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by: Citlalli Sauer


Citlalli Sauer
GPA 3.75


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This 51 page Class Notes was uploaded by Citlalli Sauer on Tuesday October 20, 2015. The Class Notes belongs to PHYS182B at San Diego State University taught by A.Durghalli in Fall. Since its upload, it has received 16 views. For similar materials see /class/225320/phys182b-san-diego-state-university in Physics 2 at San Diego State University.




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Date Created: 10/20/15
DESCENT WITH MODIFICATION A DARWINIAN VIEW OF LIFE 272012 35200 AM If thins are hi hli hted like thls the are vocabular DESCENT WITH MODIFICATION A DARWINIAN VIEW OF LIFE CHAPTER 22 What is evolution and adaptation 0 Evolution two main ideas if New i l M H i i lei 2m w 3 purl 3 w i Descent of modern organisms with modification from preexisting organisms Evolutionary adaptation o Accumulation of inherited characteristics that enhance organism s ability to survive specific environments Pre DanNinian theory of evolution disuse of parts ex That silly goose thought giraffes got large necks because they kept stretching for the leaves Inheritance of acquired characteristics B These modifications are inherited by offspring i39i ujw mullgl l i quot Evolution by natural selection 0 Darwin Voyage of the Beagle Wow g Wallace Naturalist in Indonesia contracted malaria and died Process selects from what is available in the gene pool New characteristics are not created on demand Mechanism behind natural selection They based it on several observations liquotijlrfi il li397 a pmn uw Twin i Mm il ir f l i v llquot39 n mon i mm twill 3quot 0 And individuals in a population vary in their heritable characteristics From this they inferred a That individuals that are well suited to their environment tend to leave more offspring than other individuals D And overtime favorable traits accumulate in the population Think about the 100m dash track and field competition How can we change this race to reflect the process of natural selection Analogous to natural selection 0 The wild mustard plant is a good example Farmers selectively bred the plants to produce Brussels sprouts cabbage kale broccoli kohlrabi Concept 223 Evolution is supported by an ovenNhelming amount of scientific evidence Examples of natural selection CLICKER QUESTION Within a few weeks of treatment with the drug 3tc a patients HIV population consists almost entirely of 3tc resistant viruses How can this best be explained A HIV has the ability to change its surface protein to resist drugs B the patient must have become reinfected with 3tc resistant viruses C HIV began making drug resistant versions D thewere few that were resistant to the drug already Natural selection and HIV resistance The rise of MRSA HM i L39li gm m z 0 Structures or other attributes in different species that resemble each other because of common ancestry 0 Structures that are similar in function but not in structure and developmental and evolutionary origin A prime example of homologous feature is mammalian forelimbs quotquotll 5 similar u in rhil a 5399 Differences arise by some genes being switched on or off at varying times during development LN quotmm quot ii All life forms use approximately the same 20 amino acids to make proteins All use ATP as the primary form of cellular energy All use RNA and ribosomes to make protein HOMOLOGIES AND TREE THINKINGquot Trees vs Scala nature Scala nature 0 Ladder of nature see page 453 ml Evolution not about climbing ladder of nature from lower to higher Evolution is a bush with lineages branching from one another nu aiii39wj in linmlumymgi sidiw itiinu EVOLUTION OF POPULATIONS 272012 35200 AM CHAPTER 23 The Evolution of Populations The smallest unit of Evolution 0 One common misconception about evolution is that individual organisms evolve during their lifetime 0 Evolutionary process eg natural selection acts on individuals but populations evolve 231 Genetic variation makes evolution possible Mutation 0 Changes in nucleotide sequence of DNA 0 Source of new alleles and genes Point mutation change in one nucleotide base Chromosomal mutations delete disrupt or rearrange many loci on a chromosome Gene duplications duplication of whole segments of a chromosome 0 Mutation rate