View Full Version : Evolution revisited

2004-Nov-26, 05:04 AM
Hey, fellas!

This string is a shootoff of Evolution 250K, so we can discuss the following:

What's the best proof we have that evolution is not just a theory?

2004-Nov-26, 05:13 AM
I think that there is a record of the evoloutionary history of horses. They were very small once, and as they moved into the plains, they became faster and bigger.

2004-Nov-26, 06:54 AM
But is there any physical evidence today of those ancient horses? Nah.

If you are relying on the existence of species, try Coelacanthus.

2004-Nov-26, 02:09 PM
Originally posted by StarLab@Nov 26 2004, 05:04 AM
What's the best proof we have that evolution is not just a theory?
I'm not a biologist, so I'm speaking off the cuff here, but I think that staphlococcus development of immunity to all known antibiotics over the last sixty to seventy years is a good indication.

If you allow that virus's might be alive, the annual collection of new flu strains seems like a good indicator.

I saw a thing a couple decades ago about moths in London switching from being white to being grey because birds could find the white ones better on sooty buildings [as opposed to the flowering meadows that used to be their native habitat.

For larger creatures, the life-cycle is too long for us to watch it happening, unless you count the breeding of domesticated plants and animals on purpose.

Part of the problem of proof, is that strict opponents of evolution deny the fossil record. So you can use fossils to make the case to someone who is open to this subject, but you can only have a flame war about it with someone who isn't. For this reason, I urge you to be careful with this thread, and try to keep it about astronomy related topics.

Ola D.
2004-Nov-26, 02:45 PM
Mutation can be considered as a proof for evolution.
By gene mutation organisms can build up new characteristics to enable them to survive certain newly introduced enviromental conditions. Majorly, mutation is considered as disasterous; however, in this case specifically, it is a gift!

On the contrary, with all these justification, evolution is still considered as a "theory" to many.

2004-Nov-26, 04:35 PM
antoniseb, I read about the moths changing their colors after the industrial revolution. Since all the pollution turn everything gray, the dark moths survived because the birds couldn't see 'em and eat 'em. But some would claim that was just genetic drift.

2004-Nov-26, 04:44 PM
Here's a story about evolution caught in the action:
http://www.scienceagogo.com/news/200401221...trunc_sys.shtml (http://www.scienceagogo.com/news/20040122185500data_trunc_sys.shtml)

But remember Starlab, evolution is just a theory, just like the theory of gravity is a theory. The best you can hope for a theory is that it's widely accepted. Science is about always challenging existing theories to look for a better one. The moment you stop saying that something is a theory and has become a fact, you've crossed the line from science to faith.

Go ahead people, question evolution all you like, either it'll make the theory stronger, or demonstrate a new idea that explains nature even better. It's win-win.

2004-Nov-26, 04:47 PM
Originally posted by Tinaa@Nov 26 2004, 04:35 PM
some would claim that was just genetic drift.
It probably is not a profound change that prevents successful interbreding between the two groups, but it shows how one step of an evolutionary change can happen based on changing environment. [I am not claiming the prize advertised in the other similar thread].

2004-Nov-27, 01:15 AM
The moth example is perfect for at least backing up the theory. The change from one evolutionary step to the next isn't going to be stark. That's the whole idea. Changes in environment, for example, allow the usual mutants of a species to thrive. They survive while the so called normal others die. Right there is evolution happening.

I've been searching the web for something I watched on a documentary a while ago but can't find it (if anyone can please let me know, I'd like to read about it). In this doco scientists were searching for the "missing link" (which has a particular name which i also can't remember) between two recorded fossilised species of fish or insect or something. In order to go from one recorded stage to the next there had to be some inbetween stage that no one was able to previously find. They theorised what it would have looked like and how what sort of structure it would have had to be the inbetween stage. Eventually they found what they were looking for and the animal displayed the perfect inbetween stage of the two recorded speices. They showed how the environmental change at the time the first one diedout changed to allow the middle stage to exist. this environmental change didn't last very long and the next stage was born.

