Evolutionary Biology

, Volume 43, Issue 4, pp 582–595 | Cite as

Life With or Without Names

  • M. CasiraghiEmail author
  • A. Galimberti
  • A. Sandionigi
  • A. Bruno
  • M. Labra
Synthesis Paper


The terms ‘life’, ‘species’ and ‘individuals’ are key concepts in biology. However, theoretical and practical concerns are directly associated with definitions of these terms and their use in researchers’ work. Although the practical implications of employing definition of ‘species’ and ‘individuals’ are often clear, it is surprising how most biologists work in their field of study without adhering to a specific definition of life. In everyday scientific practice, biologists rarely define life. This is somewhat understandable: the majority of biologists accept the standard definition of life without exploring it, but this represents a bad attitude. In this essay, we update the concepts of life, species, and individuals in the light of the new techniques for massive DNA sequencing collectively known as high throughput DNA sequencing (HTS). A re-evaluation of the newest approaches and traditional concepts is required, because in many scientific publications, HTS users apply concepts ambiguously (in particular that of species). However, the absence of clarity is understandable. For most of the last 250 years, from Linnaeus to the most recent researches, identification and classification have been performed applying the same process. On the contrary, through HTS, biologists have become simply identifiers, who construct boundaries around the biological entities and do not examine the taxa at length, resulting in uncertainty in most readers and displeasure in traditional taxonomists. We organised our essay to answer a basic question: can we develop new means to observe living organisms?


Life Species Individual Biological entities High throughput DNA sequencing Next generation sequencing HTS NGS 



The authors are indebted to the anonymous reviewers whose acute comments allowed us to improve consistently our work. Authors are also indebted with Paul D. Roberts and Joanna Schultz for the linguistic revision of the manuscript.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.


  1. Arslan, D., Legendre, M., Seltzer, V., Abergel, C., & Claverie, J. M. (2011). Distant mimivirus relative with a larger genome highlights the fundamental features of Megaviridae. Proceedings of the National Academy of Sciences USA, 108, 17486–17491.CrossRefGoogle Scholar
  2. Atran, S. (1990). The cognitive foundations of natural history. New York: Cambridge University Press.Google Scholar
  3. Avise, J. C., & Ball, R. M, Jr. (1990). Principles of genealogical concordance in species concepts and biological taxonomy. In D. Futuyma & J. Atonovics (Eds.), Oxford surveys in evolutionary biology (pp. 45–67). Oxford: Oxford University Press.Google Scholar
  4. Bagatto, B., Crossley, D. A., & Burggren, W. W. (2000). Physiological variability in neonatal armadillo quadruplets: Within- and between-litter differences. The Journal of Experimental Biology, 203, 1733–1740.PubMedGoogle Scholar
  5. Barnes, R. D. (1982). Invertebrate zoology. Philadelphia, PA: Holt-Saunders International. ISBN 0-03-056747-5.Google Scholar
  6. Blackwelder, R. E. (1967). Taxonomy: A text and reference book. New York: Wiley.Google Scholar
  7. Brucker, R. M., & Bordenstein, S. R. (2012). Speciation by symbiosis. Trends Ecology. Evolution, 27, 443–451.Google Scholar
  8. Brucker, R. M., & Bordenstein, S. R. (2013). The capacious hologenome. Zoology, 116, 260–261.PubMedCrossRefGoogle Scholar
