Great Ideas Project: Origin of Sex Essay -- DNA Biology Biological Pap

Great Ideas Project: Origin of Sex Sex, though usually used in terms of reproduction, is actually quite separate: it refers to the splitting and recombining of genetic material through the meiosis (fission) and fertilization (fusion) of genomes in such a way that, when they are reproduced, the new generation of cells contains a different set of genes than that of its parents. Sex is by no means necessary for reproduction. Asexual reproduction, or parthenogenesis, is actually about twice as efficient for population growth; there is thus a â€Å"two-fold cost† of sex in reproduction. There are many benefits to sex, however, that outweigh its inefficiency. Among these benefits are the opportunities for the repair of damaged DNA, the rapid recombination of genes to more readily adapt to changing environments, and the elimination of the accumulation of deleterious mutations from a population. It is easy to find benefits to sex; finding a theory for the origin of sex is not nearly as simple. There are many cont ested theories for what made organisms evolve in a pattern which is less efficient for population growth, but no sure-fire answers.[1] The predominant theory for the origin of sex has always been the benefits of DNA repair. In an asexual haploid cell, if both sides of a DNA strand were damaged—for instance, if the thymine and adenine erred and became unrecognizable—since the cell would have only one copy of the information, there would be no chance for the cell to repair the damage and the cell would either die or be able to pass on only grossly mutated genes. However, an asexual diploid cell and a sexual cell each contain an extra set of chromosomes providing the template to repair that damaged DNA strand. Using DNA r... ...rsity Press [2] Michod, Richard E. (1998). Origin of Sex for Error Repair. Theoretical Population Biology, 53, 60-74 [3] Mauro Santos, et. al. (2003) Origin of Sex Revisted. Origins of Life and Evolution of the Biosphere, 32, 405-432 [4] Dacks, Joel and Roger, Andrew J. â€Å"The First Sexual Lineage and the Relevance of Facultative Sex.† Journal of Molecular Evolution (1999), Issue 48 pg 779-783. [5] Leboeuf, Adrian. â€Å"UCSB Researchers Study Advantages of Sexual Reproduction† Daily Nexus, volume 82, issue #28 [6] Crow JF. â€Å"Advantages of Sexual Reproduction† PMID: 8062455 [7] Rothschild, Lynn J. â€Å"The Influence of UV Radiation on Protistan Evolution.† Journal of Eukaryotic Microbiology (1999), Issue 46 no. 5 pg. 548-555. [8] Sterrer, Wolfgang. â€Å"On the Origin of Sex as Vaccination.† Journal of Theoretical Biology (2002), Issue 216 pg. 387-396.