Study Guides (248,454)
Canada (121,548)
Biology (1,112)
BIOL 359 (30)

Midterm I Lecture Summary.docx

8 Pages
Unlock Document

BIOL 359
Jonathan Witt

Topic I: Science and Intelligent Design Theory Intelligent design theory: Alternative “scientific theory”? To promote the presence of an intelligent designer, promoted by the Discovery Institute and Center for Cultural Renewal, an alternative to Darwinian Evolution?? - Religious school board members asking for it to be included in science classes against parents - Of Pandas and People = Supplemental Biology Text - William Paley (1802): Complex eye  Eye maker - Micheal Behe: Irreducible complexity, cannot function if any protein is removed, hence there is no way there are any functional precursors that has arisen through selection e.g. the flagella o Eel sperm contains no outer dynein & no central pair complex, yet it functions just fine Scientific terms vs. Vernacular terms - Scientific o Fact: Repeatedly confirmed observation, accepted as “true”, never final, will always undergo modification o Scientific Theory: Explanation of some aspects of the natural world (Facts) that incorporates facts, laws & tested hypotheses, must be falsifiable & internally consistent o Scientific Hypothesis: Statement that leads to deductions/predictions that can be tested. If tested to be incorrect, original hypothesis is abandoned or modified o Scientific Law: Descriptive generalization about how some aspects of the natural world behaves under specific specified circumstances (Prescriptive) - Vernacular o Facts are about the same o Hypothesis: Similar to a guess o Law: Descriptive to prevent someone doing certain things Science vs. ID Theory - If we observe a structure that’s complex, then we should invoke the existence of something that’s even more complex to explain its existence?  Internally Inconsistent - Why are the designs so lousy? E.g. the Human appendix Topic II: A Short History of Evolution - Evolutionary biology began in the 1859s after the publication of the On the Origin of Species - Before evolution, Plato  Aristotle, God’s creation following a plan “The Great Chain of Being” o Changing would imply imperfection - Linnaeus “Father of Taxonomy” – Homosapiens - Lamarck: The 1 person to explore the issue of evolution, Inheritance of acquired characteristics (e.g. giraffe’s neck)  Spontaneous generation, and evolve towards a perfect form - Erasmus Darwin: Species are modified descendants of earlier forms - Georges Cuvier: Supporter of catastrophism “Earth’s features had been primarily modeled by great catastrophes that resulted from forces that no longer operates today”, popular POV until modern geology o Tries to reconcile geological history with the age of the Earth according to the Bible - James Hutton: Father of modern geology, responsible for the Principle of Uniformitarianism “today, same as we see operating in the past”, evidence presented by Charles Lyell, ended the era of catastrophism - Charles Darwin: Naturalist on the H.M.S Beagle ship  Finches o Worked on his idea for 20 years until he received a letter from Alfred Wallace, announced idea at Linnean Society in London in 1858  All species have descended without interruption from 1 or few original forms of life  Theory of natural selection to explain - The evidence for evolution was well accepted, but the mechanism of inheritance was unknown - Johann Gregor Mendel: Basis for modern genetics, compatible with natural selection - The Origin of Species + The Theory of Genes  Modern Synthesis/Neo-Darwinian Synthesis o Natural selection acts on genetic variation in populations “Population Genetics” 1 - Present molecular developmental genetics reveals deep homologies in genes controlling development Topic III: Evidence for Evolution - Evolution: Descent with modifications, or change in population of allele frequencies - Homology: Similarity from common ancestry, despite differences in function - Analogy: Similarity due to similar in function, not common ancestry - Special creations vs. Evolution o Special creations: Species do not change over time, each species created separately, young earth o Evolution: Species change over time, common ancestor, old earth o E.g. Domestication of Dogs, all are descended from wolves through phylogenetic analyses, result of selective breeding by humans (lots of biological changes in minimal geological variations) - The 2 modes of evolution: o Microevolution: Small changes within species (e.g. changes in allele frequencies) o Macroevolution: Larger phenotypic changes that is sufficient to place an organism in a different higher level taxon (combination of microevolution over time) - Descent with Modification o Soapberry bugs: Short beaks are descendants of long beak bugs o House sparrows: Rapid spread over North America, populations evolved differences in body size & coloration o Vestigial structures & organs: Useless structures that serve no functions in the organisms that possess them, but do have functions in closely-related species  Snakes legs from reptiles with limbs; Flightless bird wings from birds that can fly  Human coccyx from ancestor with tails; Human erector pili muscle from furry ancestors - The Fossil Record o If there is no evolution, same organisms should exist throughout the entire Fossil Record o If there is evolution, organisms inhabited the Earth change & there should be strong geographic patterns with respect to similar organisms  E.g. Extinct organisms: Irish elk & Trilobites  Law of succession: Fossils in a given geographic region are more closely related to the extant fauna of that region than they are to organisms in a different geographic region  Extant organism (Living) vs. Extinct organism (Fossil)  Transitional forms: Intermediate forms between the past & present organisms  E.g. Archaeopteryx, between dinosaur & bird (birds are descendants of didnosaurs)  E.g. Basilosaurus, between mammals & whales (with rudimentary pelvis bones)  Relatedness: The mockingbirds, finches, shared ancestry within phylogenetic trees - Phylogenetic Trees (Different rotation but essentially the same*) o Phylogenetics: Study of ancestory/descendent relationships o Phylogeny: Hypothesis of ancestory/descendent relationships  The closer in time the species shared a common ancestor, the more closely they are related  Polygon: If all 3 species are equally related to each other, they are sister taxa o Homology: Common ancestry, tested with pseudogenes  Genetic Homology  Pseudogene: A copy of the parent gene with no introns & no promoter regions “no expression”, they are free to accumulate mutations @ a rapid rate, used to