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Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
Evoluzione orizzontale e ontologia biologica
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Evoluzione orizzontale e ontologia biologica

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Lectures at the University of Padua, Department of Biology, "Evolution and phylogenetics" class, prof. Telmo Pievani …

Lectures at the University of Padua, Department of Biology, "Evolution and phylogenetics" class, prof. Telmo Pievani

http://www.epistemologia.eu

"Tree-making should be part of our evolutionary toolkit (see below), but not the backbone of the evolutionary metanarrative that we seem to feel obliged to defend from anti-scientific attack" W. Ford Doolittle

Chimeras and Consciousness, una vertigine cosmica di devozione alle connessioni: continuità nel tempo, reticolazione nel tempo, connessione nello spazio, dal micro al macro. L’aspetto che più interessa in questo corso è la reticolazione nel tempo, cioè la forte tendenza della vita ad evolvere non con separazioni nette, bensì con connessioni continue e pervasive, anzi, nel suo insieme, come un tutto organico.
Non ci sono soltanto gli "ultras" della reticolazione, o i "lateralisti" fondamentalisti, ma l’attenzione è presente in parallelo in diversi campi, e noi infatti cercheremo di immaginarne le implicazioni per l’albero della vita e la filogenesi. Quattro storie parallele: filogenesi dei batteri, simbiogenesi theory, parabola di Ernst Mayr, studi ibridazione negli animali.

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  • 1. 1Evoluzione orizzontale e ontologia biologicaEmanuele SerrelliPadova, 8-9 maggio 2012emanuele.serrelli@unimib.ithttp://www.epistemologia.eu
  • 2. 2SelvesGroupsEarthChimerasConsciousness
  • 3. 3Selves
  • 4. 4. . .the “selves” of viruses, utterly depend on theirphysical contact with bacterial or other living cells. Ifnot connected to a cell, a virus is as inert as a lump ofsalt or a cube of sugar. The basic element of life, theself, is the sensitive bacterial cell; but a virus, as acourier and an integrator of genes into bacteria andnucleated organisms (animals, plants, fungi andproctotists), can be very important to specificevolutionary trajectories.(William Day, ch. 2, p. 17)Selveshttp://jonlieffmd.com/blog/are-viruses-alive-are-viruses-sentient-virus-intelligence
  • 5. 5Selveshttp://microbes.nres.uiuc.edu/NRES512.htmRymer et al. (2012)
  • 6. 6Selveshttp://microbes.nres.uiuc.edu/NRES512.htmhttp://microbes.nres.uiuc.edu/NRES512.htm
  • 7. 7GroupsBen Jacob et al. (2004)
  • 8. 8GroupsBressan (2012)
  • 9. Groups9Murray Bowen photo by Andrea Maloney Schara (1979)http://ideastoaction.wordpress.com/2012/08/29/murray-bowen/
  • 10. 10
  • 11. 11ChimerasChimera di Arezzo, Museo Archeologico, Firenze
  • 12. Chimeras12Vad Drisse (2011)
  • 13. Chimeras12Vad Drisse (2011)Margulis et al. (2006)
  • 14. Chimeras13Invertebrates...http://in2uract.wordpress.com/2011/11/24/strengthening-your-immune-system/
  • 15. Chimeras14Alves et al.LemurFamily: Galagidaehttp://collections.burkemuseum.org/mtm/images/mtm_slideshows/3027712362_de1ae16a96_o.jpg
  • 16. Chimeras15
  • 17. Chimeras16http://neurosciencefundamentals.unsw.wikispaces.net/The+Neurons+that+Shaped+Our+Worldhttp://www.ted.com/talks/vs_ramachandran_the_neurons_that_shaped_civilization.html
  • 18. Consciousness17LemurFamily: Galagidaehttp://collections.burkemuseum.org/mtm/images/mtm_slideshows/3027712362_de1ae16a96_o.jpgGeorge Mobushttp://faculty.washington.edu/gmobus/Background/evolutionsTrajectory.html
  • 19. Consciousness18http://thecampbellgrp.com/glonal-network/
  • 20. 19SelvesGroupsEarthChimerasConsciousness
  • 21. 20
  • 22. 21http://evolutionschool.fc.ul.pt
  • 23. 22For there is, after all, one true tree of life, theunique pattern of evolutionary branchings thatactually happened. It exists. It is in principleknowable. We don’t know it all yet. By 2050 weshould—or if we do not, we shall have beendefeated only at the terminal twigs, by the sheernumber of species. ... [H]undreds of separategenes ... are found to corroborate each other’saccounts of the one true tree of life (Dawkins2003, p. 112; see also Eldredge 2005, p. 227).
