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FUTURES: De-Extinction – A Project of Mammoth Ambitions

by Sally Chase

Humanity’s insatiable curiosity got the better of them once again.


Under the guise of addressing climate change, but really just because they thought it would be pretty awesome, a team of geneticists and businessmen resurrected a creature approximating the woolly mammoth. It was indeed awesome, and fueled calls for more experiments, more species.


International zoos were filled with quagga, sabre-toothed tigers, dodos, short faced kangaroos, dunkleosteus, elephant birds, Irish elk, opabinia, camelops, great auk, lesser bilby, sea minks, and wooly rhino. Conservation efforts flagged, on the other hand, as one of their driving rationales—species preservation—appeared moot.


Eventually, of course, animals escaped, decimating local ecosystems, and interbreeding with wild relatives with varying degrees of success. Mutants multiplied, and novel pathogens proliferated. A few previously stable populations went extinct, and the global food supply went wobbly for a time.


Blame was too distributed for anyone to face real consequences for the disaster, and with the lines that were crossed, scientists soon turned the technology on human embryos, promising to do better. Before long, the first ‘optimized’ baby was conceived, her genes tweaked and tailored by CRISPR, nourished in a synthetic womb, and unleashed, parentless, into an uncertain future.  


Colossal goals


In 2021, Harvard Medical School biologist George Church and a company called Colossal want to repopulate Siberia with wooly mammoth lookalikes in an attempt to restore by means of their traffic and natural fertilizer a now-mossy tundra into a thriving grassland. The project involves tweaking in elephant DNA select genes responsible for traits such as hair, fat, and skull shape, then growing the resulting embryos to a weight of 200 pounds in synthetic wombs.

2021年,哈佛医学院生物学家George Church和一家名为Colossal的公司希望在西伯利亚重新养殖长毛象,试图通过交通和天然肥料,将长满苔藓的苔原恢复为一片繁荣的草原。该项目包括调整大象的DNA,选择负责毛发、脂肪和头骨形状等性状的基因,然后在人造子宫中将产生的胚胎培育到200磅重。

Church and Co. aren’t alone in dreaming up plans for de-extinction. A biotech firm called Revive & Restore has its sights set on animals like the passenger pigeon and heath hen, with a focus on “enhance[ing] biodiversity through the genetic rescue of endangered and extinct animals.” The nonprofit connects scholars and stakeholders, funds initiatives, and furthers experiments. Foundational research and breeding work for Passenger Pigeon de-extinction is now complete, setting the stage for CRISPR-Cas-9-powered gene editing of the fowl’s hopeful forerunners.

Church和Colossal并不是唯一一个想出免灭绝计划的公司。一家名为Revive & Restore的生物技术公司将目光投向了候鸽石南母鸡等动物,专注于“通过基因拯救濒危和灭绝动物,增强生物多样性”。该非营利组织将学者和利益相关者联系起来,资助计划,并进一步开展实验。候鸽灭绝的基础研究和育种工作现已完成,为对候鸽有希望的祖先进行CRISPR-Cas-9驱动的基因编辑奠定了基础。

UC Santa Cruz ecology and evolutionary biology professor Beth Shapiro outlines the three primary paths to creating “proxies” for extinct animals, on the recognition that de-extinct species will never be “exact copies” of their forebears. The three routes currently under consideration include genetic engineering (featured in the wooly mammoth and the Passenger Pigeon projects), cloning preserved samples (think Jurassic Park’s amber-entrapped mosquito), and back-breeding, a type of selective breeding for ancestral traits. Back-breeding is the method of choice for Rewilding Europe’s auroch initiatives, which are well on their way to recreating the ancestors of modern cattle with the goal of encouraging grazing-facilitated biodiversity across Europe

加州大学圣克鲁兹分校生态学和进化生物学教授Beth Shapiro概述了为灭绝动物创建“代理”的三条主要途径,因为她认识到,未灭绝的物种永远不会是它们祖先的“精确复制品”。目前正在考虑的三条途径包括基因工程(以长毛象和候鸽项目为特色)、克隆保存的样本(想想《侏罗纪公园》中的琥珀诱捕蚊子)和反向繁殖(一种针对祖先特征的选择性繁殖)。反向繁殖是欧洲野生化计划的选择方法,该计划正在努力重建现代牛的祖先,目标是在整个欧洲鼓励放牧促进生物多样性。

De-extinction has received popular culture attention as well, with Neuralink co-founder Max Hodak tweeting his shower thoughts: “we could probably build Jurassic Park if we wanted to. wouldn’t be genetically authentic dinosaurs but [shrugging emoji]. maybe 15 years of breeding + engineering to get super exotic novel species.”

反灭绝也受到了流行文化的关注,Neuralink联合创始人Max Hodak在推特上发表了他的淋浴想法:“如果我们想,我们可能可以建造侏罗纪公园。”基因上不会是真正的恐龙,但(耸肩的表情符号)也许需要15年的育种和工程技术,才能得到超级外来的新物种。”

Some in the scientific community are skeptical about de-extinction efforts’ ultimate feasibility, citing the novelty of the technology and methods involved, like in Colossal’s case, the fact that eggs have never before been harvested from an elephant. (Also, “All ancient DNA is crap,” explains paleo-geneticist Thomas Gilbert.)

科学界的一些人对反灭绝努力的最终可行性表示怀疑,他们认为所涉及的技术和方法很新颖,比如在Colossal的案例中,从未从大象身上采集过卵细胞。(此外,“所有古代DNA都是废话,”古遗传学家Thomas Gilbert解释道。)

Others are concerned with the ethics of the endeavor, pointing to environmental, animal rights, and other moral considerations. Shapiro’s book How to Clone a Mammoth, for instance, surveys a number of relevant conundrums. 


