Multi-locus Analyses Reveal Four Giraffe Species Instead of One
Julian Fennessy, Tobias Bidon, Friederike Reuss, Vikas Kumar, Paul Elkan, Maria A. Nilsson, Melita Vamberger, Uwe Fritz, Axel Janke 6,
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Publication stage: In Press Corrected Proof
Publication History
Published: September 8, 2016 Accepted: July 14, 2016 Received in revised form: June 14, 2016
Received: May 6, 2016
Highlights
• Four genetically distinct giraffe clusters suggest separation into four species
• This is the first study using nuclear sequences and analyzing the Nubian giraffe
• Rothschild’s giraffe should be subsumed into the nominate Nubian giraffe
• A giraffe survey genome produces valuable markers for phylogenomic analyses
Summary
Traditionally, one giraffe species and up to eleven subspecies have been recognized [ 1 ]; however, nine subspecies are commonly accepted [ 2 ]. Even after a century of research, the distinctness of each giraffe subspecies remains unclear, and the genetic variation across their distribution range has been incompletely explored. Recent genetic studies on mtDNA have shown reciprocal monophyly of the matrilines among seven of the nine assumed subspecies [ 3, 4 ]. Moreover, until now, genetic analyses have not been applied to biparentally inherited sequence data and did not include data from all nine giraffe subspecies. We sampled natural giraffe populations from across their range in Africa, and for the first time individuals from the nominate subspecies, the Nubian giraffe, Giraffa camelopardalis camelopardalis Linnaeus 1758 [ 5 ], were included in a genetic analysis. Coalescence-based multi-locus and population genetic analyses identify at least four separate and monophyletic clades, which should be recognized as four distinct giraffe species under the genetic isolation criterion. Analyses of 190 individuals from maternal and biparental markers support these findings and further suggest subsuming Rothschild’s giraffe into the Nubian giraffe, as well as Thornicroft’s giraffe into the Masai giraffe [ 6 ]. A giraffe survey genome produced valuable data from microsatellites, mobile genetic elements, and accurate divergence time estimates. Our findings provide the most inclusive analysis of giraffe relationships to date and show that their genetic complexity has been underestimated, highlighting the need for greater conservation efforts for the world’s tallest mammal.
Received: May 6, 2016; Received in revised form: June 14, 2016; Accepted: July 14, 2016; Published: September 8, 2016
© 2016 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
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