averages 1 in every 100000 genes per generation Sexual recombination o In sexually reproducing organisms sexual recombination produces most of the variability in each generation o Crossing over during prophase I independent assortment during metaphase I Variation within a population o Discrete characteristics classified on an eitheror basis 0 Eg flower color in pea pants o Quantitative characteristics vary along a continuum within a population 0 Eg height and weight vl n 5 v Jl l39 llmilng m a l w i in o Describes a population that in not evolving ie allele frequencies don t change o Five assumptions behind HW equilibrium 0 No mutation 0 Large population size 0 No gene flow 0 No natural selection 0 Random mating Allele and genotype frequencies o Allele frequencies o p frequency of allele 1 o q frequency of allele 2 o p q 1 o Genotype frequencies 0 pAZ frequency of homozygous dominant o qAZ frequency of homozygous recessive o 2pq frequency of heterozygotes o pAZ 2pq qA2 1 HW equilibrium population genetics and human health o HW equilibrium can be used to estimate of human population carry the allele for an inherited disease o PKU is a recessive genetic disorder 0 O 0 Frequency of homozygous w the disorder is qA2 00001 What is the frequency of the dominant and recessive alleles p 99 pq1 so 1 01 99 q 01 if qA2 0001 than q square root of 0001 01 the frequency of carries heterozygous people who do not have PKU is pA2 2pq qA2 1 looking for the 2pq algebra if a population has the following genotype frequencies AA 42 Aa 46 aa 12 what are the allele frequencies A 65 square root of 42 a 35 square root of 12 if the frequency of the recessive allele is 30 the frequency of the heterozygous carriers would be CLICKER QUESTION o The frequency of carriers heterozygous people who do not have PKU is o 098 0 00099 0 00001 WHY q2 00001 q 001 p 099 p2 2pq q 21 2990100198 CLICKER QUESTION WHY If a population has the following genotype frequencies AAO42 Aa046 aa012 What are the allele frequencies 0 A065 a035 P2 042 2pq046 q2 012 p065 WHY 2pq 2o7o3 o42 CONCEPT 233 NATURAL SELECTION GENETIC DRIFI39 AND GENE FLOW CAN ALTER ALLELE FREQUENCIES IN A POPULATION Genetic Drift Statistically the smaller a sample the greater the chance of deviation from a predicted result twill iii frillJchfl E5 Tends to reduce genetic variation k K CRCR CWC Cuf a We quot0 Ckcu ll f 2 n c u Ckcu it if CII39CW Cucw Cue CRLR kcu chw quotk c r39 CRCR 54 v u Ckcw Cnc w Generation 1 Generation 2 p frequency of Cquot 07 p 05 1 frequency of C 03 q 05 Example of genetic drift F6 Ulil jl l39 0 Ti on island ia l at El39l Fl39kil l lr o POPULATION BOTI39LENECK CRC L39ch dick CNCR fleck ckcli Generation 3 p10 100 it frequency of red allele is low on original population mwalm wi wfr quotmil llli l f lll39wwl l liuulwcnr ll l guilgmlltsulcmv 0 Frequency of red allele is low in original pop 0 Many survivors of tidal waves happen to harry red allele 0 Frequency of red allele is higher in new population 0 CHANCE EVENTS 0 Frequency of red allele is low in original pop 0 The only person whith red allele happens to fall out of a tree and dies New pop has no red allele 0 BO39ITLENECK EFFECT AND REDUCTION OF GENETIC VARIATION Prebottleneck Postbottleneck lllinois 1820 Illinois 1993 R ge of greater prairie chicken a P I t Number Percentage Location PFquot 3 390quot of alleles of eggs S39ze per locus hatched l Illinois 1930 19605 1 000 25000 quot 52 93 1993 lt50 37 lt50 l Kansas 1998 no bottleneck 750000 58 99 k 7 1 1 Nebraska 1998 75000 5 8 96 no bottleneck 200000 1 Minnesota 1998 4000 53 as no bottleneck Ecuyrlghl 2005 Pearson Euucanam Inc puuhsmng as Pearson Ben amm Cummmgs GENE FLOW Genetic additions to or subtractions from a population resulting from the movement of fertile individuals or gametes Migration among populations Tends to reduce variation among populations over time Migration High little genetic variations between populations POP 16POP2 Migration low more genetic variation between populations CONCEPT 234 NATURAL SELECTION IS THE ONLY MECHANIS THAT CONSISTANTLY CAUSES ADAPTAVE EVOLUTION o Natural selection differential success in the reproduction of different phenotypes resulting from their interactions with the environment fitness TOM DICK HARRY SIZE 6 3 5 10 5 5 200le 185 lbs 125 lbs CHILDREN 2 3 5 COMMENTS Ladies man Athlete NERD Out of Tom Dick and