Environmental factors help limit gene flow between different giraffe species

Oct 23, 2013
Giraffe
Giraffe in its natural environment. Photographed by Miroslav Duchacek (from Czech Republic) in Africa. Credit: Wikipedia.org

Giraffe species may only breed with each other based on the timing of rainfall in their local environments, according to new research published October 23 in the open-access journal PLOS ONE, by Henri Thomassen and colleagues at UCLA.

Three types of species in East Africa are genetically distinct and rarely intermingle, even though they live in close proximity to each other. Given that these different giraffe species are capable of long-distance travel, and are known to breed together in zoos, it remains a mystery how they maintain such genetic diversity in the wild and why they choose to stay only within their species range.

To answer these questions, the authors here used a suite of powerful analytical methods and climate data to analyze the specific environments of genotyped giraffes. They tested four hypotheses that might explain the maintenance of these three distinct giraffe species: isolation-by-distance, physical barriers to dispersal, general habitat differences resulting in habitat segregation, or regional differences in the of rainfall.

They found that regional differences in the timing of precipitation, and the resulting increase in local vegetation and plants ("greening"), could best explain the source of . Each species seems to be tied to their local seasonal cycle of greening, which is markedly different among species, suggesting that annual climate cycles may help maintain genetic and phenotypic divergence in giraffes.

Explore further: Adaptability to local climate helps invasive species thrive

More information: Thomassen HA, Freedman AH, Brown DM, Buermann W, Jacobs DK (2013) Regional Differences in Seasonal Timing of Rainfall Discriminate between Genetically Distinct East African Giraffe Taxa. PLoS ONE 8(10): e77191. DOI: 10.1371/journal.pone.0077191

add to favorites email to friend print save as pdf

Related Stories

World's first mapping of America's rare plants

Oct 17, 2013

The results of a major international research project show that climate stability plays a crucial role in the distribution of plants on Earth. Rare species in the Americas are restricted to areas of California, ...

Salamanders spell out evolution in action

Jul 06, 2011

Lungless salamanders (Ensatina eschscholtzii) live in a horseshoe-shape region in California (a 'ring') which circles around the central valley. The species is an example of evolution in action because, while neighboring popula ...

Recommended for you

Orchid named after UC Riverside researcher

12 hours ago

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

15 hours ago

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

15 hours ago

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Macrocompassion
not rated yet Oct 26, 2013
Gee! One can only have hi-balls in season.

More news stories

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...