The Extinction of the Giant Deer: Case Study

  • Words 2785
  • Pages 6
Download PDF

The Irish elk, Megaloceros giganteus, is undoubtedly one of the most legendary creatures of prehistory. Its name is particularly misleading, considering it is neither exclusively Irish nor an elk, but rather an extinct deer species that ranged from Ireland to Siberia primarily in the Pleistocene epoch. M. giganteus is a frequent subject of scientific study; its notoriety stems from its rather uncommon features. More accurately nicknamed, the giant deer stood over two meters tall and brandished an antler rack that could stretch nearly four meters across (Petrie 1988). Naturally, the novelty of its size has influenced and motivated research. Arguments concerning the time period and cause of the extinction of M. giganteus, often in relation to their antlers, have persisted for centuries and still lack definitive conclusions. However, a summary of the trends in research could illuminate the shifts in belief over time, as well as suggest the most convincing answers based on current evidence.

Trends in the Research

First, the question of antler origin and purpose must be addressed. Perhaps one of the earliest and most referenced analyses was presented by Gould in 1974. After acknowledging that there was a positive allometric relationship between body and antler size, he theorized that selection acted in favor of both large bodies and antlers. To justify this, based on observation of extant deer species, he argued that intraspecific competition, probably through display, between males was likely; dominance and reproductive opportunities were awarded to the individual with the biggest antlers (Gould 1974). A decade later, Kitchener agreed with Gould’s idea, but questioned whether a physical feature of such magnitude could develop for display purposes alone, positing that M. giganteus employed their antlers in fights. He supported this by modelling the way in which the antlers could have been wielded in combat, as their structures appear to be adapted for withstanding and applying force (Kitchener 1987). The topic has been revisited periodically, but Kitchener’s assessment is generally regarded as plausible.

Click to get a unique essay

Our writers can write you a new plagiarism-free essay on any topic

Although scientists can agree on antler usage, the repercussions of their size are constantly debated. In particular, their antlers have been cited as the trigger for their extinction. For historical reference, Gould mentioned that their decline has been attributed to a number of possibilities since the first specimen was found in the seventeenth century, including bad air, distemper, and Roman slaughter (1974). Operating on the assumption that M. giganteus went extinct with the onset of the Younger Dryas cooling period, he proposed the breadth of their antlers was detrimental when trying to navigate the newly established, dense forests (Gould 1974). Barnosky was the next scholar to introduce a noteworthy rationale, which was also related to the Younger Dryas climate change, but in a slightly more complex manner; M. giganteus would have required substantial energy intake to grow and support large bodies and antlers, so the reduction of forage quantity and quality rendered maintenance of winter fat reserves impossible, which wiped out the population through winterkill (1986). He rejected the possibility of human influence, as the earliest recorded human arrival on Ireland happened after the giant deer was gone (Barnosky 1986). This theory was later elaborated upon by Moen, who designed a model of the mineral intake necessary to support antler growth. When compared with the forage availability at the time of their extinction, Moen concluded that growth must have been supplemented by absorbing minerals from their skeleton; because of this, the tension between sexual selection for large size and environmental conditions favoring smaller size was too great to reconcile, and the M. giganteus population was extinguished (1999). This explanation seemed to be the most likely means of death, as it incorporated a myriad of concepts that had previously been presented.

However, the emergence of contradictory information changed everything. Radiocarbon dating of newly discovered specimens suggested some of the giant deer survived past the Pleistocene and into the Holocene, with some migrating from Ireland to Scandinavia (Stuart et al 2004). This new range is expressed in Figure 1. Such a drastic expansion of knowledge led to a reevaluation of their extinction. Previously, it was assumed M. giganteus was particularly vulnerable to extinction because of their antlers, but the new temporal range meant they were one of the last species of Pleistocene megafauna to go extinct (Worman & Kimbrell 2008). Worman & Kimbrell suggested the extinction was not initiated by increased male mortality from nutritional deficiencies as believed; sexually selected traits are generally highly adaptable, so the giant deer should have been able to evolve smaller antlers in response to environmental stress (2008). Instead, they hypothesized the insufficient nutrition reduced female reproduction and lowered the M. giganteus numbers to a dangerous level; in addition, the discovery of survival into the Holocene, combined with earlier evidence of human settlements, revealed the possibility of human interference after all (Worman & Kimbrell 2008; Lister & Stuart 2019). Therefore, even if hunting was minimal, it could have been enough to push the already vulnerable M. giganteus to complete extinction.