Harry Who had the greatest fitness o Tom 0 Dick Harry YEAH GO NERDS Original population A l I 1 E 2 1 E 396 gt u C a a u g u f Original Evalved Phenotypes lur color population population 39 l 1 em e a a Directional selection 1 Disruptive selection 0 Stabilizing selection CLICKER QUESTION A population of seedcracker finches has small and large billed birds specialized in soft and hard seeds respectively If climate change resulted in a loss of the soft seeded plants what type of selection would then operate on the finch population o Disruptive o Directional o Stabilizing o Sexual l A L o Can result in sexual dimorphism liliil39 E 7 a if F l t c Sexual dimorphism this way because th V 7 ill quot AThat peahen is all like DAMNN LOOK AT THEM FEATHERS The preservation of Genetic Variation o Diploidy maintains genetic variation in the form of hidden recessive alleles Balancing selection occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population 0 Heterozygote advantage 0 Frequency dependent selection Heterozygote advantage o Some individuals who are heterozygous at a particular locus have a greater fitness than homozygotes Sicklecell allele causes mutations in hemoglobin but also confers malaria resistance Comllngsz Psarsan Education Inc i publishing as Feavsnn Banlamm Cummings CLICKER QUESTION Immigration of individuals into a population in H W equilibrium will not upset the equilibrium if They are beyond the age of reproduction Females and males are in equal populations They mate randomly in the new population They arrive in large numbers ORIGIN OF SPECIES 272012 35200 AM 2 739 quot a 39 i 397 V I Concept 241 The biological species concept emphasizes reproductive isolation o Species Latin for kind or appearance CLICKER QUESTION Which pair is two different species 0 Two dragonflies that look similar 0 Or a terrier or a great dane Dogs are different breeds but of the same species Ward o Cannot be applied to o Asexual organisms o Fossils o Organisms about which little is known regarding their reproduction Speciation Dependent on 0 Reproductive isolation 0 Genetic divergence Isolated population verges l i l Gene flow l Populatlon five individuals are shown Barrier to gene flow t prezygo c barrigrs Habitat Isolation Temporal isolation Behavioral isolation Mechanical Isolation lndivit iuals 0 different specues 3 mi Elie j Postzygotic barriers Often prevents the hybrid zygote from developing into a viable fertile adult o EX Mule is fertile quotprezygo c barriers u Gametic Isolation iiipostzyg tic barriersm Reduced Hybrid Viability Reduced Hybrid Fertility Hybrid Breakdown cwyngme 2005 Pearson Educaiion ma Dublismng as Pearson Beryamm Cummmgs PRETEST IS FEB 26 EXAM IS FEB 6 8 CLICKER QUESTION Which of the following is not considered a requirement for speciation to occur 0 0 0 Pop must be isolated from one another Isolated pop must become genetically distinct from one another Exchanges of genetic information must be restricted between pop High level of gene flow among pop must occur Limitations of the BSC 4 Grizzly bear U arctos V Polar bear U maritimus A Hybrid grolar bear m Fem mm me They produce a viable fertile offspring quotA V CLICKER QUESTION Two species of pine are found in the same habitat but release pollen at different times during the year this is an example off isolation 0 Geographical o Ecological o Temporal o Behavioral Is gametic isolation a Prezygotic or Postzygotic isolating mechanism o Prezygotic o Postzygotic o It depends on the species whether it acts pre or postzygotically o It can either depending on the time of year CONCEPT 242 Speciation can take place with or without geographic separation o Speciation can occur in two ways m ll 13L lii i quotu l39 fiigl r l lf 5 linen 5 quot a Allopatric speciation b Sympatric speciation Single species homogeneous habiTaT Geographic barrier isolcrres populations Gene ric drifT mLITaTion ncrfural selecTion cause geneTic divergence Barrier removed popula rions mix bLI139 don39T inferbreed Examples of Allopatn39c Speciation Augean wwluuon D mum mum Figure 246 is missingggg It shows two different species ofsquirrels that live on opposite sides ofthe grand canyon A formosus A nuttingi Atlantic Ocean Isthmus of Panama Pacific Ocean A panamensis A millsae 2011 Peavson Educalmn Inn Establishing Reproductive Isolation initialpgpulation 5 i a x