Agnosticism, Atheism, Christianity, Creationism, Culture, Education, Faith, God, Intelligent Design, Religion, Science, Truth

The Evidence for Evolution Part 1

When I was growing up, I never for a minute considered that evolution might be true. I already “knew” that the Bible was the inerrant word of God, so evolution was simply error. And in my high school biology classes, our teacher made it clear that she had to teach us about evolution by law, despite the fact that she didn’t believe in it herself. I had a handful of friends who believed it, but we never really talked about it. Even if they had, I knew they weren’t “true” Christians, so it was no surprise that they held “inaccurate” ideas.

Many years later, after I had left Christianity, I decided to give evolution another look. I was completely blown away by the amount of evidence I encountered. And so many of the criticisms I had heard against it, that it was “only” a theory, that the fossil record contradicted it, that it had never been observed, that positive mutations were so rare there hadn’t been enough time for this diversity of life to develop, etc were all untrue.

Now as I stated in my last post, I don’t think evolution and religion have to be at odds, so I’m not trying to criticize religion in this post. I think there are many ways for Christians to hold onto their faith while also accepting what science tells us about evolution. So without further ado, here’s the first post in a series that will present some of the evidence for evolution:

Geographic Distribution — Microevolution
When Charles Darwin was a young man, he spent 5 years traveling the world via the HMS Beagle. During the voyage, he managed to spend some time in the Galapagos Islands, about 600 miles off the western coast of South America. One of the things that really struck him was the diversity among the various species of finches there. He identified at least 14 different species, each of which had beaks that were specially suited to their particular food source: ” three species of ground-dwelling seed-eaters; three others living on cactuses and eating seeds; one living in trees and eating seeds; and 7 species of tree-dwelling insect-eaters” [1].

This type of variation is known as adaptive radiation, and it’s a form of microevolution. In case you’re not aware, microevolution is a term for the changes that occur over time within a species — different breeds of dog, variations in height among a population, etc. Almost no one objects to this type of evolution. Macroevolution is a term for the changes that occur over time from one species to another. Quite a number of people object to this version of evolution; however, it’s really no different than microevolution. It just requires a longer period of time.

How did Darwin’s finches evolve once they reached the Galapagos Islands? As they settled among the different islands, they encountered different food sources. Scientists believe the first finches that arrived there were of the ground-dwelling, seed-eating variety. Some of the birds wound up in places where their typical diet was more scarce, but larger, harder seeds were available. As you might imagine, the birds with thicker, stronger beaks could eat that food more easily than the birds with thinner, weaker beaks. They survived better, and simply out-bred the others. Since they were separated from the rest of the finch population, the changes in their physiology became more and more pronounced over time. So there are two factors that are very important in evolution: separated populations and scarce resources.

But the importance of geographic distribution goes much further than this example. Islands are isolated from the other main land areas. Not-so-coincidentally, they also have vastly different plants and animals. Hawaii, for instance, had no land animals until the arrival of humans. There were only birds, bats, and insects living there. Considering how far away Hawaii is from other land masses, it makes sense that if any animals were to migrate there, they would be flying animals. However, if God had created all animals exactly as they are today all at one time, there’s no obvious reason why he would have left Hawaii barren. If it had been teeming with the typical creatures we find elsewhere, that would have been good evidence against evolution.

Australia is also isolated from the other continents, and it provides another fascinating example. Prior to humans, Australia had no placental mammals (dogs, cats, deer, horses, etc). Instead, it contained many species of marsupials that never developed anywhere else in the world. While koalas and kangaroos are some of the most familiar to us, there are other marsupials that developed in Australia to fill niches left empty by the animals most of us are more familiar with. For instance, Australia had no wolves, but Tasmanian tigers developed to fill a similar role. Australia had no cats, but the Thylacine developed to fill that niche. Instead of rats, Australia has bandicoots and bilbies. If God had created all animals just as they are all at one time, why create marsupial versions of animals when there are perfectly good placental animals that could have filled the same roles? And why do it in such an isolated spot? But when you look at it from the view of evolution, it makes much more sense. Marsupials found their way to Australia long, long ago, when Australia, Antarctica, Africa, and South America were all part of a larger continent, Gondwana. When that continent broke up, and Australia began to drift away, the isolation necessary for evolution was achieved. As time went by, more and more changes occurred among marsupials, culminating in the various species we know of today.

