Monkey

This is something I havn't really touched on yet.

How does new genetic information arise?

I mean, chickens rarely develop teeth because that particular gene has been turned back on because their ancestors used to have them, but does anyone have information/examples on the production of new information?

Rephrased, sorry.

RBH

I'm not sure the locution "how much of genetic change" is due to this or that is a sensible question - what's the unit of measurement in which the "how much" is expressed? And the phrase "evolution of new genes" doesn't make a whole lot of sense to me, either. A gene is not the unit of analysis in evolution.

However, here are some references that address the sense of your question.

RBH

Tim Thompson

The argument that evolution cannot create "new information" is one of the common creationist lines. It's also typically untenable. One obvious and simple way to create new information is the process of duplication & divergence. Gene duplication is well known to occur, even at the level of a single gene. The rates of duplication are also known. This leads to the conclusion reached by Lazcano & Miller in 1994, that abiogenesis & early evolution should only take about 10,000,000 years. It should be clear enough that lengthening the genome by duplication, and creating new gene functions by divergence, certainly constitutes the addition of "new information" by any reasonable definition of "information".

How long did it take for life to begin and evolve to cyanobacteria
A. Lazcano & S.L. Miller
Journal of Molecular Evolution 39(6): 546-554, December 1994
Abstract: There is convincing paleontological evidence showing that stromatolite-building phototactic prokaryotes were already in existence 3.5 x 10(9) years ago. Late accretion impacts may have killed off life on our planet as late as 3.8 x 10(9) years ago. This leaves only 300 million years to go from the prebiotic soup to the RNA world and to cyanobacteria. However, 300 million years should be more than sufficient time. All known prebiotic reactions take place in geologically rapid time scales, and very slow prebiotic reactions are not feasible because the intermediate compounds would have been destroyed due to the passage of the entire ocean through deep-sea vents every 10(7) years or in even less time. Therefore, it is likely that self-replicating systems capable of undergoing Darwinian evolution emerged in a period shorter than the destruction rates of its components (<5 million years). The time for evolution from the first DNA/protein organisms to cyanobacteria is usually thought to be very long. However, the similarities of many enzymatic reactions, together with the analysis of the available sequence data, suggest that a significant number of the components involved in basic biological processes are the result of ancient gene duplication events. Assuming that the rate of gene duplication of ancient prokaryotes was comparable to today's present values, the development of a filamentous cyanobacterial-like genome would require approximately 7 x 10(6) years-or perhaps much less. Thus, in spite of the many uncertainties involved in the estimates of time for life to arise and evolve to cyanobacteria, we see no compelling reason to assume that this process, from the beginning of the primitive soup to cyanobacteria, took more than 10 million years.

However, it is also well known that duplication does not come only in steps of single genes. It is most likely that large evolutionary steps take place by duplication of large chunks of the genome at once.

Minimal Model for Genome Evolution and Growth
Li-Ching Hsieh et al.
Physical Review Letters 90(1): paper 018101, January 10, 2003
Abstract: Textual analysis of typical microbial genomes reveals that they have the statistical characteristics of a DNA sequence of a much shorter length. This peculiar property supports an evolutionary model in which a genome evolves by random mutation but primarily grows by random segmental duplication. That genomes grew mostly by duplication is consistent with the observation that repeat sequences in all genomes are widespread and intragenomic and intergenomic homologous genes are preponderant across all life forms.

The ability of the genome to grow physically is indisputable. Given that, it's hard to imagine how anyone can seriously believe that the appearance of "new information" is at all mysterious or impossible, though creationists commonly do. There are many papers on the application of information theory to evolution of the genome by thomas Schneider. See Schneider's AntiCreationst page, and his Evolution of Biological Information page, which include Schneider's response to William Dembski's criticism of Schneider's work.

One of the weaknesses of the creationist position is that they fail to properly understand what "information" is. In fact, there is more than one kind of information theory, and you have to understand which kind of information is applicable to a given task. Schneider shows that they don't understand Shannon information, and Mark Chu-Carroll shows that there are other kinds of information that creationists ignore ("How to Measure Information").

The real truth is that this is just one more in the long list of examples of creationists not knowing what they are talking about.

Dr.GH

Tim, Thanks for the references. As always they are to the point and highly useful. GH

RufusAtticus

Monkey, here is my take on the issue.

INFORMATION
Individuals don't evolve. Populations do. So in linking information theory to evolution, one must consider the information in the population, which creationists do not do. Biologically, information can refer to different things. Pseudogenes, contain information about evolutionary history but not information that can be selected upon. In the context of this discussion, it would be best right now to consider the genetic information underlying traits, with an interest in adaptable traits. It is difficult to determine a way to measure the amount of this information, but one possibility is the size of the proteome. This is the number of unique proteins produced in the population and includes all loci and alleles. Whenever a mutation produces a novel allele, it adds information to the population. In other words, there is a new trait for selection to act upon. Here are two examples of the effects of information in a population.

Jeff knows something about Gina: "Gina is neat." Thus he has information about Gina. Before he leaves town, Jeff replicates this information by telling it to two people, Nick and Randy. Because neither of them pays attention, they don’t replicate the information exactly. Nick thinks "Gina is sweat," and Randy thinks "Gina is near." We can measure the about of information about Gina by the number of non-redundant attributes people ascribe to her. Here, the amount of information about Gina has doubled: from "neat" to "sweat and near." Clearly when we remember that it is the population that’s important to evolution, it is obvious how mutations can add information for selection to act upon.

Take this example retrieved from LocusLink [1], the only difference occurs in the 7th codon (6th amino acid because the first one, 'm,' gets cut off). The letters refer to amino acids [2].
Each allele does not encode the exact same information since each one produces a distinctly different product. A single point mutation has enough effect on the information contained in the genome that it can determine whether an individual dies from malaria or not. In the presence of malaria, HBB-S is maintained because of heterozygote advantage. However, HBB-C also offers resistance to malaria, but the most fit genotype is the homozygote.[3] It is expected to become the most common allele in parts of Africa if the environment stays the same. These mutations have clearly added new information to the population. Selection then acts on this new information, changing the make up of the population. Thus, evolution happens.

It is important to realize that evolution occurs even if information is lost. It also occurs when information is gained or without any change in the amount of information at all. Thus no-new-information arguments do not actually address evolutionary theory. By focusing on individuals and not populations, no-new-information claims never even get close to disproving evolution. In fact, the actual claim, when applied to biology, is that the information capacity of an individual's genome cannot increase. However, this claim is false because there are known types of mutations that can increase the length of the genome and thus its capacity to hold information. Ernst Mayr discusses this origin of new genes in his latest book:

1. http://www.ncbi.nlm.nih.gov/LocusLink/
2. http://www.chem.qmul.ac.uk/iupac/AminoAcid/AA1n2.html
3. Modiano D. et al. (2001) Haemoglobin C protects against clinical plasmodium falciparum malaria. Nature: 414 pp 305-308
4. Mayr E. (2001) What Evolution Is. Basic Books.

Monkey

Thanks guys, that was helpful.