An article published in the journal “Current Biology” describes a genetic research on giraffes and proposes the division of these animals into four distinct species with a number of subspecies. A team of researchers led by Professor Axel Janke, a geneticist at the Senckenberg Biodiversity and Climate Research Centre and Goethe University, Germany, examined the DNA of 190 giraffes across Africa and concluded that there are four highly distinct groups. The consequences of this research could also affect the giraffe conservation attempts.
Giraffes are among the African species whose population is declining, from more than 150,000 specimens of 30 years ago to less than 100,000 today. The Giraffe Conservation Foundation (GFC) is a nongovernmental organization that runs international programs to try to prevent their extinction, including the possibility to mix different subspecies transferring specimens in protected areas. However, before proceeding with initiatives of that kind it was necessary to understand their consequences, hence this genetic study.
Skin biopsies of 190 giraffes made throughout Africa by the research team in collaboration with the GFC provided DNA samples which include all nine subspecies of giraffes generally recognized until now. Actually the situation was already quite complex with discussions regarding the actual number of existing subspecies and the results of this study may bring more of them.
According to the researchers, the genetic analysis shows that there are four groups of giraffes with such genetic differences that they should considered different species despite their similar appearance. The new species proposed are:
- Southern giraffe (Giraffa Camelopardalis)
- Masai giraffe (G. tippelskirchi)
- reticulated giraffe (G. reticulata)
- northern giraffe (G. camaleopardalis), which includes the Nubian giraffe (G. c. Cameleopardalis) as one of its subspecies.
A research in the history of the various species of giraffe indicates that their last common ancestor lived between 400,000 and 2,000,000 years ago. The analysis was done on both cell nucleus DNA and on mitochondrial DNA, which is passed through the mother, with the same results on the distinctions among the various groups.
A division into species has important consequences on the management of giraffe conservation programs. Julian Fennessy of GFC explained that there are less than 4,750 specimens of northern giraffe and less than 8,700 of reticulated giraffe. If they are considered distinct species it will be possible to better define their status at the International Union for the Conservation of Nature (IUCN).
Right now, the giraffe is considered as a minimal risk species but a division into species could greatly change the status of at least two of them. It’s an important evaluation and for this reason the genetic research will continue. A few months ago another genetic research on giraffe was published which aimed in particular to understand this animal’s peculiarities, this time the purpose is to increase the chances of survival of the giraffe.
