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. I’m not sure I agree with this, ” 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.”
    I always thought the Marsupials evolved after the breakup as there are no marsupials anywhere else in the world. I assumed some rat came along, grew a pouch and that evolved into what Marsupials we see there today.
    Is there evidence to support they came to the Australian region before the break?

    Like

  2. As an open-minded person, I will concede the two can coexist. How long is 7 days in “god terms”? And the Bible tells of the creation of Man and animals in a few sentences, with no details. Is science merely discovering the ways in which god made all this happen? SO. I will allow the possibility, but I think most Abramic believers (Jews, Christians and Muslims) refuse to accept the possibility of evolution in spite of all the evidence.

    Like

  3. Hayden — great question. Here are two articles that provide more info (the latter is a bit over my head, but it might be helpful too):
    http://articles.latimes.com/2010/jul/28/science/la-sci-marsupial-20100728
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2910653/

    Don — thanks for the comment! Glad to have you chime in again. I feel much the same way you do about the problems b/t religion and evolution. Most Christians I know have a difficult time rationalizing the two — in many ways, I have a hard time with it too. But I agree that in an effort to be open-minded and find some common ground, I can see ways to fit them together.

    Like

  4. Sometimes I wonder why this subject is so important to so many. We’re here now. Why does it matter how we got here? Why not just enjoy the life we have?

    Like

  5. nan, why wouldn’t it matter? Why not try to figure this mystery out? Of course, if there are those who don’t want to know, or don’t care to know, then I suppose there is nothing stopping them from doing nothing or from leaving a discussion involving it.

    Like

  6. William, you summed it up perfectly … it’s a “mystery.” And for mystery lovers, it is probably the greatest mystery of all because it’s essentially unsolvable.

    I just asked the question because I feel many people are so focused on our “origin,” they fail to simply enjoy the life they have.

    And thank you very much, but I don’t intend to take your veiled suggestion that I leave the discussion.

    Like

  7. @ Nan
    The reason it matters, Nan, is there are two sides to this ”mystery”
    and the danger of not pursuing a scientific line of inquiry is it leaves the door wide open for the likes of Ken Ham , William Lane Craig and other dingbat Creationists and Fundamentalists who will have our children inculcated with religious diatribe.
    “God did it. Accept it or be damned.

    As to it being essentially unsolvable. Well, the end of the path is far off in the distance so I wouldn’t be so eager to count my chickens just yet….

    Like

  8. I agree about the “dingbats;” however, after years and years of debate, I don’t see any of them changing their thinking. What’s the old saying? “God said it, I believe it, and that settles the matter.”

    Yes, it’s possible that one day the “real truth” about the origin of humans may be revealed but unfortunately, probably not in my lifetime.

    Like

  9. @Nan
    Ask Nate about not “Changing thinking” I reckon he might just smile and shake his head. πŸ™‚

    As for “real truth”, well that’s probably what some folk said about flying, just before two fellers called Wright appeared on the scene.

    Like

  10. I’m enjoying your blog and look forward to reading some more!

    @nan: You said: “. . . I feel many people are so focused on our ‘origin,’ they fail to simply enjoy the life they have.”

    Aren’t religious people equally concerned with our origin? They simply assign to something different: god. How many times have I heard the question (and how many times did I used to ask), “Do you ever wonder where you came from and where we’re going after life?”

    It’s funny . . . I’ve said your line up there many times when people ask me about death. “I can’t be certain, but I’m just planning on my consciousness ending, nothing else. Religious people are so worried about the afterlife that they don’t just enjoy the life they have right now.”

    Also, you yourself have directly benefited from the amount of people who have dedicated hours to the study of our origins. Medicine and our understanding of disease, etc, have been SO PROFOUNDLY affected by it.

    Like

  11. Nan, yeah, i’m sorry. I wasn’t implying or hinting at you specifically leaving, necessarily. But I get annoyed when people say things like “it’s a waste of time,” or “there are better things to spend your energy on…”

    It’s a cheap way of trying to avoid the conversation. If you feel it’s a waste, then don’t waste your time with it. If everyone just assumed that things that are currently unknown will always be unknown, then we wouldn’t really have any advances in anything.

    i’m sure you’re a very intelligent, well meaning person, but your earlier “who cares” post is simply silly and juvenile.

    If we look, we may not find, that’s true, but the only way to ensure this mystery isn’t solved is for no one to try. I guess we’ll leave it to god, whichever one actually may deserve the credit…

    Like

  12. Thanks for the links Nate. I finally got time to read them.
    Soooooooooo because the Opossum has the oldest RNA and lives in South America, all Marsupials came from South America? They don;t have any fossil traces about where these little farts came from?

