Tim Blackburn at University College London and his colleagues compiled data from the Red List on 247 species of plant, amphibian, reptile, bird and mammal that have disappeared since 1500. They found that invasive species are the second most common threat associated with the losses, behind hunting, fishing or harvesting. For amphibians, mammals and reptiles, invasive species were the number one threat.
Much of the conversation about CRISPR–Cas9 has revolved around its potential for treating disease or editing the genes of human embryos, but researchers say that the real revolution right now is in the lab. What CRISPR offers, and biologists desire, is specificity: the ability to target and study particular DNA sequences in the vast expanse of a genome. And editing DNA is just one trick that it can be used for. Scientists are hacking the tools so that they can send proteins to precise DNA targets to toggle genes on or off, and even engineer entire biological circuits — with the long-term goal of understanding cellular systems and disease.
In The Origin of Species (1859), Charles Darwin asserts that “species and groups of species gradually disappear one after another, first from one spot, then from another, and finally from the world.” From the Darwinian perspective, species adaptation and extinction are not only inexorable natural forces, but are also necessary to sustain the astonishing biodiversity of this planet. Of course, Darwin was writing just at the cusp of the modern era, right before industrialization and other anthropogenic factors began to accelerate extinction rates beyond natural background levels. We are now in the midst of a global biodiversity crisis caused by interacting forces such as climate change, the illegal trade in endangered species, habitat loss and ongoing modernization around the globe. Indeed, the International Union for the Conservation of Nature (IUCN) believes that extinction is proceeding at up to 1,000 times or more the natural rate.
Is it heresy to suggest that Darwin’s understanding of extinction may no longer be entirely true? What if we now have the scientific tools to bring back at least some of those disappeared ghost species that haunt our imagination? De-extinction refers broadly to the use of biotechnological tools such as reproductive cloning, genome sequencing and assisted reproduction in the effort to “bring back” extinct species such as the woolly mammoth, the Tasmanian tiger (thylacine), or the moa. Critics worry that de-extinction distracts our focus from those species currently on-the-brink in favor of fantastical “resurrection” projects and contend that scarce conservation resources are best spent on those extant species that we could potentially save. Yet de-extinction done ethically could enrich global biodiversity by reintroducing “lost genes” to the global genome and re-instating keystone species that played an important role in maintaining healthy ecosystems that are now under threat. We do not have to pit conservation against de-extinction; instead, we need to start thinking now about how we can harness all of the tools at our disposal to reinvigorate the environmental movement and replenish nature.
The Genetic Rescue Foundation is an increasingly visible stakeholder in the de-extinction and bio-conservation debate. Started by David Iorns, an expat Kiwi who lives and works in Silicon Valley, the Genetic Rescue Foundation uses innovative methods such as crowdfunding and social media to generate broad public and financial support for the use of biotechnology in conservation. Recently, the Foundation launched The Kakapo 125 Project, which intends to sequence the genome of every remaining live kakapo in New Zealand. The information gleaned from the project will be invaluable in ensuring that this iconic Kiwi species has the best possible chance to survive into the 21st century.
The Genetic Rescue Foundation is also a key player in a collaborative effort to bring back the moa. Originally, the island that became New Zealand hosted nine different species of these flightless birds (Dinornithiformes). Approximately 600 years ago, the moa abruptly went extinct for reasons that have been scientifically contested. The dominant theory today, based on recent ancient DNA studies, suggests that the moa’s demise was caused primarily by the arrival of Polynesians who hunted them, though variables such as climate change, disease or volcanic eruptions have also been mooted. As early as 1922, the Dunedin Star newspaper noted that “one of the oldest and certainly one of the most heated scientific controversies that ever engaged the attention of the New Zealand public was that which raged over the question as to the date of extinction of the moa.” Archival analysis further suggests that Kiwi interest in the moa dovetailed with both the public dissemination of Darwinian ideas about evolution in the late 1800s, and again with the early stirrings of a national—as opposed to colonial—identity immediately following World War I.
