Thread: Please explain some of the evidence of Evolution

I would like someone to tell me what kind of evidence (fossil records, etc.) there are in favor of Evolution. I'm not trying to bash it, I just don't really know much about it. Anytime I've discussed it or been "taught" about it there has never been any real evidence. Everyone just acts like it is common sense and anyone who doesn't believe it is less intelligent or something. I realize that there isn't any real evidence for any kind of theology (which I guess evolution could be considered?) but I just wanted to know what kind of facts are out there so that I can make an educated decision for myself. I'm really not being condescending, I genuinely want to know what I'm missing.

Some theory:

http://www.ucmp.berkeley.edu/history/evolution.html

Some evidence:

http://www.txtwriter.com/Backgrounde...Vcontents.html

This is a huge subject with converging lines of evidence from all sorts of fields. You can have a Googlefest with it. Get a pot of coffee going, and search away! Stay away from sites claiming to disprove evolution until you learn what evolution is really about. Most (all?) of those sites don't understand basic science.

Remember - There is no debate in the scientific community as to whether evolution occurrs. Only about details of the mechanisms of evolution. Have fun.

this made me think about 2 words evolution and revolution (rebellion not rotation)

evolution occurs as a natural process taking an organism from one state ofexistence to another.
revolution is also the changing of a state of existence but is done consciously by the organism and is brought about by the disatisfaction of the state of existence that is to be changed from.

not sure if i made that clear, or if i was stating the obvious!
anyone know if these words have an etymological relationship?

The site I see proponents of evolution linking to most often is this one: http://www.talkorigins.org/ .

Though I've only skimmed it (I'm always interested in learning, but I don't need to be convinced about evolution) it seems to be a very well organized and educational site.

everything i know about evolution came from a TV series called Evolution, i think it was done by the BBC, but i never found it in any store i went to

Originally Posted by Wierzenskizzle

I would like someone to tell me what kind of evidence (fossil records, etc.) there are in favor of Evolution. I'm not trying to bash it, I just don't really know much about it. Anytime I've discussed it or been "taught" about it there has never been any real evidence. Everyone just acts like it is common sense and anyone who doesn't believe it is less intelligent or something. I realize that there isn't any real evidence for any kind of theology (which I guess evolution could be considered?) but I just wanted to know what kind of facts are out there so that I can make an educated decision for myself. I'm really not being condescending, I genuinely want to know what I'm missing.

On your journey, be sure to distinguish between 'evolution' and the 'theory of evolution' when making enquiries. Evolution is obviously a fact but sometimes gets carried over into the theory of evolution, then the distinction becomes a little fuzzy.

Jan Ardena.

I'll be lazy, since it's such a basic question:

What is Evolution?
Evolution is a change in the gene pool of a population over time. A gene is a hereditary unit that can be passed on unaltered for many generations. The gene pool is the set of all genes in a species or population.

The English moth, Biston betularia, is a frequently cited example of observed evolution. [evolution: a change in the gene pool] In this moth there are two color morphs, light and dark. H. B. D. Kettlewell found that dark moths constituted less than 2% of the population prior to 1848. The frequency of the dark morph increased in the years following. By 1898, the 95% of the moths in Manchester and other highly industrialized areas were of the dark type. Their frequency was less in rural areas. The moth population changed from mostly light colored moths to mostly dark colored moths. The moths' color was primarily determined by a single gene. [gene: a hereditary unit] So, the change in frequency of dark colored moths represented a change in the gene pool. [gene pool: the set all of genes in a population] This change was, by definition, evolution.


http://www.talkorigins.org/faqs/faq-...o-biology.html
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So, other examples of evolution are the evolution of HIV, of which there are several types now; the evolution of bird flu into a form that can infect mammals; the recent shortening of the snow lotus ( http://www.theglobeandmail.com/servl...enceandHealth/ ), the domestication of animals like dogs, etc...

Oh, and there are fossils that show the same kind of thing.

Thanks to all of you who responded, and thanks for the websites. What was the name of Darwin's book, and/or would I be likely to find it in a local bookstore?

"The Origin of Species", Charles Darwin. Got my copy at Borders bookstore.

Also, are there any books or websites or anything that let you see the fossils lined up in some sort of ascending order or something like that? I've heard people say that the fossils records record change, I just think it would be cool to see a line of fossils (like the diagram of the ape turning to man). Thanks.

It would be somewhat incorrect to say "ascending". Evolution is just change. Some animals evolve to appear more simple than their ancestors.