To begin with, there are environmental questions. Conservation ecologist Dennis Murray thinks candidates for de-extinction should be weeded out according to their probability of harming existing ecosystems and animals. There should be a functional space for chosen candidates in the targeted habitat, and low odds that the population will spin out of control. Oftentimes the land moves on and thrives without a given species, in which case bringing back the species could do more harm than good. If connected organisms up, down, or across the food chain have moved on, de-extincting a creature could amount to introducing an invasive species, one that could decimate or starve out other populations, destroy the landscape, and generally upset the existing balance.     

首先,有环境问题。保护生态学家Dennis Murray认为,应该根据它们对现有生态系统和动物的伤害概率,将它们淘汰掉。在目标栖息地应该为被选中的候选者提供一个功能性空间,减少失控的可能性。在没有特定物种的情况下,土地继续移动并繁荣,在这种情况下,让物种回归可能弊大于利。如果食物链中连接在一起的生物继续生存,那么使某一生物灭绝就相当于引入一种入侵物种,这种物种可能会导致其他种群的灭绝或饿死,破坏景观,并破坏现有的生态平衡。

A group of University of California – Santa Barbara scientists developed a set of species-selection guidelines to try to mitigate some of the potential undesirable ecological outcomes of de-extinction. They recommend choosing recently extinct, functionally unique animals with the ability to return to a healthy-sized population. Despite the best laid plans of scientists and conservationists, however, the results could be a mixed bag in terms of increasing local biodiversity and restoring the land to a previous state. 


Then there is the issue of what rights animals have. London School of Economics philosopher Heather Bushman thinks we should worry about the physical and emotional distress of mammoth-proxies raised outside the confines of devoted communities and family units, which would likely support them in more natural circumstances. “You don’t have a mother for a species that—if they are anything like elephants — has extraordinarily strong mother-infant bonds that last for a very long time,” she explains. The creatures’ distress weighs against other competing goods.

接下来是动物拥有什么权利的问题。伦敦经济学院的哲学家Heather Bushman认为,我们应该担心猛犸象克隆体的身体和精神状态,它们在热心的社区和家庭单位之外长大,这可能会在更自然的环境中支持它们。她解释说:“对于一个物种来说,如果它们像大象一样,但它们没有母亲,这个物种有非常强烈的母子关系,并能持续很长时间。”这些生物的痛苦比其他竞争产品更重要。

Princeton philosopher Peter Singer has also argued that animals deserve moral consideration due to their ability to suffer—to think otherwise, he says, is ‘speciesism,’ an unfounded preference for one’s own kind—and animals’ interests must be taken into account when deciding the maximally beneficial course of action. Some Kantians and virtue ethicists reach similar conclusions about how humans should treat animals, via different logical routes. Others, in the ‘animal rights’ camp, take a stronger position still: that animals bear equal rights to humans and should never be treated as mere means. On this view, any animal experimentation is off limits.  

普林斯顿大学哲学家Peter Singer也认为,由于动物有承受痛苦的能力,它们应该得到道德上的考虑——他说,不这样想就是“物种主义”,是一种对自己同类毫无根据的偏好——在决定最有利的行动方针时,必须考虑动物的利益。一些康德主义者德性伦理学家通过不同的逻辑路径,得出了关于人类应该如何对待动物的类似结论。“动物权利”阵营的另一些人则采取了更强硬的立场:动物与人类享有平等的权利,不应仅仅被当作手段对待。在这种观点下,任何动物实验都是禁止的。

As with other dilemmas involving emerging technologies and various interest groups, weighing and balancing competing claims can prove a complicated undertaking. The issue of de-extinction touches the general public and future generations in addition to scientists, conservationists, the environment, and animals. Thoughtful people disagree, for example, about the moral relevance of potential or currently non-extant beings. While scientists have an interest in advancing their careers and pursuing their passions, careful thought is required about the risks their work could expose the world’s population to, and what decision-makers should be invited to the table given the stakes.


Also at stake is the value of wildness. If biodiversity, or the natural wonder people experience in contemplating long-lost species, are things in themselves valuable and worth pursuing, or are beneficial for their effects in other spheres, that’s a potential point in the de-extinction column, depending on how carefully reintroduction can be managed.


If, on the other hand, experts have reason to believe that the technologies created along the way will ring bells that can’t be unrung, tempt less principled labs or regimes to cross sacrosanct ethical lines, or subject humanity to risks disproportionate to the expected benefits, that may prove argument enough to discontinue de-extinction efforts.


Colossal, for instance, expects “to spin off new forms of genetic engineering and reproductive technology.” Potential applications include drought and disease resistant organisms and improvements to artificial womb technology. The container capable of nourishing for weeks lamb fetuses “developmentally equivalent to the extreme premature human infant” pioneered by the Children’s Hospital of Philadelphia that Colossal hopes to build upon is already influencing abortion debates in surprising ways, for example, as a third option opens up for parents and children.


One reason initiatives like Colossal are difficult to evaluate ethically is their wide range of unknowns and unintended consequences. Decision-makers can’t definitively fill out cost-benefit analyses with only a rough sketch of outcomes and no clear understanding of where the technology might lead, or how it might shape seemingly unrelated discussions.


The mammoth ambitions of de-extinction projects are likely to generate provocative practical and philosophical questions on the way to reviving lost species.