Flying_fish Eagle Owl Eyes - Picture 1 of 4 in Vision 23900-004-B66A6F45 Trypanosoma%20brucei%20rhodesiense%20fig3 img354 File:Haeckel Sacculina.jpg Optimum ORCHIDEJ Catasetum saccatum Chiloglottis formicifera #2 Catasetum saccatum Chiloglottis formicifera Chiloglottis formicifera #1 MRAVENEC Zacryptocerus varians Atta, Acromyrmex: bigger workers – cutting leaves, soldiers – their protection, small workers – chewing leaves, growing fungi casent0103758_p_1_high File:Acromyrmex octospinosus.jpg File:Atta colombica workers cutting whole plant.jpg atta_closeup Oecophylla Oecophylla smaragdina Oecophylla smaragdina, I_ALW1 OecSma8 File:AntsStitchingLeave.jpg File:SSL11903p.jpg parasites ´ hosts life-history strategies = timing and way of investing to survival and reproduction through the whole life of an individual eg. timing of sexual maturity, aging, number and size of offspring, semelparity vs. iteroparity Eg.: guppies, northern Trinidad and Tobago: upper and lower part of the river separated by waterfalls ® barrier both for guppies and predators upper: moderate predation pressure (Rivulus hartii) lower: strong predation pressure (eg. Crenicichla alta) ® different coloration, antipredatory behaviour, life-history parameters (different number and size of offspring, age of the first reproduction, timing of senescence) fewer but larger offspring, later reproduction many small offspring, early reproduction evolutionary trade-off David Reznick, John Endler et al. (1990): transfer of 100 males and 100 females from high-predation site to low-predation site ® after 5 and 12 years females produced fewer larger offspring this characteristic heritable high-predation site guppies form larger and tighter shoals What the evolutionary theory must explain: origin of complex adaptation origin of traits such as recombination, sexual reproduction, programmed life span including senescence and death, segregation distortion etc. which do not (or seemingly do not) provide organisms any benefit cooperation within and between ´ antagonism within species (eg. infanticide) and between species (eg. host castration by parasites) „harmful“ adaptations (eg. bee sting) ADAPTATION process of adapting trait of an organism trait which allows better survival and reproduction natural selection necessary but also considering history (flea winglessness ´ Collembola) nature06614-f2 Collembola Protura Insecta File:Isotoma Habitus.jpg File:Scanning Electron Micrograph of a Flea.jpg springtail has no wings because all its ancestors were wingless flea has lost its wings secondarily … likewise wingless species of fruit flies etc. GLABER Heterocephalus glaber Fukomys sp. Výsledek obrázku pro heterocephalus glaber bulb eating theory adaptations known for a long time - philosophers, natural theologians (St. Augustine, St. Thomas Aquinas, William Paley) notion of a watchmaker, today „argument from design“ ´ David Hume Richard Dawkins: Blind Watchmaker Explaining adaptations: supernatural being lamarckism, adaptive mutation zebra and lion: the ability of muscle strengthening is itself adaptive orthogenesis ... mechanism? natural selection File:Blind Watchmaker.jpg Coadaptation = complex adaptation requiring coordinated changes of more than 1 part Herbert Spencer: giraffe´s neck – parallel changes of bones, muscles, and vessels ´ genes do not act independently gene level (® gene complexes, „supergenes“) organ level species level ... see also Origin of sexual reproduction giraffe 1. Functional intermediary traits File:Diagram of eye evolution.svg File:Vertebrate n octopus eyes.png vertebrates octopus cephalopods, vertebrates EVOLUTION OF COMPLEX TRAITS Nautilus Evolution of camera-type eye: How can a half-eye be functional? cephalopods: photosensitive organs ® independent origin 50-100´ in different groups of invertebrates Nilsson & Pelger (1994): layer of photosensitive cells between dark cell layer below and transparent protective layer on top random changes <1% ® less advantageous changes rejected criterion = ability to distinguish objects in space (optical physics ® potential for quantification) Evolution of a complex camera-type eye – computer simulation: ~ 1000 steps: pinhole eye ~ 2000 steps: camera-type eye ~ 400 000 generations d = diameter Evolution of a complex camera-type eye – computer simulation: exaptation = function shift, ie. usage of a trait for another purpose Eg.: mammal cranial sutures (birth relief) suture probably enabled brain growth 2. Exaptation Complex traits seldom originate de novo, rather modification of existing structures François Jacob (1977): evolutionary tinkering http://www.sebiology.org/membership/images/Darwin2.jpg must have been other purpose! Eg.: bird feathers single origin theropod dinosaurs Prum and Brush (2002): „Concluding that feathers evolved for flight is like maintaining that digits evolved for playing the piano.