o u a 39n 1 2 1 1quot 9 i Ii 1 T quotI Some flies Some flies raised on raised on starch medium Mating experiments maltose medium after 40 generations Female Female Starch Starch Starch Maltose population1 population 2 J E 5 e a 22 9 535 S 18 15 o D 2 w 2 8 a m E a E N m c s g 8 20 2 g 12 15 G B s E lt0 a O o Mating frequencies Mating frequencies in experimental group in control group Copyright 2008 Pearson Education inc pubiishmg as Pearson Benjamm Cummnngs Single species homogeneous habi ra l Environmem al change Two habi iai39s populcn ions isola red by habi rai Environmen i al pressure To odop39i genetic divergence Sufficienf divergence reproduc i39ive isola i ion Kim Sympahic spadalion r3 original populaiion I x llf rfx 95 x r x x f f gt 35 tftra lef a s s 39 2n 6 4n 1 2n 4n Failure of cell Gametes Offspring with division after produced tetraploid chromosome are diploid karyotypes may duplication gives be viable and rise to tetraploid fertile tissue Ecpyvlgumzma Peslstvamcsllmt W Dubllgmng PeersmEer amquuvmnlngs Species B Unreduced 2 3 gamete Unredtuced with 4 Hybrid gtme e f chromosomes with 7 mm 7 I I J chrqmosomes chromosomes Meiotic x re A l X rrINormal Viable fertile Normal hybrid gamete allopolyploid n 3 2n 10 cauyrmmma mm Emcallmv lnc publlslvlng as Pearson am lamln summms CLICKER Plant species A has a diploid number of 12 Plant species B has a diploid number of 16 A new species C arises as an allopolyploid from A and B the likely diploid number for C would be 0 o 14 0 056 In cichlid fish 0 Sympatric speciation has resulted from nonrandom mating due to sexual selection Monochromatic Normal light orange light P pundamilia P nyererei Dowilghl 2095 Pearson museum lnc publishing as Pearson Beulamm Cummlngs All but which of the following are likely to promote sympatric speciation 0 Gene flowi n n n n n n n n n n n n n n n n n n n n n n n n r o Ecological isolation 0 Temporal Isolation o Polyploidy CONCEPT243 Hybrid Zones provide opportunities to study factors that cause reproductive Isolation Possible outcomes for hybrids Possible outcomes Hyb d zone Reinforcement OR 0 Fusron Hybrid on Stability Isolated population dive Gene flow Barrier to Population gene flow five individuals are shown Cauyrlgm o 2095 Pearson Educauon lnc nunusmng as Pearson aemamm oummmgs Firebellied toad Bombina bombina Yellowbellied toad Bombina variegala Allele trequency log scale r r r r 40 30 20 10 10 20 Distance from hybrid zone center km Convnghl 2003 Pearson Education lnc pubrsmug as Pearson Esmeum Cummings the breakdown of reproductive barriers fusion Pundamilia nyererei Pundamilia pundamilia Pundamilia turbid water hybrid offspring from a location with turbid water Couyvlghle zona Pearson Educalion in publishing as Pearszm Eexuamm Cummings The origin of a new plant species by hybridization coupled with accidents during nuclear division is an example of o Allopatric speciation o Allopolyploidy o Autopolyploidy 0 Hybrid inviability HISTORY OF LIFE ON EARTH 272012 35200 AM I A V39Im jlwHrHlrm A 39 O aquot I y j n i w it I l 1 ill NW 55 l s l Mill 1 l y A l 3 Early Earth Earth is about 46 billion years old 0 Radiometric dating of meteorites and moon rocks o Life arose about 38 billion years ago 0 Chemical traces in rocks 38 BYA 0 Fossil bacteria in rocks 35 BYA o No spontaneous generation now but must have happened then V 43 33 me Abundant energy to drive reactions 0 Frequent storms with much lightning o Frequent volcanic eruptions o Frequent meteor impacts 0 UV light from the sun molecules 339 Sample or chemical analysis Electric spark simulates lightning They used gases of primeval atmosphere Organic molecules appear after only a few days Alternative Hypothesis First organic compounds might have been synthesized near hydrothermal vents Extraterrestrialorigin cagyngm 2003 F251an Educalmn Inc publishing as P251an Ben amln Cummings Abiotic Synthesis of Polymers o Small organic molecules polymerize when they are concentrated on hot sand or clay E Aliemnes hmrl 0 Clay Inmplme l d Iron pyrile 7 Rate ol dehydinlion synlhesrs exceeds rule 01 hydrolysis Arlenmes link lhmuali sugarphosphate ounds Arlenlrms alli uCi 39 macils Uraclls link my mull sugabphosplmle bonds and liyilrogerrlwud to adeuuies Protobionts o Aggregates ofabiotically produced molecules surrounded by a membrane a Liposomes can form when lipids or