Evolution – A MOOC … (Well Not Quite) (RJS)

On many occasions I’ve been asked about details of evolution – a very complicated subject and one not directly in my line of expertise, although I am able to read much of the literature. The chief complaint is the lack of a good, trustworthy, resource presenting a simple (but not too simple) outline of evolutionary theory for the layman (or the pastor).  Dennis Venema, Associate Professor of Biology at Trinity Western University in British Columbia and Senior Fellow at BioLogos, has also seen this need and is putting together a string of posts that provide an introduction to evolutionary biology. Dennis is a Christian – and a friend.

It is an overstatement to call this series of posts a MOOC – but it is a valuable resource nonetheless and I would like to give it a shout out here for those who may be interested.

From the blurb on his page Dennis’s research focuses “on the genetics of pattern formation and signaling, using the common fruit fly Drosophila melanogaster as a model organism. The superior genetic and molecular biology tools available in Drosophila make this organism second to none for developmental biology studies. Current projects include investigating the role of several cell-cell junction and cytoskeletal components during frizzled-independent tissue patterning of the pupal wing in flies.”  Ok, this may seem a bit esoteric to many of us … but this kind of research, along with his teaching experience, give Dennis the expertise in genetics and evolution to write a useful introduction – Evolution Basics. Eight posts are available thus far, and more are planned.  The topics include such important concepts as “Evolution as Scientific Theory“, “Variation, Artificial Selection and Natural Selection“, and the ever popular “Evolution and the Human Lineage“.

Consider the idea of Evolution as Scientific Theory:

In common English usage, “theory” means something like “guess” or “hunch”. It means something speculative, uncertain. In science, however, the meaning is almost exactly the opposite. In science, a theory is an idea that has stood the test of time. This difference between the common usage and the scientific usage of the word is a frequent source of confusion for nonscientists. In science, a theory is a well-tested idea – an explanatory framework that makes sense of the current facts available, and continues to make accurate predictions about the natural world.

Theories get their start as merely an idea, or hypothesis (plural = hypotheses). This literally means “less than” (hypo) a theory (thesis)”, and the name is appropriate. What scientists call a hypothesis is basically what nonscientists call a “theory” in the common English sense we discussed above. It’s an idea that makes sense, and fits with what we already know, but as such does not yet have much (or even any) experimental support. Here is where science departs from other approaches to knowledge: the key feature that distinguishes science from other activities is hypothesis testing. Rather than merely entertain a hypothesis as an interesting idea, scientists use a hypothesis to make specific predictions about the natural world, and then test to see if these predictions can be supported with experimental evidence.

So, what does any of this have to do with evolution? Simply this: despite what many evangelical Christians have been told, evolution is a theory in the scientific sense. It started off as a hypothesis, and scientists have been trying to reject that hypothesis to no avail. In the present day evolution is an explanatory framework that has withstood 150 years of testing, and continues to make accurate predictions about the natural world. Like heliocentrism, our ideas about evolution have developed significantly since the 1850s.

Today the evidence for evolution can be represented as a tapestry of many different threads woven together (an analogy not original to me). There is evidence from paleontology, from comparative anatomy, from embryology, from genetics, from cellular biology. These threads all weave together to form a consistent picture of evolutionary change. Threads are constantly added and some are occasionally revised and removed. We don’t, by a long shot, understand all of the details of biology yet – there is redundancy, recruitment of building blocks to serve a variety of functions, and a systems level feedback – much of which we are only beginning to understand. While it is virtually certain that parts of our current understanding of evolutionary biology is wrong, it is exceedingly unlikely that corrections and developments will make plausible a young earth or special creation view of origins. Intelligent design is slightly different – while some proposals have not held up to scrutiny, we know so little about the origin of life that it is unwise to make any kind of firm pronouncement. Any statement about the presence or absence of design in the origin of life of necessity represents a philosophical position.

To say that evolution is “only” a theory and thus should be taken with a grain of salt – as so many evangelical critics are wont to do – is to misunderstand the scientific meaning of the word theory.

