GEOL 204 1 26 12 01 26 2012 Paleontology the study of fossils and prehistoric life o Simultaneously a subset of the fields of biology and geology Fossils the physical remains or traces of behavior of organisms preserved in the rock record The Fossil Record The totality of fossils and the information they contain in the strata of the Earth Prehistoric before written history In the Beginning Our long quest for origins o Every culture has tried to use what they had available to understand origins and beginnings o Often their stories were radically different o Check for links on the website o Common beliefs in worldwide folktales These thoughts were the dominate thoughts for people for thousands of years The world is not that much older than Humanity Human history at least as folktales extends back practically to the beginning of the world People lived as much as they do at the present day for most of history There isn t much room for a prehistory Life forms of the world are largely unchanged since the beginning of time exception for monsters etc Physical features of the landscape are largel unchanged since the beginning of time Rocks are aboriginal from the origin they were formed at creation and are not produced by events in the history of the Earth o But what about fossils Are often part of the solid rocks themselves How to reconcile existence of fossils with rocks as old as creation Remains of magical beings Demonic creation Sports of nature Traces of incomplete creation Organic appearing crystal Nicolas Steno 1638 1686 Looked at fossils using microscopes and found that fossil shark teeth were exactly the same as modern shark teeth but were found in rocks as old as time So he thought that rocks were not aboriginal but in fact products of this world He said that layers of rocks were made up over time and that fossils are remains of once living things buried at the time the rocks were formed when the rocks were still sand mud etc Established using layering sequences of dirt to figure out time of fossil Baron Georges Cuvier 1769 1832 Recognized that fossils are the remains of unknown organisms But why are they unknown Human caused extinction was already discovered the Dodo bird etc Discovered natural extinction The reason we don t see these fossilized organisms is because they are gone dead and entirely extinct Fossils are the remains of extinct organisms not a single existence of that species is alive today The strata of the earth contain unique different sets of fossils in each of them There isn t just one fossil world but instead there is a succession of fossil worlds each with its own distinctive animals and plants And all were prehistoric before written history Even up to the 1860s people argued that no humans ever lived with the extinct creatures But then a discovery was made and people understood that humans were in the fossil record but they were found in only the most recent layers of fossils Wasn t until the mid 19th century that the idea of a human prehistory existed Each earlier phase was vastly more ancient than the previous 1 31 12 The Nature of Science How We Keep From Lying to Ourselves Science o Not just a body of knowledge o The systematic acquisition and application of knowledge about the structure and behavior of the physical universe gained via empirical evidence through observation measurement and experimentation o A type of inquiry into nature characterized by the availability of empirically testable hypotheses o From the Latin scio I know o Humans lack and will always lack total knowledge Info from the past has been lost our brains have a capacity limit we don t know about the future etc o Information about the world around us is limited to our senses which can be amplified by instruments o World follows patterns rules of operation o These can be understood or at least approximated by models o Through repeated cycles of observation and testing and occasionally wholesale replacement of models we can more closely approximate the actual conditions of the world around is Arguments Science is therefore a self correcting process o Not simply taking the opposite position of an opponent o A connected series of statements intended to establish a proposition stating ones case o Science needs more than the argument itself Argumentation cannot suffice for the discovery of new work since the subtlety of nature is greater many times than the subtlety of argument Francis Bacon Empiricism o Evidence based o Observations data measurements Science deals only with issues that have some direct manifestation in the natural world o PEARL Physical Evidence and Reasoned Logic o Humans see patterns in Nature Some real but some false patterns Humans cant help but see faces in things Our brains are programmed to see these things o Method to sort between real and false patterns and to evaluate the relative support of different patterns The Hypothetico Deductive Method aka The Scientific Method o Hypotheses Formal statements of a pattern that appears to exist in a set of observations In contrast to theories hypotheses are primarily about the pattern itself not about an explanation of the pattern o Scientific inquiry proceeds from the formulation of hypotheses based on previous observations and subsequent testing of these hypotheses from additional observations o Scientific hypothesis must be falsifiable aka testable If you were wrong how would you know it There must be some way you can evaluate it an experiment where it is possible to show it is wrong o Not all hypotheses are falsifiable Some subjective and thus not scientific What can be asserted without evidence can be dismissed without evidence Some testable in principle but cannot be tested at present because of limitations speculations In fact all hypotheses are speculations until they Technically we don t prove things in Science we Hypotheses can be rejected but cannot be 100 are tested disprove hypotheses proven Uncertainty is part of science Provisionally accepted based on failure to disprove The more and more tests a hypothesis is subjected to and survives the more confidence we are in its validity facts Thinking like a Scientist claim o Keep an open mind but be skeptical of any unsubstantiated o Evaluate the quality of evidence of a claim o Make sure that a claim hypothesis can be tested o Try to falsify the hypothesis i e look for disconfirming o Consider alternative explanations multiple working o Other things being equal