other organic molecules are added to water The chicken orthe egg 0 Now 0 DNA 9 RNA 9Protien 0 Need proteins to synthesize more DNA 0 Then o Ribosomes to catalyze reactions Possible Sequence leading to first Prokaryotes Possible Sequence Leading To First Pr39okaryotes sel replicating system enclosed in a selectively permeable protective lipid sphere enzymes and DNA RNA other proteins spontaneous formation of lipids carbohydrates amino acids proteins nucleotides under abiotic conditions Which of the following statements does not support the hypothesis of an RNA world 0 Single stranded RNA can assume many 3D shapes specified by their nucleotide sequence 0 Some RNAs are important catalysts in modern cells 0 The oldest known fossils contain traces of RNA 0 RNA can store genetic info Oxygen has a in uence on the formation of complex organic molecules because 0 Positive because it increases metabolism 0 Positive because it acts as a coenzyme 0 Negative it prevents photosynthesis 0 Negative it is highly reactive CONCEPT 252 the fossil record documents the history of life Fossils document the history of life 0 Sedimentary strata reveal the relative ages of fossils o Fossils near surface more recent 0 Deeper fossils more ancient 0 Fossil records shows great changes in organisms through time pre em V Rhamgleasaurus Victor 5 a plesiosaur o m m E gt V Dimmmdon a E c S v Casts uf ammonites l i 200 175 300 270 gt Hallucigenia p n a c c 565 525 500 l gt Tappania a unicellular eukaryo e 600 A Fussili ed stromalolile 3500 1500 Cauyrlgh 20ua Pearsnn E uuaunn inc publishing as Pearson Eeuyamm Cummings Dating of fossils 0 Order of fossils in rock strata tells us the sequence in which they were laid down 0 This provides relative ages not absolute dates u will if 0 Can determine absolute ages of fossils o Radioactive isotopes decay into a daughter isotope at a fixed rate O i Mi l i 39 39 X39 397 l 397 1 x V I I I l V quot I I I 1 l l I 4 m I 5 E Accumulating daughter 9 E isotope I 9 g o 3 g Remaining 8 5 parent u 2 isotope l l 1 2 3 4 Time halflives nmyngmam PHA KVM Illlmlvm w WWW uPtmum mam rllnvlilrg CARBON 14 decays into nitrogen 14 and has a 12 life of 5730 years If you can find a fossil with exactly equal amounts of c14 and N14 when did that organism die 0 Recently 0 5730 years ago 0 11460 years ago 0 17190 years ago Concept 253 key events in life s history include the origins of single celled and multi celled organisms and the colonization of land What were the earliest organisms like 0 First organisms were prokaryotes o Bacteria amparchea o Fed on accumulates organic molecules heterotrophic some were likely autotrophic Oxygenic photosynthetic bacteria evolved bn 35 amp 27 BYA o 002 H20 9 food 02 0 Oxygen begins accumulating in the atmosphere 27 BYA Caayrlghl e 2005 Pearson Educallnn Inc pubnshing as Pearson Beniamin Cummings Which is correct sequence of events o Anaerobic cells gt 02 gtphotosynthesisgt aerobic cells o Photosynthesis gt 02 gt anaerobic cells gt aerobic metabolism plmviue millsgig 73 awaiting ii itsilwli m The First Eukaryotes Oldest fossils of eukaryotic cells are 21 BY old o Endosymbiotic theory lr1liimflmvni in i w liiilllquotl larder l iuoi 0 Were possibly undigested prey or internal parasites or mutualists Plasma membrane Cyt P39aSm Ancestral DNA prokaryote v Endoplasmic reticulum Nuclear envelope Aerobic heterotrophic k Photosynthetic prokaryote prokaryote Mitochondrion f 39 39 Ancestral heterotrophic Mitochondrion eukaryote Plastid Ancestral photosynthetic eukaryote Cnvyngnl 2005 Pearson Euunanan m publishing as Pearson Elememm camnmgs What evidence suggest that eukaryotic cells formed symbotic relationships with bacteria Both chloroplasts and mitochondria contain DNA that is distinct from that found in the nucleus of the eukaryotic cells Similarities in inner membrane structure and functions Both chloroplasts and mitochondria have their own ribosomes and make proteins independent from the cell A the above Endusvmbmsws a eukarvutes Eucarya s ma gay w fa 9 3quot a J gt muse s 65 ggvgifxa q g e d 9 k t e umquumnw ESTJZ Tquot Av mum s unm nmm quotmaymm mummm duck anamgv shuwsmme sca es mvn ved m we mser m We an earth Colonization of land Animals 1 Origin of solar system and Prokaryotes Multicellular eukaryotes Singlecelled eu karyotes Atmospheric oxygen Conyllihl L we PutMn 54mmquot m nub