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DNA said to disprove war elephant myths

Jan. 13, 2014
Courtesy of the University of Illinois
and World Science staff

Through DNA anal­y­sis, re­search­ers say they have dis­proved years of ru­mors and hear­say sur­round­ing the only known bat­tle be­tween Asian and Af­ri­can ele­phants.

“What eve­ry­one thinks about war ele­phants is wrong,” said Al­fred Ro­ca of the Uni­vers­ity of Il­li­nois at Urbana-Champaign, who led the re­search.

Af­ter Al­ex­an­der the Great’s prem­a­ture death, his vast king­dom was di­vid­ed among his gen­er­als. “Be­ing gen­er­als, they spent the next three sev­er­al cen­turies fight­ing over the land in be­tween,” Ro­ca said.

The bat­tle took place in 217 B.C. be­tween Ptol­e­my IV, king of Egypt, and An­ti­ochus III the Great, king of the Se­leu­cid king­dom that reached from mod­ern-day Tur­key to Pa­ki­stan. His­tor­i­cal records say An­ti­ochus’s an­ces­tor traded vast ar­eas of land for 500 Asian ele­phants where­as Ptol­e­my es­tab­lished trad­ing posts for war ele­phants in what is now Er­i­trea, East Af­ri­ca.

In the Bat­tle of Raph­ia, Ptol­e­my had 73 Af­ri­can war ele­phants and An­ti­ochus had 102 Asian war ele­phants, ac­cord­ing to Po­lyb­i­us, a Greek his­to­ri­an who de­scribed the bat­tle at least 70 years lat­er.

“A few of Ptol­e­my’s ele­phants ven­tured too close with those of the en­e­my, and now the men in the tow­ers on the back of these beasts made a gal­lant fight of it, strik­ing with their pikes at close quar­ters and wound­ing each oth­er, while the ele­phants them­selves fought still bet­ter, put­ting forth their whole strength and meet­ing fore­head to fore­head,” wrote Po­lyb­i­us in The His­to­ries.

“Ptol­e­my’s ele­phants, how­ev­er, de­clined the com­bat, as is the hab­it of Af­ri­can ele­phants; for un­able to stand the smell and the trum­pet­ing of the [A­sian] ele­phants, and ter­ri­fied, I sup­pose, al­so by their great size and strength, they at once turn tail and take to flight be­fore they get near them.”

Over the years, there has been a lot of specula­t­ion about Po­lyb­i­us’s ac­count.

“Un­til well in­to the 19th cen­tu­ry the an­cient ac­counts were tak­en as fact... that is why Asian ele­phants were giv­en the name Ele­phas max­imus,” said Neal Ben­ja­min, an Il­li­nois vet­er­i­nary stu­dent who stud­ies with Ro­ca. “Af­ter the scram­ble for Af­ri­ca by Eu­ro­pe­an na­t­ions, more spec­i­mens be­came availa­ble and it be­came clear­er that Af­ri­can ele­phants were mostly larg­er than Asian ele­phants. At this point, specula­t­ion be­gan about why the Af­ri­can ele­phants in the Po­lyb­i­us ac­count might have been small­er.”

In 1948, Wil­liam Gow­ers rea­soned that Ptol­e­my must have fought with for­est ele­phants that fled from larg­er Asian ele­phants, as Po­lyb­i­us de­scribed. That idea has stuck. But there has been ev­i­dence that Ptol­e­my used sa­van­na ele­phants in­stead, the re­search­ers said.

“Us­ing three dif­fer­ent [DNA] mark­ers, we es­tab­lished that the Er­i­tre­an ele­phants are ac­tu­ally sa­van­na ele­phants,” said Ad­am Brandt, a doc­tor­al can­di­date in Ro­ca’s lab­o­r­a­to­ry and co-author of the pa­per. That would be rel­e­vant be­cause the coun­try, with the northern-most popula­t­ion of ele­phants in East Af­ri­ca, is where Ptol­e­my is said to have set up trad­ing posts for them.

“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.”

