pressingon said:
As I don't have the time to respond to everything posted since I last visited, let me pick a couple and elaborate on those:
Karl, you asked me to identify issues I believe evolution has yet to resolve, which prevent it from being considered fact.
1. Irreducible complexity. If life evolved by chance from organic compounds, how do organisms, even simple single-celled life, develop when a certain level of genetic complexity is required for such to occur? Research has shown that even the most simple single-celled life forms have an immense amount of genetic information that must be present for the organism to survive.
1. Notice your premise "if life evolved by chance ..." Evolution is
not chance! Selection is the exact
opposite of chance; it is pure determinism. Getting life from non-life is also not chance; it's chemistry. Chemical reactions are determined by the properties of the molecules involved. It's not chance. Research has shown that the first protocells formed from proteins that in turn formed from amino acids by polymerization had
more information than modern cells.
http://www.theharbinger.org/articles/rel_sci/fox.html
http://www.christianforums.com/t155621
2. It has been shown that all "irreducibly complex" structures can be made by one or more routes of Darwinian selection. I urge you to read this article. If it goes over your head, then please ask about it:
http://www.cbs.dtu.dk/staff/dave/articles/jtb.pdf
2. Information generation via mutation. This goes back to irreducible complexity to some extent, although somewhat separate as well. For complex life to arise from single-celled organisms, additional genetic information must be developed (not genetic traits, information). Mutations have been shown almost unilaterally to cause genetic information LOSS rather than gain.
That last sentence is simply untrue. The generation of information in plants and animals is a
two-step process. First is variation, which you call "mutations". Then is
selection. Now, what mutations do is create
choices for selection to work on. Making choices, and picking among several possibilities, is hou you increase information. This is from creationist Willam Dembski's discussion of information in
No Free Lunch, so there is no "evolutionist" bias here:
"Suppose that an organism in reproducing generates N offspring, and that of these N offspring M succeed in reproducing. The amount of information introduced through selection is then -log2(M/N). Let me stress that this formula is not an case of misplaced mathematical exactness. This formula holds universally and is non-mysterious. Take a simple non-biological example. If I am sitting at a radio transmitter, and can transmit only zeros and ones, then every time I transmit a zero or one, I choose between two possibilities, selecting precisely one of them. Here N equals 2 and M equals 1. The information -log2(M/N) thus equals -log2(1/2) = 1, i.e., 1 bit of information n is introduced every time I transmit a zero or one. This is of course as things should be. Now this example from communication theory is mathematically isomorphic to the case of cell-division where only one of the daughter cells goes on to reproduce. On the other hand, if both daughter cells go on to reproduce, then N equals M equals 2, and thus -log2(M/N) = -log2(2/2) = 0, indicating that selection, by failing to eliminate any possibility failed also to introduce new information. "
Now, it is observed repeatedly that more offspring are produced than those who actually reproduce. So, let's do some calculations on Dembski's equation looking at these numbers.
1. In a population, there are 4 offspring born but selection eliminates 3 and only one reproduces. So we have N = 4 and M = 1. -log(2) (M/N) = -log(2) (1/4) = -(-2) = 2. We have gained 2 "bits" of information in this generation. Selection does increase information.
2. Let's take a more radical example. An antibiotic kills 95% of the population. So we have 5 bacteria that can reproduce out of 100. N = 100, M =5. -log(2) (5/100) = -log(2) (.05) = -(-4.3) = 4.3. Now information has increased 4.3 "bits". The more severe the selection, the greater the increase in information.
3. Let's take a less severe example. A selection pressure such that of 100 individuals, 99 survive to reproduce. -log(2) (99/100) = -log(2) (.99) = - (-0.01) = 0.01.
So now we have only an increase of 0.01 "bits" in this one generation due to selection. But remember,
selection is cumulative. Take this over 1,000 generations and we have an increase of 10 "bits". Now, Nilsson and Pelger have estimated, using conservative parameters, that it would take 364,000 generations to evolve an eye. D-E Nilsson and S Pelger, A pessimistic estimate of the time required for an eye to evolve. Proceedings of the Royal Society of London, B. 256: 53-58, 1994. Taking that over our calculations shows that the eye represents an increase of 3,640 "bits" of information.
Finally, note that selection
must result in an increase of information by Dembski's equation. Any fraction always has a negative logarithm. With the negative sign in front of the logarithm (-log) that means that the value for information must be positive as long as selection is operative. The only way to get loss of information is for the number of individuals that reproduce (M) to be greater than the number born (N). This is obviously not possible.
How then, have we gone from single-celled life with hundreds or thousands of base genetic pairs to humanity, with billions of base genetic pairs?
By a combination of chemistry and evolution. We can go into the details in as much "complexity" as you would like.