smng as Palm Baniamm Cummings l VOCABULARY 272012 35200 AM CHAPTER 22 Evolution descent with modification The remains or traces of organisms from the past superimposed layers of rock that are made from compressed layers of sediment the study of fossils the principle that events in the past occurred suddenly and were caused by mechanisms different than those operating the present Georges Cuvier The mechanisms of change is are constant over time Charles Lyell Characteristics of organisms that enhance their survival and reproduction in specific environments a process in which individuals with certain inherited traits leave more offspring than individuals with other traits Modifying species over many generations by selecting and breeding individuals that posses desired traits by humans similarity in characteristics because of common ancestry structures such as the arms forelegs flippers and wings of different mammals that represent variations on a structural theme that was present in their common ancestor remnants of features that served important functions in the organism s ancestors EX Some snakes still have the remnants of the leg bones from their ancestor a diagram that reflects evolutionary relationships among groups of organisms the independent evolution of similar features in different lineages the geographic distribution of the species the slow movement of earth s continents over time M the large continent of all the landmasses that existed 250 million years ago CHAPTER 23 Evolution on the smallest scale the change In allele frequencies in a population over generations the percent or average of the of loci that are heterozygous differences in the genetic composition of separate populations a change in the nucleotide sequence of an organism s DNA A group of individuals of the same species that live in the same area and interbreed producing fertile offspring all the alleles of for all the loci in all individuals of the population The principle that frequencies of alleles and genotypes in a population remain constant from generation to generation provided that only Mendelian segregation and recombination of alleles are at work The condition describing a nonevolving population one that is genetic equilibrium A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next Effects of genetic drift are most pronounced in small populations Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population genetic drift that occurs when the size of a population is reduced as by natural disaster or human actions Typically the surviving population is no longer genetically representative of the original population the transfer of alleles from one population to another resulting in the movement of fertile individuals or their gametes The contribution an individual makes to the gene pool of the next generation relative to the contributions of the other individuals in the population Directional Selection Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals Disru tive Selection Natural selection in which individuals on both extremes of a phenotypic range survive or reproduce more successfully than do individuals with intermediate phenotypes Natural selection in which intermediate phenotypes survive or reproduce more successfully than do extreme phenotypes Sexual Selection A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates Marked differences between the secondary sex characteristics of males and females A direct competition among individuals of one sex usually the males in vertebrates for mates of the opposite sex Selection whereby individuals of one sex usually females are choosy in selecting their mates from individuals of the other sex also called mate choice Natural selection that maintains two or more phenotypic forms of in a population Greater reproductive success of heterozygous individuals compared with homozygotes tends to preserve more of a variation in a gene pool A decline in the reproductive success of individuals that have a phenotype that has become too common in a population sort of like how boring uninteresting people are usually forever alone Genetic variation that does not appear to provide a selective advantage or disadvantage CHAPTER 24 An evolutionary process in which one species splits into two or more species Evolutionary change below the species level change in the allele