“ Bird feathers: 1. thermoregulation 2. protection against solar radiation 3. signaling 4. sense of touch (like vibrisses) 5. pray catching 6. defence 7. water protection File:Tyrannosaurus BW.jpg Soubor:Albatros ceja negra - paso drake - noviembre 2005.jpg microraptor Dilong paradoxus thermoregulation Microraptor gui: gliding birds: active flight dilong_paradoxus T. rex Eg.: lobe-finned fishes – seabed movement ® shore climbing Stephen J. Gould, Elizabeth Vrba (1982): avoiding teleology: the term „preadaptation“ ® exaptation = broader meaning – including originally neutral traits likewise term co-option File:Panderichthys BW.jpg File:Tiktaalik BW.jpg File:Acanthostega BW.jpg Eg.: insect cuticle (integument ® skeleton); mammalian mammary glands (sweat glands) Panderichthys (Rhipidistia) Tiktaalik Acanthostega Evolutionary constraints time lag: neotropical anachronisms Cresentia alata old_fruits.jpg genetical constraints: overdominance (lethal system of chromosome 1 in Triturus cristatus) Are adptations always optimal? http://www.hlasek.com/foto/triturus_cristatus_ha7543.jpg physical constraints: mass grows with third power bone strength grows with second power (bone cross-section) http://theactionelite.com/site/wp-content/uploads/2015/01/423b13dfbe5f7401dfa0f2110d348d18.jpg http://room226.weebly.com/uploads/5/3/4/4/5344580/3275028_orig.jpg?321 ontogenetic constraints: deviation of production of various phenotypes or restriction of phenotypic variation caused by structure, character, composition or dynamics of the ontogenetic system pegasus Pegasus´s wings cannot arise de novo http://plato.stanford.edu/entries/innate-acquired/figure4A.jpg ontogeny is „canalized“ David Raup (1966): morphospace described by 3 variables W = expansion rate D = tightness of the coil T = translation rate only some shapes realized III.8.jpg historical constraints change of adaptive landscape Eg.: laryngeal nerve – one of branches of the vagus nerve (nervus vagus) nerv.jpg Myllokunmingia > 530 MY http://faculty.baruch.cuny.edu/jwahlert/bio1003/images/amphioxus_wm.jpg http://upload.wikimedia.org/wikipedia/commons/thumb/e/eb/Lancelet's_circulatory_system_scheme.png/6 40px-Lancelet's_circulatory_system_scheme.png amphioxus http://4.bp.blogspot.com/-47RBn97-DF0/TlMl4-Z5xlI/AAAAAAAAMQM/OGI6uBxwqdA/s1600/giraffe+recurrent+l aryngeal+nerve.png trade-off of various adaptive needs: parallel breathing and eating when the secondary palate is absent trade-off between life-history parameters (number of offspring ´ age of the first reproduction) time distribution between various activities (eating, recreation, …) conflict at different levels: selection at the gene level vs. selection at the organismal level Methods of study of adaptation: structural complexity: the more complex, the higher probability of a trait being adaptive usefulness, demonstration of function: Bergmann and Allen rule, falcon wing ´ accipiter wing etc. comparative method: association with phylogenetic analýysis experiment Sometimes even an experiment is not conclusive whether the trait is adaptive ® danger of confusing function and effect: eg. alkaloids and terpenes of plants (repelling insects ´ waste products of metabolism) File:Polarfuchs 1 2004-11-17.jpg Plik:TAzooAnimal3.jpg [USEMAP] non-phylogenetic statistical methods assume that all the compared species are equally related ... Is every trait adaptive? physical and chemical laws: hemoglobine colour, return of a fish to water cultural inheritance of some behavioural patterns drift: pseudogenes; shift to parthenogenesis in Drosophila mercatorum; loss of structures due to accumulation of lethal mutations correlation with the selected trait: hitchhiking, pleiotropy multiple peaks in the adaptive landscape Flying_fish multiple peaks in adaptive landscape: cryptic or aposematic colouration; locomotion of kangaroos ´ zebras phylogeny: winglessness, eusocial behaviour of mole rats zorilla zorilla skunk File:Striped skunk.jpg http://cdn2.arkive.org/media/EB/EB5BC604-FBB2-49E5-AF95-3D1CE7ACE28E/Presentation.Large/Red-kangaro o-hopping.jpg http://rennersafaris.com/wp-content/uploads/2014/06/Impala-Running-05441.jpg kangaroo antelope Is every trait adaptive? Stephen Gould, Richard Lewontin (1979): The spandrels of San Marco and the Panglossian paradigm: A critique of the adaptationist programme. Proceedings of the Royal Society of London, Series B, 205: 581-598.