Mammoths?

Remember Jurassic Park? Well now, a team of Harvard biologists are talking about resurrecting the woolly mammoth. But there are many nuances here.

Mammoths died out in the Tundra 4000 years ago. But the mammoth genome has been sequenced from specimens that have been preserved in the Siberian permafrost.

preserved-mammoth

Permafrost preserved body of a baby mammoth                        

The closest living relative of the mammoth is the Asiatic elephant. By comparing the genome of these two animals, scientists can understand at the molecular level how these animals differed. Finally, bits of elephant DNA can be replaced with mammoth DNA.

Woolly Mammoth (left), Asian Elephants(right)

In 2015, the Harvard team had already grown elephant cells in a lab dish with a little but of mammoth DNA. Now they have announced that they are only “a couple of years” away from creating embryos. But a great many challenges and pitfalls remain.

One of the most important ideas to have come into biology in the past 20 years is that DNA is not pre-destiny. The environment in which a creature lives and the kind of challenges it faces actually trigger various parts of the genome and bring out different traits. The genome is then something of a recipe book and which recipe gets used depends on the environment.

To give one extreme example, in reptiles like crocodiles, the gender is determined by the temperature of the nest where the eggs incubate. Temperatures between 32-33C (89.6 to 91.4F) result in male crocodiles while warmer and cooler temperatures result in females.

 nilecrocodile

Nile Crocodile

What this means is that if you were to put a true woolly mammoth embryo inside an elephant, what happens in the womb would still be critical to the animal’s development. The nutrients, environmental conditions and gene regulating hormones the fetus will experience will be those for an elephant. How will the fetus develop in this case is anybody’s guess. Some of the effects of these conditions may not be noticeable till adulthood.

This is not the first time these problems have had to be faced. In 1999, the bucardo or Pyrenean Ibex was facing extinction. The last specimen, a female named Celia was tagged by scientists and her cells were taken and stored. In 2000, she was killed by a falling tree.

pyrenean_ibex

Bucardo

A Franco-Spanish team of scientists led by Jose Folch tried valiantly to bring the species back from the dead. Celia’s DNA was inserted into goat eggs from which the original DNA had been removed. These eggs were then injected into goat surrogate mothers. Of the 57 goats thus impregnated, only one had a successful delivery. Carl Zimmer described what wildlife veterinarian Alberto Fernandez-Arias saw at the birth.

As Fernández-Arias held the newborn bucardo in his arms, he could see that she was struggling to take in air, her tongue jutting grotesquely out of her mouth. Despite the efforts to help her breathe, after a mere ten minutes Celia’s clone died. A necropsy later revealed that one of her lungs had grown a gigantic extra lobe as solid as a piece of liver. There was nothing anyone could have done.

Finally, even if we assume that we are able to produce a healthy mammoth offspring. There are no mammoth matriarchs alive with the necessary gut bacteria to inoculate it to teach the baby how to live like a mammoth, how to survive in the tundra or where the migration paths lie. Finally, how important is it that the steppe the mammoths lived on 4000 years ago has changed forever?

In India, there is the tale of Dina Sanichar. In 1867 hunters discovered a  6 year old boy living in the jungle supposed to have been raised by wolves. He howled like a wolf, walked on all fours and ate from the ground. He was eventually weaned off raw meat which he preferred to cooked food, but never learnt to talk till the day he died in 1895.

At the moment, the Harvard team is focusing on 14 specific genes controlling adaptations necessary for surviving in the cold such as smaller ears, subcutaneous fat, greater hair and cold adapted blood.

As one scientist pointed out we are unlikely to see a mammoth anytime soon. Instead, we are likely to see a very hairy elephant that can survive in snowy conditions.

One scientist estimated the cost of creating a mammoth at around a billion dollars. So why, aside from scientific curiosity (which I totally understand) are we doing this?

The number one reason listed on the project’s website is to confront climate change. With the vanishing of mammoth herds at the end of the Pleistocene, their habitat changed forever. The grassland ecosystem turned into a swampy coniferous forest. Some people believe that the grasslands insulated the tundra’s permafrost which is now melting to release greenhouse gasses trapped for thousands of years. Dr. Sergey Simov believes that reintroducing grazers could restore the biodiverse grassland ecosystem and also insulate the permafrost.

In this respect the introduction of mammoth (or mammophant) herds could be an exercise in ecological management like the reintroduction of wolves in Yellowstone National Park or beavers in Scotland.

References

https://www.theatlantic.com/technology/archive/2013/03/the-10-minutes-when-scientists-brought-a-species-back-from-extinction/274118/

http://www.bbc.co.uk/programmes/p04tv5vl

https://www.theguardian.com/science/2017/feb/16/woolly-mammoth-resurrection-scientists

http://www.livescience.com/1154-global-warming-doom-male-crocodiles.html

http://www.olimba.com/326/10-Feral-Human-Children-Raised-by-Animals

https://www.forbes.com/sites/sarahhedgecock/2017/03/01/what-the-woolly-mammoth-de-extinction-project-actually-means/#733b2ae44a61

http://reviverestore.org/projects/woolly-mammoth/

http://www.scottishbeavers.org.uk/

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