Saturday, March 03, 2007

The Making of the Fittest

I mentioned in an earlier post that I attended Sean Carroll's lecture at KU Thursday night. He is a Professor of Molecular Biology, Genetics and Medical Genetics at Wisconsin University-Madison. He is also the author of a few books on evolutionary biology.

Carroll did a fine job of explaining the mechanisms of evolution, and he used some interesting creatures to provide examples of the process.

I think the Ice Fish example was my favorite. I have heard of this fish, but I had never seen pictures of it. It has a transparent, pale looking appearance which is due to the interesting fact that it’s blood is colorless, and cells are present in only 1% of it’s blood. They completely lack red blood cells making it unique in comparison to other vertebrates. Due to the extreme cold water in their habitat in the South Atlantic Ocean, this adaptation has made it easier for them to pump blood thru their capillaries.

Carroll gives an account of how this particular fish adapted to it’s environment through evolutionary processes. He explains how, through dramatic environmental changes that took place over millions of years, the ice fish evolved in order to adapt to these changes and their DNA record can tell us a bit about their history.

He explained how the DNA record can tell us what was lost, modified, and gained through evolutionary mechanisms of this fish and other creatures as well.

A key loss was their globin genes. In other Antarctic fish, there are two globin genes located in their DNA which account for their red blood cells. But, in the Ice Fish, there is only a remnant of one of these genes left. So, although they have had an entire loss of red-blood cells, there is this remnant part of the gene which accounts for red blood cells we find in other fish, yet it has no function in the Ice Fish and is left “rotting” within their DNA.

Then there is a modification to their tubulin genes which has aided in adaptation to the cold habitat they live in, and a key invention (gain) would be an antifreeze gene which arose from preexisting DNA code.

Carroll tells us that the DNA record shows how species are created and that earth and life evolved together. Shifts in lifestyle are reflected in DNA of pertinent genes, and Darwin's principles of natural selection aid in these changes.

He gave various examples of how natural selection works. One was an example of the change in uniform color of soldiers throughout early history. British at one time wore bright red uniforms which were easily spotted by the enemy, and rather than lose more soldiers to a fashion statement, they resorted to khaki uniforms in order to blend in to their environment. Obviously, the khaki would aid in self preservation.

Then he mentioned the rock pocket mouse, which was a favorite of Eugenie Scott’s when she lectured here at KU a few months ago. This little mouse seems to be their replacement to the famous Peppered Moth example.

Carroll explained that there is one single gene (Mc1r) that accounts for these mice being either black or khaki. Obviously, if their habitat is dark in color such as the Pinacate lava flow in Arizona those mice that are black will survive due to the fact that they blend in with their environment and are difficult for owls or other predators to see. Those that were khaki would not survive to pass on their genes and therefore, the black mice would become the prevalent mice in the area. The opposite would occur in a habitat that blended with the khaki mice coloring - their genes would pass on to their offspring and you would find a greater number of khaki mice in the area.

He also gave example of gene differences which affect the opsin in birds and fish and how mutations that occur will be advantagous for certain animals in their particular habitat, and the cause of it is merely a mutation in their gene that is passed down. If the capability is no longer needed or used, it may mutate further and it would be no loss or gain because it is no longer needed.

For example, the clown fish has a perfect opsin gene. This works well for this little fish in it’s bright and colorful environment. But, the coelacanth has 4 mutations to it’s opsin gene which disrupts it’s vision. Considering it’s deep sea environment, these mutations don’t hinder it’s lifestyle.

That pretty much wrapped up the evidence he gave for evolution. I can't say that I have much of a problem with these examples, as they are perfect examples of how species adapt to their environments. I don’t think that any of them give any solid support for macroevolutionary claims, and though Carroll argues strongly for evolution, he mentions the massive amount of information packed in these DNA structures several times.