determine the age of the organism o More species share the older processed pseudogenes o Human only share the most recent 3 with chimps & gorilla  Humans would be much better off with their own set of genetic codes “immune to diseases transmitted across species” 2 o rRNA sequences are one of the most conserved region of the genome  was chosen to construct the tree of life  Structural Homology  Vertebrate arms, natural selection tinkers the basic plan  variations  Plants with the same basic structure  Developmental Homology  Similar embryonic forms branches into different adult forms  Hernias: Intestine protrudes into the scrotum sac due to weakness in the groin - Ring species: Single species in the process of diverging into 2+ species o E.g. Siberian Greenish Warbler: Can no longer recognize/mate with each other - Analogy: Similar in function, independent evolution - The age of the Earth (Uniformitarianism vs. Catastrophism) o Uniformitarianism: Assigned dates to various rock strata  relative dating scale  Radiometric Dating: Rate of decay not influenced by temperature, weather or anything else  Measured as in half-lives, potassium-argon dating for volcanic rocks (argon = gas = bubbles out)  Earth is about 4.6 Billion years old (same for meteroids or moon rocks) o Plate tectonics: Fossils of the ostrich bird, correspondence between fossil, biological & geological data Topic IV: Introduction to Natural Selection - Darwin’s great contribution: The formal development of a mechanism that explains how evolution can occur - Natural selection: Differences in the survival & reproduction of phenotypes results in different contribution to the next generation, hence a change in the frequency of heritable phenotypic variations in population o Not just survival of the fittest but must also contribute to the next generation - More offspring “universal”  Struggle for existence  heritable variation in phenotypes due to genotypes  Those best adapted to current conditions are more likely to survive & reproduce o Changes in allele frequencies & gene frequencies are NOT the same o Only changes in population allele frequencies results in evolution - Population genetics: The study of allele and genotype frequencies & their changes in entire populations - Evolutionary fitness: The # of offspring an individual contributes (more offspring = greater fitness) o Viability/Mortality Selection: Ability to survive to reproductive age o Sexual Selection: Ability to procure a mate (Mating success) o Fecundity Selection: Family size, measures the # of female gametes produced (e.g. litter size)  Excess fecundity is universal in nature  E.g. About 2 eggs per female Atlantic cod survive to reproductive success - Adaptation: Trait that increases an individual’s fitness compare to those that doesn’t have the trait o Natural selection  Adaptive evolution “↑ # of frequencies of that trait in the next generation” - Darwin’s Theory of Natural Selection (4 Postulates) o Individuals within species are variable, some of these variations are heritable, more offspring are produced than survive, the survival & reproduction of individuals is not random but are naturally selected  Heritability: The proportion of trait variation in a population that is attributable to genetic factors, not environmentally induced differences (slope from 0 to 1)  E.g. Pepper selection by rats, the mild ones are eaten compare to the hot ones & the composition of the population changes from 1 generation to the next  E.g. Finches on Daphne Major, different beaks mostly due to variation in food “feeding polymorphism” 3  Species flock: Ancestor that originally colonized the land and diverges off into more different species  They have variable beak size, body weight & wing span, variation has a genetic basis (measured heritability, strong correlation), drought selection, only a fraction of the population survived to reproduce, since seed availability changed o Drought caused the abundance of small seeds to decrease  After the drought there is an increase in average beak depth o NS does not produce new variations on its own, it simply acted on heritable phenotypic variations & altered the frequencies of different phenotypic variants (mutation & recombination produces new variations)  Natural selection is dynamic: Phenotype favoured in one generation can be very different than those favoured in a subsequent generation  Introduction of The Cane Toad to Australia  South America, introduced to Australia to control Sugar Cane Beetle populations  Possess skin glands that secrete highly toxic substances, predators died in large #s  Snakes with large jaws & stout bodies were able to ingest cane toads & they were eliminated from the population  ↓ in jaw size & ↑ in slenderness (non-random) - Natural selection: o Acts on individuals, but consequences occur in populations o Acts on phenotypes but results in changes in allele frequencies (environmental – 0 heritability vs. genetic components – 1 heritability) – NOT GENOTYPE FREQUENCIES o Backward looking, acts on the parents, offspring are better adapted in the environment that their parents lived in (always a generation behind, DOES NOT anticipate the future) o Can produce new traits via mutation o Does not lead to perfection, all organisms are equally successful in their own environment  E.g. Gonopodium, bigger is preferred by females but it creates drag when it swims  Antagonistic selection: 2 component of NS acting in opposition to each other, can’t optimize both at the same time, resulting in compromises between the 2 forces “equilibrium” o Non-random & not progressive: Goal is to increase adaptation, but doesn’t lead towards some predetermined goal, no trend towards more advanced forms of life o Does not act for the good of the species (E.g. Geladas Baboons  Infanticide) - Human Induced Selection in Natural Populations o Only animals over a certain size can be taken o E.g. Ram Mountain Alberta, only restriction is that horns must be greater than a minimum specified size, hunting season is prior to breeding season  Larger horns = Less fitness  Mean male horn length declined over a 30 years period o E.g. Evolution of bacterial resistance to antibiotics: MDTB Topic v: Mutation & Genetic Variation - Mutation: The ultimate source of all genetic variations, provides raw material for other evolutionary forces such as NS or GD. It is any heritable change in DNA (Germ-line mutations not somatic mutations) o Point mutations: Synonymous “No AA change” or non-syrdnymous “changes AA”, many are synon
More Less

Related notes for BIOL 359

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.