  9. Cain, A. J. (1954). Animal species and their evolution. London: Hutchinson University Library.Google Scholar
  10. Cantino, P. D., & de Queiroz, K (2000). Phylocode: A phylogenetic code of biological nomenclature.
  11. Carstens, B. C., Pelletier, T. A., Reid, N. M., & Satler, J. D. (2013). How to fail at species delimitation. Molecular Ecology, 22, 4369–4383.PubMedCrossRefGoogle Scholar
  12. Casiraghi, M. (2012). Being an individual (or a species) in a symbiotic world. Paradigmi, 3, 59–69.Google Scholar
  13. Claridge, M. F., Dawah, H. A., & Wilson, M. R. (Eds.). (1997). Species: The units of biodiversity. London: Chapman and Hall.Google Scholar
  14. Claverie, J. M., & Abergel, C. (2010). Mimivirus: The emerging paradox of quasi-autonomous viruses. Trends in Genetics, 26, 431–437.PubMedCrossRefGoogle Scholar
  15. Cracraft, J. (1983). Species concepts and speciation analysis. Current Ornithology, 1, 159–187.CrossRefGoogle Scholar
  16. Crick, F. H. C. (1968). The origin of the genetic code. Journal of Molecular Biology, 38, 367–379.PubMedCrossRefGoogle Scholar
  17. Cronquist, A. (1978). Once again, what is a species? In L. V. Knutson (Ed.), BioSystematics in agriculture (pp. 3–20). Montclair, NJ: Alleheld Osmun.Google Scholar
  18. Darwin, C. (1859). On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life (1st ed.). London: John Murray.Google Scholar
  19. de Queiroz, K., & Cantino, P. D. (2001). Phylogenetic nomenclature and the PhyloCode. Bulletin of Zoological Nomenclature, 58, 254–271.Google Scholar
  20. Dobzhansky, T. (1935). A critique of the species concept in biology. Philosophy of Science, 2, 344–355.CrossRefGoogle Scholar
  21. Dobzhansky, T. (1937). Genetics and the origin of species. New York: Columbia University Press.Google Scholar
  22. Dobzhansky, T. (1950). Mendelian populations and their evolution. American Naturalist, 74, 312–321.Google Scholar
  23. Dodson, J. J., Gibson, R. J., Cunjak, R. A., Friedland, K. D., de Leaniz, C. G., Gross, M. R., et al. (1998). Elements in the development of conservation plans for Atlantic salmon (Salmo salar). Canadian Journal of Fisheries and Aquatic Sciences, 55(Suppl 1), 312–323.CrossRefGoogle Scholar
  24. Dupré, J. (2010). The polygenomic organism. The Sociological Review, 58, 19–31.CrossRefGoogle Scholar
  25. Dupré, J., & O’Malley, M. A. (2009). Varieties of living things: Life at the intersection of lineage and metabolism. Philosophy and Theory in Biology, 1, e003.CrossRefGoogle Scholar
  26. Eigen, M. (1993). Viral quasispecies. Scientific American, 269, 42–49.PubMedCrossRefGoogle Scholar
  27. Eldredge, N., & Cracraft, J. (1980). Phylogenetic analysis and the evolutionary process. New York: Columbia University Press.Google Scholar
  28. Ereshefsky, M. (2001). The poverty of the linnaean hierarchy: A philosophical study of biological taxonomy. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  29. Flot, J., Hespeels, B., Li, X., Noel, B., Arkhipova, I., Danchin, E., et al. (2013). Genomic evidence for ameiotic evolution in the bdelloid rotifer Adineta vaga. Nature, 500, 453–457.PubMedCrossRefGoogle Scholar
  30. Floyd, R., Abebe, E., Papert, A., & Blaxter, M. (2002). Molecular barcodes for soil nematode identification. Molecular Ecology, 11, 839–850.PubMedCrossRefGoogle Scholar
  31. Fontaneto, D., Herniou, E. A., Boschetti, C., Caprioli, M., Melone, G., Ricci, C., & Barraclough, T. G. (2007). Independently evolving species in asexual bdelloid rotifers. PLoS Biology, 5, e87.PubMedPubMedCentralCrossRefGoogle Scholar
