Evolution with a Purpose http://web.mit.edu/manoli/evolution/www/main.html1 of 8 11/18/2003 5:53 PMEvolution with a Purpose6.868 Final Paper - Manolis KamvysselisSome like Netscape frames, and some don'tDisclaimerThis article was written before i knew any biology. It has a lot of misconceptions about how things work, and uses all the wrongvocabulary. Please at least read "non-coding region" every time i wrote "introns". Despite the embarassment, i leave this online forhistorical purposes only. Then again, some ideas are worth a thought, knowing that it was all theoretical and abstract, prior to any bioknowledge on my part.MotivationOn page 318 of The Society of Mind, Marvin Minsky suggests that "we can easily conceive how machinery could exist inside an animal,to purposefully direct some aspects of its evolution." Fascinated by the idea, but unhappy with my background in the matter (high-schoolbiology), I ended up having to read quite a few pages to avoid making a report full of air. Starting with some basic assumptions andintuitions listed in Section IV, I searched a few interesting biology books I could find on the topic, and I propose here some mechanismsthat would enable a new theory of evolution presented in section V.The metaphor - DNA is a computer program and exons are where the data is stored.The purpose of most of our DNA remains unclear to scientists today. Only one tenth of our genetic code is used to create all known proteins in our bodies.It is this paper's hypothesis that this tenth which has been mapped to protein creation is simply data stored in variables, and that the largest part describes how this data should be used.If we think of DNA as a huge computer program, most of it would describe operations to be performed and meta-information in some genetic programming language, and only a fraction of the program would contain genetic data that actually encodes a human'sgenotype.Purpose - to develop goals and constraints for such a languageThe purpose of this paper is to envision such a genetic language for encoding meta-information in a string of DNA.I tried to use biological evidence and knowledge about genetic mechanisms in basing my hypothesis, but the proposal is by nomeans based on biological observation, but merely a thought experimentThe only contribution of this paper to genetics would be to pay more attention to introns as intelligently constructed rather thangarbage accumulated over generationsVision - DNA encodes what species learned about survival and about EvolutionJust like information about the individual is encoded in the DNA data (extrons), in this meta-information (introns) would be accumulated knowledge about evolution itself.This information would be used to favor mutations more likely to yield the fittest individuals. It would be thus guiding the evolutionary process, directing it, providing it with a purpose.I. Darwin and Evolution. The non-evolutionist humans are becoming extinct under the pressure of Darwin's theory of evolution, and this is a good thing. Under thesame name of Darwin, however, seems to have disappeared the notion of purpose in the natural sciences. It is taboo to study why a certainmutation occurs, and how it is related to the environment, the previous mutations, the genetic history of the species.a. Random change and testing.Evolution with a Purpose http://web.mit.edu/manoli/evolution/www/main.html2 of 8 11/18/2003 5:53 PMThis fear of seeking purpose-directed mutations has come about to avoid mixing engineering and biology. Evolution doesn't have apurpose. Building humans or intelligent creatures is certainly not one of them. It is wrong to think that nature is aiming to populate allniches available, land, water, air. In fact, the beauty of Darwin's theory comes from this very fact, that there doesn't have to be a purposefor evolution to occur. All the magic comes from the fitness function that lets only the fittest survive.b. Intermediate steps must be advantageous. However, as one tries to simulate evolutionary processes in purely random mutation and selection, the time it takes for a fit individual toappear is combinatorial in the number of elements that compose it. Simultaneous mutations yielding the ability to fly instantaneouslycould simply not have occurred. It is therefore thought that each small step towards wings was advantageous to the individuals that werethus able to survive enough generations until the final mutation which allowed them to fly. In fact those advantages need not be related toflying, but could be useful in providing heat dissipation, walking balance, or rain protection.c. Co-evolution of environment and Individuals.Another notion that has to be incorporated in understanding species evolution is how they relate to a changing environment. Changes inindividuals make changes in their environment to which individuals have to adapt. Individuals evolve and shape an environment whichshapes them. II. Strong evolutionary evidence unaccounted for by Darwin The Darwinian model of Evolution has successfully provided an explanation for many discoveries about our natural world, andrevolutionized a field with the powerful idea of random mutation and natural selection. However, even though this theory is beautiful byits simplicity and powerful by its predictions, there are many important points that it misses about evolution in general.a. Evolution speed is exponential in the number of possible permutationsEven with the notion of advantageous intermediate steps, it is hard to believe that more complicated species evolved faster than lesscomplicated species. Indeed, the more complex species become, the harder it should get for new interesting features to arise with simplerandom mutation. The number of possible mutations increases as the DNA becomes longer, and the likelihood of simultaneous mutationsyielding interesting phenotypes is very slim. Evolution has demonstrated the opposite of what a random process would display. The morecomplicated species became, the less time it took to evolve to even more complicated species.Time Frame:Origin of the Earth 5 billion yearsBacteria and algae 3 billion yearsFilamentous algae 2 billion yearsMarine invertebrates 600 millionFish, land plants 400 millionAmphibians 300 millionDinosaurs 200 millionMammals 150 millionPrimates 20 millionb. Mutation rates do not correspond to evolutionary rates. The Homo species evolved more rapidly than frogs, chimps, etc. That is, humans