Open AccessComplex phylogeographical patterns, introgression and cryptic species in a lineage of Malagasy dung beetles (Coleoptera: Scarabaeidae)
Author(s) -
WIRTA H.
Publication year - 2009
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/j.1095-8312.2008.01156.x
Subject(s) - biology , scarabaeidae , introgression , species complex , ecology , dung beetle , rainforest , population , phylogeography , genetic diversity , zoology , phylogenetics , phylogenetic tree , biochemistry , demography , sociology , gene
Many taxa, including dung beetles, exhibit small‐scale microendemism in Madagascar, which has contributed to the high level of species' diversity on the island. Species in the genus Nanos are numerically dominant in the dung beetle communities in rainforests in eastern Madagascar, but typically just one species occurs in any one locality. The two northern species, N. clypeatus and N. dubitatus , cannot be distinguished by either a mitochondrial or a nuclear genetic marker (cytochrome oxidase subunit I and internal transcription spacer 2). One population of the southern N. viettei is genetically highly divergent, although morphologically indistinguishable. Genetic data indicate that introgression occurred from N. dubitatus to N. viettei 1–2 Mya, and these species may continue to hybridize. Complex genetic patterns have mostly evolved within the last 2 Myr. During this time, the glacial cycles in the northern hemisphere were reflected in the oscillating climatic conditions in Africa, which repeatedly fragmented and re‐united the rainforests in eastern Madagascar, possibly leading to the observed complex phylogeographical patterns in Nanos . © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 942–955.