Wednesday, November 28, 2007

Evolution Conversation, Part 2: Evolution Like Gravity?

Below is the start of the meat of this conversation. We let Chip go first, since he is older, and you will find his opening statement below. Mark then responds with his own opening statement.

I confess I have not read anything by Darwin, but I have a pretty good grasp of the three elements claimed to be necessary for evolution to occur. They are:
1) Natural selection, which simply says that organisms better suited for survival tend to live and pass on their genetic material to later generations while those ill-suited for survival tend not to pass on theirs.
2) Genetic mutation, which means that new characteristics can appear unpredictably in the "family tree" of an organism.
3) Lots of time, which is required for an essentially random processes to generate changes that might actually give an organism a survival advantage. Of these three, I think the first is noncontroversial. Most everyone seems to agree that natural selection occurs. We have observed it in all kinds of organisms from the famous
peppered moths to the parasite that causes malaria.

Many Christians take issue with the third element, claiming that the earth is nowhere near as old as scientists make it out to be. Some even adhere to a strict interpretation of Genesis that puts the creation about 6,000 years ago. This is despite overwhelming evidence that the earth is far older. For example, many Christians love to point to some instances in which material taken from living trees was declared by carbon-14 dating to be hundreds of years old. They seem to think that this discredits all the evidence from radiometric dating. But radiometric dating has been shown to be highly reliable, and the amount and proportions of various radioactive materials present in the earth's crust are consistent with an earth that is at least 5 billion years old. If God created the earth 6,000 years ago, he gave it a great backstory, which scientists have been trying to piece together. My only quarrel with the way Darwinist's make use of time is that they don't have nearly enough of it. If the universe were 100 times as old as it is generally believed to be (about 15 billion years), it would still not be nearly enough time for all the random changes needed to produce the astounding variety and complexity of life on earth.

However, the biggest problem for Darwinism is what we know about genetic mutation. We know that small mutations are rarely significant. We know that big mutations are always catastrophic and usually produce sterile offspring. The problem is that small mutations cannot account for the complex structures that suddenly emerge in the fossil record, and big mutations can't produce any evidence of viability.

Another problem for Darwinism is the inadequacy of its explanations for how living things began in the first place. All attempts to produce the most basic self-replicating organisms in the laboratory from inorganic material have failed. About the only thing they have shown is that life could not have arisen from nonliving antecedents. It begins to look more and more as if the first living things must have been intentionally designed to be complex, self-replicating structures.


Mark offers his opening statement in response to Chip.

I'll start off by stating that there is no debate in the scientific community in regard to macro evolution. Like gravity, macro evolution happens, there is no doubt about either. It's a fact. What is not established fact are the mechanisms for macro evolution. What scientists debate is not if gravity and evolution happen, but how.

The "controversy" about evolution is generated by those who do not understand or do not accept the fact of evolution. I'll say that I'm not keen on debating the fact of evolution. To me, it's as pointless as debating whether the Earth is round or flat.

Here is a picture showing some shared genetic traits between two species. Scientists consider this genetic evidence "overwhelming."

Two Peas in a Pod
It's a fact there is only one way for parents to pass genes to their offspring and that's through inheritance. A creationist would say that God created these species as is. There is no science to support this. So then, what is the scientific explanation of the shared genes evident in this picture? Common ancestry, of course. If there is an alternative scientific theory that explains HOW species share the same genetic traits, the world hasn't heard it yet.

Just to clarify, I'd like to ask Chip, what position are you advocating? Do you take Genesis literally? You don't believe the Earth is 6k-10k old rather, 4.5 billion years old? Are you a theistic evolutionist? If it's the latter, I'll grant you that God could have created the very first micro organism and used evolution from then on in a "guided" process through natural selection. If nature selects which traits survive, it's certainly not a random process at all. If evolution were a true random process like a million monkeys banging on a million typewriters to produce Shakespeare, then 4.5 billion years wouldn't be enough time. Here is an experiment that debunks notion evolution is a random process and demonstrates the effectiveness of mutation coupled with natural selection ...

Evolution IS a Blind Watchmaker (It's less than 10 minutes long)


Another point mentioned is that evolution can't explain the origin of life. This is off topic. Evolution posits nothing about life's origin. You're actually speaking about abiogenesis.

The issue I'm most interested in exploring in the course of our conversation is what motivates Christians to attack evolution, probably one of the most established scientific theories since Galileo and the scientific method 400 years ago. The only people who have trouble accepting common ancestry are theists. To me, this indicates that their objections are largely religious in nature, not scientific. Why for example, don't theists advocate "intelligent falling" instead of the theory of gravity? Scientists don't even know what gravity is. It's a huge "gap" in gravitational theory. Perhaps God is responsible for gravity.

In the end, those who take the Bible literally cannot accept the fact of evolution because it contradicts Genesis. It would topple their world view. So, fundamentalist Christians (using the term only to indicate biblical literalism) are forced to deny that which is obvious to the rest of the world. Isn't it strange that secular peoples all over the world have no scientific objection to common ancestry? Most opposition to evolution seems to be localized to Christian fundamentalists in the United States, for religious reasons and not scientific objections.

You said,"I also agree with Nick that science has limits. In particular, it is very good at answering "how" questions and very poor at answering "why""

If science is very good at answering "how?" and religion is good at answering "why?" then why is religion attempting to answer "how?" specifically, in regard to evolution? Science answers "how?" with evolution. Religions answer with different "truths." Not surprising really, since religion is geared to answering "why" and not "how."

"Whenever human beings make an honest effort to get at the truth, they reliably transcend the accidents of their birth and upbringing. It would, of course, be absurd to speak of “Christian physics” or “Muslim algebra.” And there is no such thing as Iraqi or Japanese -- as distinct from American -- science. Reasonable people really do have a monopoly on the truth." - Sam Harris


I find it interesting how they take different approaches early on. Chip has referred to some of the classic problems with Evolution. Rather than to go on the defensive right away, Mark focuses on the "overwealming evidence" for Evolution. In addition, Mark makes a great point about who it is that actually has a problem with Evolution, saying "Most opposition to evolution seems to be localized to Christian fundamentalists in the United States." A very interesting point.

How would you respond to this?

2 comments:

Matt said...

Nick wrote...

Rather than to go on the defensive right away, Mark focuses on the "overwealming evidence" for Evolution.

I'm not sure you are giving full shrift to Mark's arguments here. In response to Chip's opening, Mark responds with his own opening statement about what he calls "the fact of evolution." Following that, however, he deftly circles back and directly answers two of Chip's arguments (abiogenesis and "not enough time"), and lays the foundation to undermine the third (mutations are either inconsequential or deleterious).

Nick said...

Hi Matt. Yeah, I think the key to my statement was "right away." You are correct in saying that he comes around to respond to Chip's objections, but he certainly starts with the "overwhealming evidence for evolution."