2004-Nov-27, 02:58 AM
:huh: Well yes .. we should be carfull with this subject becouse we dont want to offend or upset any one. We are a diverse comunity with people of all cultures and beliefs... so how do I say this without bringing the wrath of some apone me. Oh well here goes anyway... :rolleyes: The resone its difacult to prove the evolution theory is becouse of the ignorance of removed specific reference to a subset of people who dispute evolution. Now settle down a minut, Im not trying to upset them... Its just that you will never convinse the non evolutionest of there error becouse they disalowe (wont let you) use carbon dating or anything that might make their theory look shaky.. I would try to argue that the resone I axept the theory as fact is that the alternative seems so silly to me. So thats it then and to any whom I have offended I am humbled and sorry.
We have many examples of insects that have altered becouse of changing enviroments. I would even sagest that the bigger, fatter and lazy race of young people I see daily are an evolutionary change, right in our face.
Could I sagest the Ant infestation of our hommes is allso a evolutionary change.
My rediculuse spelling is a....... lets not go there.

2004-Nov-27, 05:43 AM
Maybe people do not accept evolution not because there isn't proof of it, but because evolution cannot explain some things. As we are seeing, there is plenty of proof, but maybe evolution does not explain things such as... I don't know... you find out, okay?

Dave Mitsky
2004-Nov-27, 11:40 AM
Why not work the question from the opposite direction and see what happens?


Dave Mitsky

2004-Nov-27, 01:15 PM
Originally posted by Dave Mitsky@Nov 27 2004, 11:40 AM
Why not work the question from the opposite direction and see what happens?
Thanks Dave, It's nice to have a list of the usual complaints against evolution, and a workable set of rebuttles. I am not sure what Starlab had in mind when he started this thread, but we are trying hard to not turn it into this kind of debate. So while I'm thankful for your list, I will have to squash further debate on it.

2004-Nov-27, 02:10 PM
If you are going to discuss evolution, it would be best to define what it is. I keep sensing in this string some of the baggage that comes with the word, that has nothing to do with the scientific concept. Example 1: the evolutionary ladder, that has as its intent the improvement of species. Example 2: that some species are more evolved or less evolved than others.
In the first case, the various reproductive schemes of sexuality, hermaphroditism, conjugation, syzygy, etc., only conserve whatever diversity was already present at the time of the organism's formation. They do not contribute, period.
In the second case, all creatures now alive are equally evolved. They are only 'more' evolved than extinct creatures.
In its original form, evolution had as its only source of diversity the phenomenon of mutation. Random violence upon genetic material by the environment (radiation, harsh chemicals, random breakage) creates new, different creatures. Most are monsters, which die. The very few neutral and pro-survival mutations are conserved by the reproductive process. Net result-- species become diverse. After a very long time (with luck) a widely diversified population is culled, by whatever environmental change comes up next (prolonged drought, extreme temperature change, asteroid impact, food species die-off). Wide sectors of the population, sometimes entire phyla, die, and their share of the diversity along with them. The offspring of the survivors determine the new level of diversity. Best authority on this kind of evolution: Stephen J. Gould.
In modern times two new kinds of evolutionary 'strategy' have been seen. Unlike the random acts of violence depicted above, these are directed, in the sense that they represent choices by the organisms.
1) Cooperative strategies. These include the usual sorts of living-together strategies, such as parasitism, commensalism, and so forth. The new twist is 'merged' creatures, more so even than lichen (=alga + fungus-- neither can live well without the other). Example: a paramecium-like animal, motile, hunts and ingests a single-celled alga. Before digestion can take place, it 'notices' that whenever it moves into the light, the alga gives off food. Result-- a new creature, able to move about, either to hunt prey or seek light for photosynthesis-- genus Euglena, an animal that can be a plant when it needs to. Primary expert on these strategies: Lynn Margulies.
2) Lysenkoism/Lamarckianism-- the genetic transmission of acquired characteristics. A formerly discredited doctrine, given new life by recent findings. Two examples come to mind: 1) Within your immune system T-cells and their helpers detect the presence of pathogens, and form immune reaction chemicals upon their surfaces. These cells then migrate to the sites of T-cell production, exchange a loop of genetic material with the 'mother' cell, which then begins production of disease-fighting variants of the contributing T-cell. If this had not happened, numerous times, you would already be dead. 2) The Escherischia coli which lives in your gut and helps you to digest the cellulose in vegetables, is the same as the E. coli that lives on your skin, but for the exchange of a few plasmids (loops of DNA). At the first chemical signal that the host has died, both can transform by the same mechanism to a phage version, which eats the decaying body. This area of research is too new to have a generally acknowledged leading expert.
I apologize for the length of this post, but it seemed necessary that we not be separated by a common language. My ex-wife uses a language which she calls English, which uses the same words as the English I speak, all of which have different meanings from the ones I use.
The point, of course, is that [ removed sad closing comment -a ] Steve

