mapping1 UbxHomMutant carroll1 rotatinghox Hox%203 File:Punctuated-equilibrium.svg mammal-evolution-718983-sw http://mrfranta.org/wp-content/uploads/2013/11/Horse-evolution.jpg RATE OF EVOLUTION PUNCTUATED EQUILIBRIA Rate of evolution: difference between trait values in time t2 and t1 time interval t2 - t1 Haldane (1949) 1 darwin = e-fold change in a trait over 1 million years horse.jpg image by fossilguide http://bio3520.nicerweb.com/Locked/chap/ch05/5_08-speed_of_change.jpg G. G. Simpson: evoluce bradytelic (slow) horotelic (standard, eg. horses) tachytelic (fast) Haldane (1949): Tertiary horses – 0.04 darwins domestication – 103 darwins Kuertén (1959): Holocene mammals – 12.6 darwins Pleistocene mammals – 0.5 darwins Tertiary mammals – 0.02 darwins … differences caused by different time intervals disadvantages: 1. factor e is not biologically natural 2. uses absolute time 3. does not take into account measured time interval 4. impossible to compare areas/volumes/linear dimensions Þ Haldane (1949), Gingerich (1993): 1 haldane = change measured in units of standard deviation per generation Theory of punctuated equilibria: Stephen Jay Gould, Niles Eldredge (1972) stasis vs. rapid change punctuatedequilibrium naturalhistory simpsons tmp S.J. Gould N. Eldredge stasis vs. rapid change Foraminiferan age vs. shell size gradualism stáze Mechanism? peripatric speciation macromutation – R. Goldschmidt, The Material Basis of Evolution (1940): „hopeful monsters“ A population of mollusks is experiencing stasis A small portion of the population is cut off from the rest The small, isolated population experiences strong selection and rapid change Peripatric speciation and punctuated equilibria The small, isolated population undergoes rapid change The small population is reintroduced to the rest of the population The formerly isolated population out-competes the ancestral population The population returns to stasis Here evolution happens in a sharp jump http://upload.wikimedia.org/wikipedia/commons/2/2e/Charles_Darwin_seated_crop.jpg Species of different genera and classes has not changed by the same rate or to the same degree (see „living fossils“). Periods during which species were changing were short relative to periods during which they stayed unchanged. http://upload.wikimedia.org/wikipedia/commons/a/a7/Richard_dawkins_lecture.jpg R. Dawkins: Blind watchaker Except of (nonexisting) completely constant rate there is only variable rate – species change either in discrete steps (punctuationism) or gradually. Therefore, stasis is only an extreme case of slow evolution. Punctuational proces typical for language evolution: changes play an important role in periods of divergence of a new language Bantu, Indoeuropean and Austronesian group: 10-33% differences connected with language splitting How to explain stasis? genetic or ontogenetic constraints habitat tracking – glacial/interglacial cycles short-term local divergence – rapid changes spatially limited Relation between micro- and macroevolution Steven M. Stanley (1975): macroevolution separated from microevolution S.J. Gould (1980): „deposition of neo-Darwinism from the throne“, „effective death of neo-Darwinism“ Modern Synthesis narrow, extrapolationistic and reductionistic Is macroevolution really different from microevolution? evolution of horses Darwin´s finches mammal evolution http://pronkpapers.files.wordpress.com/2010/08/matrioshaka_dolls.jpg http://4.bp.blogspot.com/-AfuZ2_s4YXY/UFjZgmmB8LI/AAAAAAAALp8/8Yla-HUMoUw/s640/the-beatles-matryosh ka-dolls.jpg evolution as „matryoshka“ mcfaddenhorsephylo2005 Evolution of horses: 2 dental dimensions mean rate can be explained by acting of directional selection (sufficient 2 selective deaths/million of individuals/generation) if Ne < 104 individuals, can be explained by drift alone likewise also other fossils horseevol browsing grazing c1x17b-finches Darwin´s finches: with known age of Galapágos enough time for diversification to 14 species (in fact more complicated – reversions, possible extinction of some species) img_021 Evolution of mammals from therapsid reptiles: changes gradual large differences between reptiles and mammals are adaptive in individual links Þ same mechanisms as in microevolution Relation of macroevolution and ontogeny Ernst Haeckel – biogenetic law (= recapitulation l.): ontogeny recapitulates phylogeny (eg. gills during mammal embryonal development) J. F. Meckel, E. Serres: embryos display traits of embryos of species preceding on the Scala