delcoder wrote:[From Post 305] ... Consider the long term experiment conducted by Lensky. 50,000 generations of bacteria were studied for 20 years. The E Coli was separated into 12 populations. One of the populations developed the ability to metabolize citrate in the environment after about 23,000 generations. Proof of evolution? Not hardly. Buried in Lenski's notes and not in his press releases was the fact that the gene expression that finally allowed the E Coli to metabolize citrate was the fact that two other expressions had occurred prior to the final enabling expression. It seems all three were involved in the adaptation of citrate metabolism of the population.
Are you aware of what that does to the mathematical probability this newly acquired ability was acquired by chance? Consider there are approximately 3200 genes in the E Coli DNA. Since each can be either turned on or off that makes 6400 possibilities. Try 1 in 262 billion. If that's not enough to convince you the odds are prohibitive, consider genes can code for multiple proteins and a single mutation can affect only the ability alter only one such code. ...
delcoder wrote: [From Post 320] Virtually everyone in biology that has enough math to figure out the odds of three gene mutations that work in concert know they are far too prohibitive to give them any credibility in the real world. This has been the dirty little secret of Neo-Darwinian evolution for decades.
Your argument seems to be that the probability of a double or triple mutation is mathematically so low that evolution by natural selection is unlikely. This is pure hogwash.
According to Lenski, whose work you seem to admire,
E. coli is a very common bacterium. Theres some hundred billion billion (10^20) of them in the world. A billion
E. coli cells currently live in your own bowels. Mutations are rare events; however, [e]ven if [
E. coli cells] divide just once per day, and given a typical mutation rate of 10^-9 or 10^-10 per base-pair per generation, then pretty much every possible double mutation would occur every day or so [to each gene]
[1]. Lenskis
E. coli in the lab typically divide 6-7 times per day. Thats a lot of opportunity for evolution.[Ibid.] Periodic evolutionary innovations are not surprising if you actually do the math.
Your claim (not mine) is that the odds of a triple mutation in
E. coli is 1 in 262 billion. Well, considering that there are 100 billion billion
E. coli in the world, and
E. coli divides 6-7 times per day, then those are pretty likely odds, wouldn't you say? What makes you think that evolution by means of natural selection is mathematically unlikely?
delcoder wrote:[From Post 305] ... Buried in Lenski's notes and not in his press releases was the fact that the gene expression that finally allowed the E. Coli to metabolize citrate was the fact that two other expressions had occurred prior to the final enabling expression.
Are you really suggesting that Lenski was trying to hide or bury results? If so, this is more hogwash. Lenski talks about a potentiating mutation right in the abstract of the article that describes his findings.
[2] This article is publically available to anyone who has the ability to do a Google search or bold enough to ask a librarian for assistance.
delcoder wrote:[From post 317] ... Consider Lenski's 50,000 generation E Coli experiment in which one of 12 populations developed the ability to metabolize citrate. Buried in his notes are the facts that this newly developed ability was due to mutations in three genes. ...
By definition,
epigenetics is the study of heritable changes in gene expression caused by
mechanisms other than changes in the underlying DNA sequence. Changes in DNA sequence are known as
mutations.
You claim that in
Lenski's experiment, the newly developed ability to metabolize citrate was due to mutations. Since you have mentioned "gene mutations", you are no longer discussing epigenetics. It seems like you dont even know the meaning of the terms that you are talking about here.
