BIO3400 1nd Edition Exam 1 Study Guide Lectures 1 5 Lecture 1 What is Evolutionary Biology The study of the processes that produced the diversity of life on Earth Major questions Where did Earth organisms come form Where are there so many different kinds Why do organisms have the features they do Levels of Evolutionary Biology Microevolution changes in gene frequencies and trait distributions that occur within populations and species Macroevolution large evolutionary change typically refers to the evolution of differences among populations that would warrant their placement in different genera or higher level taxa What is Ecology The study of relationships between organisms and their environment Molles 2010 The scientific study of the interactions that determine the distribution and abundance of organisms Krebs 1972 Levels of Ecology Individual organisms how do otters thermoregulate in an ocean environment Populations what factors determine otter population growth Interactions how do otter predation influence urchin populations Communities what factors influence the species diversity in kelp forests Ecosystem how does kelp harvesting influence energy cycling in the kelp forest community Biosphere what role does atmospheric CO2 play in ocean acidification Evolution and Ecology are Closely Linked Population growth and regulation Predator prey relationships Ecological niches and adaptive radiations Lecture 2 Unit 1 Introduction to Evolution Assumptions of the Scientific Process Observations reflect real phenomena These phenomena are governed by natural causes Natural causes can be discovered by observation and experimentation There is consistency in the causes that operate in the natural world These assumptions are the we aren t living in the matrix assumptions Science as a Way of Knowing Guess compute consequences of the guess compare to experimentation or observation of the natural world if disagrees wrong Scientific Terminology Fact an objective and verifiable observation Hypothesis educated guess Theory law an explanation of a natural phenomenon based on a weather of well documented evidence Hypotheses and theories explain interpret facts Doubt and Uncertainty in Science Theories and hypotheses are never proved right they can only be proved wrong Theories and hypotheses are always subject to revision or rejection A single experiment doesn t disprove a well established theory we have to check to make sure Example of the Scientific Process Peptic Ulcers Hyperacidity Theory 1950s Excess stomach acid is the primary cause of peptic ulcers reduction in stomach acid will successfully treat peptic ulcers acid reduction is a successful treatment in some patients o Inconsistent observations Acid reduction is ineffective for some patients Antibiotics successfully treat peptic ulcers Bacteria are observed in gastric biopsies SOO Helocobacter pylori Theory 1982 The bacteria H pylori is the primary cause of peptic ulcers 1 Antibiotics will be a successful treatment 2 Infection with the bacteria will cause peptic ulcer Both 1 and 2 were confirmed Robin Warren and Barry J Marshall received the Nobel prize in medicine in 2005 Major Benefits from Science Electricity All plastics Modern ag Modern medicine Weather forecasting New sources of energy Computing What is evolution Change over time What is biological evolution Change in allele frequencies over time Evolution is not change within an individual s lifetime Evolution is not ontogenetic changes from training learning or acclimation Individuals do not evolve populations evolve Evolution is change in the genetic constitution of a population over time Evolution is happening all the time It is the natural state for populations It cannot be stopped History of Evolutionary Thought Before the 18th century the traditional view was o The earth was 6 000 years old o All species came into being at once in their present forms o Species were fixed over time and did not change Before Darwin Early Evolutionary Thinking Hierarchical classification of life on Earth Carl Linnaeus 1707 1778 Published Systema Naturae in 1735 Classified thousands of plants and animals Created the binomial classification of species ex Homo sapiens KEY IDEA all species can be classified into hierarchical groups based on similarities to one another Early explanations for why species change Jean Baptiste Lamarck and Erasmus Darwin Erasmus Darwin Charles grandfather published philosophie zoologique in 1809 Internal forces cause organisms to change within their lifetime These acquired characteristics are inherited crane with long legs WRONG KEY IDEAS inheritance species change over time by accumulating small changes Population Growth and Regulation Thomas Malthus 1766 1834 Published An Essay on the Principle of Population 1798 All populations have the potential to grow exponentially Most natural populations are not growing Populations are held in check by limited resources diseases predation etc KEY IDEA NOT ALL INDIVIDUALS WILL BE ABLE TO REPRODUCE TO THEIR FULL POTENTIAL Uniformitarianism Charles Lyell 1797 1875 Catastrophism vs uniformitarianism Published Principles of Geology in 1830 The earth has been shaped by gradual forces and these forces are still acting today The earth must be very old Requires a very very long timescale KEY IDEA very slight changes over very long time periods can produce enormous change Darwin and Wallace the development of a theory to explain how and why species change Charles Darwin 1809 1882 Developed an interest in natural history at a young age Attended med school in Edinburgh 1825 o Ignored med studies in favor of geology and biology o Attended Cambridge to train to be a clergyman 1827 1831 Again favored natural history Voyage of the Beagle 1831 1836 Variation among very similar species on the different islands Galapagos tortoise Saddleback vs domed shell Long vs short neck Darwin s mechanism to explain evolution natural selection Organisms leave many more offspring than survive to the next generation but populations are not usually increasing This a struggle for existence is always occurring individuals are competing for limited resources Individual organisms differ from each other in many aspects of what we would not call the phenotype eg Body size coloration behavior These difference can affect how good individuals are at obtaining food avoiding predators or mating Therefore some will leave more offspring have higher fitness than others If the