Can you prove evolution to me?

Question

No, I'm not some sarcastic right-wing Christian fundamentalist trying to mock evolution. I'd like for people who know science to prove to me evolution. I know it's not easy to "prove" evolution, but can you at least show me how evolution is the logical solution?

Answer 1

First, as you may know, it is never possible to "prove" anything in science. All science can do is come up with the best posssible explanation for a set of facts (evidence).

Evolution is the best possible explanation for a number of facts in a number of different categories (sorrry this is long ... but there is a LOT of evidence):

1. Genetic evidence - These are the genes that we have in common with other primates. E.g. the fact that we have a huge number of genes (as much as 96%) in common with other great apes. Genetic evidence shows that we are more closely related to chimps than to the other great apes, and more closely related to great apes than to other primates (monkeys).

2. Molecular evidence - These are commonalities in DNA ... which is separate from genetic commonalities ... much of our DNA does not code for genes at all. But random mutations (basically 'typos') enter into DNA at a known rate over the centuries. This is called the 'molecular clock' and again gives excellent evidence of when humans diverged from other apes (about 6 million years ago, according to this molecular clock).

3. Fossil evidence - This is a huge category, but it can be summarized into three main subcategories: (a) stratigraphy - fossils always appear in a certain order in the rock layers ... more highly developed versions of an organism are always in higher layers than less-developed organisms; (b) dating - based on such methods as ratios of radioactive elements, we can tell how old a specimen is, and this confirms what species are older than others and how much time they had to develop; (c) geography - the location of the specimen on the planet is always consistent with the presumed location the species evolved ... e.g., we don't find kangaroo fossils in Egypt, only in Australia.

4. Speciation in the lab - Despite what some creationists say, speciation *has* been demonstrated in the laboratory. This is very difficult, because it can take thousands of generations ... and therefore experiments lasting for decades. But with certain fast-reproducing species like fruitflies and some plants, it has been done.

5. Proteins - These are the proteins in common with other primates. This includes things like blood proteins (the things that give us our A, B, O blood typing and the Rh factor (the plus/minus thing) which incidentally stands for 'rhesus monkey'); the exact structure of the insulin molecule; and my favorite, the photophigments: The photopigments are the three proteins responsible for color vision. The specific proteins found in human color vision are exactly the same as those found in Old World primates (the great apes and the monkeys found in Africa and Asia). These proteins are absent in New World primates (the Central and South American monkeys), and from all other mammals. In fact among the New World primates, only the howler monkey has color vision ... but these use slightly *different* proteins, coded on different locations and chromosomes, than humans and the OW primates. This is yet more evidence of a closer link between humans and the OW primates.

6. Vestigial structures - These are structures that are useless, almost useless, or just badly 'designed' (a word I use figuratively), that can only be explained in terms of descent from animals in which they were more useful. Things like wisdom teeth and the appendix are classic examples ... but my favorite is the plantaris muscle: The plantaris muscle is a long thin muscle in your calf that serves no useful purpose in humans. It is so useless that surgeons commonly harvest it for use in reconstructive surgery (such as heart surgery). In fact, it is so useless that 9% of people have no plantaris muscle at all. So why is it there? Because it serves a very important purpose in other primates ... specifically, grasping with the feet.

7. Homology - These are structures and proteins that have commonalities between species, but have a different function. The simplest examples are the fact that all terrestrial vertebrates have four limbs, and most have five fingers (e.g. bats, dolphins, whales, birds, reptiles, etc.). There are also homologous proteins. But my favorite are the five bones in the inner ear of humans and other mammals, which correspond in structure to the five bones of the hinged jaw of reptiles. These are evidences that evolution will often take structures left over from a now useless function, and repurpose them for a new useful function.

8. Embryology - This includes things like tails and gill folds in human embryos and those of all other mammals. But this also includes things that are evidence of other creatures are related to our branch ... such as legs and five webbed fingers, and distinct leg-buds in the embryos of dolphins.

9. Virology, bacteriology - This includes the development of immunity to antibiotics and antivirals. E.g., the tuberculosis bacterium currently affecting the world is quite different from the strain of TB that was around before antibiotics.

10. Taxonomy - The very division of organisms into categories and subcategories is explained by the idea of common descent. For example, all primates are mammals, all mammals are tetrapods, all tetrapods are vertebrates. This indicates that all primates sprung from a common mammal ancestor, and all mammals sprung from a common tetrapod vertebrate ancestor (i.e. that the development of a spinal cord came *before* the split between mammals and other animals, like fish, amphibians, and reptiles). If there were a *single* invertebrate mammal, that would throw the entire "common descent" theory out the window ... but there isn't.

(And there's more ... but I'm as tired of typing as I am sure you are tired of reading.)

However, a bigger point is this: while all of these independently are evidence of evolution, they get even stronger when considered *together*. For example, the molecular clock places the split between humans other apes at about 6 million years ago ... and the fossil record shows that humans and other apes split about 6 million years ago. And the split between New World and Old World primates suggested by the structure and genetic locations of photopigment proteins, is further confirmed by the molecular and fossil evidence.

Again, nothing *proves* evolution. But all of these facts are very very difficult to explain without it. Evolution provides simple explanation for all of it.

Answer 2

Logic only proves things in maths.
It is very hard to prove anything in reallity.
Laser beams mobile phones etc all work on unproven theory.
So does evolution.

Look up the Scientific Method to see how logic does play a part in scientificc enquiry.

Particulary get to know the concept of a working hypothesis.
(evolution is a working hypothesis i.e. it helps to explain observed phenomena; a lot of other 'Ideas'dont seem to contribute any understanding to that same phenomena.)