Naturae http://highermeaning.org/Authors/LSO/MansPlace/fig1.jpg http://monarch-butterfly.info/images/monarch%20butterfly%20photo%20(2).jpg ´ specialized larval forms (= non-terminal addition): zoëa of crabs, Müller´s larva of echinoderms, caterpillar of butterflies etc. terminal vs. non-terminal addition http://www.dnr.state.sc.us/marine/sertc/images/photo%20gallery/P%20armatus%20ZI.jpg http://i.ndtvimg.com/mt/cooks/2014-11/crab.jpg http://www.photomacrography.net/forum/userpix/97_seaurchinlarva800.jpg C:\Users\Dell\Downloads\caterpillar_macro-wallpaper-960x540.jpg http://www.sustainablesushi.net/wp-content/uploads/2008/12/seaurchin.jpg Karl Ernst von Baer – embryological laws: Vertebrate embryos pass through stable stages during their development which are not identical to any animals species. Embryos of related species are similar to each other and dissimilar to adults of ancestral species. Karl Ernst von Baer – embryological laws: 1st law: General traits of a large animal group appear in the embryo earlier than special traits (eg. cartilage in bony fishes). http://www.nature.com/ncomms/journal/v4/n2/images/ncomms2429-f5.jpg General principles of ontogeny and evolution: modularization and individualization: serial homology and homonymy http://www.corpshumain.ca/en/images/Squelette_colonne_(FF)_en.jpg http://animaldiversity.ummz.umich.edu/site/resources/anatomical_images/teeth_types.jpg What Is Homodont Dentition https://classconnection.s3.amazonaws.com/152/flashcards/1734152/jpg/homodont1351569134864.jpg General principles of ontogeny and evolution: heterotopy = change of the position of a trait phenotypic expression (eg. photosynthesis in succulent stem; sesamoid bones – patella, ossified tendons in dinosaur tails, „panda´s thumb“) http://www.sportsinjuryclinic.net/images/knee/jumpers-knee-large.jpg http://evolution.berkeley.edu/evolibrary/images/pandathumb2.gif General principles of ontogeny and evolution: heterochrony and allometry http://image.slidesharecdn.com/2013swallamolgula-130828113053-phpapp01/95/billie-swalla-transcripto me-sequencing-reveals-heterochronic-shift-of-chordate-gene-networks-in-molgulid-ascidians-3-638.jpg ?cb=1377707570 Heterochrony: = change of timing of ontogenetic events: 1. speed of the process 2. timing of the process Somatic traits Reproductive org. peramorphosis paedomorphosis hypermorphosis Megaceros giganteus hetero.jpg acceleration ® peramorphosis hypermorphosis ® peramorphosis Heterochrony: Somatic traits Reproductive org. peramorphosis hypermorphosis -- deceleration acceleration acceleration -- paedomorphosis Somatic traits Reproductive org. peramorphosis hypermorphosis -- deceleration acceleration acceleration -- paedomorphosis progenesis -- acceleration neoteny deceleration -- Heterochrony: hetero.jpg neoteny ® pedomorphosis progenesis ® pedomorphosis Neoteny/paedomorphosis in Triturus (Ichthyosaura, Mesotriton, Lissotriton, Ommatotriton) neoteny Ambystoma mexicanum neoteny: http://i.imgur.com/DVqp4Sl.jpg Neoteny in humans? Neoteny.jpg Head: rounded skull slender cranial bones reduced brow ridges large brain flat face broadened face hairless face hairs ontop head large eyes ear shape small nose small teeth small upper and lower jaw Genitals: absence of baculum (os penis) presence of hymen anteriorly oriented vagina Limbs/posturer: legs longer than hands foot structure upright posture „Naked“ body http://3.bp.blogspot.com/-ZGWqrMqskjc/UbbFaX-M0II/AAAAAAAAAeM/XdWcR8MMsDI/s1600/humans+100000years. jpg Human neotenic features compared to the chimp*) (Wikipedia): *) some of them are not, in fact, neotenic! Origin of macroevolutionary novelties: change of function of a gene product: pigment producing enzyme ® change of coloration digestive enzyme ® change of sexual habits loss of function: genes suppressing own pathogenicity deletion of host proteins recognized by parasites (eg. CCR5-D32 deletion in the CCR5 gene ® resistency to the HIV and variola …. 