Should Scientists Clone Extinct Species?

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Magdalena Pop
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Cloning makes it possible to bring extinct species back to life. But is that a good idea?

What could be more thrilling than cloning dinosaurs? And then letting them roam free on an island! Well, Jurassic Park showed us how this could have terrifying results.

Did you know?

The gastric brooding frog went extinct in the early 1980s. The scientists behind the Lazarus Project tried to bring it back. TIME magazine named the project one of the 25 Best Inventions of 2013.

That movie was released more than 25 years ago. Now, scientists have figured out how to bring extinct species back to life. 

Species that have gone extinct within the last few thousand years could be candidates for de-extinction. The process is also called resurrection biology or species revivalism. And all it requires is some preserved cells or traces of DNA.

But is it really a good idea to have great auks, sabretooth cats and woolly mammoths roaming the Earth again?

Extinct animals include great auks, sabretooth cats and woolly mammoths
Extinct animals include great auks, sabretooth cats and woolly mammoths (Sources: John Gerrard Keulemans, Wikimedia Commons; Charles R. Knight, Wikimedia Commons and Wikimedia Commons).

How do you clone an animal?

Somatic cell nuclear transfer (SCNT) is one way of cloning an animal. It requires intact cells from an extinct species. First, scientists remove the nucleus from an egg cell of a closely related still-living species. Then they replace it with the nucleus from the cell of the extinct species. 

For example, they could replace the nucleus of an elephant’s egg cell with the nucleus from the cell of a woolly mammoth. This replaces the elephant’s genetic code with that of the woolly mammoth. 

An electrical pulse causes the cell to start multiplying. If all goes well, an embryo will develop. The embryo is then placed in a female animal from the species that provided the egg.

Did you know?

SCNT was used to create Dolly the sheep, the first cloned mammal.  

Somatic nuclear cell transfer was used to clone Dolly the sheep
Somatic nuclear cell transfer was used to clone Dolly the sheep (Adapted from Graphic_BKK1979 via iStockphoto).

However, it can be very hard to find intact cells from extinct species. Usually, scientists can only find pieces of DNA. These partial DNA samples may have been preserved in permafrost or in museum specimens. Pieces of DNA can be used to help reconstruct the genome (genetic blueprint) of an extinct species. 

First, genes responsible for extinct traits are synthesized in a lab. They can then be gradually spliced (inserted) into the genome of a closely related living animal. This process is called genetic engineering.

How have cloning efforts gone so far?

The first attempt at de-extinction was made in 2009. Scientists used preserved cells to clone a Pyrenean ibex. This species of wild goat went extinct in January 2000. 

A Pyrenean ibex (Capra pyrenaica) in Spain
A Pyrenean ibex (Capra pyrenaica) in Spain (Osado [CC BY 3.0] via Wikimedia Commons).

The attempt was successful. However, the clone had a defective lung. It died just seven minutes after it was born. Dolly the sheep suffered a similar fate. She died at the age of six, after tumours were found in her lungs. In fact, most clones are unhealthy and live short lives.

Why do clones often die young? It’s because DNA taken from adult cells has been damaged by aging. Every time a cell divides, there are mutations and small losses of DNA. Over time, this damage builds up. Scientists also damage DNA during the cloning process. This happens no matter how carefully they handle the DNA.  

Did you know?

Scientists could avoid problems related to DNA damage by using stem cells. In fact, stem cells could revolutionize cloning.

Is de-extinction a good idea?

De-extinction supporters say we have a moral obligation to bring back some extinct animal. They point out that humans are directly responsible for the extinction of many species. For example, the passenger pigeon, Steller’s sea cow and the dodo all disappeared because of hunting, habitat destruction and disease. 