But that may be jumping the gun a little. It’s one thing to talk about differences among finches, but one species changing into another is a completely different matter. How could that be possible? We’ll get into that; just follow along.

Part 2 can be found here.

104 thoughts on “The Evidence for Evolution Part 1”

  1. Hi Jason,

    Thanks for your comment. I’ll state up front that I’m no expert on evolution, and I have no stake in it — if it ever turns out to be incorrect, that will be no skin off my back. However, the overwhelming consensus of scientists in the fields of anthropology, archaeology, geology, biology, astronomy, and geology believe in an old universe and the theory of evolution. That doesn’t necessarily make them right, but it’s at least something to consider.

    To your point about a global flood, I wasn’t trying to purposefully ignore it. It’s just that the evidence doesn’t bear it out as an actual event. There’s not a good explanation of where all the water would have come from, for one thing, or how all existing species would have fit onto one boat, or how every species from the entire earth could have gotten to Canaan. There are also ancient cave paintings (like those in France’s Lascaux caves) that would not still be there, had they been submerged in a global flood. The Cosquer Cave (also in France) is good evidence of what happens to these cave paintings when submerged.

    There’s also some good information here that detail some other problems with the flood idea:
    1) Why do the earth’s mountains appear to have different levels of erosion, if the flood was the cause of it all?
    2) Why is there no evidence in ice core samples (that go back at least 40,000 years) or tree rings (go back more than 10,000 years).
    3) Why do we have our current polar ice caps, since they would have been broken off their foundations by the flood?
    4) Why is the fossil record sorted in a manner that’s consistent with evolution?
    5) Why are there “surface” features (like evidence of raindrops, animal burrows, footprints, cave systems, meteor craters, etc) in layers that are far from the surface?

    To your second point, from what I can gather, most biologists do not agree that genetic material is only lost and never gained through mutation. It’s not uncommon for a gene to be duplicated and for that gene to later gain a new or different ability. You can see some info on that here, here, and here.

    Again, this topic is not my forte. There are others who frequent this blog that could probably discuss this more intelligently than I’m able to. I assume from your comment that you do not believe in evolution. If that’s so, could you explain why? As I said at the beginning, the vast majority of experts in these related fields are convinced that evolution is true. While that’s not a guarantee that they’re right, it does carry a lot of weight with me. Why do you think they’re wrong?

    Thanks again for the comment. 🙂

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  2. Nate, I was about to reply, but you beat me to it and said it all. 🙂

    This link is another interesting article on gene duplication. By my reading it has been observed in labs. Jason, is there information you have read that shows that the info that Nate and I have provided about gene duplication is false?

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  3. Jason, I think Nate did a good job of responding to your comment, but I have at least an hour’s worth of material rebutting anything you might have to say about the “global” flood that was plagiarized from a local Euphrates River flood in Iraq in 2900 BCE, if you care to contest his response.

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  4. Thanks for the replies.

    I was advocating neither for or against the flood’s existence. Allow me to clarify my point to all who may have misunderstood. Nate, you attempted to discredit the Christian view of the creation by stating “if God had created all animals exactly as they are today all at one time, there’s no obvious reason why he would have left Hawaii barren.” Since you are attacking a Christian view, it is important to approach the argument as a Christian, otherwise the argument is immediately discredited (In the same way, I assume you would hope for a Christian arguing against atheism to approach said argument as an atheist). Because you failed to fulfill this requirement for a strong argument by completely disregarding the Christian account of the flood, your point becomes quite futile and weak in the eyes of a Christian (or person of similar belief), which is your apparent target audience. Finally, such a weak argument implies a “quickly-thought-out and unreliable article.” That was my point.

    I understand and acknowledge the scientific arguments against the flood and will not attempt to disprove them. I will, however, specifically address Nate’s fourth point: Why is the fossil record sorted in a manner that’s consistent with evolution? The answer is quite simple. Evolution is based on the very same fossil record. Using this evidence to advocate for the reliability of evolution itself is circular reasoning. Also, evolution, being a product of science, is subject to new scientific discoveries, and may therefore constantly adapt to new data– new fossil records. In the same way that new discoveries sometimes change and build onto the evolutionary theories, others fall in line and support old theories.