frequencies in a population over generations Evolutionary change above the species level including the origin of a new group of organisms or a shift in the broad pattern of evolutionary change over a long period of time Examples include the appearance of major new features of organisms and the impact of mass extinctions on the diversity of life and its subsequent recovery Definition of a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring but do not produce viable fertile offspring with members of other such groups A population or group of populations whose members have the potential to interbreed in nature and produce fertile viable offspring but do not produce fertile viable offspring with members of other such groups The existence of biological factors barriers that impede members of two species from producing viable fertile offspring Offspring that results from the mating of individuals from two different species or two true breeding varieties of the same species Ligers A reproductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted A reproductive barrier that that prevent hybrid zygotes produced by two different species from developing into viable fertile adults Example Ligers can t breed Morholo ical Secies Concet A definition of species in terms of measurable anatomical criteria Ecolo ical Secies Conce A definition of species in terms of ecological niche the sum of how members of the species interact with the nonliving and living parts of their environment Ph loenetic S ecies Concet A definition of species as the smallest group of individuals that share a common ancestor forming one branch of the tree of life Alloatric Seciation the formation of new species in populations that are geographically isolated from each other Allool loid A fertile individual that has more than two chromosome sets as a result of two different species interbreeding and combining their chromosomes A geographic region where different species meet and mate producing at least some offspring of mixed ancestry a process in which natural selection strengthens Prezygotic barriers to reproduction thus reducing the chances of hybrid formation Such a process is likely to occur only if hybrid offspring are less fit than members of the parent species In the fossil record long periods of apparent stasis in which a species undergoes little or no morphological change interrupted by relatively brief periods of sudden change CHAPTER 25 A collection of abiotically produced molecules surrounded by a membrane or membranelike structure An RNA molecule that functions as an enzyme catalyzing reactions during RNA splicing A method for determining the absolute ages of rocks and fossils based on the halflife of radioactive isotopes The amount of time it takes for 50 of a sample of a radioactive isotope to decay The division of Earth s history into time periods grouped into three eons Archaean Proterozoic and Phanerozoic And further subdivided into eras periods and epochs Layered rock that results from the activities of prokaryotes that bind thin films of sediment together A process in which a unicellular organism the quothost engulfs another cell which lives within the host cell and ultimately becomes an organelle in the host cell also refers to the hypothesis that mitochondria and plastids were formerly small prokaryotes that began living within larger cells A hypothesis for the origin of eukaryotes consisting of a sequence of endosymbiotic events in which mitochondria chloroplasts and perhaps other cellular structures were derived from small prokaryotes that had been engulfed by larger cells A relatively brief time in geological history when large hardbodied forms of animals with most of the major body plans known today appeared in the fossil record This burst of evolutionary change occurred 535525 million years ago Period of time when global environmental changes led to the elimination of a large number of species throughout earth Period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill vacant ecological roles in their communities Evolutionary change in the timing rate of an organism s development Paedomorphosns the retention in an adult organism of the juvenile features of its evolutionary ancestors o Any of the master regulatory genes that control 272012 35200 AM


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