Then consider the fact that the fossil record (apart from extinctions)
Demonstrates evolution from the point of view of life generally becoming more sophisticated as time goes on.

There are some great other answers here too. I would add vestigal organs. The occaisional baleen whale and others are born with full external legs. (many whales have vestigal internal legs) Some humans are born with tails. A creationist I knew had extra nipples down his front similiar to a dog!

Recently some hox genes were turned on artificially in some mice and there ear bones tried to form a reptillian jaw!

Answer 3

Because of its very nature .. we won't get a hard proof like in mathmatics.

The pepered moth story is a classic example of relatively late evolutionary processes. See wikipedia below

But even this classic example is argued not to be a proof.

The more long term evolutionary processes are questionable .. but make sense. If you find in the stone some critter and we have a rather fundamentally better critter now .. it often points to what is now known as evolutionary processes.

Even harvard is going to take a closer look...see msnbc article

What often is not explained by any theory .. but fits more often on the evolutionary side .. is large improvements in short periods of time.

for example;
Modern Man, Cro_magon, and Neanderthal all can be explained by evolutionary processes known today .. and there is evidence that all three lived side by side .. and much evidence that Neanderthal was not so dumb. But how did we make the jump from really any of the earlier species. Those folks were significantly different. I am mainly thinking of the jump from homo habilis to homo erectus and the jump from homo erectus to homo sapiens. each species lived for what appears to be a long time, and then relatively quickly changed into the next type.

one doesn't have to be an athiest or even non-christian to believe in evolutionary processes.

I also like the Intellegent Design argument .. That god is guiding evolution and other things but that now has been over funded by fundamentalists recently so more recent documents are suspect.

James Hogan, one of my favorite scientist sf authors has his heritics's corner for alternative ideas. see link:

enjoy

Answer 4

Evolution is the best *scientific* theory for how life on Earth came into being. It is based on several lines of scientific evidence. No single type of evidence by itself is sufficient, but taken together, they are compelling.

1) The fossil record. The history of many living things is preserved in the fossil record. The physical changes in a species over time is apparent in the fossil record. It's limitation is that not all species get preserved as fossils.

2) Biogeography. This is the geographical distribution of species. Islands often have native species found nowhere else, but they are most closely related to species on the nearest mainland or neighboring island. Islands that are in different parts of the world but with very similar environments have vastly different species. This correlates with plate techtonics. Where land masses were once joined, related species are found.

3) Comparative anatomy. Anatomical similarities indicate relatedness. Homologous structures share the same anatomical set-up and indicate descent from a common ancestor. The typical example of this are the same bone arrangements found in a human arm/hand, cat foreleg/paw, whale flipper and bat's wing. Each have unique functions, but the bone arrangements are the same.

4) Comparative embyology. Closely related organisms go through nearly identical developmental stages as embryos. All vertebrates go through a stage with gill slits and tails (including humans). These structures may look very different in the adult, but their presence in the embryos indicate a common ancestor.

5) Molecular biology. The more similar 2 DNA sequences are, the more closely related are those 2 organisms. The DNA sequences between any 2 humans is strikingly identical. The difference in DNA sequences between humans and chimpanzees is only about 5%. There's also the fact that the DNA code is universal among living things (all living things have DNA, and it is deciphered in the same way in all organisms).

All of these lines of evidence complement, support and reinforce each other as the scientific explanation of life's origins. It is based on objective evidence from a variety of sources.

Answer 5

The first answer is a very good one. To really understand the majority of the science you would probably need a degree in anthropology, genetics, biology, and geology. If you want to get a good overview class, I would suggest taking a physical anthropology class from a local college. Or you could just do a lot of research on the subject. Like I said, there is so much to learn on the subject, it is hard to have a starting point.

Answer 6

We know for a fact that new species have replaced earlier species ever since life appeared on Earth. If you can think of a feasible scientific theory to explain this, other than biological evolution, you stand to become famous overnight. Until then, evolution is the only tenable theory that has been proposed that explains the observed evidence. That's how science works.

Answer 7

Yes, you're the before picture and I am the after picture. Thanks for the 2 pts.

God could have evolved us all for countless ages on the astral plane in what we call a dream and then brought the entire world into physical existence 6,000 years ago. Science cannot disprove this possibility (study quantum theory and the effects of a concious entity paying attention to an electron or photon) and religion does not specifically or implicitly rule it out, and there's no way for us to know for sure. We don't know and there is no way for us to know. More importantly, it does not matter. Please stop arguing one retarded side of this debate AND the other because both could easily be true. We are little kids in the universe and we need to worry about growing up a lot more than arguing over details in history. We say that "proving" one side of this or the other will "prove" the existence of God or not. There is no way for us to prove one side or the other, since both could be true, proving one side or the other wouldn't prove or disprove God, and it's just another part of the giant distraction from the important stuff.

Answer 8

You can't "prove" evolution. Scientist have found many examples supporting it, but have yet been able to prove it. There really is a difference!

Answer 9

Let's see - there's the fossil record (I'm not exactly sure how far back that goes, but it is known life existed about 3 to 3.5 billion years ago), that coincides with tectonic activity during Earth's history - and, like you said, it is the only logical solution to explain the variety of life we see today.

Answer 10

All I need to do is to look at the fetus of any living animal to show that evolution exists. In the beginning of life, many animals look the same. In the beginning, most animals start off as female. In the beginning, we have tails breath liquid.

The human embryo to fetus is a perfect example of evolution.

http://www.cbu.edu/~aross/embryo/10mmPig.jpg -- pig embryo very similar to human embryo

http://anti-ageing.us/graphics/mouse_embryo.jpg -- mouse embryo -- very similar to human embryo

This is proof to me that animals and humans arose from very similar origins.