Wednesday, April 15, 2009

What is meant by the word “Evolution”?

A major challenge to Christians studying the biological sciences is the concept of evolution and how it is presented to them. Part of this challenge is that the word “evolution” means different things to different people. Further, sometimes these different meanings are conflated, intentionally or unintentionally, which adds to the confusion.

One meaning of evolution is “change over time.” In population genetics terms the change that is meant is in allele frequencies in a population. In time I hope to write a separate post describing population genetics but the incidence of a particular allele or gene variant in a population changes from generation to generation for various reasons, including natural selection and random variation. In this sense you evolved from your parents because your allele frequencies differ from those of your parents. While this may be an attractive concept for teenagers :-), its relevance to the grand evolutionary scenario is limited.

A second meaning of evolution is this grand evolutionary scenario, “From Monad (single celled bacterium) to Man” as the Darwinist philosopher Michael Ruse coined the phrase. This is also commonly called macroevolution. The distinction between microevolution and macroevolution is not straightforward and probably deserves another blog post. This is the evolution which Charles Darwin proposed in his Origin of Species and later evolutionary theory has expanded to include the origin of life (yet another post?).

Finally, the word evolution can be used to describe a naturalistic worldview, one that denies the existence of a Creator who plays any role in the evolution of life. It is this worldview held by the atheist Richard Dawkins, who stated that evolution allowed him to be an “intellectually fulfilled atheist.” In a naturalistic worldview, the “laws of nature” is the only game in town, regardless of the evidence.

As Reformed Christians in science we have an obligation to listen to what the creation tells us, recognize God’s hand in creation (Romans 1:20) and strive to honor him in our study of the creation. When it comes to evolutionary biology, what the creation tells us may not be straightforward and the evidences might not always be what we “want” them to be. But that will have to be the subject of future posts.


Arnold Sikkema said...

These points all relate to biological evolution; in addition, there are the matters surrounding physical evolution. Cosmology, astrophysics, and geology include questions of the origin and development of the cosmos as a whole, of stars and galaxies, and of planetary systems. While all of these are usually in the mainstream coupled together with one another and with biological evolution into a grand naturalistic narrative, it is not necessarily the case that if one accepts big bang theory (whose development was a shock to atheists as it implied a "creation" moment) one must also accept "from Monad to Man", or vice versa.

And going beyond biological evolution, the grand secularist narrative also encompasses a fully naturalistic evolutionary psychology and social evolution, including the evolution of religion. Upon these there are certainly significant and clear Christian perspectives, but not simple outright rejection, as recent developments in neuroscience (for example) do have much of interest to report.

Tony Jelsma said...

I agree that biological evolution is not the same as physical evolution, or rather, physical evolution cannot be extrapolated to biological evolution. Living things contain information e.g. DNA sequences, which cannot be reduced to their chemical components. Living things are also energetically distinct from their environment i.e. they are not at equilibrium and do not move toward equilibrium as long as they are alive.

hjvb said...

Apr. 16 - In the eyes of evolutionists there is no distinction between macro- and micro evolution. That is because they are determined that there is no such distinction, otherwise their extrapolation (from presently observed microevolution to eons-long macro-evolution) doesn't work anymore. However, there is a clear distinction between the two: micro-evolution doesn't add genetic material whereas macro-evolution is thought to produce new information.

Herman van Barneveld

Tony Jelsma said...

Thanks Herman. In my blog post I said the distinction between micro- and macro-evolution is not that straightforward. Would you call the fish-to-amphibian-to-reptile-to-mammal transition macroevolution?
Curiously, in a July 6, 2007 paper in Science describing the sea anemone genome, the genetic content in this primitive invertebrate was shown to be similar to that of vertebrates. Their argument would be that the evolution from sea anemones to humans was more of a reorganization of genetic information than an addition.
So what would you define as macroevolution, with new genetic information?

hjvb said...

When God created the world he created organisms with their genome. Since that time no DNA sequences have been added. However, God made creatures with such an array of potential variabilities, that groups of offspring become more similar and can be considered a species distinct from other original created kinds. Macroevolution insists that new functional DNA sequences appeared on the scene over time.

Herman van Barneveld

Tony Jelsma said...

Herman, I am sympathetic to your argument that macroevolution requires new genetic information. There are points in the macroevolutionary sequence where new information seems to be required, e.g. origin of life, origin of animals, origin of plants. However, you have not responded to my earlier question about whether the vertebrate evolutionary sequence is microevolution or macroevolution. The point of people responding to this blog is that we have a fruitful discussion. We're not interested in responding to every stone thrown in our direction unless we can have a dialogue.
Finally, your comment that "God created organisms with their genome. Since that time no DNA sequences have been added" is an assertion that comes from your interpretation of Genesis 1, not a statement based on evidence. Our blog wants to discuss the evidence, not deal with assertions.
So, is vertebrate evolution microevolution or macroevolution? On what basis? Let's look at the evidence and then continue the discussion.

Anonymous said...

When God created the world he created organisms with their genome. Since that time no DNA sequences have been added. Herman, this comment left me wondering the following: if it could be demonstrated that new genetic information has been added to an organism's genome in the recent past, would that invalidate the Genesis accounts in your view?

Dennis Venema