  32. Foster, J. A., Bunge, J., Gilbert, J. A., & Moore, J. H. (2012). Measuring the microbiome: Perspectives on advances in DNA-based techniques for exploring microbial life. Briefings in Bioinformatics, 13(4), 420–429.PubMedPubMedCentralCrossRefGoogle Scholar
  33. Frank, U. (2007). The evolution of a malignant dog. Evolutionary development, 9, 521–522.CrossRefGoogle Scholar
  34. Funkhouser, L. J., & Bordenstein, S. R. (2013). Mom knows best: The universality of maternal microbial transmission. PLoS Biology, 11, e1001631.PubMedPubMedCentralCrossRefGoogle Scholar
  35. Galimberti, A., Spada, M., Russo, D., Mucedda, M., Agnelli, P., Crottini, A., et al. (2012). Integrated operational taxonomic units (IOTUs) in echolocating bats: A bridge between molecular and traditional taxonomy. PLoS ONE, 7(6), e40122.PubMedPubMedCentralCrossRefGoogle Scholar
  36. Ghiselin, M. T. (1974). The economy of nature and the evolution of sex. Berkeley: University of California Press.Google Scholar
  37. Gilbert, W. (1986). The RNA world. Nature, 319, 618.CrossRefGoogle Scholar
  38. Gould, S. J. (1985). The flamingo’s smile. Reflections in natural history. New York, London: WW Northon & Company.Google Scholar
  39. Gould, S. J. (2002). The structure of evolutionary theory. Cambridge: Harvard University Press.Google Scholar
  40. Guarner, F., & Malagelada, J.R. (2003). Gut flora in health and disease. Lancet, 361, 512–519.PubMedCrossRefGoogle Scholar
  41. Harlan, J. R., & De Wet, J. M. J. (1963). The compilospecies concept. Evolution, 17, 497–501.CrossRefGoogle Scholar
  42. Harper, J. L. (1977). Population biology of plants. London: Academic Press.Google Scholar
  43. Hedlund, B. P., & Staley, J. T. (2002). Phylogeny of the genus Simonsiella and other members of the Neisseriaceae. International Journal of Systematic and Evolutionary, 52, 1377–1382.Google Scholar
  44. Henderson, B. (2005). Moonlight in protein hyperspace: shared moonlighting proteins and bacteria-host cross talk. In M. J. McFall-Ngai, B. Henderson, & E. D. Ruby (Eds.), The influence of cooperative bacteria on animal host biology (pp. 347–374). New York: Cambridge University Press.Google Scholar
  45. Hendry, A. P., Vamosi, S. M., Latham, S. J., Heilbuth, J. C., & Day, T. (2000). Questioning species realities. Conservation Genetics, 1(1), 67–76.CrossRefGoogle Scholar
  46. Hennig, W. (1950). Grundzeuge einer Theorie der Phylogenetischen Systematik. Berlin: Aufbau Verlag.Google Scholar
  47. Hennig, W. (1966). Phylogenetic systematics (trans: D. D. Dwight, & R. Zangerl). Urbana: University of Illinois Press.Google Scholar
  48. Hey, J. (2001). The mind of the species problem. Trends in Ecology & Evolution, 16, 326–329.CrossRefGoogle Scholar
  49. Huxley, T. H. (1851). Upon animal individuality. Proceeding in Royal Institute, 1, 184–189.Google Scholar
  50. Huxley, T. H. (1870). Biogenesis and abiogenesis. Collected Essays, 8, 229–271.Google Scholar
  51. Huxley, J. (1932). The individual in the animal kingdom. Cambridge: Cambridge University Press.Google Scholar
  52. Kaas, R. S., Friis, C., Ussery, D. W., & Aarestrup, F. M. (2012). Estimating variation within the genes and inferring the phylogeny of 186 sequenced diverse Escherichia coli genomes. BMC Genomics, 13, 577.PubMedPubMedCentralCrossRefGoogle Scholar
  53. Kitcher, P. (1984). Species. Philosophy of Science, 51, 308–333.CrossRefGoogle Scholar
  54. Kornet, D. (1993). Internodal species concept. Journal of Theoretical Biology, 104, 407–435.CrossRefGoogle Scholar
  55. La Scola, B., Audic, S., Robert, C., Jungang, L., de Lamballerie, X., Drancourt, M., et al. (2003). A giant virus in amoebae. Science, 299, 2033.PubMedCrossRefGoogle Scholar