  • 24. 23http://edge.org/conversation/lynn-margulis1938-2011
  • 25. SET - Serial Endosymbiosis Theory for the origin ofeukaryotic cells24http://img.scoop.co.nz/stories/images/0903/a8de5c88b14851860daa.jpegImage courtesy of Lynn Margulis
  • 26. 25http://img.scoop.co.nz/stories/images/0903/a8de5c88b14851860daa.jpegImage courtesy of Lynn Margulis
  • 27. 26
  • 28. 26
  • 29. 27Virolution at the pro- and eukaryotic levelVillarreal & Ryan
  • 30. 281957Molecular phylogen.SSU rRNA (Woese)19871990s on 2004
  • 31. 29W. Ford Doolittle1957In the case of higher plants and animals, species canbe grouped into genera, families, and orders on thebasis of their evolutionary relationships, or phylogeny.Such classifications are called natural classifications. Inthe bacteria, however, only a few broad lines ofevolution are dimly perceivable, and the finer details ofphylogeny remain completely obscure. The existingsemiofficial classification of bacteria, Bergey’s Manual,is thus an arbitrary one, and is useful only to the limitedextent that it serves as a ‘‘key’’ for identification.(Steiner et al. 1957)Phylogeny of bacteria
  • 32. 30W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.phylogenies based on the sequences of ‘‘informationalmacromolecules’’ are not only more unambiguouslyquantifiable but closer to what it is that actually evolves—genes and the genome....extend the universal Tree of Life downward to itsdeepest roots among the prokaryotes
  • 33. 31W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)
  • 34. 32W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)Lateral, Horizontal gene transfer at the prokaryotic level:gene donations of bacteria: e.g. resistance of bacteria againstantibiotics
  • 35. 32W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)Lateral, Horizontal gene transfer at the prokaryotic level:gene donations of bacteria: e.g. resistance of bacteria againstantibiotics...microbiologists had uncovered a phenomenon thatmight have given them cause to worry that theevolution of genes might not always be tree-like, andthat gene trees might not always be species trees.
  • 36. 33W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)Why few of us thought that LGT wouldinterfere seriously with universal treeconstruction is an interesting question forthe historian and sociologist...
  • 37. 34W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)1987In the extreme, interspeciesexchanges of genes could beso rampant, so broadspread,that a bacterium would notactually have a history in itsown right; it would be anevolutionary chimera, acollection of genes (or geneclusters), each with its ownhistory...
  • 38. 35W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)1987Fortunately the matter isexperimentally decidable.Were an organism anevolutionary chimera, then itsvarious chronometers wouldyield different, conflictingphylogenies.
  • 39. 36W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)19871990s on
  • 40. 37W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)19871990s onAssessing how many of a genomes’ geneshave been laterally transferred at some time inits history will always be technically difficult andfraught with definitional problems, although fewwould now claim that the fraction is less thanone half, and many would accept that it is morethan 95%. It turns out to be simpler to ask howmany and which genes might possibly haveavoided LGT in the last four billion years.