2004-Nov-27, 04:11 PM
Originally posted by wstevenbrown@Nov 27 2004, 02:10 PM
If you are going to discuss evolution, it would be best to define what it is.
I agree. The term has evolved since Darwin wrote his seminal work. It also means different things depending on the community of people you are speaking with. We will do well to adopt a unified and modern scientific definition for the term here. The late Stephen Jay Gould's take on it suits my usage pretty well.

2004-Nov-28, 01:52 AM
My favorite author on this subject is Daniel Dennett whose foundational premise is that evolution, both pre-biological and biological, is an algorithm naturally occuring and mindlessly applied by the universe. The essence of the algorithm is very simple. Modify, test, modify. Modify is randomly (within the constraints of the physics of molecules and their environment) applied and test is the purposeless function of natural selection. See Darwin's Dangerous Idea. See this (http://www.msnbc.msn.com/id/6534243) for the latest input from natural selection. Remember we are natural. I have repeated an input I made in another thread which is my version of what Dennett posits.

Consider the proto-stellar cloud in semi-stasis with collapse being initiated by a compression wave from a nearby explosion from a supernova. At first the controlling forces are those attributable to gravity, electricity, and magnetism (for now thermodynamics is considered to be a manifestation of the latter two interacting with gravity). Sometime later molecules with special electric charge controlled affinities for each other and being cast about in the mess form special conglomerates that eventually lead to living organisms (either in the cloud or, later, on the planets or moons).

These special conglomerates in the mess do not represent a new force, rather they introduce a special organizing process both causing and being dependent upon sets of strange attractors within the mess (directing the degree of order in the chaos) to produce a "quasi-discriminating" effect favoring the building of ever more complex carbon based molecules leading eventually to self replication. This causes the three dominant forces to be applied to the mess in a more orderly way and different from what was happening prior to the exercising of the affinities. Normally, we do not ascribe consciousness to this level of organization, but this prerequisite has put us on our way first to microbes thence to multicellulars thence to consciousness thence to technology development, thence to interstellar exploration, thence to engineering the universe.

Sometime later some of the conscious critters develop technology and begin to mold the universe into configurations of their liking including the building of planets, the moving of stars, the unwrapping of black holes, configuration control of clusters of galaxies, managing cosmological expansion, etc.

Note that we have recently experienced a quantum leap in how natural selection will be applied by consciously directing the modification of ourselves and most other members of our biota as well as the pre-biota. The real fun is about to begin.

Although no proof has been presented, I hope the plausibility of mindless, watchmaker-free-initiated evolution has been enhanced. I think Dennett is on the right track and moving in the right direction.

Ola D.
2004-Nov-28, 05:41 PM
Originally posted by antoniseb@Nov 26 2004, 02:09 PM
I saw a thing a couple decades ago about moths in London switching from being white to being grey because birds could find the white ones better on sooty buildings [as opposed to the flowering meadows that used to be their native habitat.

The moth thing isn't an example of a genetic change, it's only that the grey moths were capable to survive ; on the other hand, the white species were lead to extinction. I actually don't consider that as a proof.

