Human Biology Book Notes Chapter One Science and the Real World 1 1 How does Science Impact the Everyday World We look to Scientists for factual information to tell us about the natural world just as we look to politicians for political solutions and journalists to tell us about current events Scientists are our eyes and ears on the natural world Society brings issues to scientists and scientists bring issues to society global warming stem cell research Through their discoveries scientists present society with options from which society then chooses either in the marketplace or the political arena Science and technology have always been in the business of providing options to society but more so now than in the past EX development of the internet computer technology reproductive fertility options genetically modified foods DNA fingerprinting cloning 1 2 What is Science Science as a Body of Knowledge Science a way of learning an activity carried out under certain loosely agreed to rules a body of knowledge about the natural world a collection of insights about nature the evidence for which is an array of facts Theory insights of science related set of insights well supported by evidence that explains some aspect of nature some pieces are in dispute but as a whole they stand as a scientific theory EX Big Bang Theory In everyday life a theory is little more than a hunch an unproven idea that may or may not have any evidence to support it Different than a theory in a scientific context The Importance of Theories Much more valued entity than a fact as the theory has an explanatory power while a fact is generally an isolated piece of information EX the universe being 14 billion years old is a fact but it explains very little in comparison to the Big Bang Theory Facts are important theories couldn t be supported or refuted without them BUT science is in the theory building business not the fact finding business 1 Science as a Process Arriving at Scientific Insights When science is viewed as a process scientific method it could be defined as a means of coming to understand the natural world through observation and the testing of hypotheses Scientific Method a means of coming to understand the natural world through observation and the testing of hypotheses The process by which scientists investigate the natural world Involves testing of hypotheses through observation and experiment as aided by the tools of statistics Observation a piece of the natural world is observed to work in a certain way Question Broadly speaking is one of 3 types What Why or How The observation is made a question is presented a hypothesis is created an experiment is conducted and a conclusion is drawn Formulating Hypotheses Performing Experiments Following the formulation of the question a hypothesis or multiple hypotheses are proposed that might answer the question Hypothesis a tentative testable explanation for an observed phenomenon Several hypotheses are proposed to account for the same observation To determine which may be correct experiments controlled tests of the question are conducted Not all hypotheses receive experiments as scientists usually have an idea of which hypothesis is the most promising so not all need to be tested The Test of Experiment Pasteur and Spontaneous Generation Louis Pasteur conducted experiments in 1860 to see if life regularly arises from life or if it is generated spontaneously through the coming together of basic chemicals Meat broth in glass flasks showed that no growth appears in the broth unless dust is admitted from outside Reject spontaneous generation hypothesis Life did grow when the neck of the flask was broken or when the flask was tilted Idea of spontaneous generation was not banished w this set of experiments The results of these particular experiments theorized that life spawns from life Variable An element of an experiment that is changed compared to an initial condition An adjustable condition in an experiment EX shape of the flask neck in Pasteur s experiment or the tilt of the flask Control Condition a separate group where we do not change the independent variable Independent variable is held steady An experimental condition that exists prior to the introduction of any variables that are being tested for EX broth filled flask left sitting straight up w its particle trap intact 2 Other Kinds of Support for Hypotheses Some scientific questions are difficult or impossible to test purely through experiment EX Are birds direct descendents of dinosaurs We can examine DNA from modern birds but not from dinosaurs We can use observation to test a hypothesis as well observing dinosaur and bird fossils When is a Theory Proven Provisional Assent to Findings Legitimate Evidence and Hypotheses Nothing is ever proven every finding is given only provisional assent meaning it is believed to be true for now pending the addition of new evidence This is what separates science from belief systems such as those that operate in culture politics or religion Scientists rarely think of this just as we rarely question why we drive on the right side of the road Every theory and fact in science is subject to modification and everything scientists know is subject to change The principle of science s openness to revision is one of 3 important scientific principles having to do w hypotheses and evidence Every assertion regarding the natural world is subject to challenge and revision based on evidence Results obtained in experiments must be reproducible Different investigators must be able to obtain the same results from the same sets of procedures and materials Any scientific hypothesis or claim must be falsifiable meaning open to negation through means of scientific inquiry EX the assertion that UFO s are visiting the Earth does not rise to the level of a scientific claim because there is no way to prove that this is not so 1 3 The Nature of Biology Biology the study of life Life is not simple to define so there are characteristics given to things that are living Can assimilate and use energy bacterium needs energy source no less than humans do we use energy in the form of food bacterium use things such as the remains of vegetation in the soil Can respond to their environment we leave our homes if we smell gas bacterium moves away if it encounters something noxious Can maintain a relatively constant internal environment We sweat when we get hot 3 Possess an inherited information base encoded
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