Giraffe Genes Offer New Insight Into Distribution
Giraffes, popular sightings on an African safari, are not popular when it comes to scientific study. These long-necked giants are poorly understood compared to the continent's other wild animals, but new research of giraffe genes are offering new insight into their distribution.
The findings were published in the journal BMC Evolutionary Biology.
For instance, South African Giraffes (Giraffa camelopardalis giraffa) - one of nine recognized subspecies - are found farther north than previously assumed. They were believed to reside in southern Botswana and South Africa alone.
"However, according to our studies, the distribution areas prove to be much more complex. South African Giraffes also occur in northeastern Namibia and northern Botswana," study author Friederike Bock from the Biodiversity and Climate Research Center (BiK-F) said in a statement.
Likewise, another giraffe subspecies, the Angola Giraffe (Giraffa c. angolensis), occur not just in Namibia and northern Botswana, but in in northwestern Namibia and southern Botswana as well. Though the slight variation in their distribution across Africa may seem inconsequential, it tells scientists that these two subspecies actually live side by side.
According to the research team, the fact that two genetically distinct subspecies could develop within the same region may be the result of geographical conditions some 500,000 to two million years ago. During that time, the mountain range along the East African Rift Valley was sinking, creating vast wetlands and lakes which giraffes were unable to cross.
"These large bodies of water may have separated the populations for long periods of time," added BiK-F researcher Dr. Axel Janke.
Female giraffes specifically could not navigate across long distances, which contributed to the separation of maternal lines within the species.
These fascinating animals, which roam the open grasslands of the African savannah, are often confused with one another. Though no two individuals have the same spotted coat, according to National Geographic, giraffes from the same area appear remarkably similar.
So for the study, researchers created a profile of the subspecies' mitochondrial DNA, using tissue samples from about 160 giraffes from various populations.
"Our focus was on giraffes in southern Africa, in particular in Botswana and South Africa. There, we sampled populations that had not been genetically analyzed before," Bock explained.
This way, Bock and his colleagues can identify genetically each unique subspecies and the relationships between various populations.
Not only do these findings give scientists a more comprehensive understanding of giraffes in general, but the new insights also can lead to protection measures for the imperiled species. According to estimates by the World Conservation Organization IUCN, the world's giraffe population is about 100,000 individuals, and decreasing. The population has dwindled by more than half in recent years.
By learning more about their distribution, conservationists can learn how to better protect one of Africa's iconic species.