In evolution, a species should adapt its conditions and hence modify accordingly.
An example would be , as Anton previously posted, the development of new strains of bacteria and viruses.. I'm using that as an example, yet I not sure if it can stand as a proof, because this is what we actually observed through the past decades. Other facts were mostly assumptions built on theories.

Ola D.
2004-Nov-28, 06:15 PM
To make things clearer to all:

Evolution is divided into two parts; micro-evolution and macro-evolution.
Micro-evolution is the slight changes in the organism's set of genes, which we all agree upon that this is not a theory and a fact. We actually have the proof for that which is the bacteria thing.

Macro-evolution is the radical change in a species. For instance, like fish developing to frogs or insects to birds. This is the concept which conflicts with our reality; and thus considered a theory. Now that's something else and this is the concept that should be proven ;)

2004-Nov-28, 08:25 PM
:huh: Same thread, diferent slant. "What of the next step."
Since the introduction of the home PC the computing power of these machines has doubled every two years since that date. In less than twenty years the lap top or its modern equivilant will have more computing power than the human brain. :blink: (a lot sooner in my case)lol :P Is this evolution. No its not, but its of some concern. Can we servive the logic of the machines. We are not esentual for the machines servival,They dont need us. we could be heading for our own extinction. :unsure:
Can I prove evolution has taken place.? Yes of corse I can... Look around your self. We have evolved.

2004-Nov-29, 02:06 PM
No its not, but its of some concern. Can we servive the logic of the machines. We are not esentual for the machines servival,They dont need us. we could be heading for our own extinction.
Not unless we equip them to reproduce themselves and don't control the off switch.

Ola D.
2004-Dec-06, 09:32 AM
Here's a very interesting explanation that some evolutionary biologists consider it as a possible proof for evolution. This fact suggests a possible origin for mitochondria and chloroplasts which are found in eukaryotic cells (Animal and plant cells).

Both mitochondria and chloroplasts contain a ring of deoxyribonucleic acid (DNA) double helix, just like that contained in a bacterial cell. They also contain small ribosomes (organelles responsible for protein synthesis) like those in prokaryotes (nucleus lacking cells, e.g Bacteria). These features have caused some evolutionary biologists to sugget that these organelles may be descendants of free-living prokaryotic organisms that came to inhabit larger cells. It seems a fanciful idea, but not an impossible one.

Present day prokaryotes are similar to fossil prokaryotes, some of which are 3500 million years old. By comparison, the earliest eukaryote cells date back only 100 million years. Hence, as eukaryotes evolved, they must have been surrounded by prokaryotes that were long-established organisms. It is possible that, in the evolution of the eukaryotic cell, prokaryotic cells (which at one stage were taken up into food vacuoles for digestion) came to survive as organelles instead. If so, they will have become integrated into the biochemistry of their "host" cell, with time.

Though it may be possible, do you think that such a suggestion real? And does it support the theory or makes it sound even more freaky?

2004-Dec-06, 02:09 PM
By comparison, the earliest eukaryote cells date back only 100 million years. Hence, as eukaryotes evolved, they must have been surrounded by prokaryotes that were long-established organisms. It is possible that, in the evolution of the eukaryotic cell, prokaryotic cells (which at one stage were taken up into food vacuoles for digestion) came to survive as organelles instead.
You may be off on the estimate of how long eukaryote cells have been around. Dinosaurs, built out of eukaryotic cells as were the plants some of them ate, endured over 250 million years (one galactic year) before dying out ~65 million years ago. My spin is that eukaryotes resulted from the attempt of prokaryotes to eat each other ending in a tie, an essential link in the series of events leading to us.

Ola D.
2004-Dec-06, 03:26 PM
By comparison, the earliest eukaryote cells date back only 100 million years.

I meant "1000 milion years ago".
Sorry for the missing "0" :)

2004-Dec-07, 05:11 AM
I don’t think one is ever likely to find the “Theory of Evolution” growing into anything more certain than a theory. No one could want it to become dogma; knowledge received without question and therefore with little understanding.