Artificial and Natural Selection in the Dog. Dennis uses examples of artificial and natural selection in the domestication of dogs (a subspecies of the gray wolf) to illustrate some of the features of evolution. Artificial selection has been used for millenia to artificially select for traits and features. Nature provides variations – and humans have added some tendency for selection in the selective breeding of dogs for desired traits. The dachshund shown to the right (image from wikipedia) is the result of many generations of selective breeding taking available of natural variations.

The Canis lupus species also provides an example of natural selection for a trait that is separating the dog from the wolf. The dog has a new gene, a duplication of a gene for an amylase enzyme found in the pancreas and involved in starch metabolism. Dogs, Dennis tells us, have 2 to 15 copies of this gene. Wolves have but one copy. Apparently duplication of this gene is a “relatively” common occurrence (rare but non-negligible). Gene duplication is a potent pathway in evolution. In this case the dog, cavorting with humans, consumes a fair amount of starch. Thus there is a selective advantage for duplicate copies of the gene, and the production of more amylase enzyme. There is no selective pressure for preservation of multiple copies of this gene in wolves who eat but little starch – and they continue to possess but one copy.

Duplication of the gene for the production of the amylase protein also occurred in the human lineage – here however the duplication was followed (or accompanied) by a change that modified the function of one of the copies resulting in production of the amylase enzyme in the saliva as well as in the pancreas (where it is found in dogs). Far more detail can be found in Dennis’s posts (Natural Selection and the Human Lineage Part 1 for example) – and in the references provided there.

If you are interested in understanding more of evolutionary biology, and why the theory is so convincing, I recommend this series of posts on BioLogos. From time to time (including the post today) we can discuss some of the issues here as well.

What does it mean to say that an idea is a theory?

What is the opposite of theory?

What would is take to prove or disprove a theory?

If you wish to contact me directly you may do so at rjs4mail[at]att.net

If interested you can subscribe to a full text feed of my posts at Musings on Science and Theology.

  • http://bobcornwall.com Bob Cornwall

    This is an excellent summation of the nature of a scientific theory — with an example of how it works. Please folks, read this carefully!! Let’s stop this silliness about what a theory is!!

    Thanks Scot for sharing this so we can get on with important conversations!

  • http://christianityandvirtue.wordpress.com David Russell Mosley

    RJS,

    Thanks for this! It is difficult ground to cover, especially when trying to keep in mind non-scientists. I’m curious, have you read Cunningham’s book (Darwin’s Pious Idea)? Any chance of a series on it?

    Yours,
    David

  • http://EnglewoodReview.org Chris Smith

    It is important to add that as a science, evolution works from the assumption of a methodological naturalism — i.e., describing natural phenomena only in terms of natural phenomena. I think when we talk about evolution as a theory and as one that works from the assumption of methodological naturalism, it is not at all incompatible with our Christian faith.

    The problem is the conflating of methodological naturalism and metaphysical naturalism (the belief that the universe consists only of natural phenomena), a mistake made by both fundamentalist creationists and scientific atheists (Dawkins, et al).

  • http://EnglewoodReview.org Chris Smith

    I should clarify that when I said that fundamentalist creationists make the mistake of metaphysical naturalism, I meant that they do so in how they understand and portray evolution.

  • Scott Eaton

    RJS,

    Thanks for recommending this. I bumped into Venema’s articles just a few days ago and wondered if it was worth the time. Now I know!

    Many Christians seem to misunderstand the nature of scientific theory. I’m no scientist, but one thing I do know (as pointed out in the article) is that the word theory as in “theory of evolution” means more than just a guess. But I’m not so sure others understand this as I frequently hear some say things like, “Evolution is just a theory and not a fact!” Unfortunately, in my ignorance, I used to say this too. If Christians (or even the public in general) are ever going to possibly accept evolution, I think they first need to understand what is meant by “theory.” The article “Evolution as Scientific Theory” might be the most important one.

  • Triston

    The evidence for macroevolution is less than a hunch or guess. The evidence in the fossil record is completely against macro evolution. And that is what scientists still hold to, unfortunately. The only evidence they have is for micro evolution (small evolutionary changes within distinct species). What they do not have evidence for is macro evolution (i.e. common ancestry). The well tested theory that has held the test of time is that God made distinct species according to their kind. That’s the truth.

