| Popis: |
Evolution is a competitive game and cheating wins against fair competition. If one group cheats successfully, then that group gains an advantage and the other groups need to find a similar strategy in order to survive. Examples of evolutionary cheating include having learned aerobic respiration at a time when biology perceived molecular oxygen to be a metabolic waste product. The full range of symbiotic associations from cooperation to predation can also be perceived as representing efforts to gain a competitive advantage because, after all, if you cannot successfully work together with your potential competitors then either stealing what they have created or simply eating your competition may prove to be the more successful route. It also is important to understand that the process of natural selection does not act upon individual species as if they were independent entities. Instead, natural selection acts upon the homobium, which is a term suggested by Bernhard Frank in 1877 to describe the combination of a species and its associated symbionts. This essay presents a summary of mutualistic symbioses including the adoption of mitochondria which are the aerobic power house of eukaryotic life, chloroplastids in their many forms among which are algal and bacterial symbionts that provide fixed carbon from photosynthesis, and bacteria as well as cyanobacteria that serve as nitrogen fixing symbionts of plants. The biological activity of endogenous viruses also qualifies them as mutualistic symbionts, and they too are part of the homobium that defines their host. |
