Evolution for transhumanists

"In the broadest sense, evolution is merely change, and so is all-pervasive; galaxies, languages, and political systems all evolve. Biological evolution ... is change in the properties of populations of organisms that transcend the lifetime of a single individual. The ontogeny of an individual is not considered evolution; individual organisms do not evolve. The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to the next. Biological evolution may be slight or substantial; it embraces everything from slight changes in the proportion of different alleles within a population (such as those determining blood types) to the successive alterations that led from the earliest protoorganism to snails, bees, giraffes, and dandelions." - Douglas J. Futuyma in Evolutionary Biology, Sinauer Associates 1986 Evolution is a process that results in heritable changes in a population spread over many generations. "In fact, evolution can be precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next." - Helena Curtis and N. Sue Barnes, Biology, 5th ed. 1989 Worth Publishers, p.974 Charles Darwin - Wallace Reproduktion Variation Selektion fitnesslandskap använda utanför biologin memer teknikhistoria ekonomi "You have loaded yourself with an unnecessary difficulty in adopting Natura non facit saltum teleologi progressionism Lamarck modernt bråk ökar komplexiteten? Gould random walk brevid mur The traditional notion of progress as an increase in perfection or optimality has been abandoned, for it rested on a view that goes back to the late neo-Platonists - the idea that all of reality is arranged in a heirarchy of incxreasing perfection. This is called the scala naturae, and is often referred to the Ladder of Perfection. Modern evolutionary science does not think that the path of evolution is a ladder, although Lamarck did. The current view is best summed up by a phrase of Gould's - evolution is a bush, not a tree. utvecklingsträd inte topp, utan brett - igelkotten har evolverat lika länge som vi. Biologists define evolution as a change in the gene pool of a population over time. Earth Formed 4.5 Billion Years Ago Oldest rocks 4.3 billion years Oldest microfossils are 3.5 billion years old Possible Origins of Life on Earth Extraterrestrial origin, panspermia Special creation, supernatural or divine forces Evolution from inanimate matter Content of biological examination Only scientific origin permitting testable hypotheses via fossils Miller and Urey selfish genes pherical Protocells Aggregations of microspheres 1-2 mm diameter Arise from amino acids or fats suspended in water Internal fluid very different from external environment Molecules have hydrophobic regions Possess growth-promoting metabolic reactions Divide into daughter cells with same characteristics as parent Evolutionary Change in Natural Populations Is Adaptive lokalt bra, ingen plan transhumanister felanvänder evolution ofta "personal evolution" Some Genetic Variation Maintained by Natural Selection Sickle-Cell Anemia Peppered Moths and Industrial Melanism reservoarer genetisk variation The Fossil Record The Molecular Record Homology Development gälar, svans Vestigial Structures Human ear muscles Whale pelvic bone fig 21.9 Four-footed "missing link" whales cirkelarter Patterns of Distribution Organisms on islands most closely resemble forms on nearest continent Evolution of Different Groups Proceed at Different Rates tryck, evolverbarhet alife optimal mutationsfrekvens Fast and Slow Periods of Change Punctuated equilibria: evolution proceeds in spurts fig 21.12 Occurs when populations are small Different from parent population by founder effect Rapid adaptation to novel ecological circumstances Stasis: lack of evolutionary change Large populations Diverse and conflicting selective pressures mycket i världen följer power-laws Scientific Creationism Attempts to Explain Diversity Literal interpretation of the Bible Religious, non-scientific perspective Earth much younger than scientists believe All organisms created as they exist today Arguments to present as theory comparable to evolution Acceptance of premise that it is truly scientific Lacks empirical scientific evidence Does not infer principles from observation Assumptions do not lead to testable hypotheses Denies scientific facts assembled over centuries Implies deceptive creator Evolution provides scientific explanation Controversy about how evolution operates, not that it operates warför viktigt transhumanister? Lamark evolution of evolvability - Kelly? These types of questions are central to the field of evolutionary biology, which was plagued at the beginning of the century by internal tensions between Darwinians and geneticists. In the 1930s the two sides reconciled their differences into the "neodarwinian synthesis," which, paradoxically, resulted in the division of the field into discrete areas of study. These different perspectives have yet to be integrated into a cohesive view of evolutionary change. http://www.stanford.edu/class/history133/Provine/Adaption.html http://www.talkorigins.org/faqs/modern-synthesis.html "Evolution has never been observed." Biologists define evolution as a change in the gene pool of a population over time. One example is insects developing a resistance to pesticides over the period of a few years. Even most Creationists recognize that evolution at this level is a fact. What they don't appreciate is that this rate of evolution is all that is required to produce the diversity of all living things from a common ancestor. The origin of new species by evolution has also been observed, both in the laboratory and in the wild. See, for example, (Weinberg, J.R., V.R. Starczak, and D. Jorg, 1992, "Evidence for rapid speciation following a founder event in the laboratory." Evolution 46: 1214-1220). The "Observed Instances of Speciation" FAQ in the talk.origins archives gives several additional examples. "Evolution violates the 2nd law of thermodynamics." inlärningsprocess öppna system "The theory of evolution says that life originated, and evolution proceeds, by random chance." standardargumentet antar enbart slump populationsdivergens koevolution värd-parasit symbios massutdöenden pga slump isolation små populationer hybridiseringsbarriärer sexuell selektion Geographical isolation Ecological isolation Temporal isolation Behavioral isolation Mechanical isolation Prevention of gamete fusion Adaptive Radiation Existence of closely related species within a genera Evolved recently from common ancestor Most pronounced in sharply discontinuous habitats Darwin`s Finches fig 22.9 gruppselektion? homosexualitet? http://www.mhhe.com/biosci/genbio/rjbiology/ http://phylogeny.arizona.edu/tree/phylogeny.html Darwin constantly reminds the reader that natural selection does not operate to make all parts of an organism exquisitely adapted to its surroundings, as the natural theologians would have one believe: Natural selection tends only to make each organic being as perfect as, or slightly more perfect than, the other inhabitants of the same country with which it comes into competition. Baldwin-effekten During the first part of this century the incorporation of genetics and population biology into studies of evolution led to a Neo-Darwinian theory of evolution that recognized the importance of mutation and variation within a population. Natural selection then became a process that altered the frequency of genes in a population and this defined evolution. This point of view held sway for many decades but more recently the classic Neo-Darwinian view has been replaced by a new concept which includes several other mechanisms in addition to natural selection. Current ideas on evolution are usually referred to as the Modern Synthesis which is described by Futuyma; "The major tenets of the evolutionary synthesis, then, were that populations contain genetic variation that arises by random (ie. not adaptively directed) mutation and recombination; that populations evolve by changes in gene frequency brought about by random genetic drift, gene flow, and especially natural selection; that most adaptive genetic variants have individually slight phenotypic effects so that phenotypic changes are gradual (although some alleles with discrete effects may be advantageous, as in certain color polymorphisms); that diversification comes about by speciation, which normally entails the gradual evolution of reproductive isolation among populations; and that these processes, continued for sufficiently long, give rise to changes of such great magnitude as to warrant the designation of higher taxonomic levels (genera, families, and so forth)." - Futuyma, D.J. in Evolutionary Biology, Sinauer Associates, 1986; p.12 In other words, the Modern Synthesis is a theory about how evolution works at the level of genes, phenotypes, and populations whereas Darwinism was concerned mainly with organisms, speciation and individuals. tautologi? The current understanding of fitness is dispositional . That is to say, fitness is a disposition of a trait to reproduce better than competitors. Fitness is a statistical property.