    I will read these articles and research further into evolution, but just as you made sure to make so clear, I am also no expert. I based my earlier reply on past research of mine, and I still support my claims, but I will be sure to research further and read the articles you posted. I have not been able to fully read these articles in such short time, since I am currently quite busy. Saying that, I will definitely be sure to do so. I have responded now in order to address what I can. Hopefully, I will get back with you soon enough. Again, any responses are welcome.

    Jason

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  5. jason, I’m still not sure I’m understanding your point. What about the biblical flood and evolution?

    And you said, “Evolution is based on the very same fossil record. Using this evidence to advocate for the reliability of evolution itself is circular reasoning.”

    This is not an example of circular reasoning. Circular reasoning would be like, “We know that Mel Gibson’s William Wallace never lies, because he told us he never lies, and since he never lies, we can trust everything he says.”

    Or, “Evolution is true because religion is silly, and since religion is silly and doesn’t teach evolution, we know that evolution is true.”

    Or, “we know the bible is god’s word, because the bible is the only book that tells us about jesus, and jesus says the bible is god’s word.”

    But I think I see where you’re coming from in your comment, but you may ought to look at the comment in its context instead of in a vacuum. The two theories briefly hinted at in the article were evolution and creationism. If everything was created all at once, we’d expect to see the fossils all mixed up at every level. If evolution was correct, we’d expect to see the fossils separated by more complex fossils near the surface and descending to lesser and lesser complex fossils in deeper levels. As it stands, the fossil record supports one theory over another. How is this circular?

    You were correct is saying that evolution, as anything else we know, will change and shift as we learn more. It is one of the virtues of science. It encourages learning.

    I assume you would hope for the non-religious arguing against creationism to approach said argument as a non-religious. Because you failed to fulfill this requirement for a strong argument by completely disregarding the obvious interpretation of the author’s comment regarding the fossil record, your point becomes quite futile and weak in the eyes of most people here, which is your apparent target audience. Finally, such a weak argument implies a quickly-thought-out and unreliable comment.

    Now, if you’d like to discuss the fossil record or any other form of evidence, we are all ears (eyes).

    But this is just me. I may be mistaken, so take the above for what it’s worth.

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  6. Hi Jason,

    Thanks for your follow-up comment. I appreciate the feedback about my original post, and I’ll keep your points in mind. I’m pretty busy myself right now, so take as much time as you need in researching those articles. I hope they’re helpful, and if you run across anything interesting, please feel free to come back and share it with us! You’re welcome here any time.

    Take care,

    Nate

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  7. Hey Nate! Great start–just 2mon ago I FINALLY, after being out of church and most religion for over 5yrs, read back-to-back Origin of Species and Why Evolution is True.

    I really can’t describe (though for you, probably no description is necessary) how surprised I was. Mostly I had accepted evolution since my loss of faith, but I hadn’t actually RESEARCHED it. Reading up on it was an eye-opener–all the ministers in my church had LIED to me about evolution…either that or they were woefully uninformed while thinking themselves experts. I had always wondered how scientists, who are supposed to be so smart, could believe in a theory so STUPID…guess it was only the version I was getting that was stupid. At summer Camp one year there was even a lecture on “7 Proofs of Creation” or some such, and one was “Dogs don’t mate with cats”. It was some sad attempt at discrediting the idea of Speciation.

    I would like to say something in reply to Jason about the Flood. I’m not sure why a Flood would change what kinds of animals were on Hawaii. Sure, all the animals were gone with the flood, but if God hadn’t figured a way to get them all back, then there would be no Kangaroos in Australia–they couldn’t Hop over the Indonesian islands. So, if God got the Roos to Australia, he could have gotten Mammals and Freshwater Fish to the Oceanic Islands.

    The bit on Geographical Distribution, in both books, was pretty compelling evidence for me. The evidence is clear that Mammals do very well on oceanic islands, as they’ve mostly taken over all the islands they’ve been introduced into…so if God did it all, why did he leave those out? Why are the only animal types those we would expect to find IF evolution were true? Only those creatures (bats, birds, certain plants, insects) that could possibly survive a short oceanic voyage are found on these remote islands. But there are NO amphibians (for they die very quickly in saltwater), except where they’ve been introduced by humans, like in Hawaii, where they’ve largely taken over.