Unanswered Questions

Evidently, the trends in research concerning M. giganteus are complex, and many questions remain. For example, comparison of all discovered specimens shows notable morphological differentiation; there is documented variation in skull shape, antler positioning, limb length, and more (Lister 1994). However, this cannot currently be explained by any pattern: measures of chronology, geography, climate, and vegetation show weak correlation, or none at all, with the phenotypic fluctuations (Lister 1994). The phenomenon is further complicated by the uncertainty of whether the catalogued specimens represent a cohesive genetic lineage or disconnected populations that diverged physically due to genetic isolation (Lister 1994). Even without a decisive answer, the diversity suggests some form of mutation and adaptation.

In addition, the role humans played in the extinction of M. giganteus is slowly falling into place, but still lacks definitive proof. Although evidence of human presence has been found, no specimens indicate that they were hunted; in rare cases, marks on the bones only suggest butchery after death, never the way in which they died (Lister & Stuart 2019). Even excavated tools made from giant deer antlers cannot prove hunting, as the antlers appear to have been shed naturally (Lister & Stuart 2019). Because the samples are so few in number and inconclusive, the effect humans had on M. giganteus cannot be verified. While many scientists support the theory that hunting finalized the extinction process, it is still entirely possible that hunting had absolutely no impact, or never occurred at all.

Determinations of the geographical spread of M. giganteus have been blurred by the expansion into the Holocene. Admittedly, the available data is limited, but it appears to indicate an eastward migration in response to climate change, followed by constriction to a small area, and ending with extinction; this is mysterious, as giant deer had previously survived interglacial periods and eventually re-expanded their range (Stuart et al 2004). Therefore, it is unknown why the species had thrived before but declined in this instance. One potential explanation involves the morphological variety—perhaps the resulting adaptive niche restricted viable environments for survival (Lister 1994). Yet, this explanation falls short in light of the parallels between the extinctions of M. giganteus and the woolly mammoth; the woolly mammoth also continued into the Holocene with markedly compressed range and eventual death (Stuart et al 2004). If the similarities between the timelines of the two megafaunal species are considered to be more than pure coincidence, all hypotheses for extinction that revolve around characteristics unique to M. giganteus, like the antlers, are suddenly flawed.

Finally, despite so much study over centuries, the phylogeny of M. giganteus has yet to be fully assessed. Gould pointed out that the speciation of the giant deer is cryptic, as the species materialized in the fossil record rather abruptly, and it exhibits no obvious connection to prior intermediate forms (1974). In addition to the enigmatic ancestry, the closest related extant species to M. giganteus is also unknown. Many scientists have pursued phylogenetic analysis through morphology and DNA sequencing, but the results are debated; some research suggests the giant deer is more related to the red deer or wapiti, while other studies show a sister-group relationship with the fallow deer (Lister et al 2005). This is evident from Figure 2, which positions M. giganteus next to the fallow deer (Dama dama); the clade with M. giganteus diverges in a soft polytomy, as the creators acknowledge they were unable to infer a clearer relationship between the species (Kolb et al 2015). In comparison to the other unanswered questions about M. giganteus, this might be the least surprising, considering how difficult it can be to establish phylogenies of long-extinct species. However, further analysis of genetics could shed some light on the other aspects of the giant deer that are still shrouded in mystery.