  56. Lederberg, J., & McCray, A. T. (2001). Ome Sweet ‘Omics—A genealogical treasury of words. Scientist, 15, 8.Google Scholar
  57. Li, Y., Hui, H., Burgess, C. J., Price, R. W., Sharp, P. M., Hahn, B. H., & Shaw, G. M. (1992). Complete nucleotide sequence, genome organization, and biological properties of human immunodeficiency virus type 1 in vivo: Evidence for limited defectiveness and complementation. Journal of Virology, 66, 6587–6600.PubMedPubMedCentralGoogle Scholar
  58. Linnaeus, C. (1758). Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis 1 (10th ed., pp. 1–824). Stockholm: Laurentius Salvius.Google Scholar
  59. Mallet, J. (1995). A species definition for the modern synthesis. Trends in Ecology & Evolution, 10, 294–299.CrossRefGoogle Scholar
  60. Mallet, J. (2006). Species concepts. In C. W. Fox & J. B. Wolf (Eds.), Evolutionary genetics: Concepts and case studies (pp. 367–373). Oxford: Oxford University Press.Google Scholar
  61. Margulis, L. (1993). Symbiosis in cell evolution: Microbial communities in the Archean and Proterozoic Eons. New York, USA: W.H. Freeman.Google Scholar
  62. Matschie, P. (1900). Über geographische Albarten des Afrikanischen elephantens. Sitzungsberichte Gesellschaft naturforschunde Freunde Berlin, 8, 189–197.Google Scholar
  63. May, R. (2010). Tropical arthropod species, more or less? Science, 329, 41–42.PubMedCrossRefGoogle Scholar
  64. Mayden, R. L. (1997). A hierarchy of species concepts: The denoument in the saga of the species problem. In M. F. Claridge, H. A. Dawah, & M. R. Wilson (Eds.), Species: The units of biodiversity (pp. 381–423). London: Chapman and Hall.Google Scholar
  65. Mayr, E. (1940). Speciation phenomena in birds. American Naturalist, 74, 249–278.CrossRefGoogle Scholar
  66. Mayr, E. (1957). Species concepts and definitions. In E. Mayr (Ed.), The species problem (pp. 371–388). Washington, DC: AAAS.Google Scholar
  67. Mayr, E. (1963). Animal species and evolution. Cambridge, MA: The Belknap Press of Harvard University Press.CrossRefGoogle Scholar
  68. Mayr, E. (1969). Principles of systematic zoology. New York: McGraw-Hill.Google Scholar
  69. Mayr, E. (1970). Populations, species, and evolution: An abridgment of animal species and evolution. Cambridge, MA: Belknap Press of Harvard University Press.Google Scholar
  70. Mayr, E. (1998). Two empires or three? Proceedings of the National Academy of Sciences, USA, 95, 9720–9723.CrossRefGoogle Scholar
  71. McCutcheon, J. P., McDonald, B. R., & Moran, N. A. (2009). Origin of an alternative genetic code in the extremely small and GC–rich genome of a bacterial symbiont. PLoS Genetics, 5, e1000565.PubMedPubMedCentralCrossRefGoogle Scholar
  72. McFall-Ngai, M. (2008). Are biologists in ‘future shock’? Symbiosis integrates biology across domains. Nature Reviews Microbiology, 6, 789–792.PubMedCrossRefGoogle Scholar
  73. Minelli, A. (1993). Biological systematics: The state of the art. New York: Chapman & Hall.Google Scholar
  74. Minelli, A. (2009). Perspectives in animal phylogeny and evolution. Oxford: Oxford University Press.Google Scholar
  75. Minelli, A., & Fusco, G. (2012). Classification. In eLS (online Encyclopedia of Life Sciences). Chichester: Wiley & Sons.Google Scholar
  76. Mishler, B. D. (1999). Getting rid of species (p. 307). Species: New interdisciplinary essays.Google Scholar
  77. Mishler, B. D., & Theriot, E. (2000). The phylogenetic species concept sensu Mishler and Theriot: Monophyly, apomorphy, and phylogenetic species concepts. In Q. D. Wheeler & R. Meier (Eds.), Species concepts and phylogenetic theory: A debate (pp. 44–54). New York: Columbia University Press.Google Scholar