A type of DNA called mi­to­chon­drial DNA, or mtDNA, passes only from moth­er to off­spring. Fe­male ele­phants stay with their na­tal herd while the males dis­perse to mate with dif­fer­ent popula­t­ions. So mtDNA could be a tell­tale sign of wheth­er there had been for­est or Asian ele­phants in the Er­i­tre­an popula­t­ion at one time.

“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 said. “The most con­vinc­ing ev­i­dence is the lack of mtDNA from for­est ele­phants in Er­i­trea.”

Ro­ca and Brandt hope their find­ings will aid con­serva­t­ion ef­forts.

“This popula­t­ion is iso­lat­ed and may be in­bred,” Brandt said. They “will re­quire hab­itat restora­t­ion and pre­serva­t­ion to min­i­mize the pos­si­bil­ity of hu­man con­flict. That’s really the is­sue—not hav­ing a place to go.” The pa­per is pub­lished in the Jour­nal of Hered­ity and is availa­ble here.


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Through DNA analysis, researchers say they have disproved years of rumors and hearsay surrounding the only known battle between Asian and African elephants. “What everyone thinks about war elephants is wrong,” said Alfred Roca of the University of Illinois at Urbana-Champaign, who led the research. After Alexander the Great’s premature death, his vast kingdom was divided among his generals. “Being generals, they spent the next three several centuries fighting over the land in between,” Roca said. The battle took place in 217 B.C. between Ptolemy IV, king of Egypt, and Antiochus III the Great, king of the Seleucid kingdom that reached from modern-day Turkey to Pakistan. Historical records say Antiochus’s ancestor traded vast areas of land for 500 Asian elephants whereas Ptolemy established trading posts for war elephants in what is now Eritrea, East Africa. In the Battle of Raphia, Ptolemy had 73 African war elephants and Antiochus had 102 Asian war elephants, according to Polybius, a Greek historian who described the battle at least 70 years later. “A few of Ptolemy’s elephants ventured too close with those of the enemy, and now the men in the towers on the back of these beasts made a gallant fight of it, striking with their pikes at close quarters and wounding each other, while the elephants themselves fought still better, putting forth their whole strength and meeting forehead to forehead,” wrote Polybius in The Histories. “Ptolemy’s elephants, however, declined the combat, as is the habit of African elephants; for unable to stand the smell and the trumpeting of the [Asian] elephants, and terrified, I suppose, also by their great size and strength, they at once turn tail and take to flight before they get near them.” Over the years, there has been a lot of speculation about Polybius’s account. “Until well into the 19th century the ancient accounts were taken as fact by all modern natural historians and scientists and that is why Asian elephants were given the name Elephas maximus,” said Neal Benjamin, an Illinois veterinary student who studies elephant taxonomy and ancient literature with Roca. “After the scramble for Africa by European nations, more specimens became available and it became clearer that African elephants were mostly larger than Asian elephants. At this point, speculation began about why the African elephants in the Polybius account might have been smaller.” In 1948, William Gowers reasoned that Ptolemy must have fought with forest elephants that fled from larger Asian elephants, as Polybius described. That idea has stuck. But there has been evidence that Ptolemy used savanna elephants instead, the researchers said. “Using three different [DNA] markers, we established that the Eritrean elephants are actually savanna elephants,” said Adam Brandt, a doctoral candidate in Roca’s laboratory and co-author of the paper. That would be relevant because the country, with the northern-most population of elephants in East Africa, is where Ptolemy is said to have set up trading posts for them. “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.” A type of DNA called mitochondrial DNA, or mtDNA, passes only from mother to offspring. Female elephants stay with their natal herd while the males disperse to mate with different populations. So mtDNA could be a telltale sign of whether there had been forest or Asian elephants in the Eritrean population at one time. “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 said. “The most convincing evidence is the lack of mtDNA from forest elephants in Eritrea.” Roca and Brandt hope their findings will aid conservation efforts. “This population is isolated and may be inbred,” Brandt said. They “will require habitat restoration and preservation to minimize the possibility of human conflict. That’s really the issue—not having a place to go.” The paper is published in the Journal of Heredity and is available online.