Evidence for evolution?

Question

This is not an argument thread. I will not reply to any debate or arguments against evolution. This is a list thread only, please.

I'm going to write a comprehensive essay for the sole purpose to prove to my family members who don't believe in evolution that it's true.

I already know a crap load about evolution, but I'd like people to list everything they can think of that is proof of evolution. I probably already know most of it but the purpose of this is so I don't miss anything.

I'll start out:

Vestigial structures: we have structures that serve no purpose but are just remnants of ancestors who did use it. For example, the tailbone.

Answer 1

You already said vestigial structures, but I just want to add that my current favorite vestigial structure is the 5th pharyngeal pouch. Creationists always try to come up with some fuction for any vestigial structure, but I doubt many of them know what a pharyngial pouch is. Pharyngeal pouchs are structures that arise during early embryonic development. They form the gills in fish. In humans, the make the bones of the inner ears, and a couple other things. In some species, they make the lower jaw, among other things. Anyhow, all species have them. All species have exactly six. In humans, the 5th one is quite small and doesn't do anything, but it is there, and then disappears. Developmental biologists agree, it has no function in humans.

Now, to add a few new ones:

1. Microevolution can be observed in both a controlled laboratory setting and in nature.

Creationists will tell you that microevolution does not prove macroevolution. This is true. However, it does provide evidence that macroevolution may be possible. Taken in the context of the other evidence for evolution, microevolution provides a mechanism by which macroevolution could occur. On its own, it doesn't prove that macroevolution occurs, but it does suggest that it is possible.

2. The fossil record.

Although the fossil record does not provide a “complete” record as fossils form only under certain conditions, it does show a gradual change in the morphology of species as well as numerous extinct species. There are a number of methods used to date fossils, and the time period from which a fossil comes can be determined with reasonable accuracy.

In vertebrates, there are two main types of jaw bones. One arises from one of the pharyngial pouches (I don't remember which one), and the other arises de novo at some point during development. In adult animals, the two types are distinguished by the type of joint that connects the upper and lower jaw bones. All existent species of vertebrate have either one or the other. However, there's actually an exinct species that has jaws with two joints, one of each type.

3. Imperfect structures (the blind spot of the mammalian eye, for example).

I want to mention the bind-spot of the mammalian eye specifically because creationists often hold up the human eye up as an example of something that is too perfect to occur by "chance" (i.e. as the result of the natural selection of beneficial changes among random mutations).

There are also numerous examples where the morphology of a species is constrained by similar patterns in its ancestors (quadrupeds, vertebrates, etc.).

4. Developmental biology reflects evolutionary lineage.

Creationists like to bring up a man named Haeckel in response to this argument. Haeckel suggested that development reflects evolutionary origin. It was later discovered that several of the sketches he used as evidence over-exaggerated certain features, and some were of different embryos all together. However, many of his sketches do accurately reflect the morphology of the embryo. Haeckel's methods were sometimes wrong and his ethics were poor, but it just so happens that his theory turned out to be fairly accurate.

Any developmental biologist can tell you that embryos of related species show similar morphology in the early stages of development. The point at which their development begins to diverge shows a strong correlation with the relative point at which the evolution of the two species diverged. Human embryos look similar to chimpanzee embryos for a lot longer than they look similar to cat embryos, but all three develop similar structures in the early stages of development. The early embryos of humans, chimps, and cats are similar to each other but quite different from, say, a sea urchin embryo. This is based on photographs of actual embryos taken by respectable scientists, NOT on Haeckel's drawings.

I find it rather funny that creationists try to argue that because one scientist was a fraud we should disregard all of developmental biology.

5. Genetic analysis shows similarities among species reflecting evolutionary origins.

The main point here is that recent work has shown that the extent of genetic divergence among species is consistent with the expected separation based on the fossil record and morphological evidence. This supports the conclusions drawn from the other evidence.

Genetic analysis often reveals remnants of a gene that is functional in one species but not another (i.e. a mutation occurred that made the gene non-functional, but most of the sequence is still intact). Why would God have created non-functional sequences that are extremely similar to functional genes found in related species?