He never explained how this toolbox of information evolved and certainly didn’t come anywhere near giving an explanation for the origin of new body plans. We are simply to assume that these adaptation mechanisms have the capability to support the notion that everything we see in the world today evolved from that first common ancestor. Certainly we find similarities between all living creatures in our chemical and physical make-up, but that doesn’t necessarily conclude that the evolutionary interpretation of common ancestry is the most accurate explanation for these similarities. This link provides another interpretation to consider. Also, Stephen Meyers mentions DNA in a section titled “Novel Body Parts” in this peer reviewed article, which is an interesting read. Here is one more article to peruse on the subject.

When considering the origin of these first life forms, how do evolutionary mechanisms account for the messages and information being passed on from generation to generation? Where did that information evolve from if there were not intelligence involved?


Carroll’s second part of the lecture focused on Intelligent Design. He urged his audience to continue their fight against ID. He, of course, mentioned Judge Jones ruling on Intelligent Design and provided a couple of his quotes rejecting ID as science. I’m not sure if those were actually Jones’ words or if they were some of the phrases Jones copied from the ACLU attorney’s notes. Either way, I’m trying to figure out whether scientists like Carroll actually understand ID or if they are so vehemently opposed to anyone questioning their pet theory that they reject ID regardless of it’s merit.

It certainly seems to me that ID doesn’t negate one word of what Carroll lectured on last night, so I’m struggling to figure out why he feels threatened by the design inference. The only problem I can see is that Carroll believes that his simple examples of natural selection along with other evolutionary mechanisms and DNA pattern mutations can account for the vast amount of information packed into each body plan we observe in nature today. ID doesn’t necessarily reject common descent, but it does reject the idea that the information we observe in every living creature evolved without a source of intelligence.

He then went on to mention a few ways in which to try to reach the public and sell them on evolution.

One suggestion was to spend more time with the general public in trying to explain to them how evolution works, and do that by giving more lectures similar to his. Scientists from the crowd were also considering the best way to go about reaching the public. It was kind of funny because it appeared to me that I was probably the only doubting Thomas in the room, and I wondered how they were going to get others like me to listen to them with the attitudes displayed. Carroll was pretty good at being considerate of those who reject areas of the ToE right up until the end of the lecture. During the Q&A, he got a bit lively about the complete ignorance of those who don’t agree with his science, and poked fun of us a bit as well. At one point, I had decided that after the lecture, I’d ask him a few questions about mutational gene comparisons between various body types, but after a few of the comments at the end, I no longer felt comfortable doing that.

Carroll felt that the best approach to reaching the public was to infiltrate the churches. The idea being that scientists should share their ~vast unquestionable knowledge~ of evolution with the churches and convince clergy and parishioners that evolution in no way conflicts with their faith beliefs and that religious beliefs and evolution are compatible. Now, of course, that will work with those congregations that no longer consider scripture the way in which Christ, the Apostles, and the early Christians accepted it (as God’s inerrant word to his people). For some, it has becoming increasingly hard to clarify what exactly they do believe within the pages of scripture as they have to keep adjusting it to fit with current (and ever changing) scientific data. Which areas of scripture are historic and which are merely analogies, metaphor or parables?

He mentioned that he grew up in the Catholic schools and was taught evolution by the clergy, but of course his definition of evolution is quite ambiguous, so it’s hard to tell exactly what that teaching entailed. Of course, the Catholic church doesn’t reject common descent, but many Catholics I know personally question it, and it appears that the new Pope is not at all opposed to Intelligent Design. Even many churches who question a “literal interpretation” of various historical events in the bible embrace design because it doesn’t necessarily reject common descent.

So, all in all, it was an interesting lecture, but I’m still not convinced that ID is not science. In fact, the more I hear about DNA and other sources of information, the more excited about ID I become.

I had a weird dream the night of the lecture. I dreamt that I was back at Forum Hall and Carroll had just finished with his lecture. I went down to talk to him, and there were a couple creationists there asking him questions and getting a bit put off with his answers. I can’t remember what they were saying, but everyone else around was giving them strange looks, like “What the heck is wrong with these people.. why don't they get it?”. So, I hightailed it out of the lecture hall. I can’t believe I actually dreamt that, but it’s the gosh honest truth. I must be taking this crap too seriously.