Posted on 12/22/2007 2:06:52 PM PST by blam
Not one but 'six giraffe species'
Anna-Marie Lever
Science and nature reporter, BBC News
Giraffe populations have dropped by 30% over the past decade
The world's tallest animal, the giraffe, may actually be several species, a study has found.
A report in BMC Biology uses genetic evidence to show that there may be at least six species of giraffe in Africa.
Currently giraffes are considered to represent a single species classified into multiple subspecies.
The study shows geographic variation in hair coat colour is evident across the giraffe's range in sub-Saharan Africa, suggesting reproductive isolation.
"Using molecular techniques we found that giraffes can be classified into six groups that are reproductively isolated and not interbreeding," David Brown, the lead author of the study and a geneticist at the University of California Los Angeles (UCLA), told BBC News.
"The results were a surprise because although the giraffes look different, if you put them in zoos, they breed freely."
Spots and maple leaves
The study also found that the two giraffe subspecies that live closest to each other - the reticulated giraffe (Currently: Giraffa camelopardalis reticulate) in North Kenya, which has reddish round spots; and the Maasai giraffe (Currently: Giraffa camelopardalis tippelskirchi) in South Kenya - separated 0.5 to 1.5 million years ago.
SOME GIRAFFE FACTS
* The familiar animals can grow up to 6m (20ft) in height
* Their remarkable tongues grow up to 45cm (18in) long
* Adult giraffes can weigh in excess of 1,000kg (2,200lbs)
* Long legs enable speeds of up to 35miles/hour (55km/h)
These results are interesting as giraffes are highly mobile animals. They frequently range over several hundred square kilometres and are capable of long distance movements of some 50-300km (30-170 miles), which means different populations are likely to meet.
Mr Brown added: "There are no rivers or forests to prevent breeding, but some evolutionary process is keeping the two groups reproductively separated."
The researchers have suggested this separation may be being driven by ecological differences, such as differences in vegetation at a micro-level, or even sexual selection.
"The female Maasai giraffe may be looking at the male reticulated giraffe and thinking, 'I don't look like you; I don't want to mate with you'," Mr Brown explained.
Need for conservation
Mr Brown also highlighted the conservation implications of this study: "Lumping all giraffes into one species obscures the reality that some kinds of giraffe are on the brink.
"Some of these populations number only a few hundred individuals and need immediate protection."
Over the past decade there has been a 30% drop in giraffe numbers, with total numbers under 100,000.
It is hoped that classifying current subspecies as fully fledged species will help inform conservation plans to save the most threatened populations. These include:
The Nigerian giraffe (Currently: Giraffa camelopardalis peralta). The last 160 individuals are found in found in West and Central Africa.
The Rothschild giraffe (Currently: Giraffa camelopardalis rothschildi). The last few hundred can only be found in a few protected areas in Kenya and in Murchison Falls National Park, Uganda. The animals' status is currently under review by an International Giraffe Working Group (IGWG). Its evidence will inform the IUCN Red List of threatened and endangered species.
The genetic research was supported by the US-based Wildlife Conservation Society.
http://www.scs.uiuc.edu/~mcdonald/WorldHaplogroupsMaps.pdf
Maps of the world showing the distribution of Y chromosome and the MTDNA haplogroups throughout the world.
Of note:
R1
The undifferentiated R1 lineage is quite rare. It is found only at very low frequencies in Europe, Central Asia, and South Asia. This lineage possibly originated in Europe and then migrated east into Asia.
>>> R1a
The R1a lineage is believed to have originated in the Eurasian Steppes north of the Black and Caspian Seas. This lineage is believed to have originated in a population of the Korgan culture, known for the domestication of the horse (approximately 3000 B.C.E.). These people were also believed to be the first speakers of the Indo-European language group. This lineage is currently found in central and western Asia, India, and in Slavic populations of Eastern Europe.
>>> R1b1
Haplogroup R1b1 is the most common haplogroup in European populations. It is believed to have expanded throughout Europe as humans re-colonized after the last glacial maximum 10-12 thousand years ago. This lineage is also the haplogroup containing the Atlantic modal haplotype.
http://htmlsd.com/haplogroups.htm
Thanks. I’ve already done my DNA. I’m yDNA R1b and mtDNA ‘V’ (which you don’t show in that chart). ‘V’ is mainly Saami, Laplanders.
R1b Genographic Migration Map
Gee...well, then all those species must be endangered, right...
DNA Ice Age Refuges 12,000 Years ago
Interesting!
I wonder what giraffe would taste like.
“Some of these populations number only a few hundred individuals and need immediate protection.” “
The sum and substance of this article’s agenda is that if giraffes can be divided by the infamous “trinomial (subspecies), then funding can be justified.
This is the old Lumpers v. Splitters argument. Those wanting to split species based on minor coat patterns are either grad students seeking a thesis or established scientists seeking Endangered Species Act funding.
The rest of us know what a giraffe knows - If it looks like one, it IS one.
“separated 0.5 to 1.5 million years ago.”
Dang, I had no idea a giraffe could get that old.
> > > > > > “separated 0.5 to 1.5 million years ago.”
> > > Dang, I had no idea a giraffe could get that old.
This ‘scientist’ is running neck and neck with the inventor of Piltdown Man for my awed respect...
Horses and donkeys can mate. Granted, their offspring are always sterile, but they do produce offspring.
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