  78. Mora, C., Tittensor, D. P., Adl, S., Simpson, A. G. B., & Worm, B. (2011). How many species are there on earth and in the ocean? PLoS Biology, 9, e1001127.PubMedPubMedCentralCrossRefGoogle Scholar
  79. Moreira, D., & López-García, P. (2009). Ten reasons to exclude viruses from the tree of life. Nature Reviews Microbiology, 7, 306–311.PubMedGoogle Scholar
  80. Moya, A., Peretó, J., Gil, R., & Latorre, A. (2008). Learning how to live together: Genomic insights into prokaryote–animal symbioses. Nature Reviews Genetics, 9, 218–229.PubMedCrossRefGoogle Scholar
  81. Murgia, C., Pritchard, J. K., Kim, S. Y., Fassati, A., & Weiss, R. A. (2006). Clonal origin and evolution of a transmissible cancer. Cell, 126, 477–487.PubMedPubMedCentralCrossRefGoogle Scholar
  82. Naciri, Y., & Linder, P. (2015). Species delimitation and relationships: The dance of the seven veils. Taxon, 64, 3–16.CrossRefGoogle Scholar
  83. Nelson, G. J., & Platnick, N. I. (1981). Systematics and biogeography: Cladistics and vicariance. New York: Columbia University Press.Google Scholar
  84. Nimis, P. L. (2001). A tale from Bioutopia. Nature, 413, 21.PubMedCrossRefGoogle Scholar
  85. O’Hara, A. M., & Shanahan, F. (2006). The gut flora as a forgotten organ. EMBO Reports, 7, 688–693.PubMedPubMedCentralCrossRefGoogle Scholar
  86. Orgel, L. E. (1968). Evolution of the genetic apparatus. Journal of Molecular Biology, 38, 381–393.PubMedCrossRefGoogle Scholar
  87. Parsons, I., Lee, M. R., & Smith, J. V. (1998). Biochemical evolution II: Origin of life in tubular microstructures in weathered feldspar surfaces. Proceedings of the National Academy of Science, USA, 95, 15173–15176.CrossRefGoogle Scholar
  88. Paterson, H. E. H. (1978). More evidence against speciation by reinforcement. South African Journal of Science, 74(10), 369–371.Google Scholar
  89. Paterson, H. E. H. (1981). The continuing search for the unknown and unknowable: A critique of contemporary ideas on speciation. South African Journal of Science, 77, 113–119.Google Scholar
  90. Paterson, H. E. H. (1985). The recognition concept of species. In E. Vrba (Ed.), Species and speciation (pp. 21–29). Transvaal Museum: Pretoria.Google Scholar
  91. Philippe, N., Legendre, M., Doutre, G., Couté, Y., Poirot, O., Lescot, M., et al. (2013). Pandoraviruses: Amoeba viruses with genomes up to 2.5 Mb reaching that of parasitic eukaryotes. Science, 341, 281–286.PubMedCrossRefGoogle Scholar
  92. Pleijel, F. (1999). Phylogenetic taxonomy, a farewell to species, and a revision of Heteropodarke (Hesionidae, Polychaeta, Annelida). Systematic Biology, 48(4), 755–789.CrossRefGoogle Scholar
  93. Pleijel, F., & Rouse, G. W. (2000). Least-inclusive taxonomic unit: A new taxonomic concept for biology. In Proceedings of the Royal Society of London—Series B: Biological Sciences, 267(1443), 627–630.PubMedPubMedCentralCrossRefGoogle Scholar
  94. Poulton, E. B. (1904). What is a species? In Proceedings of the entomological society of London 1903, lxxvii–cxvi.Google Scholar
  95. Prusiner, S. B. (1982). Novel proteinaceous infectious particles cause scrapie. Science, 216, 136–144.PubMedCrossRefGoogle Scholar
  96. Rajilić-Stojanović, M., Smite, H., & De Vos, W. M. (2007). Diversity of the human gastrointestinal tract microbiota revisited. Environmental Microbiology, 9, 2125–2136.PubMedCrossRefGoogle Scholar
  97. Raper, K. B. (1935). Dictyostelium discoideum, a new species of slime mold from decaying forest leaves. Journal of agricultural research, 50, 135–147.Google Scholar
