User talk:Basiec

The Evolution Inbreed Theory of Aging  Abstract  This theory proposes that aging has evolved to reduce the

impact of inbreeding. Inbreeding reduces the vitality of animals and consequently reduces

the survival abilities of the species. In order to prove the above hypothesis one will

have to show that there was a correlation between the aging rate and the

inbreeding potential after many generations of inbreeding.

valid four conditions must be met: (a) Aging does occur in wild populations.  (b) Inbreeding does occur in wild populations.  (c) Inbreeding is mostly harmful to

species.  (d) Aging reduces the impact of inbreeding.  (e) There is a correlation between aging and the

inbreeding potential.  Aging does occur in wild populations .

For this hypothesis to be valid aging only has to occur under natural conditions (9). Terminal aging does not have to occur but can be approached because of phenomena such as dominance (male or female). <b> Inbreeding does occur in wild populations</b>. Moderate inbreeding is common in mammal and bird populations(10). Inbreeding is mostly harmful to species.

All well-studied naturally outbreeding species show depressed reproductive fitness in inbred individuals(2). <b> Aging reduces the impact of inbreeding</b>   Aging affects inbreeding by the reduction in reproductive capacity(3). There is a correlation between aging and the inbreeding potential. William R. Swindell1 and Juan L. Bouzat showed this to be the case(6).  General Discussion  Thereis a very large variation in the average age of a

large number of animal species. This indicates genetic regulation (4). The regulation is

probable controlled by switches similar to the myostatin protein switch (7). One would

expect an occasional aging prone animal that does not age. This does not happen

because the rate of aging is probably genetically regulated at the cell type level. This will

not be obvious unless the genetic regulation of senescence in all cell types are stopped.

One could redefine aging as pressure against inbreeding or PAI. PAI=(ACA/IP)(alpha). ACA

is the average chronological age of the population. IP is the inbreed potential of the

population at the time it evolved. Epistasis could explain inbreed depression. Thus the

chronological age will be PAI(IP).The inbreed potential is made up of all the factors that

increase the likelihood that inbreeding will occur. It is a measure of the proportion of DNA

that is inbred. It can vary from 0 to 100%. The Allee effect is not important here because

the population level would not have reached the necessary critical low level. Alpha is not

been defined at this point in time. One can test this theory by predicting that if an IP lasts

long enough (with no gene flow between the high PAI and low PAI population) that the

descendants of the animals with a low IP will eventually evolve longer lifes than those

populations with the high IP in spite of genetic drift. <b> Aging

mechanism </b> According to the Hardy-Weinberg principle genes will be preserved in a large population. Subject to the condition that breeding is random (R). Inbreeding will result in the elimination of lethal alleles. The sub lethal alleles will depress vigor. The set of sub lethal alleles expressed later in life may result in senescence or aging. Protection provided by certain genes against hazards which include free radicals and natural radiation may be the mechanism through which the IP is  modulated. The genetic regulation may be indirect(5). In other words the ratio of normal to redundant (defective) cells is probably predetermined by a genetic program. The Gompertz curve will be shifted to the right. <p editor_id="mce_editor_0">It is known that related species often have different rates of aging. This means that populations of animals with a low or high PAI evolve other changes besides the rate of aging. For this reason it is very unlikely that two or more groups of similar species that have different rates of aging will be observed in nature at the same time. In order to prove the above hypothesis one will have to find closely related species with different rates of aging and IPs. The naked mole rat lives much longer(6) than other rats(7) may be an example. Conclusion Weismann's first hypothesis could be right after all. Aging may be

an evolved adaption. (J. Coetzee MS Medical Science UCT ) agingtheory@gmail.com Literature Cited

1. Peter Crnokrak, Derek A. Roff (1999) Inbreeding depression in the wild Heredity 83 (3),260–270. 2. Frankham, R. 1995a. Conservation genetics. Annual Review of Genetics 29:305-327. 3.http://www.actuaries.org.uk/files/pdf/library/JIA-079/0239-0273.pdf<br /=""> 4.Science 23 December 2005: Vol. 310. no. 5756, pp. 1911 - 1913 5. Gavrilov L.A.,Gavrilova Journal of Theoretical Biology, 2001, 213(4): 527-545 6. Genetics. 2006 January; 172(1): 317–327. doi: 10.1534/genetics.105.045740. 7.http://www.ncrr.nih.gov/newspub/jul00rpt/muscle.asp<br /=""> 8. Cooperation Among Animals: An Evolutionary Perspective (Oxford Series in Ecology and Evolution) (Paperback) by Lee Alan Dugatkin (Author) (9) Hans-Georg Müller et al: Aging Cell (2004) 3, pp125–131. (10) http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1691061&amp;blobtype=pdf