  • Phil Miller

    The well tested theory that has held the test of time is that God made distinct species according to their kind. That’s the truth.

    So does that mean that Adam took the time to give names to all 1 million known insect species (not to mention all the ones that haven’t been discovered yet).

    In any case, there’s plenty of evidence for “macro” evolution (a term I’ve only ever heard Christians use) once you start looking things on a genetic level. As far as the fossil record, the chance of any living organism being fossilized is pretty low. There actually are some fossils that could be described as transitional forms, as well.

  • EricW

    The well tested theory that has held the test of time is that God made distinct species according to their kind.

    And just exactly how and when and where and by whom has this theory been well-tested? What and where are the peer-reviewed scientific papers that demonstrate that the theory holds true and continues to hold true after repeated experimentation and observation?

  • RJS

    Perhaps we can look at this a bit differently.

    The time tested theory is that God has created each according to its kind much the same way he wove me in my mother’s womb (Psalms)

    The method by which he brought forth diversity is evolutionary creation. This is now a time-tested theory of process and mechanism.

  • http://deadheroesdontsave.com MikeB

    there actually are some fossils that could be described as transitional forms, as well.

    When studying a fossil we will label A.

    What scientific and logical factors would cause me to accept the hypothesis that A is a transitional form of B?

    What scientific and logical factors would cause me to accept the hypothesis that A is not a transitional form of B?

  • AHH

    MikeB @10,
    For this reasonable question (and related issues), I would point you to the fine resource “Taxonomy, Transitional Forms, and the Fossil Record”, by Keith Miller, a geology professor and committed Christian:
    http://www.asa3.org/ASA/resources/Miller.html

  • Bev Mitchell

    Folks,

    I’m reluctant to get into this discussion because I think that approaching this from the biology side has serious limitations, not the least of which is the commitment required to understand some very interesting, but very involved modern biology (molecular, developmental, physiological systems level thinking and even ecology). For the literalist, conservative Christian, even should she have the time to do all this study, she will still need to confront a major challenge to the way Scripture is interpreted. So, I tend to direct people in that direction first. Peter Enns’ work, which many here know, is one place to begin. The current series by Denis Lamoureux on Enns’ blog is a simplified and well presented version of the same approach.

    Having said that, as a biologist, I am always delighted to see people want to understand biology better. A good understanding of the dynamism of the living world can be used by the Spirit to fill us with much praise to the one who makes all of this possible. I haven’t read the six chapters up so far by Dennis Venema, but a quick glance suggests that it alone may not leave you prepared enough for what is going on in evolutionary biology these days. Nevertheless, it’s great that Dennis is doing this, and I hope many take RJS up on her suggestion to follow along. We’ll see how much he goes into the newest ideas. I hope he can find a popular way to do so.

    Now to the current post. The comments on today’s post re the state of evolutionary biology mostly do not reflect the current state of affairs. There has been much new evidence just over the last ten or fifteen years that hardly ever enters into the biblical literalist/evolutionary biology “debate”. Macroevolution is a big part of the story, but developmental biology has to be integrated into the modern synthesis to explain how it all works. In short, modern molecular genetics is showing that there are networks of gene regulators (usually expressed in the embryo) that help explain how organisms that share the vast majority of their genes can have such radically different phenotypes – for example humans and chimps. Its largely a matter of using the same genes in quite different ways, very often during development. That appears to be the main way macroevolution comes about. See my post here http://www.patheos.com/blogs/jesuscreed/2013/03/07/the-music-of-life-rjs/ for a musical metaphor of how this works.