But, a little understanding of epistemology might be helpful:

A theory is an explanation of a set of related observations or events verified multiple times by detached groups of researchers, and capable of producing experimental predictions for a given category of systems. One person cannot create a theory; he can only create an hypothesis.

A theory is much more complex and dynamic than a law. A law is an observation about a single action, whereas a theory explains a whole series of related phenomena. Theories don’t change into laws.

Components of a theory can be changed or improved upon, made more elegant or concise, without changing the overall acceptance and usefulness of the theory as a whole. Theories lead to predictions that are later confirmed by experiment; and failed predictions that require re-thinking, and, most interesting and exciting, modifications and a deeper understanding of the phenomena.

We have lots of theories; and the things just stay theories: the Germ Theory of Disease; the Atomic Theory, the Special Theory of Relativity, the General Theory of Relativity, the Theory of Gravitation, the Theory of Plate Techonics, and many others.

The best of theories, including the Theory of Evolution, have been, or will be, shown to be in-complete: though they explain a lot of phenomena, and predict many new results. Eventually new experiments show a discrepancy between observation and theory, but the original theory may still be a very good approximation, and the key to a new explanation.


2004-Dec-10, 10:53 PM
There are theories and there are theories.
There are theories which try to explain new phenomena. There are old theories whose basic premise has been proven over and over again. They stood up to years of vigorous scientific research and discussion. Large volumes of other scientific work in practice and in theory is based upon them.

They become scientific law quite distinct in origin from religious beliefs.
Theory of Gravity and the Theory of Evolution can be safely placed into that category based upon having weathered the Scientific Method of research and evaluation over and over again.

Of course at their fringes these Laws get refined by theories trying to explain certain details of their workings.

I belief gravity explains some aspects of my physical surroundings, and I belief evolution explains some biological aspects of my surroundings but but
eventhough I no longer question their fundamental basis, this does not make them part of my religious beliefs.

2004-Dec-11, 01:25 AM
Originally posted by Frankw@Dec 10 2004, 10:53 PM
Hi Frankw,
Welcome to the forum.
I appreciated your moderate stance. Thanks.

2004-Dec-11, 07:35 AM
Frankw may have a moderate stance, but it's a stance on quicksand.

Scientific theories never, ever, become scientific laws. A theory is an explanation; a law is an observation. How can an explanation turn into an observation?

Scientific theory is as good as it gets in science; but that can be incredibly good.


Gambit Star
2004-Dec-16, 05:36 AM
Heres proof of evolution !!

you were once a fetus, now you are a fully grown adult !

Ola D.
2004-Dec-16, 11:07 AM
Originally posted by Gambit Star@Dec 16 2004, 05:36 AM
Heres proof of evolution !!

you were once a fetus, now you are a fully grown adult !
Hi Gambit Star,
Welcome to the forum, and thanks for your contribution :)

Growth and development is an essential characteristic of living things. An organism wouldn't be classified as a "living thing" if it doesn't undergo cell division and cell specialistaion to grow. So, I wouldn't consider it as a proof for evolution, it's rather a proof for living.

2004-Dec-17, 07:35 PM

i have to say that i don't believe that we have any real evidenese that can lead to a definite conclution. most infomation is speculation based on what we see around us and the fossil evidense.

the only way in my mind is watch over time for proof, because atleast then we can know for sure. If there was conclusive evidense i believe it would be exactly this just done earlier in time.

Gambit star, development from a feotus to and adult is definitly not evidense of evolution but rather of growth and maturing. :huh: evolution is the elimination of an off shoot (meaning a creature with a extra thick coat for example) of a species by natural processes, leaving only the off shoot with charicteristics that allow for it's survival in it's environment.

2004-Dec-28, 05:39 PM
Just my 0.02's worth ...

Talk Origins (http://www.talkorigins.org/) is a very good site from which to get lots of good data, links, analyses, ...