  • 41. 38W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)19871990s on
  • 42. 39W. Ford Doolittle1957Phylogeny of bacteriaMolecular phylogen.SSU rRNA (Woese)19871990s on
  • 43. 40Network diagramscombines both horizontal and vertical evolutionary events in prokaryotesDagan and Martin, 2009: 2190
  • 44. 41MargulisSymbiogenesis1957Molecular phylogen.SSU rRNA (Woese)19871990s on
  • 45. 42MargulisSymbiogenesis1957Molecular phylogen.SSU rRNA (Woese)19871990s on
  • 46. Symbiogenesis43http://img.scoop.co.nz/stories/images/0903/a8de5c88b14851860daa.jpegImage courtesy of Lynn Margulis
  • 47. 44MargulisSymbiogenesis1957Molecular phylogen.SSU rRNA (Woese)19871990s onOriginal formulationof symbiosis theoryby ConstantinMereschkowsky1909
  • 48. 45How many individuals ? How many kinds ofindividuals?19We need better definitions of individualsCourtesy of Fred Bouchhard, 2013
  • 49. 46MaureenO’MalleyCentrality of Biological species and their tree1957Molecular phylogen.SSU rRNA (Woese)19871990s onErnst Mayr, the tree of life, and philosophy of biologyMaureen A. O’MalleyPublished online: 8 May 2010Ó Springer Science+Business Media B.V. 2010Abstract Ernst Mayr’s influence on philosophy of biology has given the field aparticular perspective on evolution, phylogeny and life in general. Using debatesabout the tree of life as a guide, I show how Mayrian evolutionary biology excludesnumerous forms of life and many important evolutionary processes. Hybridizationand lateral gene transfer are two of these processes, and they occur frequently, withimportant outcomes in all domains of life. Eukaryotes appear to have a more tree-like history because successful lateral events tend to occur among more closelyrelated species, or at a lower frequency, than in prokaryotes, but this is a differenceof degree rather than kind. Although the tree of life is especially problematic as arepresentation of the evolutionary history of prokaryotes, it can function moregenerally as an illustration of the limitations of a standard evolutionary perspective.Moreover, for philosophers, questions about the tree of life can be applied to theMayrian inheritance in philosophy of biology. These questions make clear that thedichotomy of life Mayr suggested is based on too narrow a perspective. An alter-native to this dichotomy is a multidimensional continuum in which differentstrategies of genetic exchange bestow greater adaptiveness and evolvability on pro-karyotes and eukaryotes.Keywords Ernst Mayr Á Philosophy of biology Á Evolution Á Tree of life ÁSpecies Á Lateral gene transfer Á HybridizationIntroductionMost philosophers of biology have in the back of their mind at least a vague image ofa tree of life that depicts bifurcating species lineages and represents the evolutionaryM. A. O’Malley (&)Egenis, University of Exeter, St Germans Road, EX4 4PJ Exeter, UKe-mail: M.A.O’Malley@ex.ac.uk123Biol Philos (2010) 25:529–552DOI 10.1007/s10539-010-9214-6
  • 50. 47MaureenO’MalleyCentrality of Biological species and their tree1957Molecular phylogen.SSU rRNA (Woese)19871990s on 2004All so-called asexually reproducingorganisms do not have species.The prokaryotes are difficultenough [to deal with], but evenwhen you get into the loweukaryotes, there is this group thatis a sort of a garbage can calledthe protists. And there are authorsI’m told that recognize 80 phyla ofprotists. God knows what there isin these 80 phyla. And most ofthem do not have species in thenormal sense. They don’t have aproper process of speciation oranything like that.
  • 51. 48But again, on the pragmatic grounds of removing the messier, more web-likeFig. 1 Six eukaryote supergroups. Reprinted from Lane and Archibald (2008), with permission fromElsevier538 M. A. O’MalleyFrom Lane and Archibald (2008), in O’Malley 2010MaureenO’Malleythere is growing evidence of gene exchange in protists (Keeling andPalmer 2008; Andersson 2009). Sequence analyses of several protistgenomes have detected bacterial genes in varying amounts, with asmuch as 4% of rumen ciliate genomes being of foreign origin (Ricard et al.2006). In the genome of the miniscule green alga, Ostreococcus tauri, thesmallest free-living eukaryote, a whole chromosome appears to havebeen acquired, although its source is not obvious (Derelle et al. 2006). Thepathogens Giardia lamblia, Trichomonas vaginalis, and Entamoebahistolytica have ‘borrowed’ large numbers of virulence and metabolismgenes from bacteria (Andersson et al. 2006; Loftus et al. 2005). Transfersbetween protists, and from other eukaryotes to protists, have also beenfound in increasing numbers, and the data for such acquisitions increasewith every genome sequence deposited in GenBank or other databases(Andersson 2009). The more lateral gene transfer in protists is studied, infact, the more that is learned about interdomain exchange as an ongoingevolutionary mechanism of genetic diversity (Andersson et al. 2006).