    There is a great book (what else?) that will bring you up to date, but you will need to have at least a good first year biology course under your belt to understand it. However, Part 3 has much that any well educated person can profit from. There is even a short philosophical/ethics discussion in Part 3 (unusual for a biology text). The reference is: Gilbert, Scott F. and Epel, David “Ecological Developmental Biology: Integrating Epigenetics, Medicine and Evolution”. A good understanding of the basic ideas and mechanisms these guys summarize, will leave you well prepared to follow the new synthesis of evolutionary biology that is currently underway

  • TJR

    Dennis Venema is an excellent teacher because he can explain complex issues of biology to people who don’t have a science background. It would be good if he could give a video explaining evolution and the most common mistakes people have about it.

  • Triston

    EricW writes: “And just exactly how and when and where and by whom has this [of God making species according to their kind] theory been well-tested?”

    You could test it right now. Take a dog and take a cat, and try and mate them together. It won’t work. That’s because they are difference species. You can take any dog and breed it with any dog, and the same goes for cats, but you can’t breed dogs and cats together. Just more evidence–that can personally test–, simple as it is, that shows each species was made according to its kind.

  • Marshall

    Shorter evolution: If your parents didn’t have children, chances are you won’t, either.

    In my life, the word “theory” shows up most often as “Theory of Operation” … the part of a technical manual that gives a high-level view of how the thing works, before we dive into the part numbers and the wiring harness assignments.

  • EricW

    @14 Triston:

    It seems to me that all you’ve proved is that if you take two different animals that are sufficiently different genetically that they can’t breed, then they can’t breed. That doesn’t prove or demonstrate “that God made distinct species according to their kind.” It just demonstrates that a modern-day dog can’t breed with a modern-day cat. It doesn’t prove anything about the origins or ancestry of dogs and cats, or show that God originally made them the distinct species they are today. I’m not saying that there was a time when dogs could breed with cats. I’m saying you’ve not answered my questions.

  • Mike M

    These responses show a good insight into how creationists “think.” They are stuck on “kinds” and haven’t developed the subtlety of thinking beyond that. I teach my youngest children (all under 12) about “kinds” such as Felines which are cat-like mammals and Canines which are dog-like mammals. of course they don’t mate: they ain’t got the hots for each other. But I teach my older (and hopefully wiser) children about “species” and how classification is a tool devised by humans to help them understand the world. For example, where do you place bonobos? They share 98% of our human genome as do chimpanzees but we are 3 different species and, personally speaking, I prefer to mate only with females of our own species as do bonobos and chimps. Preference for mating partners is only one criterion for speciation and strangely enough, cannot show up in the fossil record. In other words, I might expect my sub-high schoolers to point out that cats and dogs don’t mix but would be aghast if my older kids said something that silly.

  • http://jesus.scilla.org.uk/ Chris Jefferies

    This is a really helpful post, RJS. Thanks!

    Back in November I tried to set out some of the background to human evolution and our connection to recent and more distant species. The intention was to ask questions about the nature of heaven and where we draw the line between human and non-human.

    I’ve also posted on the processes involved in science. All of these topics are connected, of course.

  • Tim Atwater

    what is a MOOC?

  • http://deadheroesdontsave.com MikeB

    Thanks AAH – I’ll give that a read. I was always curious.

  • RJS

    Tim,

    You’ll get more info if you google the term – but basically a MOOC is a massive open online course. You can find the wikipedia description through this link.

  • Tim Atwater

    thanks RJS
    now i am reminded.

    blessings.

  • http://www.createdtobelikegod.com theophilus.dr

    The comments about the definition of a “theory” in science are good. The statement, “Remember, evolution is just a theory” is uninformed and not helpful. However, it is also not particularly helpful to make a big issue over the definition of “theory.” All theories are not created equal, even in science. The weight of evidence supporting evolutionary theory is more than the experimental evidence for “M-theory” (11 universes) or “string theory,” neither of which is directly testable by observational analysis using the scientific method. Yet they are also called “theories.” Have these theories “stood the test of time?” Not if you ask someone whose grant was funded to investigate another explanation for all of the divergent mathematical formulas. Then there is the commonly used, “Theory of Everything.” Where is that “theory” on the scale of “idea” to “a preponderance of evidence?” Better to stick to defending the term “theory of evolution” based on the strength of data supporting evolution and not on the claim that the word “theory” in science is so different from use in any other discipline.


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