How the Amhara breathe differently

By Razib Khan | January 22, 2012 12:23 pm

I have blogged about the genetics of altitude adaptation before. There seem to be three populations in the world which have been subject to very strong natural selection, resulting in physiological differences, in response to the human tendency toward hypoxia. Two of them are relatively well known, the Tibetans and the indigenous people of the Andes. But the highlanders of Ethiopia have been less well studied, nor have they received as much attention. But the capital of Ethiopia, Addis Ababa, is nearly 8,000 feet above sea level!

Another interesting aspect to this phenomenon is that it looks like the three populations respond to adaptive pressures differently. Their physiological response varies. And the more recent work in genomics implies that though there are similarities between the Asian and American populations, there are also differences. This illustrates the evolutionary principle of convergence, where different populations approach the same phenotypic optimum, though by somewhat different means. To my knowledge there has not been as much investigation of the African example. Until now. A new provisional paper in Genome Biology is out, Genetic adaptation to high altitude in the Ethiopian highlands:

We highlight several candidate genes for involvement in high-altitude adaptation in Ethiopia, including CBARA1, VAV3, ARNT2 and THRB. Although most of these genes have not been identified in previous studies of high-altitude Tibetan or Andean population samples, two of these genes (THRB and ARNT2) play a role in the HIF-1 pathway, a pathway implicated in previous work reported in Tibetan and Andean studies. These combined results suggest that adaptation to high altitude arose independently due to convergent evolution in high-altitude Amhara populations in Ethiopia.

The main shortcoming about this paper for me is that it does not highlight the evolutionary history of this adaptation. In the paper the authors compared the Amhara (a highland population) to nearby lowland populations. But did not explore the nature of the population structure and how it might have influenced the arc of adaptation. Are these very ancient adaptations? Or new ones? It seems that hominins have been resident in Ethiopian for millions of years. If this is so presumably there have been adaptations to higher elevations from time immemorial. But what if these adaptations are new?

More pointedly the Ethiopians can be modeled as a compound of an Arabian population with an indigenous East African one. If this is a genuine recent admixture event, then one might be able to ascertain via haplotype structure whether the adaptive variants derive from ancient African genetic variation, or whether they’re novel mutations. It seems that this paper is a good first step, but there’s a lot more to see here….

Citation: Genome Biology, doi:10.1186/gb-2012-13-1-r1

Image credit: Wikipedia

  • Lank

    Exciting stuff. Especially the new samples.

  • Chris Winter

    A typo (highlighted ;-):

    “In the paper the authors compared the Amhara (a highlight population) to nearby lowland populations.”

    S/B “highland”.

  • Chris Winter

    By the way: Is the woman pictured a typical Amhara?

  • Justin Giancola

    “Until know. ” I enjoy this phrase.

  • http://lablemminglounge.blogspot.com Lab Lemming

    Why is it that ethiopian/ Kenyan altitude-adapted people can use their adaptations to win long-distance running events, while andean/tibetans are not competative in these events?

  • Dwight E. Howell

    The key question is did any intruders have to pick up local genes in order to last or not. Since anatomically modern humans seem to have appeared in Ethiopia as early as anywhere the adaptions could be hundreds of thousands of years old.

    If the adaptions are fairly modern then the old adaptions could not have been all that vital.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    #6, yes.

  • http://blogs.discovermagazine.com James

    Chris, The woman pictured could be a typical Oromo or Tigrian or even Amhara but there is no doubt she is a typical Ethiopian cos Ethiopian highlands is not limited to Amhra region but rather extends all the way south to Bale mountains in Oromo region (that is where most elite Ethiopian athletes originate from) .

  • http://befeqe.blogspot.com BefeQadu

    Chris and James: the woman pictured is Tigrian (her name is Liya, I know her because she is a notable person); but the Tigrians are also in the north highlands.

  • BefeQadu know your facts

    BefeQadu,

    I doubt if you know Liya & her family at all, if you did, you would have known that she is NOT Tigray. Liya Kebede aka Lily who was actually my next door neighbour growing up in Bole Afrika Kinf aka Kebele 17 K 17 is NEVER Tigrian, rather Amhara. She is apparently married to a Tigray, not sure of that fact though. why on earth would you lie through your teeth? You want to claim anything and everything as Tigrian?

  • Zurga

    The women is a real native Amhara or Gurage or Agaw Women. These are the indigenous people of Ethiopia.
    While the Self called Oromo pastoralists and the Tigrians whoes ancestors are Beja nomads are originally from the low land areas who migrated to the Ethiopian highland in search of water and pasture.

    Zurga
    the great
    Son of Amon Raa

  • Mike

    She is one of he world’s most highly paid model. I believe she is no more a typical Ethiopian than Cindy Crawford is a typical Chicagoan.

  • Hanna

    The title is actually misleading as there are many ethnic groups in Ethiopia and the author just mentions one while showing a picture of a woman that is a member of a different group. Even what people call “Amhara” is actually a group of different ethnicity that share a common language. He should have just said “How the highland Ethiopians breathe differently”. Otherwise, Ethiopians reading this blog may believe the author to be bigoted.

  • Dina

    Liya Kebede is Amhara.

  • FIKRU

    @ http: BefQadu: you are absolutely Wrong she is not Tigree she married one. She is Amhara get it right. Liya Kebede is her full name even her last name is a Typical Amhara name.

  • yosipop

    i think the women on the picture she is not typical habesha!

  • maq

    If you have done the studies on Ethiopian highlands then you must understand that there are also Tigrayans as part of the highlands. If you have taken samples only from Amara region then that explains. By the way the capital Addis Ababa, there are many ethnic group dwellers there not just Amaras. Those who win the greatest Marathons are also from central to Southern Ethiopia the Oromos. Most of the runners are Oromos who train at high altitutdes.

  • Zelalem

    TPLF people are a disgrace for ethiopia. Even in foreign blogs they intiate ethnic conflict.
    Normally, tigray women have a bigger forehead(genbaram).Liya is different. i don’t think she is from tigray. She is ethiopian, that is enough.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    i’m sorry, this comment thread is ridiculous. i’m closing it.

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Gene Expression

This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com

ADVERTISEMENT

See More

ADVERTISEMENT

RSS Razib’s Pinboard

Edifying books

Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »