A great battle fought in the Middle East nearly 1,800 years ago, in which thousands of men and horses fought alongside hundreds of elephants, has left historians and biologists with a lingering question – one that genomic analysis has finally answered, according to the Institute for Genomic Biology at the University of Illinois.
In the Battle of Raphia, fought near Gaza between the Egyptian King Ptolemy IV and the Antiochus III the Great, King of the Seleucid kingdom, two types of elephants were used, and the outcome of the fight may have turned in part on the variety of elephants involved.
According to the records of the Greek historian Polybius, Ptolemy's army of 70,000 infantry attacked with 73 African war elephants, which were obtained through trading posts in what is now Eritrea, and Antiochus's force of 62,000 men had 102 Asian war elephants.
When the soldiers, horses, and elephants smashed into each other in the field, as Polybius has it, the African elephants were frightened by the size of the larger Asian elephants and turned round and fled back through the lines of soldiers.
The problem with the history is that African elephants are larger than Asian elephants, although that only became clear as Europeans established more colonies in Africa, in the 19th century. The Asian elephant, in fact, were given the name Elephas maximas to recognize their size.
In the past, some have speculated that Ptolemy's army was using forest elephants, or that the elephants were part of a now-extinct subgroup that was smaller than their African cousins.
"Until now, the main question remained: Did Ptolemy employ African savanna elephants (Loxodonta africana) or African forest elephants (Loxodonta cyclotis) in the Battle or Raphia?" IGB says.
"What everyone thinks about war elephants is wrong," Says IGB's Alfred Roca, who led a genomic analysis effort that he says solved the problem.
"Using three different markers, we established that the Eritrean elephants are actually savanna elephants," says Adam Brandt, a doctoral candidate in Roca's lab.
"Their DNA was very similar to neighboring populations of East African savanna elephants but with very low genetic diversity, which was expected for such a small, isolated population."
"In some sense, mtDNA is the ideal marker because it not only tells you what's there now, but it’s an indication of what had been there in the past because it doesn't really get replaced even when the species changes," Roca says. "The most convincing evidence is the lack of mtDNA from forest elephants in Eritrea."