EVOLUTION Misconceptions about Darwinian evolution evolution is just a theory in science guess hypothesis theory unifying concept that explains many observations withstand multiple tests falsifiable subject to modification dynamic suggest experiments productive evolution is about the origins of life explains how changes occurred after complex life arose evolution means atheism seeks natural explanation of natural phenomena is neutral on the role of god survival of the fittest justifies abuse of other humans or animals What is Intelligent Design William Paley 1800 obvious that there is a supernatural designer of life attempt to explain irreducible complexity of structures that need multiple components to function no natural explanation for the history of these structures What Darwinian evolution DOES propose Descent with modification that new species can arise from pre existing ones WHAT Mechanism natural selection HOW Aristotle s Great Chain of Being no movement between rungs immutable Lamarck Father of Evolution 1700s introduced notion of evolution viewed it as an unbranched series of escalators rising from spontaneously generated microorganisms more complex ones proposed inheritance of acquired characteristics loss of organs through disuse Charles Darwin studied flora and fauna of S America and Galapagos Islands for 20 years developed theory but delayed publication publish from death bed received letter from Alfred Wallace declaring natural selection published On the Origin of Species by Natural Selection context of Darwin s theory many species existed and could be grouped by common characteristics Linnaeus founder of Taxonomy 100 years prior industrial construction led to paleontological discoveries greater than 90 did not match living organisms geological studies indicating Earth much older Lyell impressed by effects of heritable variation in artificial selection of plant and animal breeding 2 postulates descent with modification natural selection natural variation in a pop that is largely heritable genetic basis not all offspring survive to reproduce because resources are limited limits to survival imposed by nature some individuals will be better adapted to environment fitter survival reproduction over time favored trait will predominate in pop trait has been naturally selected for and pop has adapted to its environment adaptations anything that increases survival reproduction structure enzyme pigment behavior etc natural selection acts on phenotypes 5 lines of evidence for evolution biogeography geographical distribution of organisms organisms on different land masses are more similar to each other than to other species on the same mass convergent evolution fossil record any remnant of a life form something has to interfere with regular processes of decomposition living fossils that haven t changed in a long time crocodiles etc identify existing species and use biogeography to identify connections to progenitor or ancestor species comparative morphology homologous structures are signs of evolution and common ancestry notion of evolution as a tinkerer vestigial structures no longer needed for a purpose molecular biology by comparing gene sequences a lineage of ancestors will often become clear with smaller differences between more closely related organisms mitochondrial DNA sequences as molecular clocks for describing divergence of species we are able to compare entire genomic sequences direct observation ex microbial resistance antibiotics act on variance in bacterial cells Are we descended from apes No we have a common ancestor that existed 5 MYA