5-14% of Europeans, in Africans and Asiatics rare) changes in gene regulation prions – incorrect translation termination Þ bovine spongiform encephalopathy, scrapie of sheep and goats, kuru, Creutzfeld-Jakob disease in humans role of gene duplications – more radical changes enabled symbiosis, gene transfer (retroviruses) homeotic genes Homeotic (Hox) genes William Bateson: „homeosis“ = anatomical changes of large extent (eg. development of an extra finger, cervical vertebra instead of thoracic, limb in ectopic position) http://zena-in.cz/media/2011/02/02/dedf77a7f783.jpg http://4.bp.blogspot.com/-Wa2WFP1p8vI/T4iBntjoKdI/AAAAAAAAAe0/OWSy9gghrvg/s1600/Central+Polydactyly +-+clinical+image.jpg http://web2.uwindsor.ca/courses/biology/crawford/355/McWilliams/ectopicleg.jpg http://www.pwrc.usgs.gov/naamp3/papers/54/54df_f4.gif Edward Lewis: homeotic genes = genes responsible for basic segmentation of multicellular animals – homeotic mutations do not change the number of segments but their identity control of transcription of other genes (eg. Ubx probably regulates hundreds of „target“ genes) determination of basic body segmentation high evolutionary conservativeness http://learn.genetics.utah.edu/content/variation/hoxgenes/images/arthropods.jpg Homeotic (Hox) genes http://www.nobelprize.org/nobel_prizes/medicine/laureates/1995/illpres/l-flies.gif Homeotic mutation Antennapedia Bithorax halteres mutation of the Ultrabithorax gene: 3rd thoracic segment (T3) ® T2 http://www2.ac-lyon.fr/enseigne/biologie/photossql/images/antennapedia.jpg http://archiwum.wiz.pl/images/duze/1996/05/96052510.GIF Hox genes: basic antero-posterior body segmentation linear clusters, same order as the segments http://www.pbs.org/wgbh/nova/genes/images/fate-03.jpg http://www.nature.com/scitable/content/33246/sadava_19_19_FULL.jpg Hox gene effects are overlapping T A carroll1 Drosophila: 1 linkage group, 2 clusters: Antennapedia (ANT-C) Bithorax (BX-C) vertebrates: 4 linkage groups The Evolution of Vertebrate Hox Cluster Organization and the History of... | Download Scientific Diagram Homeobox: 180 bp ® homeodomain 60 AA (expression regulation) http://www.evolution-textbook.org/content/free/figures/11_EVOW_Art/05_EVOW_CH11.jpg homeodomain Hox-genes are highly conservative http://www.evolution-textbook.org/content/free/figures/11_EVOW_Art/05_EVOW_CH11.jpg ParaHox genes MADS-box genes in plants http://www.nature.com/nature/journal/v392/n6679/images/392920ad.tif.2.gif http://www.nature.com/nature/journal/v409/n6819/images/409469aa.2.jpg http://scienceblogs.com/pharyngula/wp-content/blogs.dir/470/files/2012/04/i-5fe8c91c0c342c0d6a72cf6 075fe7738-mads_box_duplications.gif http://www.evolution-textbook.org/content/free/figures/11_EVOW_Art/09_EVOW_CH11.jpg http://www.evolution-textbook.org/content/free/figures/11_EVOW_Art/10_EVOW_CH11.jpg fruit fly 3 hypotheses of the origin of dipteran arrangement: Ubx protein expression: beetle dragonfly T2-T3 boundary http://www.evolution-textbook.org/content/free/figures/11_EVOW_Art/12_EVOW_CH11.jpg original function: venation development loss of function ... ... but origin of halteres in butterflies also scale morphology and wing coloration http://www.evolution-textbook.org/content/free/figures/11_EVOW_Art/18_EVOW_CH11.jpg Evolution of thoracic segments in crustaceans – shift of anteroposterior boundary of expression of the Ubx gene: thoracic segments: copepods – 6, lobster – 8, brine shrimps – 11 (ancestral) movement ® maxillipedes weak Ubx expression strong Ubx expression shift of anteroposterior boundary of Ubx gene expression = position of transition of locomotory segments and maxillipedes např. opossum shrimps: 2nd segment, prawns: 4th segment 2nd thoracic limb of opossum shrimps = transitional segment between 1st (maxillipede) and 3rd limb (locomotion) http://upload.wikimedia.org/wikipedia/commons/3/3f/Artemia_salina_4.jpg http://animaldiversity.ummz.umich.edu/collections/contributors/Grzimek_inverts/Mysida/Mysis_relicta /medium.jpg http://upload.wikimedia.org/wikipedia/commons/5/58/PSM_V04_D218_Artemia_salina.jpg Besides transcriptional factors also regulatory enhancers: http://upload.wikimedia.org/wikipedia/commons/thumb/1/12/Gene_enhancer.svg/400px-Gene_enhancer.svg. png http://condor.nimr.mrc.ac.uk/figure1.png 23-10 Macroevolutionary trends species selection trends: real ´ passive (eg. wall effect) Edward Drinker Cope: trend to bigger size Species selection: = preferential survival or proliferation of species different speciation rates different extinction rates the trait connected with differential survival or speciation these features independent of natural selection trait is heritable during speciation SS favours only nonadaptive trends (otherwise = natural selection) Necessary to prove: higher speciation rate/lower extinction rate in lineages which deviate from the average in the direction of the trend the trend and distribution of varied speciation/extinction rates are not caused by shift in fossil record the trend and distribution of varied speciation/extinction rates are not caused by natural selection 23-10