Criticism of Research

With so much confusion remaining, it is evident that former research of M. giganteus has suffered from significant limitations. It appears that opportunities for thorough analysis with meaningful results are diminished by lack of specimens more than anything else. With the exception of the hundreds of bones unearthed in Ireland that date back to the Lateglacial Interstadial period, samples are remarkably rare; only 23 specimens have been found in Scandinavia (Aaris-Sørensen 2008). Unsurprisingly, the narrow scope of samples has a serious negative impact on analysis. For example, Lister’s confusion surrounding the causes of and relationships between the morphologically distinct remains is a direct result of insufficient data (1994); the uncertainty could be quickly resolved if there were more points of comparison. Unfortunately, this problem is not easily remedied, as fossilization is rare and only occurs in very particular conditions. Yet, the recent discovery of their existence in Siberia could lead to more finds. Proposing hypothetical migratory patterns could suggest where more specimens could be found, especially when combined with knowledge of their ideal habitat as well as the topography at the time.

Even if no more fossils are found, certain techniques could be used to supplement data. When questioning why M. giganteus failed to re-expand their range after eastward migration, Lister & Stuart speculate that the population was essentially trapped by the expansion of forested land (2019). One potential solution is to study the vegetational history of the area to determine whether the giant deer population actually did deteriorate as a result of forestation, or if they had access to other suitable habitats but were weakened by another factor. Another option is to carefully evaluate the connections between the woolly mammoth and the giant deer. Information about the former species is far more accessible, given the extensive phylogenetic data and frozen specimens. If researchers ascertained why exactly they shared an extinction narrative, perhaps relevant details about the woolly mammoth could be extrapolated to the giant deer.

Beyond executing more studies, the field might benefit from dismantling the framework that emerged from excessive investigation into the Irish Lateglacial category. As previously stated, the vast majority of specimens have been from this area; as a result, they have been regarded as the standard representation of the entire species, though they comprise a group that is small both temporally and geographically. Even the term “Irish elk” lends credence to this position. Defining a species that has been traced to a much broader time and space by one specific collection could certainly produce false assumptions, such as when discussing the different physical traits noted across specimens. If the Irish elk is designated as the norm and every other specimen is a deviation, it could obscure other possible explanations. For instance, there is a chance the Irish Lateglacial category is unique somehow because of insular evolution. In fact, Barnosky’s theory of extinction by winterkill was based exclusively on fossils found in the Ballybetagh bog in Ireland, calling into question the validity of the claims he made, like seasonal sexual segregation and the function of antlers as social display (1986). Future research should seek to detach from expectations rooted in preferential treatment of one cluster of giant deer.

In Evolutionary Context

Matters relating to M. giganteus have played vital roles in discussions of broader evolutionary topics. Ironically, though qualities of its extinction are still debated, M. giganteus was used to prove that extinction as a general concept actually happened; Gould (2007) writes that, in 1812, paleontologist Georges Cuvier “had resolved two pressing issues: by minute anatomical description, he proved that the Irish Elk was not like any modern mammal; and by placing it among many fossil mammals with no modern counterparts, he established the fact of extinction and set the basis for a geologic time scale” (p. 83). Thus, the study of the giant deer began influencing predominant evolutionary beliefs centuries ago.

Later, during the emergence of Darwinian theory, M. giganteus was repeatedly presented as support for conflicting opinions on natural selection. Anti-evolutionists argued that the massive antlers endorsed orthogenesis, or predetermined and directed evolution; overgrowth was considered the cause of extinction at the time, and natural selection would not logically produce a trait that was deleterious (Gould 2007). In response, Darwinians proposed the concept of allometry, or relative growth of physical features—selection for large bodies would be unintentionally accompanied by large antlers (Gould 2007). The debate between orthogenesis and allometry in regards to M. giganteus spread, and the giant deer remained a common example for either position. As examined in “Trends in the Research”, theorization about selection for antler size has persisted, as scientists question the roles of competition and sexual selection.

In conclusion, it is clear that the study of M. giganteus is principally focused on the concept of extinction. Many of the proposed explanations for the extinction have incorporated prominent evolutionary topics, such as the effects of isolation on speciation, phylogenetic analysis, and modern synthesis. In this way, any deliberation about the extinction of the giant deer tends to be inseparable from a larger evolutionary context. Given M. giganteus’s role in the development and proliferation of ideas that are widely accepted today, like natural selection and extinction, the giant deer is a species that historically shaped, and is currently shaped by, evolutionary theory.


