Fall 2021 Children's Sneak Previews

Would A Visit To Páirc Quaternary Be Better Than Jurassic Park?

De-extinction sounds like science fiction brought to life: the resurrection of species long lost to the natural world, some for centuries or even millennia. With cutting-edge gene-editing tools like CRISPR [Clustered Regularly Interspaced Short Palindromic Repeats] scientists can now isolate DNA fragments from animals preserved in permafrost or museum specimens, piece together missing sequences, and edit living cells to revive ancient genetic lineages. And while dinosaurs are out of reach, due to their age and the poor preservation of their DNA, scientists have turned their attention to species from more recent times, notably the Quaternary Period, which includes creatures such as woolly mammoths and the Tasmanian tiger.

But before we consider the future of woolly mammoths in the Arctic or dodos in Mauritius, it's worth revisiting one early attempt at de-extinction. In 2003, scientists achieved what seemed like a feat of genetic engineering: reversing extinction, if only for a moment. Researchers brought back the Pyrenean ibex, a species of wild mountain goat. The last of its kind, a female named Celia, had died in 2000. By injecting Celia's preserved DNA into a domestic goat egg cell, scientists created a viable embryo, which they then implanted into a surrogate. This ibex clone was born but survived only a few minutes, succumbing to a lung defect. Though the attempt failed to produce a healthy animal, it marked a pioneering step, showcasing the potential of de-extinction technology.

In the two decades since, advancements in cloning and gene editing have transformed de-extinction from speculative fantasy into a potential reality. Today, scientists can compile functional genomes of recently extinct species with surprising accuracy. And companies such as Colossal Biosciences, based in Texas, are actively pursuing the return of the woolly mammoth, the dodo, and the Tasmanian tiger. Their goal: to "enrich biodiversity, replenish vital ecological roles, and bolster ecosystem resilience." But while technology may be catching up to ambition, the ethical and environmental questions remain.

Why the push for de-extinction?

Proponents argue that de-extinction could play a vital role in ecosystem restoration. Many extinct species, including the woolly mammoth, were considered keystone species, meaning they shaped their environments in ways that supported entire ecosystems. Mammoths, for example, maintained Arctic grasslands by trampling down trees and shrubs, encouraging grasses that sequestered carbon and helped keep permafrost intact. Theoretically, reintroducing mammoths could help to restore lost Arctic ecosystems and perhaps even combat climate change by encouraging carbon storage.

Colossal Biosciences, spearheading this movement, plans to develop mammoth-like hybrids by inserting DNA from preserved mammoth specimens into the genomes of Asian elephants. They aim to produce their first mammoth calves by 2028.

Other projects include reviving the dodo to restore its ecological role in Mauritius, and reintroducing the thylacine, an apex predator, in Tasmania. Yet critics question whether the resources for these ambitious projects might not be better invested in conserving species currently at risk of extinction.

AI render by American company Colossal Biosciences on what their 'hybrid' thylacine could look like in the wild

Celtic fauna, and Irish ecosystems

Imagine if these techniques could be applied to Irish ecosystems. While we may not see mammoths in Connemara or dodos along the Wild Atlantic Way, Ireland's rich fossil record holds traces of species that shaped its ancient landscapes. Fossil records in Irish peatlands have revealed fascinating snapshots of a vanished world, including large mammals like the Irish elk (Megaloceros giganteus), whose fossils are often found in our bogs.

If the Irish elk were brought back, although the return of such species remains highly unlikely, managing its presence in today's Ireland would require careful planning. Large herbivores like the elk influence vegetation by browsing and grazing, which could reshape plant communities. The elk would need vast spaces to roam, likely in designated reserves or controlled areas, to prevent issues like crop damage or road hazards. Imagine seeing an Irish Elk on the M50. With no natural predators left in Ireland, population control would rely heavily on human management, involving significant resources to balance the elk's ecological role with modern land uses and conservation priorities.

A cleaner is dwarfed by the remains of a Giant Irish deer, at the Natural History Museum in Dublin. The deer had the largest antler span of any known deer, living or extinct, with examples measuring up to four metres along the curvature of the antler. The deer were almost two metres tall at the shoulder and would have weighed up to 800-900 kilos. The final extinction of the Irish deer came about 10,600 years ago when a cold phase of climate, lasting about 400 years caused changes in the vegetation of the island, about two thousand years before man arrived in Ireland. Picture (2002): PA /Haydn West

Just because we can, should we?

As exciting as the concept of de-extinction may be, the practical and ethical implications are complex. Reviving extinct species requires vast resources, raising questions about whether it is the best use of funds in a world facing immediate threats to biodiversity.

Matt James, our Chief Animal Officer on caring for a Woolly Mammoth 🦣 on the MeatEater podcast pic.Twitter.Com/Y4n9jhyvLy

— Colossal Biosciences® (@colossal) September 24, 2024

There are also significant logistical challenges to consider. Scaling up reintroduction efforts to have meaningful ecological effects would require massive populations. For mammoths to restore the Arctic's mammoth steppe, tens of thousands would be needed across vast areas of Siberia, Canada, and Alaska. There's also the very real threat of unintended consequences such as the spread of hybrid animals beyond designated areas or unforeseen ecological impacts, which could disrupt current ecosystems in unpredictable ways. This draws into question if we could control the technology.

Preserving the present, not reviving the past

De-extinction represents a bold step into uncharted territory, one that challenges us to rethink our relationship with the natural world. For some, the thought of mammoths roaming the Arctic or thylacines prowling Tasmania is thrilling; for others, it's a distraction from more pressing issues. Bringing back the Pyrenean ibex may have lasted only minutes, but it reminds us of the delicate balance of life and extinction, and the limits of what technology alone can accomplish.

