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].Agiraffe 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.
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