That’s right, yet another interesting story from the world of science – one that certainly puts yet another nail in the coffin of the idiocy that is young earth creationism. The story covers findings that certain types of bacteria found in parts of the human digestive system can be traced back through human populations thus allowing human migration patterns to be measured in yet another independent manner.
A bacterial parasite known to cause stomach ulcers is shedding new light on ancient patterns of human migration across the Pacific region, according to an international study.
In the latest edition of Science, researchers report that their study of the distribution of Helicobacter pylori genotypes has given further weight to the theory that Australia was first populated around 30,000 years ago.
H. pylori is particularly useful for studying the movement of human populations because it is extremely widespread, and is transmitted from mother to child.
Co-author Professor Barry Marshall, a microbiologist at the University of Western Australia, says H. pylori is a lot like mitochondrial DNA, which is also used to investigate human migration patterns.
“You catch H. pylori off your mother,” he said.
“All of us carry our mothers’ mitochondrial DNA and that goes all the way back through the generations.”
H. pylori has a further advantage in that it contains thousands of genes, compared to just 37 genes in DNA, and differs between populations.
“It was found over the last few years that each human racial group carried a Helicobacter that was relatively unique in that group,” Professor Marshall said.
By studying the genetic sequences of hundreds of Helicobacter samples taken from populations around the world, researchers were able to map the points in time at which different Helicobacter genotypes went their separate ways.
Using this information, they established that two different waves of migration brought humans to the Pacific region.
The first wave, which split from the original Asian population between 37,000 and 31,000 years ago, diverged again into the Australian and New Guinean populations 23,000 to 31,000 years ago.
These dates are similar to those obtained from studies of mitochondrial DNA, but much later than the dates suggested by archaeological findings, the authors report.
A second wave dispersed from Taiwan 5,000 years ago to populate Melanesia and the Polynesian islands.
Professor Marshall, who, along with colleague Dr Helen Windsor, has been investigating the prevalence of Helicobacter in indigenous populations, says the research adds another piece of independent information to the migration puzzle.
“There was a little bit of argument, I believe, as to how long ago indigenous people came to Australia and that was related to discrepancies in carbon dating,” he said.
“But I think that number of 30,000 years seems to be the consensus at the moment.”
In 2005, Professor Marshall and fellow Australian researcher Robin Warren received the Nobel Prize for Physiology or Medicine for discovering the link between H. pylori and stomach ulcers.