Rather than re-populating the world with ancient species, perhaps our efforts would be better spent addressing the conservation challenges we face today. By protecting the species and ecosystems we still have, we honour the legacy of what's been lost, without risking the unintended consequences that could arise from de-extinction. After all, some mysteries of the past might be best left untouched, preserving a certain magic that only the fossil record can offer.

The Conservation Of Mass

Figure 3: A forest system

Because of conservation of mass, if inputs exceed outputs, the biomass of a compartment increases (such as in an early successional forest). Where inputs and outputs are equal, biomass maintains a steady level (as in a mature forest). When outputs exceed inputs, the biomass of a compartment decreases (e.G., a forest being harvested).

The availability of individual elements can vary a great deal between nonliving and living matter (Figure 5). Life on Earth depends on the recycling of essential chemical elements. While an organism is alive, its chemical makeup is replaced continuously as needed elements are incorporated and waste products are released. When an organism dies, the atoms that were bound in biomolecules return to simpler molecules in the atmosphere, water and soil through the action of decomposers.

Each organism has a unique, relatively fixed, elemental formula, or composition determined by its form and function. For instance, large size or defensive structures create particular elemental demands. Other biological factors such as rapid growth can also influence elemental composition. Ribonucleic acid (RNA) is the biomolecular template used in protein synthesis. RNA has a high phosphorus content (~9% by mass), and in microbes and invertebrates RNA accounts for a large fraction of an organism's total phosphorus content. As a result, fast-growing organisms such as bacteria (which can double more than 6 times per day) have especially high phosphorus content and therefore demands. By contrast, among vertebrates structural materials such as bones (made of calcium phosphate) account for the majority of an organism's phosphorus content. Among mammals, black-tailed deer (Odocoileus columbianus; Figure 6) have a relatively high phosphorus demand due to their annual investment in calcium- and phosphorus-rich antlers. Failure to meet elemental demands can lead to poor health, limited reproduction, and even extinction. The extinction of the majestic Irish Elk (Megaloceros giganteus) is thought to have been caused by the shortened growing season that occurred during the last ice age, which reduced the availability of the calcium and phosphorus these animals needed to grow their enormous antlers.

Figure 4: All types of natural and even human-designed systems can be evaluated as ecosystems based on conservation of mass.

Individual organisms, watersheds, and cities receive materials (inputs), transform them, and export them (outputs) sometimes in the form of waste.

Obtaining the resources required for metabolism, growth, and reproduction is one of the central challenges of life. Animals, particularly those that feed on plants (herbivores) or detritus (detritivores), often consume diets that do not include enough of the nutrients they need. The struggle to obtain nutrients from poor quality diets influences feeding behavior and digestive physiology and has led to epic migrations and seemingly bizarre behavior such as geophagy (feeding on materials such as clay and chalk). For example, the seasonal mass migration of Mormon crickets (Anabrus simplex) across western North America in search of two nutrients: protein and salt. Researchers have shown that the crickets stop walking once their demand for protein is met (Figure 7).

Figure 5: Comparison between elemental composition of the Earth's crust and the human body

The flip side of the struggle to obtain scarce resources is the need to get rid of excess substances. Herbivores often consume a diet rich in carbon — think potato chips, few nutrients but lots of energy. Some of this material can be stored internally, but this is a limited option and excess carbon storage can be harmful, just as obesity is harmful to humans. Thus, animals have several mechanisms for getting rid of excess elements. Excess nutrients are released in feces or urine or sometimes it is respired (i.E., released as carbon dioxide). This release of excess nutrients can influence both food webs and nutrient cycles.

Figure 6: Components of an animal's mass balance

This black-tailed deer consumes plant material rich in carbon but poor in other necessary nutrients, such as nitrogen (N). The deer requires more N than is found in its food and must cope the surplus a surplus of carbon. As a result, it must act to retain N while releasing excess carbon to maintain mass balance. Carbon and N mass balances suggest that deer waste should be carbon rich and low in N. Boxes show the abundance of N (green boxes) relative to carbon (gray boxes) in the diet, deer, and deer waste products.

Five Well-known Animals That Went Extinct In Britain

Elk

Eurasian elk are one of the largest deer species on the planet, second only to their North American relative, the moose. They are able to cope with the long, cold winters of Northern and Eastern Europe, as well as Asia, where there are still populations. Elk fell into extinction in the UK over 3,000 years ago, in part because of over-hunting. Their meat, skin and antlers were all sought after.

This already huge mammal actually has an even bigger extinct ancestor. The Irish elk roamed across Eurasia during the last glacial period (a cold spell marked by extensive glaciation), which ended over 11,000 years ago. From fossil discoveries, we know that its antlers could grow up to 3.5m wide and weighed 20kg each.

Brown Bear

It's not entirely clear when wild native brown bears went extinct in the UK. It could have been as long ago as the Bronze Age or as recent as the medieval period. Remains discovered in a cave in the Yorkshire Dales indicate that there were still brown bears living in Britain around 425 to 594 AD. However, these bears may have been imported into Britain from Europe by the Romans, for gladiator fighting and other entertainment.

While brown bears were one of Britain's top predators, they were also omnivores. This means they had a wide and varied diet, including everything from deer to roots and berries. Brown bears can still be found in continental Europe, North America and Asia, typically in forests and mountainous areas.

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