And Then There Were Four

Genetic analysis has recently demonstrated that there are four unique species of giraffes, not just one. In a study published in Current Biology and later highlighted in Nature News, The New York Times, and other news outlets, researchers used skin biopsies from 190 giraffes to look at nuclear and mitochondrial DNA. Analyzing these data, the researchers found that the samples could be grouped into four distinct categories based on patterns in the DNA. This supported classifying giraffes as four separate species. This is an important finding because previous research suggested that certain populations of giraffes rarely intermingled, but fell short of suggesting the existence of multiple species. The researchers’ use of a large sample size (skin biopsies from 190 giraffes) supports the validity of the researchers' claim and helps me trust their finding.

The difference between a species and a subspecies can be delineated in terms of the animals’ ability to successfully interbreed, where a subspecies is capable of interbreeding with another subspecies but a species is incapable of successfully interbreeding with another species. This definition occasionally breaks down and differentiating between species and subspecies is sometimes a topic of debate among taxonomists (Wikipedia). I think that using genetic analysis to determine separate species seems like a much better approach to filling in taxonomy charts. In addition to suggesting the existence of four separate species of giraffes, this study could help contribute to broadly defining what specific genetic differences constitute a new species.

The practical significance of differentiating between four unique species of giraffes lies mainly in their conservation. Separating them into species justifies protecting four different habitats and monitoring four separate population levels. The article pointed out that this will be important for two of the species whose current population levels are lower than 10,000. Understanding the differences between species can also help the caretakers of giraffes in zoos who manage their breeding.

Speaking of zoos, remember going to the zoo in elementary school and discovering that giraffes have blue tongues? I do! Blue tongues aside, one of the reasons this article interested me is that it seemed like this is something that we should have already known. DNA sequencing has been around for nearly twenty years, and it seems incongruent to live in a world quickly moving towards inhabiting Mars and not know the difference between several twenty-foot tall mammals wandering the savanna. In a way this finding reminds me of the discovery Barry Marshall made when he determined that ulcers are caused by a bacteria called H. pylori and not stress. Discoveries like Marshall’s and the existence of four different species of giraffes make me skeptical of what I have been taught and more excited to explore what else might be “hiding in plain sight.” For our society, discoveries like this support investing more in basic research to better understand the world around us.