Beth Shapiro on How to Clone a Mammoth:
In the time since How to Clone a Mammoth was published, I can report with confidence that a total of zero mammoths have been cloned. However, the technology that would be necessary to bring extinct species (or, more accurately, extinct traits) back to life continues to develop. To me, the most exciting progress has come from the growing community of scientists and other stakeholders who are interested in using genetic engineering approaches as a tool for conservation: a developing field of research known as genetic rescue.
Genetic rescue can mean several things. First, genetic rescue can be a new approach to help to save endangered species from extinction. Some species, such as the black-footed ferret, are under threat from extinction because their populations recently went through a population bottleneck, or a period of time when the population was very small. Population bottlenecks can be associated with dramatic losses in genetic diversity, which can be bad for the species. Black-footed ferrets that survived their population bottleneck are highly susceptible to disease, which may be due in part to the loss of genetic diversity that occurred during the bottleneck. Their susceptibility to disease hinders their conservation, as captive-bred individuals often die soon after release into their natural habitat. However, some natural history museums and the San Diego Zoo’s Frozen Zoo have older black-footed ferrets in their collections—black-footed ferrets that lived prior to their bottleneck. Because these animals lived prior to the bottleneck, their genomes will represent the diversity that used to be present in the population. Using genome-engineering technologies, scientists might be able to edit the genomes of living black-footed ferrets and introduce some of this extinct diversity, which may improve chances that the surviving population does not go extinct.
Genetic rescue can also refer to preserving an entire ecosystem. For example, although the idea is controversial, some scientists are hoping to use genome-editing technologies to help control the spread of the Zika virus. The goal would be to modify the genomes of male mosquitoes so that their offspring do not live long enough to reproduce. In fact, the US Food and Drug Administration reviewed an application to conduct field trials of these genetically modified mosquitoes in Florida. Another approach might be to modify mosquitos so that they are infertile, and to do so in a way that causes the genome to actually edit itself. While gene drives are a potentially powerful approach to control diseases, some scientists fear that gene drives could have long-term impacts on species and ecosystems, and that the risks of using this technology are not yet well enough understood. In December 2016, however, a meeting of the United Nations Convention on Biodiversity rejected calls for a global stop to research on gene drives, citing the great potential of these technologies.
Genetic rescue is not the same thing as de-extinction, but the motivation is the same: to restore interactions between species, or between species and their environment, so as to promote a healthy and diverse ecosystem. I’m thrilled that biotechnological solutions to this end are continuing to develop, and that many people seem willing to accept at least some risk and allow their use. I’m looking forward to big developments in 2017 (but these will not include the birth of a mammoth—sorry!).
Beth is an associate professor of ecology and evolutionary biology at the University of California, Santa Cruz, and director of evolutionary genomics at the UCSC Genomics Institute. Her work has appeared in numerous publications, including Nature and Science, and she was a 2009 recipient of the MacArthur Award. She lives in Santa Cruz.
Her book, How to Clone a Mammoth: The Science of De-Extinction, was the winner of the 2016 AAAS/Subaru SB&F Prize for Excellence in Science Books in the Young Adult Science Book category.
Photo Credit: Photo Credit: Kris Krüg.
GOING FURTHER
- Book/Author Resources
- In this talk with the Long Now Foundation, Beth spans the full de-extinction narrative from DNA editing all the way to revived populations in the wild—from lab work with CRISPR Cas 9 and primordial germ cells through to the ethical and practical issues of restoring a long-absent keystone species in its former ecosystem.
- Beth talks about How to Clone a Mammoth with C-SPAN2's BookTV.
- In this interview on NPR's All Things Considered, Beth talks about "If Science Could 'Clone A Mammoth,' Could It Save An Elephant?"
- Watch Beth's book trailer for How to Clone a Mammoth.
- The University of California, Santa Cruz, Paleogenomics Lab, where Beth works.
- Beth's homepage at the University of California, Santa Cruz.
- Ancient DNA, Genetic Rescue, and De-Extinction
- If you want to learn more about DNA generally, DNA from the Beginning is an animated website on the basics of DNA, genes, and heredity.
- In the "Jurassic Park" movies, scientists re-created living dinosaurs from fossilized DNA. That's science fiction, but recently, real-life scientists reconstructed the entire genetic code of an extinct cave bear. You can learn more by listening to the Cave Bear Science Update.
- CRISPR is one of the tools scientists use to look at Ancient DNA. In this video, you can watch how a group of scientists created a new technique to specifically change the DNA sequence of any organism. You can also learn about this tool, which was named the 2015 Breakthrough of the Year by Science Magazine, in this blog post.
- In Sculpting Evolution, gene drives are explained.
- Understanding Evolution explores bottlenecks and founder events.
- Scitable defines a population bottleneck.
- Learn more about Sequencing Ancient DNA in this video about the Paleogenetics Lab.
- Beth asks What to Bring Back? in this video.
- Watch as Beth explores Ancient DNA—What It Is and What It Could Be at TEDxDeExtinction.
- Beth answers the question, What Is De-Extinction? in this video.
- The Long Now Foundation explores What Genetic Rescue Means.
- What Are Traits? The Genetic Science Learning Center answers that question.
RELATED EDUCATOR RESOURCES
- In the accompanying Science NetLinks lesson on How To Clone a Mammoth, students develop an understanding of various challenges and issues with bringing extinct species back to life.
- The Introduction to Natural Selection lesson helps students develop an understanding of natural selection, specifically, how it unfolds from generation to generation.
- In the Extracting DNA lesson,students develop understanding of DNA by modeling the process of DNA extraction.
- The Cracking the Genetic Code lesson explores what the knowledge of DNA can tell us about ourselves and other organisms and species.
- In the A Mendel Seminar lesson, students learn about Gregor Mendel's discovery of a process of biological evolution: how recessive and dominant traits are passed on.
- If you want to explore the concept of extinction with your students, the Mammoth Extinction lesson, in which students explore various hypotheses concerning the extinction of the woolly mammoth, would be particularly relevant. Students who need additional review may find The Rise and Fall of the Mammoths lesson, in which students examine the evidence for evolution using the woolly mammoth and related species, informative.
- If students are struggling with basic DNA concepts, it may help to review the Gene Puzzles lesson with them. In this lesson, students examine a fictional pedigree and determine which gene is responsible for a given trait.
- Advanced students may be interested in some of journal articles Beth has contributed to. Three of them are accessible to the public: "What Is Speciation?" (2016) in PLOS Genetics; "Whole-genome sequence analysis shows that two endemic species of North American wolf are admixtures of the coyote and gray wolf" (2016) in Science Advances; and "Whole-genome analyses resolve early branches in the tree of life of modern birds" (2014) in Science.