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The biodiversity crisis: myth or reality? Philippe Bouchet National Museum of Natural History, Paris.

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Presentation on theme: "The biodiversity crisis: myth or reality? Philippe Bouchet National Museum of Natural History, Paris."— Presentation transcript:

1 The biodiversity crisis: myth or reality? Philippe Bouchet National Museum of Natural History, Paris

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3 « We are responsible for the largest mass extinction of species known in the history of the planet. » E.O. Wilson, The Future of Life

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5 « Each and every species is doomed to extinction. Ammonites and dinosaurs, for instance, did not need man to become extinct »

6 The magnitude of bidoversity: known, unknown Measuring extinctions Predictions and speculations

7 The magnitude of biodiversity: changing paradigm « Scientists have described 1.6 million species and there might be the same number still undescribed » « Scientists have described 1.8 million species but the real number may be around 10 to 100 million »

8 PROTOCTISTA Incl.: Actinopoda6000 Foraminifera Ciliophora8000 Sporozoa5000 Rhodophyta (red algae)5000 Gamophyta (green algae) Bacillariophyta (diatoms) PLANTS Incl.: Bryophyta Pteridophyta Spermatophyta FUNGI ANIMALS Incl.: Porifera Cnidaria Plathyelminthes Nematoda Arthropoda Incl.:Crustacea Arachnida Insecta Incl.:Coleoptera Diptera Hymenoptera Lepidoptera Mollusca Annelida Echinodermata6000 Chordata Incl.:Pisces Amphibia 5200 Reptilia 8163 Aves 9913 Mammalia 4629 Incl.:Chiroptera 925 Rodentia 2021 Number of described species

9 Contexte et enjeux – Un nouveau paradigme Main groups of organisms: described species From WCMC, Global biodiversity assessment. Chapman & Hall Procaryota 0.2 % Protozoa 2.4 % Coleoptera 23.8 % Algae 2.4 % Lepidoptera 8.9 % Hymenoptera 7.7 % Diptera 7.1 % Other insects 8.9 % Arachnida 4.5 % Crustacea 2.4 % Other arthropoda 1.2 % Other invertebrates 4.0 % Mollusca 4.2 % Nematoda 0.9 %Vertebrates 2.7 % Plants 14.3 % Fungi 4.2 %

10 Saola Pseudoryx nghetinhensis Wollemi pine Wollemia nobilis

11 Ethmia mariannae, Rhodes Island Cycloscala sardellae Lifou, South Pacific Gyrodactylus teuchis, France

12 Average yearly number of new species descriptions Vertebrates400 Insects7000 Other animals4000 Plants 2300 Other organisms2000 TOTAL: ca

13 World birds European Diptera

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15 Data : Coleoptera sampling on 19 trees 1143 spp Step 1 : Number of host-specific Coleoptera species 162 spp Step 2 : nb of Coleoptera species specific of 50,000 tree species spp Step 3 : Adding other canopy insect species spp Step 4 : Adding ground-dwelling insects spp Tropical insects diversity estimate (Erwin 1982)

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20 SANTO 2006 Expedition

21 Measuring extinctions: Counting Predicting

22 Red Lists :

23 Source : Liste Rouge 2004

24 Dodo Raphus cucullatus (1662) Sylviornis neocaledoniae (3500 BP) New Caledonian Lorikeet Charmosyna diadema (1913) Extinctions counted since 1600

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26 Species duration in the paleontological records Average species lifespan (million years) Mammals1 Silurian graptolites2 Echinodermata6 Planctonic foraminifera7 Cenozoic bivalves10

27 Species lifespan : 5-10 million years 5-10 million species 1-2 naturally-induced extinctions per year, i.e since 1600 Same order of magnitude as the counted number of extinctions (844 species)

28 But:Only 1.7 million described species naturally-induced extinctions per year, i.e since 1600 Higher hypothesis: 1-2 million years lifespan 1-2 naturally-induced extinctions per year, i.e since 1600 Lower hypothesis: 5-10 million years lifespan

29 But:Well-studied species: mammals and birds only (ca. 15,000 species, 1-2 million years lifespan) naturally-induced extinctions per year, i.e. 3-6 since mammals and birds species known as extinct since 1600 = times the « noise » of naturally-induced extinctions

30 Expert experts … Specialist group (Orthoptera) Specialist group (Cetaceans) Specialist group (China plants) Specialist group (Rotifera) 120 specialist groups … Species Survival Commission

31 Expert experts … Specialist group (Orthoptera) Specialist group (Cetaceans) Specialist group (China plants) Specialist group (Rotifera) 120 specialist groups … Species Survival Commission Expert

32 Anceyodonta gatavakensis Mangareva Peltiera nitida Madagascar Meligethes aeneus Italian Alps

33 Pseudoyersinia brevipennis : last seen in 1860 near Hyères (France)

34 Measuring extinctions: Counting Predicting

35 Prediction: species/area relationship

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37 Application of the insular biogeography theory to tropical forests With this parameters, a loss of 50% of tropical forests surface would induce the extinction of three million species : 1000 times the « natural » extinction rate.

38 Slope and origin may change: ? ? ? ?

39 Large range of uncertainty, but that does not change the results of this approach: the extinction rate is 1,000 to 10,000 times higher than the natural extinction rate « One third to half of the living species could have disappeared by 2050 » « One species is going extinct every 15 minutes » « species are vanishing every year » « 2-8% of the living species will become extinct between 1990 and 2015 »

40 Discoglossus pictus Hula valley

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42 Ramsar Convention on Wetlands - Ramsar site no. 868


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