Animals made extinct by humans include the passenger pigeon, Steller’s sea cow and the dodo
Animals made extinct by humans include the passenger pigeon, Steller’s sea cow and the dodo (Sources: Laslovarga [CC BY-SA 4.0], Wikimedia Commons; Emőke Dénes [CC BY-SA 2.5], Wikimedia Commons and BazzaDaRambler [CC BY 2.0], Wikimedia Commons).

Supporters also see de-extinction as a way of increasing biodiversity. This could benefit ecosystems. For example, large grazing herbivores like woolly mammoths could improve soil quality. They could turn barren tracts of Siberian tundra back into rich grassland. 

Finally, research on de-extinction could lead to ways of saving endangered species.

De-extinction opponents argue that it could take resources away from conservation efforts. This would put even more species at risk of extinction. 

Also, reintroduced species could have a hard time surviving in the wild. Many of their old habitats are gone. They would lack defence mechanisms to protect themselves from unfamiliar predators. And their immune systems might not be equipped to deal with new pathogens. Once infected, they could spread diseases to other species. 

It’s not at all clear who will win the debate. And we don’t know exactly where research on de-extinction will lead. Clearly, difficult decisions will need to be made. What would you do?

Starting Points

Connecting and Relating

  • If your pet dog or cat died due to old age, would you have it cloned if you could? Why or why not?
  • Would you like to see an animal such as the woolly mammoth brought back from extinction? Why or why not?
  • Would you want yourself or a family member to be cloned? Why or why not?
     

Connecting and Relating

  • If your pet dog or cat died due to old age, would you have it cloned if you could? Why or why not?
  • Would you like to see an animal such as the woolly mammoth brought back from extinction? Why or why not?
  • Would you want yourself or a family member to be cloned? Why or why not?
     

Relating Science and Technology to Society and the Environment

  • What do you think would be the impacts of bringing a woolly mammoth back from extinction? Consider the impacts on science, the environment and society.
  • Would you consider it an animal rights issue to use other species in the process of cloning extinct species (e.g., as surrogate mothers)? Explain. 
  • Research the events around the cloning of Dolly the sheep. What issues and concerns were raised at that time? Are those concerns still relevant today? Explain.
     

Relating Science and Technology to Society and the Environment

  • What do you think would be the impacts of bringing a woolly mammoth back from extinction? Consider the impacts on science, the environment and society.
  • Would you consider it an animal rights issue to use other species in the process of cloning extinct species (e.g., as surrogate mothers)? Explain. 
  • Research the events around the cloning of Dolly the sheep. What issues and concerns were raised at that time? Are those concerns still relevant today? Explain.
     

Exploring Concepts

  • How is cloning done? What is needed to successfully clone an organism?
  • Why do cloned animals tend to die young?
  • What might be the challenges for a cloned species that was brought back into a current environment? 
  • What species have scientists been successful at cloning? What have been the challenges of this process? (This question requires additional research using the Learn More section)
     

Exploring Concepts

  • How is cloning done? What is needed to successfully clone an organism?
  • Why do cloned animals tend to die young?
  • What might be the challenges for a cloned species that was brought back into a current environment? 
  • What species have scientists been successful at cloning? What have been the challenges of this process? (This question requires additional research using the Learn More section)
     

Nature of Science/Nature of Technology

  • Are there regulations that scientists must follow with respect to cloning? Are these rules the same for scientists around the world?
  • Just because we have the expertise to clone animals, do you think it is ethical for humans to be attempting cloning? Explain.
     

Nature of Science/Nature of Technology

  • Are there regulations that scientists must follow with respect to cloning? Are these rules the same for scientists around the world?
  • Just because we have the expertise to clone animals, do you think it is ethical for humans to be attempting cloning? Explain.
     

Media Literacy

  • How have the ways that cloning is portrayed in science fiction movies and novels affected the way society feels about the process? Explain.

Media Literacy

  • How have the ways that cloning is portrayed in science fiction movies and novels affected the way society feels about the process? Explain.