    As for “it takes a lot to go from observable Microevolution to unobservable Macroevolution”…there are fossil Giant Kangaroos in Australia; there are fossil Giant Armadillos in South America. OK, so a change in size isn’t the same as going from a fish to a land critter, but there is fossil evidence for that, too (check out Gerry Coyne’s “Why Evolution is True”).

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  8. Hello? Transitional species here —

    Sounds like, eSell, you’re ready for Richard Dawkins’ The Ancestor’s Tale, that will take you deeply into the evolutionary process, while at the same time, being highly entertaining.

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  9. Yes, thank you for the book recommendation…I’ve wanted to read something of Dawkins’ other than God Delusion, but hadn’t decided which to go with.

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  10. The Ancestor’s Tale deals strictly with evolution, not religion, tracing everything back to the first life forms. I don’t know what kinds of things you like to read, but I found it fascinating.

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  11. Yes, I’m aware of this. I’ve read God Delusion and God is Not Great…and now I’m moving “past” the initial “non-believer” stage and am interested in catching up on the Science, so at some point I will want to read several of Dawkins’ books (and enjoyed reading Carl Sagans’ Cosmos). Of course, I still have a fond place in my heart for Christopher Hitchens and aim to purchase The Portable Atheist soon…but I realize my lack of actual knowledge of the Science of it all, which is why I read Origin and Why Evolution Is True–just so I wouldn’t be going around saying “I think Evolution is true” without actually having read up in-depth on it. I made that mistake with my religion and it is not a mistake I wish to make twice…that’s why I called my blog The Perpetual Skeptic.

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  12. I was thinking about something. I am sure I am not alone in this, but I’ve heard people (whether in sunday school or the secular classroom) that the mathematical chances of the world being created without a god are… (insert crazy number demonstrating how unlikely spontaneous creation would be).

    I guess I could question the formulas and processes used in determining said “mathematical probabilities” but really, i am more curious if anyone has ever really tried to calculate the “mathematical probability” for the existence of the bible god, and everything the bible claims.

    If the alternatives to the bible are eventually all proven false, that would still not prove the bible.

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  13. Nate: I know your heart’s in the right place, unfortunately, your source isn’t —

    “This bulletin board is currently closed. The Administrator has specified the reason as to why below.

    Server move in progress – Be back soon! Hopefully… 😛“</blockquote

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  14. Ah, thanks nate. I was really more trying to state a rhetorical than ask a real question – although I would be curious to read and review such a study. The link you provided was also entertaining.

    Most of the people who cite such statistics in critique of atheism or the big bang, etc do so dishonestly (or simply by ignorance). They do so to pass themselves off as scientifically minded or to concerned with the numbers and facts, yet they wouldn’t stand to have their religion “disproven” in such a way.

    And even if you had a surprisingly high statistical probability for a god, you wouldn’t and couldn’t for a biblical god.

    I heard someone the other day bring this up as if it settled everything. paraphrased: “the statistical probability for the universe creating itself is practically nil…. therefore the bible is true.” This kind of argumentation is mind numbing.

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  15. Ah, I see what you’re saying, William. Sorry if I took your comment a little too “on the nose.” 🙂

    I agree that those kinds of “statistics” are incredibly misleading, to say the least. I mean, just think of the probability that you or I even exist, considering all the millions of sperm competing for the egg when we were conceived. Then add to that all the little decision points that led to our parents meeting, falling in love, having sex at a particular time, etc, etc. Since the probability of each of us existing is so low, should we assume we don’t exist?

    It also reminds me of the example Julia Sweeney gave when she said it was like marveling at how well gloves fit our fingers… I mean, what are the odds?! Surely our hands were designed for gloves!

    They’re really looking at the problem backward. If conditions in our universe had been different, then perhaps there would be another life form sitting on another planet around another star wondering how things could have lined up in just the right way for his existence. Instead, it’s us sitting on a planet that we’re very suited to wondering how we wound up here. Evolution answers that question pretty nicely (though maybe without the self-importance we could assume if all this had been meant just for us).

    What would really be incredible is if we were completely incompatible with our environment, yet existed anyway. What are the odds for that?! 😉

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  16. I have no clue William – I clicked on Nate’s link, just as you obviously did, and pasted the results – I even clicked on “Register,” just in case that was what was keeping me out, but it brought me back to the “Sorry” page – must be the long arm of Chialphagirl!:)

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