  • 52. 48But again, on the pragmatic grounds of removing the messier, more web-likeFig. 1 Six eukaryote supergroups. Reprinted from Lane and Archibald (2008), with permission fromElsevier538 M. A. O’MalleyFrom Lane and Archibald (2008), in O’Malley 2010MaureenO’Malley
  • 53. 49But again, on the pragmatic grounds of removing the messier, more web-likeFig. 1 Six eukaryote supergroups. Reprinted from Lane and Archibald (2008), with permission fromElsevier538 M. A. O’MalleyFrom Lane and Archibald (2008), in O’Malley 2010MaureenO’MalleyIn fungi, there is a growing list of what seem to be fungal hybrids (Schardland Craven 2003; Novo et al. 2009). Moreover, there appears to be agreat deal of LGT occurring between prokaryotes and fungi, betweenfungal lineages, and between fungi and other multicellular eukaryotes (e.g.Schardl and Craven 2003; Friesen et al. 2006; Richards et al. 2006,2009). Numerous phylogenetically discordant plasmids, transposons andgene clusters have been detected in a range of fungal lineages, and evensome whole chromosome transfers between filamentous fungi (Walton2000). In addition, there is good experimental evidence oftransformation (uptake of environmental DNA) in a few fungi (Rosewichand Kistler 2000). Whether novel DNA is acquired by hybridization or byLGT, it has either to be excluded from phylogenetic analysis or depictedas a reticulate event.
  • 54. 50But again, on the pragmatic grounds of removing the messier, more web-likeFig. 1 Six eukaryote supergroups. Reprinted from Lane and Archibald (2008), with permission fromElsevier538 M. A. O’MalleyFrom Lane and Archibald (2008), in O’Malley 2010MaureenO’MalleyThey can combine sexual and asexual reproduction (with sexualreproduction being the ancient state, since lost in many lineages), and it isstill sometimes unclear how particular fungi reproduce (Petersen andHughes 1999; Schardl and Craven 2003; Zeyl 2009). One reproductivepeculiarity of fungi involves hyphal fusion, in which fungal filamentsanastomose parasexually, through somatic recombination rather thangerm cell recombination. Large numbers of nuclei (sometimes thousands)from the different hyphae share the same enlarged cell compartment. Inmany lineages, interspecific matings are vegetatively incompatible, whichmeans that the non-self recognition of introduced genetic systems resultsin the destruction of the newly merged hyphal cells (Glass and Dementhon2006; Glass and Kaneko 2003; Giraud et al. 2008). Even when this doesnot happen, the heterokaryon products of hyphal fusion (cells withdifferent genotypes) may be unstable and produce only homokaryoticoffspring. But this is not always the case, and nor does incompatibilityrecognition happen for all hyphal fungi.
  • 55. 51But again, on the pragmatic grounds of removing the messier, more web-likeFig. 1 Six eukaryote supergroups. Reprinted from Lane and Archibald (2008), with permission fromElsevier538 M. A. O’MalleyFrom Lane and Archibald (2008), in O’Malley 2010MaureenO’Malleystudy after study has documented the adaptiveness and proliferationof plant hybrids (Heiser 1973; Arnold 2006; Arnold et al. 1999; Soltis andSoltis 2009). Much known hybridization involves genome doubling(allopolyploidy), which has played a major role in plant evolution (Adamsand Wendel 2005). Other hybridization events involve genomerecombination (homoploidy). An example of the latter, which is moredifficult to detect, is provided by the sunflowers Helianthus annuus and H.petiolaris. These parental species have three hybrid offspring (H.anomalus, H. deserticola, and H. paradoxus) that evolved between60,000 and 200,000 years ago. While the parent plants favour temperateclimates, the hybrid offspring inhabit and flourish in extreme environments,such as harsh desert conditions and salt marshes (Rieseberg 1997;Rieseberg et al. 2003). It is frequently the case that hybrid offspring havehardier characteristics than their parents, due to new gene combinationsthat allow the hybrids to colonize new ecological niches (Rieseberg andWillis 2007).
