. As biology becomes more experimental and less observational, legal concepts could emerge more strongly (unless science goes off the deep end and rejects causation and predictability). But bad luck, there really aren't any quantitative laws of (specific to) biology, instead you can study specific facts about how G, T, A and C can combine to ultimate cause blond hair or venom, which will be an application of more basic physical laws. So I think the lack of hard-core laws in biology is bad timing on the part of biology.

Lack of comprehensive biological laws, qua biological laws (as opposed to the underlying physical laws) is because biology is about stuff that is much more complicated than the physicists deal with. Subatomic particles as such have no history. They can be interchanged. Organisms do have a history and interchange symmetries are lacking. And this is just a start of the complication. Physical entities at the bottom are not the complicated (quarks have two or three components). The simplest one cell organism is much more complicated.

And so it goes....

Bob Kolker

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Consider the cell theory. Nobody will ever disprove it. It is a fact that life is made up of cells. However, in the world we live in, with all of the given physical laws, must life have evolved in the form of a cell? Must life have evolved at all? No. Given the same physical laws and combinations of elements and compounds, perhaps life would have evolved, perhaps not, and if it did, there is no guarantee that the cell would be the basic unit of life.

That is a very important observation! Super cool! There is an aspect of -contingency- that appertains to the biological realm that is lacking in the realm of fundamental physics. The specific nature of basic physical entities has been with us from the Beginning. Not so for biological entities. They came about through specific historical paths. And if we could rewind the Earth to what it was four billion years ago, it is not at all clear that we would get the same result (as you point out). S.J. Gould has made this point again and gain in his essays on natural history.

In addition to contingency, the biological realm is devoid (or nearly so) of global underlying -symmetries-, which is why we don't have any or at least many general biological laws.

General physical laws can be cranked out from an underlying Langrangian Density. No such good fortune holds for the realm of biology.

Bob Kolker

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We could get closer to a "law" by saying something like "The genetic instructions of all life is contained in DNA". The problem is that this would fail the certainty test because it hasn't been verified off-planet. If it turns out that DNA is the universal vector for genetics, that would be a stunning discovery, but until the question of life elsewhere is resolved, I don't see how there could be a law of evolution.

Our biological theories do not have to be true throughout the cosmos. They are about -life on this planet-. It is conceivable that living things on another planet might have very different machinery from that found on Earth. Biology is about Earth Life, not about Life In General. That is another way in which biology differs from physics. It is claimed that physical laws are general throughout the cosmos. We interpret what we see at a distance in the light of this assumption.

Bob Kolker

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As far as I know evolution has never been directly "observed" so it cannot be a law, but it is a theory because we have lots of evidence confirming the original hypothesis. In other words you can't watch evolution happening but you can see the evidence it leaves behind. Perhaps someday it will be possible to truly observe evolution taking place.

On a semi-related note: If we did indeed create life from chemical compounds using building blocks other then cells would cell theory cease to be true? Does that even make any sense?

Edited by Solid_Choke

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As far as I know evolution has never been directly "observed" so it cannot be a law, but it is a theory because we have lots of evidence confirming the original hypothesis. In other words you can't watch evolution happening but you can see the evidence it leaves behind. Perhaps someday it will be possible to truly observe evolution taking place.

Please look at this site:

http://www.eurekalert.org/pub_releases/200...--ned110306.php

Bob Kolker

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