BIOL 3350 Week 3 Notes
BIOL 3350 Week 3 Notes 12050 - BIOL 3350 - 001
Popular in Evolutionary Biology
12050 - BIOL 3350 - 001
verified elite notetaker
Popular in Biological Sciences
80887 - BIOL 3150 - 001
verified elite notetaker
This 4 page Class Notes was uploaded by Kennedy Deaver on Thursday January 28, 2016. The Class Notes belongs to 12050 - BIOL 3350 - 001 at Clemson University taught by Dr. Michael Sears in Fall 2016. Since its upload, it has received 23 views. For similar materials see Evolutionary Biology in Biological Sciences at Clemson University.
Reviews for BIOL 3350 Week 3 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/28/16
Chp. 3 continued - Intelligent design creationism Scopes trial o Convicted for teaching evolution o Wanted to be convicted to move to higher court o Overturned in 1968 – unconstitutional Cannot force religious ideas onto public Arguments against evolution o How can natural selection produce vertebrate eye (complex structures)? Hagfish blind but have photoreceptive eye which helps with circadian rhythms Shows that part of eye can be important o Irreducible complexity Says incremental evolution is impossible Cilia – remove some components then cilia may not function as well Eel sperm doesn’t have components that cilia has Not irreducibly complex because other organisms have less parts/less complex structures that still function o Gene co-option Crystallin in eye Most crystallin proteins can be found outside of the eye (different functions in different parts of the body) aka co-opted Same protein doing radically different things o Unscientific because not falsifiable 4 postulates are testable/have been tested Darwin’s finches Can predict where intermediate (fossils) would show up (in which strata) o Violates the second law of thermodynamics Law states that we are moving toward entropy (disorder) – within closed system BUT earth is not a closed system o Evolution is un-proven Can simulate in lab and mounting evidence of speciation in nature Sticklebacks and finches Chp. 4 Phylogeny – hypothesis of history of descent with modification from common ancestry o Only as good as what you put into it Time going left to right usually Roots – greatest common ancestor Bifurications (nodes) – most recent common ancestor showing where speciation occurred (multiple nodes on each tree) Transitions – changes in phenotypes/evolutionary modifications Tips or terminal nodes – species of interest Using morphology to distinguish Sister taxa – more closely related/closest living relatives Rotating doesn’t change the relationship between animals When is an evolutionary tree considered well supported? o Supported by multiple different data sets o Need statistical support of relationships Novelty – evolved one time and not lost, differences from common ancestor Derived character – something one thing has and another doesn’t o Shared derived characters = sister species o Transition shows when difference pops up Completed tree demonstrates nested sets of shared evolutionary derived characters Give traits certain names and same trait can have different names o Plesiomorphic mask (in sister species) vs. apomorphic mask (in whole tree) o Plesiomorphy = preexisting/ancestral character o Apomorphy = evolutionary novelty/derived character Monophyletic groups – sets of taxa that include an ancestor and ALL of its descendents Synapomorphies – help identify monophyletic groups Polytomies – parts of tree where not sure what relationship is between them o Simultaneous split between turtles, lizards, common ancestor of crocodiles and birds Outgroup analysis – include related species but not as closely related as others o All have common ancestor How do you determine which tree is best? o Parsimony – answer with least assumptions is potentially most correct o Fewest evolutionary changes required Convergent evolution makes it more difficult o Similar features in two different types of taxa Can build phylogenies using genetics Bones used to lump all artiodactyls together Use genetics o Find insertions and deletions to align o Can infer evolutionary relationships o Cannot use parts of sequence where they are all the same o Add more sites to help when problems arise Likelihood estimations o Using substitutions instead of time o Longer the branch = more genetic substitutions o More substitutions – more diverse o Model of DNA sequence evolution Probability of one nucleic acid changing into another Neighbor joining o Calculate genetic distances between species of interest o Based on random chance, ¼ chance it will be the same nucleic acid o Lower value = more closely related Bootstrapping o Generation of artificial data sets by random sampling, with replacement, from actual data set o Value gives confidence estimate Bayesian methods o What is probability of certain tree given data set o Posterior probability of tree Say all have same probability (naïve) or develop based off info you already know Values add up to 1 Highest probability = most supported Consistent trend of hippos and whales grouped together o Whales as artiodactyls Retrotransposons – jumping genes o Can copy themselves and insert themselves into other places in genome randomly o Look across different loci and see where insertions are in same spot = common ancestor Chance of this happening independently is really low Evidence from fossil record o Bridge between artiodactyls and whales o Use bones Can tumor cells move from patient to patient o Tumors on genitals of dogs is contagious o Is cancer traveling or are tumors developed from dogs’ tissues themselves? If cancer cells jumping then cancers should be more related to one another than to certain dog If dog and tumor are more related then cancer developed from dog First hypothesis supported aka tumors jumping from dog to dog (not a virus that needs to infect dog) cancer itself is infectious Evolution of body lice o Head lice and body lice are two different species o Before wearing clothes, didn’t have body lice Used to make prediction about when humans started wearing clothes o Molecular clock – when genes copied, mistakes are made Mistakes happen at regular intervals Can hypothesize how long it has been occurring o Look at lice on chimps and lice on humans o Problem: error rates depend on where you’re looking on genome Need good reason to select part of genome o Also, certain errors are more likely Can answer questions about biogeography (how have animals spread through time and lived in different habitats) o Chameleons on Seychelles island Either already there and split when islands split from India or did it float there on some land mass Use molecular clock to calculate when they arrived Second hypothesis supported
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'