Evolution of horses and their legs:

Right, ascending is a little misleading. Although, the finished product should always be better than the starting point (based on my knowledge of evolution thus far). Anyway, I really apologize for my ignorance but now I'd like to know what exactly separates the classifications of different species'? That is to say, what are the rules that seperate a mouse from a hamster? This is important because how are we to know if the horse pictures above are pictures of different species? Or, is that the point of evolution; to get a new species from an existing one, going through many different species in between? Also, how are we to know whether or not these species were always there and one just eradicated the others?

Although, the finished product should always be better than the starting point (based on my knowledge of evolution thus far).

That is not precisely correct. Early life forms were perfectly suited to their environments, but environments change. Yes, every step of the way, the more well adapted members of the species survive better, and thus transmit the changes incorporated in their bodies. Some animals like bacteria haven't changed their general form since they first evolved.

Anyway, I really apologize for my ignorance but now I'd like to know what exactly separates the classifications of different species'?

The formal classification system relies on a definition based on wether two animals can breed fertile offspring. If not, they are two separate species. But, there are exeptions. There is a series of salamander species in California who's habitat forms the general shape of a ring. Every species next to each other can breed, but those farther apart cannot. Some plants and animals are undergoing a transition right now, so it's a gradation more than a punctuated speciation event, although that happens, too.

Or, is that the point of evolution; to get a new species from an existing one, going through many different species in between?

It is commonly accepted among scientists that there is no point or goal to evolution. It is a phenomenon that just happens as a result of the changing environment and the variability of the genome. There is often no single point at which you can say the species is transforming into another. That is to say, a mother never gives birth to a baby of a different species.

Also, how are we to know whether or not these species were always there and one just eradicated the others?

That's easy, if this were the case, then we would find fossils of all modern animals in every layer of strata. Instead, we find different creatures in every layer. In early layers, for instance, there are no mammals. So, mammals must have evolved later.

I guess it all makes sense, however, I'm running into the same problem as when I started off this forum. The evidence that I now realize that I'm looking for (I've heard most of this stuff already) is the "in-between" states of animals. When I say that I want to see a fossil line up, I don't mean the (for lack of a better thing to call it) "finished product". That is to say, where are the fossil records showing several stages of development in the transformation of the Hipparion to Equus? Not just, well there are these fossils that show a seeming progression when really it could just be that those are 4 different species who never shared the same DNA. That probably sounds stupid, but the reason that is important is because you already brought up rock layers, but I seem to recall a story of a whale skeleton they found sticking straight up through the layers. What I'm trying to say is that I don't know if I'm necessarily sold on dating by rock layers. Not that I don't believe something at the bottom is older, I just don't know if I can believe that a rock layer can be a few thousand years older than one above it. That whole the Earth is billions of years old stuff has never seemed right to me. Anyway, pardon my igonorance once again, as I am probably wrong on several counts, but feel free to correct me, that's why we are here!

Not just, well there are these fossils that show a seeming progression when really it could just be that those are 4 different species who never shared the same DNA.

Yes, that is possible, but unlikely. Otherwise we would see the different species in the same deposit. You are right, though, there can be parallel development. Neaderthals were not necessarily our ancestor, but we could both have evolved from the same primate ancestor long ago. Besides, there are other examples that prove evolution happens, like the vestigal limbs of a whale.

The Earth is constantly changing, with previously deposited layers sometimes folded and distorted. There are some layers in the grand canyon for instance that are millions of years older than the layer just above. What happened was that layers were deposited on top, eroded away, deposited again, wore away again, over and over, causing gaps in the layers. Sometimes layers are even flipped upside down! But, when scientists use layers for dating, they try to find the least disturbed areas.

That whole the Earth is billions of years old stuff has never seemed right to me.

I don't blame you for being incredulous, such vast lengths of time are almost incomprehensible, but this fact has been verified by several methods.

where are the fossil records showing several stages of development in the transformation of the Hipparion to Equus? Not just, well there are these fossils that show a seeming progression when really it could just be that those are 4 different species who never shared the same DNA.

What those pictures delineate is the evolution of the normal five-toed foot into the single-toed foot of the modern horse. How we know they are not different species is by consideration of all the other features of the creatures' bones that indicate that they are the members of the same genus. There is stuff like the precise number, shape and configuration of bones in the jaw, in the main part of the skull, in the shoulder, in the upper legs and in the tail. It is these which indicate family relationship, allowing us to recognise the evolution of the hooves as an event within the one genus.

Another way we can be sure that these are the same species is because of another extinct species called litopterns, which evolved hooves that are almost indistinguishable from horses hooves. But they are definitely not horses, and their feet are a clear example of what is known as "convergent evolution".