  1. Aaris-Sørensen, Kim, and Ronnie Liljegren. “Late Pleistocene Remains of Giant Deer (Megaloceros Giganteus Blumenbach) in Scandinavia: Chronology and Environment.” Boreas 33, no. 1 (January 2004): 61–73.
  2. Barnosky, A. D. “Taphonomy and Herd Structure of the Extinct Irish Elk, Megaloceros Giganteus.” Science 228, no. 4697 (1985): 340–44.
  3. Barnosky, Anthony D. “‘Big Game’ Extinction Caused by Late Pleistocene Climatic Change: Irish Elk (Megaloceros Giganteus) in Ireland.” Quaternary Research 25, no. 1 (1986): 128–35.
  4. Gonzalez, Silvia, Andrew C. Kitchener, and Adrian M. Lister. “Survival of the Irish Elk into the Holocene.” Nature 405, no. 6788 (2000): 753–54.
  5. Gould, Stephen Jay. “The Origin and Function of Bizarre Structures: Antler Size and Skull Size in the Irish Elk, Megaloceros Giganteus.” Evolution 28, no. 2 (1974): 191.
  6. Gould, Stephen Jay. Ever Since Darwin: Reflections in Natural History. New York: W.W. Norton & Co, 2007.
  7. Kitchener, Andrew. “Fighting Behavior of the Extinct Irish Elk.” Modern Geology 11 (1987): 1-28.
  8. Kolb, Christian, Torsten M Scheyer, Adrian M Lister, Concepcion Azorit, John De Vos, Margaretha Schlingemann, Gertrud E Rössner, Nigel T Monaghan, and Marcelo R Sánchez-Villagra. “Growth in Fossil and Extant Deer and Implications for Body Size and Life History Evolution.” BMC Evolutionary Biology 15, no. 1 (2015): 19.
  9. Lincoln, G. A. “Biology of Antlers.” Journal of Zoology 226, no. 3 (1992): 517–28.
  10. Lister, A. M., C. J. Edwards, D. A. W. Nock, M. Bunce, I. A. Van Pijlen, D. G. Bradley, M. G. Thomas, and I. Barnes. “The Phylogenetic Position of the ‘Giant Deer’ Megaloceros Giganteus.” Nature 438, no. 7069 (April 2005): 850–53.
  11. Lister, Adrian M. “The Evolution of the Giant Deer, Megaloceros Giganteus (Blumenbach).” Zoological Journal of the Linnean Society 112, no. 1-2 (1994): 65–100.
  12. Lister, Adrian M., and Anthony J. Stuart. “The Extinction of the Giant Deer Megaloceros Giganteus (Blumenbach): New Radiocarbon Evidence.” Quaternary International 500 (2019): 185–203.
  13. McKinney, Michael L., and Kenneth J. McNamara. Heterochrony: the Evolution of Ontogeny. New York, NY: Plenum Press, 1991.
  14. Moen, Ron A, John Pastor, and Yosef Cohen. “Antler Growth and Extinction of Irish Elk.” Evolutionary Ecology Research 1 (1999): 235–49.
  15. Pastor, John, and Ron A. Moen. “Ecology of Ice-Age Extinctions.” Nature 431, no. 7009 (2004): 639–40.
  16. Petrie, Marion. “Intraspecific Variation in Structures That Display Competitive Ability: Large Animals Invest Relatively More.” Animal Behaviour 36, no. 4 (August 1988): 1174–79.
  17. Stuart, A. J., P. A. Kosintsev, T. F. G. Higham, and A. M. Lister. “Pleistocene to Holocene Extinction Dynamics in Giant Deer and Woolly Mammoth.” Nature 431, no. 7009 (2004): 684–89.
  18. Vislobokova, I. A. “Giant Deer: Origin, Evolution, Role in the Biosphere.” Paleontological Journal 46, no. 7 (2012): 643–775.
  19. Worman, Cedric Odriscoll, and Tristan Kimbrell. “Getting to the Hart of the Matter: Did Antlers Truly Cause the Extinction of the Irish Elk?” Oikos 117, no. 9 (2008): 1397–1405.


We use cookies to give you the best experience possible. By continuing we’ll assume you board with our cookie policy.