Also, non-coding regions of DNA show degrees of similarity that are consistent with the expected degree of evolutionary divergence. I understand how you could argue that God was essentially working form a common genetic template for all species, but why change the non-coding regions? These differences result from mutations that do not affect the phenotype of the species in any way but accumulate over time. Non-coding regions show sequences that are conserved with changes, and the number of changes is consistent with the number of mutations that would be expected to have occurred since the approximate time of existence of most recent common ancestor.

6. Homologous structures.

Homologous structures are structures that typically have similar morphological features and, often, similar functions, and are the result of evolutionary change of a single structure present in the most recent common ancestor of the two species. A homoplastic structure is one that may have a similar function and superficial appearance to another structure but is the result of convergent evolution (i.e. it was not present in the most recent common ancestry).

The most obvious examples of homoplastic structures are things like a human's hand and a gorilla's hand. A more subtle example is the human hand and the bat wing. Although the two structures clearly serve different functions, their bone structures are nearly identical. This is because the bat wing is a modified mammalian forelimb. In other word, the most recent common ancestor of the human and the bat was a mammal that had a forelimb with a bone structure similar to that of the modern human hand and other mammalian forelimbs. In humans this forelimb became the hand. In bats it became the wing.

An interesting example of homoplastic structures is the bird wing and the bat wing. Although the two structures clearly serve similar functions (i.e. flying), they are anatomically quite different. They have quite different bone structures and operate according to different mechanical mechanisms. In fact, the bat wing is structurally more similar to human hand than the bird wing. Incidentally, the bird and bat wings are homoplastic as wings but homologous as forelimbs.

That is just one example. The animal kingdom is littered with examples of structures that serve different functions but have extremely similar morphological traits, and structures that serve similar functions but show clear evidence of distinct evolutionary origin.

7. Many cellular and biochemical processes are conserved in a variety of species.

The point here is that virtually all cells utilize similar mechanisms of DNA replication and protein synthesis, share certain respiration pathways, and other biochemical processes. Related species show more similarities. For example, all plants are capable of photosynthesis, and utilize a virtually identical biochemical pathway to accomplish this. If you study cell biology you will find numerous examples of pathways that are common to different types of cells. I'm not going to go into this more here as it requires considerable background in cell biology. However, these biochemical similarities support they theory that all cells share a common ancestor.

8. Vestigial biochemical pathways (for example, pancreatic cells are light-sensitive even though they are located deep inside the body).

These are similar to vestigial structures at the cellular level. The specific example I mentioned is the light-sensitive behavior of pancreatic cells. Basically, the pancreas is located inside the body and will never be exposed to light. However, pancreatic cells grown in vitro (i.e. in a Petri dish, test tube, etc.) demonstrate light-sensitive activation of biochemical pathways similar to that seen in the cells that form the retina. There is no reason for this behavior unless this pathway is a remnant (i.e. a vestigial pathway) of a pathway present in an ancestral cell that did have come in contact with light.

There are many other examples of vestigial biochemical pathways. Like vestigial structures, their existence is easily explained by evolution but makes no sense in the context of creationism or "intelligent design."


And a few more resources:
http://www.txtwriter.com/backgrounders/Evolution/EVpage16.html
http://evolution.berkeley.edu/evosite/lines/index.shtml
http://fermat.nap.edu/html/creationism/evidence.html
I don't think any of those have anything I missed, but might be worth checking.

Answer 2

Tell them this:

Every fossil, every observation in biology points to evolution. There is nothing that goes against it or points to a different way to scientifically explain modern diversity. There is not one fossil or one piece of DNA that does NOT point to evolution. It would be hard NOT to see the concrete evidence, and only those blinded by faith can do this.

Evolution is 100% world-wide accepted fact, including the evolution of man.

There is ZERO evidence for a higher being causing anything. This is why people who are religious need faith, you can't see or study the actions of a deity, by definition. Evolution has ZERO faith and ALL evidence.