"Proof" and "prove" are not possible in science (cf maths) - the best you can do (as someone has already said) is a theory with a very wide domain of applicability that has been shown to be consistent with good observations and experiments, across the whole domain, to lots of decimal places. In this sense the best theory we have today is probably QED (consistent to 12 - or is it 16? - places!); QED is the marriage of QM and SR, and the latter a special case within GR.

In this sense, the theory of evolution is extraordinarily good - no chicken bones in Pre-Cambrian rocks, lots and lots of anti-biotic resistant strains of nasties, even Australian rabbits that are immune to myxo! A common attack on the theory - from those who don't understand much of it I might add - is 'where's the evidence that speciation is happening, today!?' The confusion that underlies this question may be a difficulty to appreciate just how long geological time is ... in multicellular animals, speciation happens ~once in a million years, but few of us can truly say we can grasp the idea of a million years. Oh, and there have been well documented speciations observed in historical times (even the last century), especially among plants.

Another confusion is between 'the theory of evolution' and 'the fact of evolution'. The latter is quite innocuous - it's simply a name given to a very well observed natural phenomenon (well, a wide range of phenomena actually) - fossil sequences, adaptations, development of (species) immunity, ... the former is the theory (actually several theories) which account for the latter.

Perhaps the most widely misunderstood aspect of the theory can be seen in references to 'progress' or even that 'humans are the pinnacle of evolution'. That evolution does not have a 'goal', that there is no more progress than a drunkard's walk can be seen by remembering that the earliest life on Earth for which there is good fossil records were bacteria, in the beginning it was the Age of Bacteria ... and it's no different today - bacteria outnumber all other forms of life, in biomass, in number, in species, in diversity, .... animals, plants, fungi ... we're all just a minor tail to the distribution of life on Earth. :blink:

2004-Dec-30, 06:52 AM
There is little point trying to convert the converted; The enquiring mind of the student or scientist will quickly grasp ideas of evolutionary changes. Some of which are obviouse some are not. You/we are never going to convinse people who beleve quiet firmly that the earth is only five or seven thousand years old. Norr should we try. They have every right to believe in this stuff they have been told is the truth. While you and I may well difer, disagree. we are not going to change this.
When you quiet elequently state that some aspects are widely misunderstood, and why. I think you are correct. A question I have is what do you think the human race may evolve into? or has our abilaty to manipulate our gene pool ment we will not evolve at all, but instead will alter ourselves to meet the new chalanges we must face. Its noted that the ethnicity of our people is changing rapidly. I can forsee in the not to distant future that all of humanity is going to be a blend of allmost every culture on earth. This has got to be a good thing. Some of them are extreemly atractive.

Darth Maestro
2004-Dec-31, 10:09 PM
I think that the findings of Acanthostega (very primitive tetrapod from the Late Devonian with eight fingers and toes bridging the evolution of limbs) and Icthyostega (well-developed limbs with five toes, just as all other land vertebrates) is substantial proof that evolution is not just a theory.

Also, I think since we now understand the concept of a black hole, the big bang is concievable that the contents of the Multiviverse/Universe could be contained into a single speck of space, as heavy as that sounds.


(apologies :ph34r: )

2005-Jan-01, 04:05 AM
Personally I think that evolution by natural selection stopped for humans when we developed societies and began to use tools which over rides any necessity to evolve extra strength or speed or whatever might be physically necessary to survive. It is possible though that brain power may be forced to evolve faster. I think we're entering an era where further "evolution" will only be what we select for and have nothing to do with actual survival.

Astromark mentioned how ethnicity is changing...this of course is because of how easily we're becoming able to travel and live wherever we want which means far more mixed race marriages. There's a term for the end result called the Race of Tan....in other words, in the long run everyone will have the same colouring (a good thing in my opinion).

2005-Jan-01, 10:02 AM
yep..! A bigger more advanced brain that works faster better or at all, would be good. and a nice shade of brown skin with dark thick hair...bring it on. We have a future, and its going to be interesting.