Abstract: The Tropical Conservativism Hypothesis and Biogeographical Conservativism Hypothesis were tested in Southern African millipedes. Latitudinal diversity gradient (LDG) was measured in the Centrobolinae Hoffman, 1980, Chilognatha Latreille, 1802, Colobognatha Brandt, 1834, Dalodesmidea Hoffman, 1980, Diplopoda Gervais, 1844, Eugnatha Attems, 1898, Harpagophoridae Attems, 1909, Harpagophoridae nomum nudem, Helminthomorpha Pocock, 1887, Juliformia Attems, 1926, Julomorphidae Verhoeff, 1924, Merocheta Cook, 1895, Oniscomorpha Pocock, 1887, Polydesmida Leach, 1815, Polyzoniida Gervais, 1844, Sphaerotheriida Brandt, 1833, Sphaerotheriinae Brandt, 1833, Spinitarsus Attems, 1909a, Spirobolida Bollman, Spiroboloidea Sylvestri, 1896, Spirostreptida Brandt, 1833 and Trigoniulidea Brölemann, 1913 to distinguish between the two hypotheses. There was a significant correlation between the number of species and latitudinal degrees away from the equator in Centrobolinae (r=-0.91, r2=0.83, n=35, p<0.01), Chilognatha (r=-0.87, Z score=-3.25, n=9, p<0.01), Colobognatha (r=-0.86, Z score=-2.92, n=8, p<0.01), Dalodesmidae (r=-0.78, Z score=-2.11, n=121, p=0.02), Diplopoda (r=-0.87, Z score=-3.24, n=9, p<0.01), Eugnatha (r=-0.85, Z score=-3.10, n=9, p<0.01), Harpagophoridae (r=-0.86, Z score=-2.90, n=8, p<0.01) (r=-0.68, Z score=-1.85, n=8, p=0.03), Helminthomorpha (r=-0.85, Z score=-3.09, n=9, p<0.01), Juliformia (r=-0.94, Z score=-3.99, n=8, p<0.01), Julomorphidae (r=-0.89, Z score=-2.02, n=8, p=0.02), Merocheta (r=-0.83, Z score=-2.68, n=8, p<0.01), Oniscomorpha (r=-0.86, r2=0.75, n=47, p<0.01), Polydesmida (r=-0.83, Z score=-2.68, n=8, p<0.01), Polyzoniida (r=-0.87, Z score=-2.97, n=8, p<0.01), Sphaerothriida (r=-0.86, r2=0.75, n=47, p<0.01), Sphaerotheriinae (r=-0.87, r2=0.76, n=46, p<0.01), Sphaerotheriini (r=-0.87, r2=0.76, n=46, p<0.01), Spinotarsus (r=-0.61, Z score=-1.41, n=8, p=0.08), Spirobolida (r=-0.82, r2=0.68, n=38, p<0.01), Spiroboloidea (r=-0.82, r2=0.68, n=38, p<0.01), and Spirostrepstida (r=-0.93, Z score=-3.78, n=8, p<0.01). An evolutionary preference for temperate environments appearing to have led to climatic constraints on dispersal based on precipitation seasonality gradients and predation was questioned.
Keywords: diversity, gradient, latitude, richness, species.
Title: The inverse latitudinal gradients in species richness of Southern African millipedes
Author: Mark I. Cooper
International Journal of Recent Research in Thesis and Dissertation (IJRRTD)
Vol. 3, Issue 1, January 2022 - June 2022
Page No: 91-112
Paper Publications
Website: www.paperpublications.org
Published Date: 04-June-2022