Bio0150 Final Review 12/14/11 11:39 AM Unit%2%%Chapter%24:%Understan d in g %E v ol u tio n %1.%Lamarck’s%theory%–%acquired%characteristics,%scala%naturae%• species%are%not%static,%but%change%through%time%–%claimed%that%simple%organism s%originate%at%the%base%of%the%chain%by%spontaneous%generation%and%then%evolve%by%moving%up%the%chain%over%time%(Lamarckian%evolu tion%is%progre ssive%in%the %sense %of%alwa ys%prod ucin g%larger%an d%m ore %com plex %species)%• created%the%great%chain%of%being%(scale%of%nature/scala%naturae)%2.%The%definition%of%evolution%(“the%unfolding”)%• descent%with%modification%–%species%that%lived%in%the%past%are%the%ancestors%of%the%species%existing%today,%and%that%species%and %their%desc end ant%sp ecies%ch ang e%throu gh %time;%de scen dan t%species %are%modified%o species%change%through%time%o species%are%related%by%common%ancestry%• change%in%allele%frequencies%in%a%population%over%time%3.%Terms:%phenotype,%genotype,%fitness,%gene%pool,%heritability,%allelic%frequency%• phenotype:%the%set%of%observable%characteristics%of%an%individual%resulting%from%the%interaction%of%its%genotyp e %w it h %th e%en v ir on ment%• genotype:%the%genetic%constitution%of%an%individual%organism%• fitness:%describ e s%th e%a b ility%to %b ot h%su r viv e%a n d%r ep ro d u ce,%a n d%is %eq u al%to %th e%a ve ra ge %contribution%of%the%gene%pool%of%the%next%generation%that%is%made%by%an%average%in d ivid u a l%of%the%specified%genotype%or%phenotype%• gene%pool:%the%stock%of%different%genes%in%an%interbreed ing%po pu lation %• heritability:%proportion%of%observable%differences%between%individuals%that%is%due%to%genetic%differences%• allelic%frequency:%measurement%that%determines%how%frequent%the%allele%expression%of%a%particular%gene%arises%in%a%population%–%the%result%should%be%in%close%correlation%w ith%the %laws %of%natural%selection,%where%more%favorable%alleles%should%become%dominant%in%a%species%over%time%4.%Understand%natural%selection%and%its%role%in%evolutionary%processes%• the%process%where%org anism s %better%ad apte d%to%the ir%environ m ent%ten d%to%su rvive%an d%prod uce %more%offspring%o the%individual%organism s%that%m ak e%up %a%popu lation %vary%in%the%traits%they%possess,%such%as%their%size%and%shape%o some%of%the%trait%differences%are%heritable,%meaning%that%they%are%passed%on%to%offspring%genetically%%o in%each%gen e ra tio n ,%m a n y %m o re %offs p rin g %ar e%p r od u c ed %th a n %ca n %po ss ib ly %su rv iv e%–%thus,%only%some%individuals%in%the%population%survive%long%enough%to%produce%offspring;%and%among%the%individuals%that%produce%offspring,%some%will%produce%more%than%others%o the%subset%of%individuals%that%surv ive%bes t%and%p rodu ce%the %m ost%offspring %is%not%a%random%sample%of%the%population%–%individua ls%with%certain%h er ita b le%t ra its %are %more%likely%to%survive %an d%re pr od u ce;%n atu ra l%sele ctio n%o ccu rs %w h en %ind ivid ua ls%w ith %ce rtain %characteristics%produce%more%offspring%than%do%individuals%without%those%characteristics%5.%Adaptation%–%seed%shape%vs.%beak%size%example%• beak%size%correlates%to%the%type%of%seed%the%bird%can%eat%–%when%a%certain%type%of%seed%isn’t%produced%then%the%bird%that%eats%that%seed%will%starve%6.%Evidence%for%evolution%and%common%ancestry%• under%evolution%by%natural%selection,%species%are%related%by%common%ancestry%and%all%have%evolved%through%time%7.%BetaTdefensin%evolution%example%• %8.%Internal%consistency%• %9.%Applications%of%evolution%and%evolutionary%medicine%• %Chapter%12:%Meiosis%1.%Have%a%complete%understanding%of%table%12.2%• chromosome%–%structure%made%up%of%DNA%and%proteins;%carries%the%cell’s%hereditary%information%(genes)%o eukaryotes%have%linear,%threadlike%chromosomes;%most%bacteria%and%archaea%have%just%one,%circular,%chromosome%• sex%chromosome%–%chromosome%associated%w ith%an%individu al’s%sex%o X%and%Y%chromosomes%of%humans%(males%are%XY,%females%XX);%Z%and%W%chromosomes%of%bird%and%butterflies%(males%are%ZZ,%females%are%ZW)%• Autosome%–%a%non%sex%chromosome%o Chromosomes%1T22%in%humans%• Unreplicated%chromosome%–%a%chromosome%that%consists%of%a%single%copy%• Replicated%chromosome%–%a%chromosome%that%has%been%copied;%consists%of%two%linear%structures%joined%at%th e%c en tr omere%• Sister%chromatids%–%the%chromosome%copies %in%a%replicated %chrom o som e %• Homologous%chromosomes%–%in%a%diploid%org a n ism%chromoso mes%that%are%similar%in%size,%sha p e,%and%gene%content%o 22%chromosomes%from%mother,%22%from%dad%• nonTsister%chromatids%–%chrom atids%belonging%to%homo logous%chrom osom es%• tetrad%–%homologous%replicated%chromosomes%that%are%joined%together%• haploid%number%–%the%number%of%different%type s%of%chrom o som e s%in%a%cell;%symb olized %n%o humans%have%23%different%types%of%chromosomes%(n=23)%• diploid%number%–%the%number%of%chrom osom e s%prese nt%in%a%diploid %cell;%symb olized %2n %o in%huma n s%al l%ce lls %ex cept%gametes%are%diploid%and%contain%46%chromosomes%(2n%=%46)%• ploidy%–%the%number%of%each%type %of%chrom o som e%p resen t%o equivalent%to%the%number%of%haploid%chromosomes%sets%present%• haploid%–%having%one%of%each%type%of%chromosome%(n)%o bacteria%and%archaea%are%haploid,%as%are%many%algae;%plant%an%animal%gametes%are%haploid%• diploid%–%having%two%of%each%type%of%chromosome%(2n)%o most%familiar%plants%and%animals%are%diploid%• polyploid%–%having%more%than%two%of%each%type%of%chromosome;%cells%may%be%triplod%(3n),%tetraploid%(4n),%hexaploid%(6n),%etc%o seedless%bananas%are%triploid,%many%ferns%are%tetraplod;%bread%w heat%is%hexaploid%2.%Significance%of%homologous%chromosomes%ad%their%relation%to%haploid%vs.%diploid%number%• %%3.%Sex%–%benefits%and%risks%• production%of%offspring%through%the%fusion%of%gametes%–%results%in%offspring%that%have%chromosome%comp lemen ts%unlike%their%siblings’%and%their%parents’%• takes%2%individuals%(male /fem ale )%to%produ ce%4%offsp ring%–%thus%two%out%of%every %four%children %that%each%female%prod uce s%sexu ally%(the%males)%can’t%have%children%of%their%own%• sexual%individuals%are%likely%to%have%offspring%that%lack%deleterious%alleles%present%in%the%parent%4.%“Meiosis%allows%for%orderly%mixing%of%genes”%–%be%able%to%explain%this%%• paternal%and%maternal%chromatids%break%and%region%at%each%chiasma,%producing