Scientists (real ones) have been studying and supporting evolution for over 150 years, and still nothing has pointed to creationism. There is clear links and transitional forms between everything in the fossil record to the Class-Family level, if not Genus-Species level. And this includes humans, which there are several 'missing links' which are well described and studied, people just choose to ignore this. Sure, there are still things we don't know, but that's why science is not stagnent and dead. We learn more every day, that's what happens when you keep an open mind and follow the scientific method.

There are some areas of evolution in which all of the pieces have not been found in the fossil record, but there is no counter theory that has even ONE piece of evidence that can not easily be explained by evolution.

Let me turn your question around, if Creationism was correct and science could definitively prove Creationism (and thus the existence of God), why would they not? That would be the greatest scientific discovery in the history of the world. No one would pass that up to maintain the 'status quo'. There is no conspiracy to hide creation evidence. Anyone who knows real scientists knows they are glory-mongers first. They love to prove others wrong to enhance their own standing. And if any scientist could prove Creation/God, it would've been done a long time ago.

Go to a museum, take a class in biology, go to reputable sites on the Internet (like AAAS: http://www.aaas.org/news/press_room/evolution or http://www.talkorigins.org ) and find out for yourself.

Answer 3

Some humans are still born with tails. These days a doctor will descreetly cut it off at birth but I worked at a nursing home and met an elderly woman, about 90 yrs old that had a small stubby tail, it was never removed.

Dogs had an opposable thumb.

Baby ape skulls look just like baby human skulls. (had a professor in college bring a replica of each in and asked the class to tell which was human and which was ape, most couldn't tell).

Dolphins once lived on land. Turtles are evolving to the point that one day they will live solely in the water.

Answer 4

- The fact that all organisms have a parent or parents and the fact that offspring inherit traits from the parent(s).

- The fact that not all individuals pass on their traits equally, ie. not all individuals survive to reproduce, or just reproduce, equally well.

- The fact that changes in the heritable traits of a population over successive generations, as determined by shifts in the allele frequencies of genes, is abundantly observed.

- The fact that DNA mutations occur. And the fact that the very rare positive mutations are observed to be selected for (and negative ones selected against) by Natural Selection. And that positive mutations are observed to spread thru populations quickly.

- The fact that mutations are observed to add information to the genome (as well as delete) via duplication of stretches and polyploidy etc.

- The fact that speciation has been observed in the lab. eg. fruit flies and plants, and in the outside environment, eg. in mosquitos and fish. And the fact that closely related species can't interbreed successfully (no, or sterile, offspring) hence stay separate.

- Observations of gradual transitions between some of the most abundant fosil species, eg. among planktic foraminifera: Globigerinoides trilobus to Globigerinoides bisphericus to Praeorbulina sicana to Orbulina universa (link). And countless other examples.

- The fossil record of 200,000 to 300,000 species which shows systematic change from one species/genus/family to the next up the geological column.

- Consistent pylogenetic trees from fossils, DNA and molecular clocks.

- Present and past biogeography - new species originating close to the old one (except in cases of extreme mobility)

- Homology - structures and proteins which are common between widely separated species, but which have a different function.

- Embryology, eg. gills & tails in mammal embryos and leg buds in dolphin embryos.

- Molecular vestiges

ok, I'm done, pfew!

Answer 5

You would fail to make believe them in evolution. You better love them and don’t argue, keep your opinion for yourself. The whole lot of scientific theories is not worth to feel unfriendly to your folks. As for evolution I guess the best data are shown by archeology and fossils you can find in Wikipedia – astonishing evidence.

Answer 6

look up pesticide resistance in locusts. Also the peppered moth and industrial revolution. Both are current examples of survival of the fittest.

Answer 7

Enraged parrots site looks very comprehensive. Do not expect to change " true believers " minds that easily, though.

Answer 8

How's this?

http://news.yahoo.com/s/ap/20061105/ap_on_sc/japan_dolphin_legs_4

Answer 9

Check out this site for lots of info on evolution.


http://wiki.cotch.net/index.php/Main_Page

Answer 10

comparing the fetus development of different species.

Answer 11

http://www.godlessgeeks.com/LINKS/Science.html

http://www.livescience.com/animalworld/top10_vestigial_organs-1.html