  98. Ridley, M. (1989). The cladistic solution to the species problem. Biology and Philosophy, 4, 1–16.CrossRefGoogle Scholar
  99. Rinke, C., Schwientek, P., Sczyrba, A., Ivanova, N. N., Anderson, I. J., Cheng, J. F., et al. (2013). Insights into the phylogeny and coding potential of microbial dark matter. Nature, 499(7459), 431–437.PubMedCrossRefGoogle Scholar
  100. Roca, A. L., Georgiadis, N., Pecon-Slattery, J., & O’Brien, S. J. (2001). Genetic evidence for two species of elephant in Africa. Science, 293, 1473–1477.PubMedCrossRefGoogle Scholar
  101. Rosen, D. E. (1979). Fishes from the uplands and intermontane basins of Guatemala: Revisionary studies and comparative biogeography. Bulletin of the American Museum of Natural History, 162, 267–376.Google Scholar
  102. Rybicki, E. P. (1990). The classification of organisms at the edge of life, or problems with virus systematics. South African Journal of Science, 86, 182–186.Google Scholar
  103. Ryder, O. A. (1986). Species conservation and systematics: The dilemma of subspecies. Trends in Ecology & Evolution, 1, 9–10.CrossRefGoogle Scholar
  104. Santelices, B. (1999). How many kinds of individual are there? Trends in Ecology & Evolution, 14, 152–155.CrossRefGoogle Scholar
  105. Sapp, J. (2004). The dynamics of symbiosis: An historical overview. Canadian Journal of Botany, 82, 1046–1056.CrossRefGoogle Scholar
  106. Sapp, J. (2010). Saltational symbiosis. Theory in Biosciences, 129, 125–133.PubMedCrossRefGoogle Scholar
  107. She, X., Jiang, Z., Liu, G., Cheng, Z., Tuzun, D., Church, D. M., et al. (2004). Shotgun sequence assembly and recent segmental duplication within the human genome. Nature, 431, 927–930.PubMedCrossRefGoogle Scholar
  108. Simpson, G. G. (1943). Criteria for genera, species and subspecies in zoology and paleontology. Annals New York Academy of Science, 44, 145–178.CrossRefGoogle Scholar
  109. Simpson, G. G. (1961). Principles of animal taxonomy. New York: Columbia University Press.Google Scholar
  110. Sokal, R. R., & Crovello, T. J. (1970). The biological species concept: A critical evaluation. American Naturalist, 104, 127–153.CrossRefGoogle Scholar
  111. Sokal, R. R., & Sneath, P. H. A. (1963). Principles of numerical taxonomy. A series of books in biology. San Francisco: W. H. Freeman.Google Scholar
  112. Staley, J. T. (2006). The bacterial species dilemma and the genomic–phylogenetic species concept. Philosophical Transactions of the Royal Society B: Biological, 361, 1899–1909.CrossRefGoogle Scholar
  113. Staley, J. T. (2009). Universal species concept: Pipe dream or a step toward unifying biology? Biotechnology Journal of Industrial Microbiology, 36, 1331–1336.CrossRefGoogle Scholar
  114. Steenstrup, J. J. S. (1842). Über den generationswechsel, oder die fortpflanzung und entwickelung durch abwechselende generationen. Copenhagen: Reitzel.Google Scholar
  115. Sterelny, K. (1999). Species as evolutionary mosaics. In R. A. Wilson (Ed.), Species, new interdisciplinary essays (pp. 119–138). Cambridge, MA: Bradford/MIT Press.Google Scholar
  116. Strand, M. R., & Grbic, M. (1997). The development and evolution of polyembryonic insects. Current Topics in Developmental Biology, 35, 121–159.PubMedCrossRefGoogle Scholar
  117. Stuessy, T. F. (1990). Plant taxonomy. New York: Columbia University Press.Google Scholar
  118. Templeton, A. R. (1989). The meaning of species and speciation: A genetic perspective. In D. Otte & J. A. Endler (Eds.), Speciation and its consequences (pp. 3–27). Sunderland, MA: Sinauer.Google Scholar
  119. Turesson, G. (1922). The species and variety as ecological units. Hereditas, 3, 10–113.Google Scholar
