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Quantifying extinction probabilities of endangered species for phylogenetic conservation prioritization may not be as sensitive as might be feared


In this study we are concerned with the general problem of choosing from a set of endangered species T a subset S of k species to protect as a priority. Here, the interest to protect the species of S is assessed by the resulting expected phylogenetic diversity (ePD) of the set T, a widely used criterion for measuring the expected amount of evolutionary history associated with T. We consider that the survival of the protected species is assured and, on the contrary, that there is a risk of extinction for the unprotected species. The problem is easy to solve by a greedy type method if the extinction probabilities of the unprotected species are known but these probabilities are generally not easy to quantify. We show in this note that the choice of the precise values attributed to the extinction probabilities—provided it respects the rank of imperilment of each species—is not as decisive as might be feared for the considered problem. The values of these probabilities have a clear impact on the selection of the species to be protected but a little impact on the resulting ePD. More precisely, if T 1 and T 2 are the two optimal subsets of species corresponding to two scenarios (two different sets of probabilities) the ePDs of T 1 and T 2, calculated with the probabilities of the first scenario—or with the probabilities of the second scenario—are not very different.

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  • Cardinale BJ, Duffy JE, Gonzalez A, Hooper DU, Perrings C, Venail P, Narwani A, Mace GM, Tilman D, Wardle DA, Kinzig AP, Daily GC, Loreau M, Grace JB, Larigauderie A, Srivastava DS, Naeem S (2012) Biodiversity loss and its impact on humanity. Nature 486:59–67

    CAS  Article  PubMed  Google Scholar 

  • Chao A, Chiu C-H, Jost L (2010) Phylogenetic diversity measures based on Hill numbers. Philos Trans R Soc B 365:3599–3609

    Article  Google Scholar 

  • Collen B (2015) Conservation prioritization in the context of uncertainty. Anim Conserv 18:315–317

    Article  Google Scholar 

  • Collen B, Pettorelli N, Baillie JEM, Durant SM (eds) (2013) Biodiversity monitoring and conservation: bridging the gap between global commitment and local action. Wiley-Blackwell, Hoboken

    Google Scholar 

  • Convention on Biological Diversity (2011) Strategic plan for biodiversity 2011–2020, including Aichi biodiversity targets.

  • Faith DP (1992a) Conservation evaluation and phylogenetic diversity. Biol Cons 61:1–10

    Article  Google Scholar 

  • Faith DP (1992b) Systematics and conservation: on predicting the feature diversity of subsets of taxa. Cladistics 8:361–373

    Article  Google Scholar 

  • Faith DP (2013) Biodiversity and evolutionary history: useful extensions of the PD phylogenetic diversity assessment framework. Ann N-Y Acad Sci 1289:69–89

    Article  PubMed  Google Scholar 

  • Faith DP (2015) Phylogenetic diversity, functional trait diversity and extinction: avoiding tipping points and worst-case losses. Philos Trans R Soc B 370:20140011

    Article  Google Scholar 

  • Faith DP (2016) The PD phylogenetic diversity framework: linking evolutionary history to feature diversity for biodiversity conservation. In: Pellens R, Grandcolas P (eds) Biodiversity conservation and phylogenetic systematics, topics in biodiversity and conservation 14. Springer, Cham

    Google Scholar 

  • Forest F, Crandall KA, Chase MW, Faith DP (2015) Phylogeny, extinction and conservation: embracing uncertainties in a time of urgency. Philos Trans R Soc B 370:20140002

    Article  Google Scholar 

  • Hartmann K, Steel M (2006) Maximizing phylogenetic diversity in biodiversity conservation: greedy solutions to the Noah’s Ark Problem. Syst Biol 55:644–651

    Article  PubMed  Google Scholar 

  • Hartmann K, Steel M (2007) Phylogenetic diversity: from combinatorics to ecology. In: Gascuel O, Steel M (eds) Reconstructing evolution: new mathematical and computational advances. Oxford University Press, Oxford

    Google Scholar 

  • Isaac NJB, Turvey ST, Collen B, Waterman C, Baillie JEM (2007) Mammals on the EDGE: conservation priorities based on threat and phylogeny. PLoS ONE 2(3):e296

    Article  PubMed  PubMed Central  Google Scholar 

  • IUCN (2012) IUCN Red List categories and criteria: version 3.1. Second edition. IUCN, Gland, Cambridge, iv + 32 pp

  • Jensen EL, Mooers AO, Caccone A, Russello MA (2016) I-HEDGE: determining the optimum complementary sets of taxa for conservation using evolutionary isolation. PeerJ 4:e2350

    Article  PubMed  PubMed Central  Google Scholar 

  • Mace GM, Collar NJ, Gaston KJ, Hilton-Taylor C, Akçakaya HR, Leader-Williams N, Milner-Gulland EJ, Stuart SN (2008) Quantification of extinction risk: IUCN’s system for classifying threatened species. Conserv Biol 22:1424–1442

    Article  PubMed  Google Scholar 

  • MacLaurin J, Sterelny K (2008) What is biodiversity?. The University of Chicago Press, Chicago, p 217

    Book  Google Scholar 

  • Mimouni E, Beisner BE, Pinel-Alloul B (2016) Phylogenetic diversity and its conservation in the presence of phylogenetic uncertainty: a case study of cladoceran communities in urban waterbodies. Biodivers Conserv 25:2113–2136

    Article  Google Scholar 

  • Mooers AO, Faith DP, Maddison WP (2008) Converting endangered species categories to probabilities of extinction for phylogenetic conservation prioritization. PLoS ONE 3:e3700

    Article  PubMed  PubMed Central  Google Scholar 

  • Moreno CE et al (2017) Measuring biodiversity in the Anthropocene: a simple guide to helpful methods. Biodivers Conserv 26(12):2993–2998

    Article  Google Scholar 

  • Nunes LA, Turvey ST, Rosindell J (2015) The price of conserving avian phylogenetic diversity: a global prioritization approach. Philos Trans R Soc B.

    Google Scholar 

  • Pardi F (2009) Algorithms on phylogenetic trees. PhD thesis, University of Cambridge

  • Pellens R, Grandcolas P (eds) (2016) Biodiversity conservation and phylogenetic systematics: preserving our evolutionary heritage in an extinction crisis. Springer International Publishing, Springer Open, Berlin, p 390

    Google Scholar 

  • Redding RW, Mooers AO (2006) Incorporating phylogenetic measures into conservation prioritization. Cons Biol 20:1670–1678

    Article  Google Scholar 

  • Steel M, Mimoto A, Mooers AO (2007) Hedging our bets: the expected contribution of species to future phylogenetic diversity. Evol Bioinform 3:237–244

    Article  Google Scholar 

  • Stork NE (2010) Re-assessing current extinction rates. Biodivers Conserv 19:357–371

    Article  Google Scholar 

  • Weitzman ML (1998) The Noah’s ark problem. Econometrica 66:1279–1298

    Article  Google Scholar 

  • Witting L, Loeschcke V (1995) The optimization of biodiversity conservation. Biol Conserv 71:205–207

    Article  Google Scholar 

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Correspondence to Alain Billionnet.

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Communicated by David Hawksworth.

This article belongs to the Topical Collection: Biodiversity protection and reserves.

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Billionnet, A. Quantifying extinction probabilities of endangered species for phylogenetic conservation prioritization may not be as sensitive as might be feared. Biodivers Conserv 27, 1189–1200 (2018).

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  • Biodiversity conservation
  • Phylogenetic diversity
  • Protected species
  • Extinction risk
  • Optimization
  • Greedy algorithm