    Like

  13. William, one more comment regarding your responses and then I’ll shut up. I did not say the study of evolution is a “waste of time” nor did I make the other statement that there are better ways to spend one’s energies. And I take offense at your insinuation that I’m “silly and juvenile” or that I have a “who cares” attitude.

    For the record, I love to research and learn. In fact, I spent the last five years doing just that in the process of writing a book on some fallacies of the Christian faith. And also for the record, I happen to believe in evolution because I done considerable reading on the subject.

    All I was trying to say is that some people spend more time thinking about how we got here than just being thankful that we ARE here.

    I will continue to read (and perhaps comment on) Nate’s very insightful blog postings because not only do I identify with him in many respects, but I have learned much from him.

    Like

  14. It’s not you, nan. it was your comment. either it came off wrong, or I took it wrong. it happens and i apologize for insulting you, i meant only to insult your comment.

    Like

  15. Hi Hayden,

    Yeah, I’m no expert on these things. However, the current scientific consensus is that marsupials first developed in South America. I don’t have any particular reason to disagree with them, even though they may be wrong about that. I’m sure if stronger evidence comes to light down the road they’ll revise their findings. That’s the beauty of science! πŸ™‚

    Thanks for reading those links. Right or wrong, I find this stuff fascinating.

    Like

  16. I completely agree with you that this is a very interesting topic. I love to discuss and read about it. I just tend to think scientists are wrong more times than they are right. Probably has something to do with my daddy issues. He was a drunk, who happened to have a masters degree in Paleontology. He found oil for Amoco Petroleum and after 30 years of experience the one thing he told me he learned is that most scientists, suck.

    Like

  17. I’ve always believed in micro evolution and the continental drift you described, but asking why would God create a different way to bear young is one in the same with why make things beautiful and complex as well as functional. Why not?

    Like

  18. I always love it when people doubt scientists. It’s not as though they are people that devout all their time to organizing and finding evidence. Sure they sometimes make some crackpot claims, but they’re trying to extrapolate from fractions of evidence that “may” be part of the truth. It’s a rather noble profession because they’re basing their ideas upon some sort of tangible evidence, rather than just saying “that doesn’t make a lot of sense to me, better not agree with the consensus of thousands of people that work in that field”.

    I’m sorry if I come off a little bit cross there, but having been one of those “I don’t get it, it’s wrong” types, I just get frustrated with those that doubt the claims of these hard working people. This change was brought about by doing research for some biologists and the epiphany occurred when I was done measuring 3000 algae water samples… dear lord, I hope that those hours looking at little gooby things under the microscope actually meant something.

    Although I will admit to you Hayden,
    it’s kinda by the seat of the pants and people don’t really know what the heck is going on most times. You just hope for the best!
    Although these weren’t commercial scientists, as I’m guessing your father may have been. Dealing with money and scientists is pretty lame, but just scientists playing with frogs out in ponds is pretty cool… Minus the mosquitos, mosquitos suck.

    Matt C

    Like

  19. Hey Matt,

    I fully agree with you that mosquitoes really do suck. On many levels. My point however, was not that you should always ridicule scientists. Just that you do have to pay attention to the details they present. Much like every other scientist out there.

    Like

  20. @Matt.
    Would that some folk were paid more attention to what theologists claim, hey?
    Then maybe we wouldn’t have to put up with all this god-crap they wish to inculcate people with..

    Like

  21. You might want to revise this article to include the biblical account of the flood, since it directly relates to more than a few points you make (e.g. Hawaii). Also, the disregard for including said event implies a quickly-thought-out and unreliable article.

    “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.”

    This is a bold statement. Microevolution is easily examined and scientifically testable today, and is a simple result of the very nature of genetic reproduction. Macroevolution, however, involves an un-testable theory, being a process that requires millions of years. As such, it can only be researched through historical science, which should not be confused with observable science.

    Secondly, Microevolution has only been observed to result in variability through the loss of genetic material, but macroevolution is said to achieve such a result through the gain of genetic material. Such a phenomenon has never been observed. The explanation of scientists in order for such an event to take place, as you know, is the occurrence of genetic mutation, and although mutations have been shown to be helpful in a few unique cases (e.g. the rat who gained a tolerance for a poison through a mutation), never has a mutation been shown to increase the amount of useful genetic material in an organism (the rat lost the genetic material that caused a reaction to the poison).

    Please reply with any thoughts or arguments.

    Jason

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s