Teaching Suggestions

  • This article can be used to support teaching and learning of Biology, Technology & Engineering, Biotechnology, Genetics and Environmental Science related to  cloning, extinction, genetic modification and biodiversity. Concepts introduced include extinct, DNA, somatic cell nuclear transfer (SCNT), nucleus, embryo, preserved, genome, genes, spliced, genetic engineering, mutations, biodiversity, ecosystems, endangered and pathogens.
  • After reading this article, teachers could have students complete a Concept Definition Web for the concept of cloning. Ready-to-use reproducibles for the Concept Definition Web learning strategy are available in [Google doc] and [PDF] formats. 
  • Using a Consequence Mapping learning strategy, teachers could have students consolidate understanding by considering the potential consequences of using cloning to bring back an extinct species, like a Woolly Mammoth. Download ready-to-use reproducibles using the Consequence Mapping learning strategy in [Google doc] and [PDF]. 
  • To go further and learn more about cloning and the development of this genetic engineering technique, teachers could have students conduct additional research and develop a timeline of cloning innovations. Students could use an online app to create and share their completed timelines (e.g., VISME, Office Timeline Online, Sutori, etc.)

Teaching Suggestions

  • This article can be used to support teaching and learning of Biology, Technology & Engineering, Biotechnology, Genetics and Environmental Science related to  cloning, extinction, genetic modification and biodiversity. Concepts introduced include extinct, DNA, somatic cell nuclear transfer (SCNT), nucleus, embryo, preserved, genome, genes, spliced, genetic engineering, mutations, biodiversity, ecosystems, endangered and pathogens.
  • After reading this article, teachers could have students complete a Concept Definition Web for the concept of cloning. Ready-to-use reproducibles for the Concept Definition Web learning strategy are available in [Google doc] and [PDF] formats. 
  • Using a Consequence Mapping learning strategy, teachers could have students consolidate understanding by considering the potential consequences of using cloning to bring back an extinct species, like a Woolly Mammoth. Download ready-to-use reproducibles using the Consequence Mapping learning strategy in [Google doc] and [PDF]. 
  • To go further and learn more about cloning and the development of this genetic engineering technique, teachers could have students conduct additional research and develop a timeline of cloning innovations. Students could use an online app to create and share their completed timelines (e.g., VISME, Office Timeline Online, Sutori, etc.)

Learn more

Should We Bring Extinct Animals Back To Life? (2016)

Life Noggin (2:54 min.) video discussing how extinct animals may be resurrected as hybrid animals, some ethical concerns, and whether or not it’s even a viable idea

Meet the Gastric-Brooding Frog (2017)

PBS Nova (5:29 min.) video introducing the gastric brooding frog and the experiment that attempted to bring it back from extinction

15 Animals That Have Been Successfully Cloned by Scientists (2017)

Article for Interesting Engineering by Christopher McFadden containing a list of animals that have been successfully cloned and some information about each cloning experiment

How Stem Cell Cloning Works (2013)

Article for Live Science by Karl Tate containing information and an infographic depicting how stem cell cloning might work in humans

Why did the passenger pigeon go extinct? (2020)

An article by The Conversation looks at research that hunters and not loss of their natural habitat that was to blame for the passenger pigeon's extinction.

References

Freudenrich, C. (2001, March 26). How cloning works. HowStuffWorks.

Knight, W. (2003, February 14). Dolly the sheep dies young. New Scientist.

Magdalena Pop

Magdalena Pop is a biochemist and educator working to increase students’ motivation for learning science. Magdalena earned a PhD at the Max Planck Institute for Biophysical Chemistry in Göttingen (Germany), where she did research on human viral infections, primarily HIV/AIDS. In 2001 Magdalena started teaching high-school science in Canada, and in 2013 became a mentor for Alberta's high school teams participating in the international Genetically Engineered Machines (iGEM) competition. Writing articles for CurioCity is one of the ways in which Magdalena follows her passion for sparking genuine excitement and curiosity about science. 

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