Mutations would eventually lead to the extinction of a species

I hope it will be intellectually stimulating. Before we go anywhere, I will need to clarify two terms that are of great importance to this debate. Specifically, we are referring to the decline of the human species, since the human genome is the most studied, and even similar phenotypical organisms like most apes have not been sequenced to any practical extent. Genetic Information does not refer to shannon information. Mutations are changes in the nucleotide bases of a genetic sequence causing a distortion of the original genetic information. By definition, any mutation causes “new information” in that it has created a new allele. There are several types of mutations which I will not go into. There are three main categories in which mutations can be classified in relation to their distortion of the genetic information: “The mutations at 1 of these categories of site are assumed to be neutral, whereas mutations at the other sites are assumed to be strongly deleterious, neutral, or advantageous. .. ”[1] This quote is partially wrong in that in the section of neutral, there are actually very few neutral mutations. Most mutations are nearly neutral, either in a deleterious or beneficial way. (See Kondrashov [2]) Mutations are regarded as “contaminations” in that they distort the “pure” information of the genome. Mutations are known to cause most of the diseases humans experience [3], besides already being degenerational to the genetic information. The Cost of Mutation is too HighIt is widely held that the genome encodes information. Hence, any mutation, by definition, is “new information. ” Is this mutation beneficial? Or is it deleterious? Mutations rarely are beneficial. In the overwhelming percentages [4] of cases, mutations causes a loss of fitness, in that it is deleterious, sometimes to the point of lethality, to the organism’s genetic information [1]. In every human individual (The most widely studied genome), there are about 100-200 new mutations,[5] besides any mutations they might already have inherited. In fact, populations face a risk of extinction simply due to fixation of reverse as well as deleterious mutations. “For a given effective population size, the selection coefﬁcient that maximizes the rate of erosion of mean Malthusian ﬁtness, obtained from delta(sR)=deltas = 0, is the solution of 2Nes + e-2Nes = 1 ors = 0:797=(2Ne). Thus, nearly neutral mutations, with s slightly less than 1/(2Ne), do the most damage to the population. .. Nearly neutral mutations that maximize the rate of erosion of mean Malthusian ﬁtness also minimize the expected time to extinction. For 2Nes> 1, the expected time to extinction increases almost exponentially with Ne with a constant selection coefﬁcient. .. [T]he required number of loci ﬁxed for mildly deleterious mutations to cause extinction is only a small fraction of the total number of loci. .. [M]any mutations, such as large deletions of unique DNA sequence, are not reversible. .. ” [6] The amount of large deletions is surprisingly large. Quite a few examples have been discovered, and each of these deletions are of the order of hundreds to thousands of base pairs. [7] These deletions of beneficial information usually leads to the extinction of the organism and occurs not too infrequently. It is estimated that deletions occur in 1/7000 live births, which is a stunningly large number. Taking into account deleterious mutations alone (Not natural selection or drifts, or any other degradational mutations), Kondrashov A. S. has estimated that humans would have died out 100 times over within just the time evolution allows for humans to have been around. [2] This forces us to consider two explanations. I. The humans will go extinct within the next five millennia. (Based on a variety of estimates that I will not source here)II. There is a reversing agent to deleterious mutations that will not allow for the extinction of the population. It is obvious that there is experimental support for (I) but not for (II). It is thus logical to assume that I must occur. (Bacterial populations are far more resistant to deleterious mutations than humans due to their fast reproductive rate, but that does not mean that they will not eventually die out. See [4])As such, experiments support the idea that mutations will be the death of organisms. The Cost of Selection too highIt has been suggested that selection via a variety of means could counteract the relentless degradation by mutation. In fact, one of the major explanations is known as recombination. It is thought that by having a large enough population which can have their sequences recombined by reproduction would reduce and maybe even nullify the harmful nett effect of mutation. Recombination has several problems which I will go into. Any beneficial mutations which would have overridden the effects from the dozens of slightly degradational mutations would not be capable of being selected for. This phenomena is known as genetic linkage, where chunks of DNA is inherited while retaining the status quo in the offspring. Genes tend to clump together in linkage blocks. This means simply that the beneficial and deleterious mutations are banded together and as such deleterious mutations cancel out the beneficial mutations. Even if these clumps can be split up, each individual gene and its accompanying regulatory DNA would have the same problem, thus this problem is insurmountable. (See citations, and ENCODE papers, too many to source)Loewe L. has estimated from mutations just from within the mtDNA (Which has remained mostly intact)would have caused humans to go extinct within 20 million years. [8] However, if all known genetic data is taken into account, ie. the fact that deleterious mutations occur in all other regions besides the mtDNA, the time t becomes vanishingly small. I am not saying here that some degradational mutations cannot be counteracted, but that the total amount cannot be counteracted, leading to extinction. There has been some notion that these only occur in small populations. This is not so. In fact, Loewe and Kondrashov has shown that it applies to the fairly large human population. Even worse is the fact that the time to extinction is much shorter in small populations. The human population is not a homogeneous population in that it has many smaller sub-populations that each have their own new set of mutations that cause the independent genetic decay of these sub-population leading to the overall extinction of the greater human population. This is an irreversible fact of science. I will not in this debate go into the "fudging" effect of noise on the genome. With that, I eagerly await to see Con's no doubt fascinating opening. I hope to learn even more of the genome from this debate.1. . http://mbe.oxfordjournals.org... (Mol Biol Evol (2008) 25 (6): 1007-1015. )2. . http://www.ncbi.nlm.nih.gov... (J Theor Biol. 1995 Aug 21;175(4):583-94. )3. . http://homepages.ed.ac.uk... (Genetics February 1, 2012 vol. 190no. 2 295-304)4. . http://www.pnas.org... (PNAS June 1, 2004 vol. 101 no. 228396-8401)5. . http://www.genetics.org... (Genetics September 1, 2000 vol. 156 no. 1 297-304)6. . http://link.springer.com... (Genetica 102/103: 21–27, 1998. )7. . http://www.nature.com... (Clancy, S. & Shaw, K. (2008) DNA deletion and duplication and the associated genetic disorders. Nature Education 1(1))8. . http://journals.cambridge.org... (Genetical Research / Volume 87 / Issue 02 / April 2006, pp 133-159)