  • 56. 52But again, on the pragmatic grounds of removing the messier, more web-likeFig. 1 Six eukaryote supergroups. Reprinted from Lane and Archibald (2008), with permission fromElsevier538 M. A. O’MalleyFrom Lane and Archibald (2008), in O’Malley 2010MaureenO’MalleyOne classic study that did not quite fit Mayr’s expectations was carried out byLewontin and L. C. Birch (1966). They argued that hybridization was a source ofvariation for adaptation to new environments in particular groups of Queensland fruitflies (then Dacus, now Bactrocera tryoni and B. neohumeralis)......because hybridization is usually investigated in relation to visibly distinguishabletaxa, it has probably been systematically underestimated in duller, more uniform typesof organisms such as little brown birds or butterflies (Mallet 2005; Dowling and Secor1997). Some classic examples include ducks (much collected during huntingseasons, and therefore well observed), birds of paradise, cichlids and butterflies(see Mallet et al. 2007). Cichlids and other freshwater fish are well known for theirhybridization capacities, partly because of the very divergent morphologies and colourpatterns produced by introgression (Koblmüller et al. 2007). In representing theseintrogressions phylogenetically, many branches have to be reticulated to make senseof incongruent gene phylogenies.Although there may be low levels of fertility in the first generation of hybrids, latergenerations frequently stabilize, often with fitness advantages in new or expandedenvironments (Anderson 1948; Arnold 2006). And although rates of hybridization maybe low, they can have major evolutionary consequences (Seehausen 2004; Dowlingand Secor 1997).
  • 57. 53Virolution at the pro- and eukaryotic levelVillarreal & Ryan
  • 58. 53Virolution at the pro- and eukaryotic levelVillarreal & RyanMuch of the known LGT in animals involves acquisitions from prokaryotes, such asgenes for cellulose biosynthesis in marine invertebrates, and glyoxylate-cycleenzymes in a number of animals (Nakashima et al. 2004; Kondrashov et al. 2006).The genomes of Wolbachia-infected insects can carry large fragments ofWolbachia DNA— nearly a whole Wolbachia genome in one case (Hotopp et al.2007).An even more intriguing example of animal LGT is that of bdelloid rotifers (amicroscopic multicellular aquatic animal), the genomes of which show evidence ofrecent and ancient acquisitions of bacterial, fungal, and plant genes (Gladyshev et al.2008). Rotifers have a life cycle that can include dessication, and as the dessicatedbody revives in the presence of water, environmental DNA seems to be integrated intothe rotifer’s genome through a combination of membrane damage and DNA repairmechanisms, and then inherited in the absence of sexual recombination. Most of theintact foreign genes code for simple enzymatic functions such as carbohydratedecomposition (rather than multi- component biochemical pathways)...Some plant-parasitic nematodes have acquired bacterial genes that enable thenematodes to modify plant cell walls, thereby damaging the plant but nourishing thenematode (Scholl et al. 2003).
  • 59. 54MaureenO’MalleyCentrality of Biological species and their tree1957Molecular phylogen.SSU rRNA (Woese)19871990s on 2004
  • 60. 55HybridizationSchwenk et al. (2008)
  • 61. 56Hybridization1957Molecular phylogen.SSU rRNA (Woese)19871990s on 2004
  • 62. 57Animal (and plant)evolutionRepresentativeWell representedby treeImpact on TOLMayr Yes Yes -Doolittle No Yes CircumscribeMargulis No No ReplaceO’Malley No NoMultidimensionalspaceHybrid. studies N/A (yes) YesSpeciation andadaptation mech.
  • 63. 58Animal (and plant)evolutionRepresentativeWell representedby treeImpact on TOLMayr Yes Yes -Doolittle No Yes CircumscribeMargulis No No ReplaceO’Malley No NoMultidimensionalspaceHybrid. studies N/A (yes) YesSpeciation andadaptation mech.58evolution of multicellularanimals and plants can still bewell understood as a branchingprocess (albeit with somefuzziness)prokaryotic evolution may be bettermodeled as a reticulated web. This isbecause prokaryotes (bacteria andarchaea) much more readily exchangegenes ‘‘across species lines’’, by severalgenetic mechanisms collectively knownas lateral gene transfer (LGT). Sinceprokaryotes comprise the majority ofliving things, and since the first two-thirds of Life’s history is exclusivelyprokaryotic, the TOL is of limitedexplanatory scope.