  120. Umen, J. G. (2015). Lost and found: The secret sex lives of bdelloid rotifers. Genetics, 200(2), 409–412.PubMedPubMedCentralCrossRefGoogle Scholar
  121. Van der Giezen, M. (2009). Hydrogenosomes and mitosomes: Conservation and evolution of functions. The Journal of Eukaryotic Microbiology, 56, 221–231.PubMedCrossRefGoogle Scholar
  122. Van Valen, L. (1976). Ecological species, multispecies, and oaks. Taxon, 25, 233–239.CrossRefGoogle Scholar
  123. von Goethe, J. W. (1807, but written in 1795). Zur morphologie. Werke, p. 7.Google Scholar
  124. Wagner, W. H. (1983). Reticulistics: The recognition of hybrids and their role in cladistics and classification. In N. I. Platnick & V. A. Funk (Eds.), Advances in cladistics (pp. 63–79). New York: Columbia University Press.Google Scholar
  125. Waples, R. S. (1991). Pacific salmon, Oncorhynchus spp., and the definition of ‘species’ under the Endangered Species Act. Marine Fisheries Review, 53, 11–22.Google Scholar
  126. Weismann, A. (1904). The evolution theory. London: Edward Arnold.CrossRefGoogle Scholar
  127. Wheeler, Q. D., & Platnick, N. I. (2000). The phylogenetic species concept sensu Wheeler and Platnick. In Q. D. Wheeler & R. Meier (Eds.), Species concepts and phylogenetic theory: A debate (pp. 55–69). New York: Columbia University Press.Google Scholar
  128. Wheeler, Q. D., Quentin, D., & Meier, R. (Eds.). (2000). Species concepts and phylogenetic theory: A debate. New York: Columbia University Press.Google Scholar
  129. Wiley, E. O. (1981). Remarks on Willis’ species concept. Systematic Zoology, 30, 86–87.CrossRefGoogle Scholar
  130. Wilkins, J. S. (2011). Philosophically speaking, how many species concepts are there? Zootaxa, 2765, 58–60.Google Scholar
  131. Wilkins, J. S., & Ebach, M. C. (2013). The nature of classification: Relationships and kinds in the natural sciences. Basingstoke: Palgrave Macmillan.CrossRefGoogle Scholar
  132. Williams, T. A., Foster, P. G., Cox, C. J., & Embley, T. M. (2013). An archaeal origin of eukaryotes supports only two primary domains of life. Nature, 504(7479), 231–236.PubMedCrossRefGoogle Scholar
  133. Willmann, R., & Meier, R. (2000). A critique from the Hennigian species perspective. In Q. D. Wheeler & R. Meier (Eds.), Species concepts and phylogenetic theory: A debate (pp. 101–118). New York: Columbia University Press.Google Scholar
  134. Wilson, D. S. (1971). The insect societies. Cambridge: Harvard University Press.Google Scholar
  135. Wilson, D. S., & Sober, E. (1989). Reviving the superorganism. Journal of Theoretical Biology, 136, 337–356.PubMedCrossRefGoogle Scholar
  136. Woese, C. (1967). The genetic code. New York: Harper and Row.Google Scholar
  137. Wu, D., Wu, M., Halpern, A., Rusch, D., Yooseph, S., Frazier, M., et al. (2011). Stalking the fourth domain in metagenomic data: Searching for and possible discovery of novel deep branches in phylogenetic trees. PLoS ONE, 6(3), e18011.PubMedPubMedCentralCrossRefGoogle Scholar
  138. Zilber-Rosenberg, I., & Rosenberg, E. (2008). Role of microorganisms in the evolution of animals and plants: The hologenome theory of evolution. FEMS Microbiology Reviews, 32, 723–735.PubMedCrossRefGoogle Scholar

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© Springer Science+Business Media New York 2016

Authors and Affiliations

  • M. Casiraghi
    • 1
    Email author
  • A. Galimberti
    • 1
  • A. Sandionigi
    • 1
  • A. Bruno
    • 1
  • M. Labra
    • 1
  1. 1.ZooPlantLab, Department Biotechnology and BiosciencesUniversity of Milan-BicoccaMilanItaly

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