By: Kristina Anderson
The Irish elk has been the focus of debate since its discovery. Even the name Irish elk is a point of debate. For starters, the Irish elk was neither exclusively Irish nor an elk. The Irish elk was the largest deer that ever lived. The name was first given because the European moose - an "elk" to the English - was the only familiar animal with antlers that even approached those of the giant deer in size. Furthermore, Ireland's exclusive claim to the giant deer vanished in 1746 when a skull and antlers were discovered in Yorkshire England. The first continental discovery followed in 1781. We now know the giant deer ranged as far east as Siberia and China and as far south as northern Africa.
In 1697, Thomas Molyneux wrote the first scientific description of Megaloceros giganteus. Molyneux argued the Giant Irish Deer was not extinct but rather the North American moose. Molyneux's limited knowledge of the North American moose allowed him to satisfy his religious conviction that God wouldn't allow any of his creatures to go extinct. Molyneux's stated:
"That no real species of living creatures is so utterly extinct, as to be lost entirely out of the world, since it was first created, is the opinion of many naturalists; and Ôtis grounded on so good a principle of Providence taking care in general of all its animal production that it deserves our assent." (Sic)
Molyneux's convictions were shared by most scientists of his time. For the next century, scientist argued as to which modern species the giant deer belonged? Opinion was equally divided between the North American moose and the reindeer. New fossil species were continuously being unearthed and eighteenth-century geologists were having increasing difficulty in arguing unknown creatures were all still living in some remote region of the globe. Had God experimented continually in both creation and destruction? If so, the world was surely older than the six thousand years literalists allowed. Extinction was the first great battleground of modern paleontology and the extinction of the Irish elk was hotly debated. Georges Cuvier, a French paleontologist, was using the giant deer to defend extinction as a natural phenomenon. By 1812, Cuvier resolved that the giant deer was unlike any modern animal and thus extinction did occur. By those scientists who accepted extinction, the debate focused on when the extinction had occurred: specially, had the giant deer survived the Noachian flood? If the giant deer had survived the flood, the next logical conclusion was people must be responsible for the extinction of the giant deer. In 1830, Hibbert implicated the Romans and the extravagant slaughter at public games. However, the Romans never conquered Ireland where the most numerous fossils of the giant deer are found. In 1851, Montel blamed the Celtic tribes, but the deer went extinct two thousand years before the Celts came to Ireland.
In 1859, Charles Darwin published the Origin of Species. Darwin's theory of natural selection required evolutionary adaptations be beneficial to the species involved. As a result, anti-darwinians searched the fossil record for adaptations that would not have benefited the species involved. The theory of orthogenesis was born. Orthogenesis proposed that evolution proceeded in straight lines and certain evolutionary trends, once started, could not be stopped even if the trends led to extinction. For example, saber-toothed "tigers" could not stop growing their teeth and mammoths could not stop growing their tusks. But by far the most famous example of orthogenesis was the Irish elk itself. The giant deer was supposed to have been bowed under by the weight of its own antlers. This excess weight caused the giant deer to become tangled in trees and mired in ponds. Thus, orthogenesis claimed the Irish elk's own antlers led to its extinction.
Darwinians, led by Julian Huxley, launched a counterattack on orthogenesis in the 1930s. Huxley noted that among modern deer species antler size increases at a higher rate compared to body size. Huxley coined the term allometry to describe this relationship. Allometry provided a comfortable explanation for the giant deer's antlers. Since Irish elk were the largest deer, the size of the Irish elk's antlers was due to an allometric relationship present in all deer. Now, increased body size could be seen as the favoured evolutionary trait. The large antlers might only have been an automatic consequence of an increased body size.
In 1973, Stephen Jay Gould questioned the traditional explanation. Gould felt the allometry theory held a "curious remnant of the older, orthogentic view". Could the large antlers have had a primary function? Perhaps, the antlers were used to combat predators and rival males or to attract females. Today, scientific studies would suggest antlers serve as a visual dominance-rank symbol designed to prevent bodily injury rather than weapons in deadly combat. The antlers of the Irish elk were arranged to display the palm of the antler fully when the animal looked straight ahead. This suggests the Irish elk's antlers were indeed used for display rather than combat.
The Irish elk had become a specialised feeder. Rapidly changing climate at the end of the last "ice age" and new plant succession resulted in the demise of seasonal grasses upon which the Irish elk depended. Darwinian evolution decrees no animal shall evolve harmful structure, but this offers no guarantee when times change. The Irish elk fell victim to its own previous success.
Sources:
- "The Case of the Irish Elk." UC Berekeley Museum of Paleontology website: http://www.ucmp.berkeley.edu/mammal/artio/irishelk.html
- "Giant Elk survived the freeze." BBC News website. June 14, 2000: http://news.bbc.co.uk/2/hi/science/nature/791385.stm
- Irish Peatland Conservation website: http://www.ipcc.ie