Today the moa is considered an iconic species, associated with a lush, primeval New Zealand that teemed with kiwis, kakapos and giant eagles. The moa is also a species at the forefront of international efforts to accomplish de-extinction over the long-term. The elusive elixir that could make de-extinction possible for the moa (among other species) is so-called “ancient DNA.” Around the world, scientists are revisiting bones and other specimens long locked up in natural history museums to see if these talismans might contain fragments of viable DNA that can then be amplified in the lab and,potentially, used in reproductive cloning projects. Thus far, the news on this front is mixed, with a recent analysis of four moa samples by the UCSC Paleogenomics Lab indicating the samples are too degraded to yield anything but a minute amount of endogenous DNA that would be prohibitively expensive to sequence. At the moment, the search for a well-preserved moa bone goes on.
The idea of bringing back the moa—as with bringing back the thylacine or the woolly mammoth—is a controversial one that sparks a great deal of public and scientific debate. Of course, public attention to the extinction crisis is one of the most important things that an organization such as the Genetic Rescue Foundation can generate. Even if the moa project does not succeed, the dialogue that has ensued and the associated knowledge and projects that can spin off from this effort are themselves invaluable contributions to our natural heritage. De-extinction—complicated, controversial and conditional—has already succeeded in bringing new enthusiasm and sources of funding into the conservation arena. If we resist the notion that extant and extinct species are in competition with each other, and focus instead on biological and environmental enrichment in the deepest sense, de-extinction could prove a journey into the past that ensures our environmental future.
|Amy L. Fletcher, PHD
Associate Professor of Political Science (The University of Canterbury) and Advisory Board Member of The Moa Revival Project, 1 March 2016
For those of you following our efforts to sequence the moa genome my apologies for the delay in publishing this update. It took a bit of time for our latest batch of samples to find their way to the UCSC Paleogenomics Lab.
Just completed the analysis of the last four samples. These are better preserved than the previous samples, but still pretty poor. The best two samples are only around 1.5% endogenous DNA (so 98.5% environmental DNA), which would make it a very expensive genome sequencing project. My recommendation would be to keep looking for a well preserved bone.
So unfortunately our second batch of samples have yielded only slightly better results than the first. I’ve discussed the sequencing efforts with many of the world’s ancient DNA and moa experts. They all agree that finding a well preserved sample is essential and that there’s not much you can do to guarantee your selected sample is high quality.
So what are the next steps?
At the moment our next plan is to undertake an excavation. There are many promising sites that have not yet been explored including anaerobic swamp locations that hold great promise for preservation.
We’re still determining the target location for the excavation. Once a site has been selected we will invite anyone who has contributed to the moa genome sequencing campaign to join us as we attempt to excavate a “fresh” specimen. Many of the preservation problems appear to be related to decay post excavation. In other words once the specimens are out of ground they decompose more quickly. We’re hoping that if we can excavate and cryopreserve rapidly then we will succeed in sourcing a sample of sufficient quality to sequence in detail.
Thank you to everyone who has supported the campaign so far. I wish I could have better news to share with you. However an excavation is an exciting proposition that presents a great opportunity to involve the community who have supported this work to-date.
Let me embrace thee, sour adversity, for wise men say it is the wisest course.
Genetically modified mosquitoes that would help fight the Zika virus are getting urgent attention from U.S. regulators as global health officials raise alarms about the pathogen’s spread.
The U.S. Food and Drug Administration is in the final stages of reviewing an application from Intrexon Corp.’s Oxitec unit to conduct a field trial in the Florida Keys, Oxitec Chief Executive Officer Hadyn Parry said in a phone interview. Parry wasn’t able to provide further details on the timing of an FDA decision.
Oxitec genetically modifies the males in a breed of mosquito known as Aedes aegypti — responsible for transmitting Zika, Dengue, Chikungunya and Yellow Fever — so that their offspring die young. The Zika virus has been spreading “explosively” in South and Central America, the World Health Organization said Thursday. Developing a vaccine could take years, drugmakers and health experts have cautioned.
Meet the Time-Traveling Scientist Behind Editas, the Biotech Company Going Public With Google’s Help
On March 15, 2013, genetic engineer George Church stood in the middle of a circular red rug onstage at the Gilbert H. Grosvenor Auditorium in Washington, D.C., describing a detailed plan for bringing a six-ton, 10-foot, fur-covered creature back from the dead.
By splicing genes responsible for traits like thicker hair, subcutaneous fat and curving tusks into the DNA of an Asian elephant, Church hopes to revive the long-extinct woolly mammoth, or at least create a version of the modern elephant that really likes the cold.