http://www.eurekalert.org/pub_releases/2007-12/bc-mef121907.php
Public release date: 20-Dec-2007
Contact: Charlotte Webber
44-020-763-19980
BioMed Central
More evidence for new species hidden in plain sight
Two articles published today in the online open access journals BMC
Evolutionary Biology and BMC Biology provide further evidence that we
have hugely underestimated the number of species with which we share
our planet. Today sophisticated genetic techniques mean that
superficially identical animals previously classed as members of a
single species, including the frogs and giraffes in these studies,
could in fact come from several distinct ‘cryptic’ species.
In the Upper Amazon, Kathryn Elmer and Stephen Lougheed working at
Queen’s University, Kingston, Canada teamed up with José Dávila from
Instituto de Investigación en Recursos Cinegéticos, Cuidad Real, Spain
to investigate the terrestrial leaflitter frog (Eleutherodactylus
ockendeni) at 13 locations across Ecuador.
Looking at the frogs’ mitochondrial and nuclear DNA, the researchers
found three distinct species, which look very much alike. These species
have distinct geographic distributions, but these don't correspond to
modern landscape barriers. Coupled with phylogenetic analyses, this
suggests they diverged before the Ecuadorean Andes arose, in the
Miocene period over 5.3 million years ago.
"Our research coupled with other studies suggests that species richness
in the upper Amazon is drastically underestimated by current
inventories based on morphospecies," say the authors.
And in Africa, an interdisciplinary team from the University of
California, Los Angeles, Omaha’s Henry Doorly Zoo, and the Mpala
Research Centre in Kenya has found that there may be more to the
giraffe than meets the eye, too.
Their analysis of nuclear and mitochondrial DNA shows at least six
genealogically distinct lineages of giraffe in Africa, with little
evidence of interbreeding between them. Further divisions within these
groups mean that in total the researchers have spotted 11 genetically
distinct populations.
“Such extreme genetic subdivision within a large vertebrate with high
dispersal capabilities is unprecedented and exceeds that of any other
large African mammal,” says graduate student David Brown, first author
of the study. The researchers estimate that the giraffe populations
they surveyed have been genetically distinct for between 0.13 and 1.62
million years. The findings have serious implications for giraffe
conservation because some among these subgroups have as few as 100
members, making them highly endangered – if not yet officially
recognised – species.
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