Afarensis is a 3.5-2.8 million year old hominin from the Kada Hadar member of the Hadar formation in the Middle Awash, Ethiopia. He is approximately 41 inches tall, weighs approximately 60 pounds and has a cranial capacity of a whopping 410 cc (approximately). Afarensis is currently considered to be transitional between apes and humans and displays some traits of both. Since he spends a lot of time on the couch watching monster movies, some observers question whether he is an obligate biped (although no one has observed him climbing a tree). He also has a blog called 
I don't know how I missed this, but Science Daily has an interesting story on the Out of Africa theory.
A team of researchers found that Helicobacter pylori and humans display signs of parallel evolution:
Using mathematical simulations, the researchers demonstrated that H. pylori must have left East Africa at the same time as man - around 60,000
*snip*
However, while man was spreading throughout the world, human populations had to repeatedly pass through what scientists call genetic bottlenecks: when a population shrinks, the gene pool also becomes smaller. These losses in genetic diversity linger, even when the population starts once again to increase in number. Since the Homo sapiens populations usually had to pass through several genetic bottlenecks on their way across the globe, their genetic diversity declined the further they journeyed from their origin in East Africa.
Scientists have now uncovered similar signs of historical population migration in the genetic makeup of H. pylori. However, the genetic diversity of the bacteria is larger than that of man. This paves the way for researchers to use H. pylori data to work out the migratory movements of modern man. "The parallels between the spread of man and of H. pylori are truly astonishing," says Achtman. "This bacterium could help us attain further information on aspects of human history that are still hotly disputed today if we analyzed H. pylori in conjunction with human data." For example, after leaving East Africa, the H. pylori population spread through limited localities in southern Africa, West Africa, Northeast Africa, India and East Asia. The genes of bacteria isolated in Europe, for instance, reveal influences from Central Asia - an indication that human immigrants came to Europe from Asia.
I wonder if Neanderthals or Homo erectus/ergaster had H. pylori as well...
Comments
Our companion species are a potent source of historical information. There was a report a year or so ago about genetic analysis of human lice yielding information about when we started wearing clothes.
Posted by: Bob C | February 19, 2007 4:34 PM
If Neanderthals or earlier hominins had H. pylori that would be really interesting. I would love to see that in Nature or PNAS!
Posted by: Jason Fox | February 20, 2007 3:18 AM
Helicobacter infects many mammals...in our lab, we have to be careful that our mice aren't infected by this bug. I can almost guarantee that the early hominids carried this bug.
Posted by: Clostridiophile | April 30, 2009 11:26 AM