ECOL 182R 1st Edition Exam 1 Study Guide Lectures 1 6 Lecture 1 Explain what Aristotle s main beliefs were Beings are fixed entities and are ranked along a continuum some are more advanced than others He called it the scala naturae of the Great Chain of Being What is Carolun Linnaeus known for Explain Binomial nomenclature and list the groups within groups He s the father of taxonomy He came up with Binomial Nomenclature It is hierarchical classification which is based on similarities and differences Domain kingdom phylum class order family genus species How do we represent relationships today Phylogeny the evolutionary history of organisms What is a phylogenetic tree Name its parts It shows who is distant and who are near their relatives The root is the common ancestor of everything Branches are what leads to each split node A clade is a common ancestor and all of its descendants What are four requirements of Charles Darwin s Natural Selection theory 1 Must be variation 2 Some variations must be genetically based 3 Certain genotypes must make more offspring than others 4 Differences among genotypes must be due to an agent of selection What are quantitative traits How are they distributed Traits that are controlled by many genes The offspring appearance for that trait is likely to be intermediate between parents They re distributed as a bell curve or a normal distribution What are the three forms of natural selection on normally distributed traits Explain them 1 Directional selection genotypes at the end of the distribution do worse 2 Stabilizing selection the average genotypes does best 3 Disruptive selection genotypes at both ends tails do best Can result in two categories of individuals Lecture 2 Define evolution A change in allele frequency over time in a population of organisms How can humans be agents of natural selection Resistance to antibiotics What is genetic drift What can it lead to What kind of populations are more susceptible It s due to changes in allele frequency from one generation to the next There isn t an agent of selection It s due to chance It can lead to loss of alleles and fixation Small populations are more susceptible to loss and fixation because role of chance is greater What is gene flow The transfer of alleles from one population to another that usually involves movement of individuals What is mutation How common is mutation Alteration of a gene that gives rise to a new allele that usually involves a change in DNA sequence It s rare per gene but common per genome What kind of variation in a trait is required for evolution to occur Genetically based variation What kind of variation will not result in evolution Environmentally based Lecture 3 What is the biological species concept The capability potential of interbreeding How do scientists use DNA while studying interbreeding species They use it to find where the breakpoints are to see the distance between different organisms and how alike they are True or false It is very easy for biologists to determine which species are interbreeding and they usually face no obstacles while doing so False There are some big problems forced interbreeding for example that make it hard to determine if some groups should actually be considered species What are two ways a population can break into two Allopatric speciation and sympatric speciation What are the two ways species are prevented from interbreeding Give examples of each 1 Prezygotic barriers occur before zygote is formed There s a barrier in space or time so these individuals never meet a Example Behavioral isolation Females won t accept mating 2 Postzygotic the mating occurs but something goes wrong after that a Hybrid unviability hybrid zygotes don t develop or die before birth b Hybrid sterility hybrics survive but are sterile What are two ways that species diverge so much 1 Natural selection can reinforce reproductive isolating mechanisms 2 Once isolated species adapt to local conditions True or false Biologists don t really know why speciation rates are different True They just know that specialization has something to do with it and that sexual selection can affect the rate as well Lecture 4 List the Four F s of Behavior that animals and plants both exhibit Feeding fighting fleeing reproducing What s the difference between asexual and sexual reproduction Asexual or vegetative needs one parent Binary fission for example Sexual needs two parents and it is much more costly How are males and females different Males initiate courtship and fight for access to females Females don t fight for males and often reject courting males What are the two problems that animal reproductive behavior poses 1 How to locate mates in the first place 2 How to choose among them True or false Although animals face problems finding choosing mates plants do not False Plants also have choosy females and sexual selection What are the two ways plants locate mates 1 Pollinate itself 2 Pollinate someone else Once they locate mates how does the female plant choose Female can 1 Prevent pollen from fertilizing the ovary 2 Only allow best males to fertilize 3 Abort ovaries fertilized by poor males Lecture 5 What are the four levels of analysis Give a brief explanation 1 Mechanism the physiological or neurological basis of a behavior 2 Development the role of age and experience in behavior 3 Function the adaptive function of a behavior 4 Evolution the evolutionary history Define altruism What are the three main explanations for it Any behavior that benefits a recipient while incurring a cost to its donor 1 Manipulation altruism is through ignorance 2 Reciprocity you scratch my back I ll scratch yours Cooperation 3 Kin selection propagating your genes by helping genetic relatives propagate theirs What are the costs and benefits of learning an instinct Benefit Gain flexibility Different lessons in different environments Cost Learning involves mistakes Requires energy and brain resources Lecture 6 What does Buffon suggest about evolution The creation of species is spread out in space and may not have been created in a perfect state Perhaps species become modified over time What did Erasmus Darwin suggest All organisms have a common ancestor What did Jean Baptiste de Lamarck suggest Life had been created long ago in simple state and has been gradually improving This change occurs though the inheritance of acquired characteristics How did Charles Darwin define evolution Descent with modification