  • 64. 59Animal (and plant)evolutionRepresentativeWell representedby treeImpact on TOLMayr Yes Yes -Doolittle No Yes CircumscribeMargulis No No ReplaceO’Malley No NoMultidimensionalspaceHybrid. studies N/A (yes) YesSpeciation andadaptation mech.A key residual question from thediscussion above is whether evolutionarybiology and its philosophy should followMayr and split evolution into two types: theprocesses and outcomes that occur with‘good’ speciators, and those that occurwith ‘bad’ speciators...a continuum perspective is the onlyremaining optionmultiple intersecting continua: asexual-sexual, much-less-exchange, uni-multicellular...an approach along these lines would be more informative than afocus on which organisms have evolved in tree-like patterns. Amultidimensional approach by no means rejects the importance ofsuch patterns, nor of the processes that gave rise to them, but itsees them as just one possible focus and not always the mostvaluable one.
  • 65. ?
  • 66. References62• Alves AL, Splendore de Borba R, Oliveira C, Nirchio M,Granado A, Foresti F. Karyotypic diversity and evolutionarytrends in the Neotropical catfish genus HypostomusLacépède, 1803 (Teleostei, Siluriformes, Loricariidae).CompCytogen 6(4): 443–452, doi: 10.3897/CompCytogen.v6i4.4028• Ben Jacob, E. et al., 2004. Bacterial linguistic communicationand social intelligence. Trends in microbiology, 12(8), pp.366–72.• Bressan D (2012). The mysterious microbial origin ofmountains. June 21, 2012. http://blogs.scientificamerican.com/history-of-geology/2012/06/21/the-mysterious-microbial-origin-of-the-dolomite-mountains/• Debernardi M, Serrelli E (2013). From bacteria to Saint Francisto Gaia in the symbiotic view of evolution. Evolution:Education and Outreach 6(4). ISSN 1936-6426 (Print),1936-6434 (Online) [DOI 10.1186/1936-6434-6-4]• Ford Doolittle, W., 2010. The attempt on the life of the Tree ofLife: science, philosophy and politics. Biology & Philosophy,25(4), pp.455–473.• Margulis L (1995). Gaia is a tough bitch. In John Brockman,ed. The Third Culture: Beyond the Scientific Revolution. NewYork: Simon & Schuster, pp. 130-140.• Margulis, L. et al., 2006. The last eukaryotic commonancestor (LECA): acquisition of cytoskeletal motility fromaerotolerant spirochetes in the Proterozoic Eon. Proceedingsof the National Academy of Sciences of the United States ofAmerica, 103(35), pp.13080–5.• O’Malley, MA. (Ed.) (2010). Special issue on the tree of life (15papers). Biology and Philosophy, 25(4).• O’Malley, M. a., 2010. Ernst Mayr, the tree of life, andphilosophy of biology. Biology & Philosophy, 25(4), pp.529–552.• Richard U. Rymer RU, Solorio FA, Tehranchi AK, Chu C, CornJE, Keck JL, Wang JD, Berger JM (2012). Binding mechanismof metal⋅NTP substrates and stringent-response alarmones tobacterial DnaG-Type primases. Structure 20(9): 1478-1489.• Sagan, L., 1967. On the origin of mitosing cells. Journal oftheoretical biology, 14(3), pp.255–74.• Schwenk K, Brede N, Streit B (2008). Introduction. Extent,processes and evolutionary impact of interspecifichybridization in animals. Phil. Trans. R. Soc. B 363, doi:10.1098/rstb.2008.0055• Van Drisse C (2011). A Russian Doll of Symbiosis. December4, http://eukaryoticmicrobe.blogspot.it/2011/12/russian-doll-of-symbiosis.html• Woese, C.R. & Fox, G.E., 1977. Phylogenetic structure of theprokaryotic domain: the primary kingdoms. Proceedings ofthe National Academy of Sciences of the United States ofAmerica, 74(11), pp.5088–90.

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