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2015 August 2

De-extincting mammoths

Filed under: home school — gasstationwithoutpumps @ 09:48
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I had posted a picture without much content that was on of my most popular blog posts: Bring back the mammoth! and in April I noticed that Beth Shapiro (a UCSC professor in ancient DNA) had published a book, How to Clone a Mammoth.  My wife bought the book from Bookshop Santa Cruz, and I just finished reading it.

There was not much new technical material in the book for me (I’ve been to several of Beth Shapiro’s and Ed Green’s talks about ancient DNA, and I’ve read papers and heard talks on the CRISPR/CAS9 system for editing DNA), but the book is a well-written description of the technology and of the ethics involved in de-extinction. Dr. Shapiro has a fine sense of humor, so book is highly readable without the dry academic tone that mars many books written by professors.

The reading level of the book is carefully judged to be accessible to most adults (about a high-school reading level), and the content should be accessible to high-school students and advanced middle-school students.  Despite the title, the book does not contain any detailed instructions on the techniques and processes used in recovering ancient DNA or editing genomes (most of which are tedious and difficult even for the grad students and postdocs who do them routinely). It does, however, provide a broad overview of the processes involved, what their limitations are, and why one might want to recover a species from extinction besides the “coolness” factor.

Dr. Shapiro is clearly in favor of de-extincting some species, but is also very clear that what she means by this is not what some people assume. She does not believe that it is possible to bring back mammoths and passenger pigeons as they were originally. What is feasible is to recover some of their lost genes and put them into closely related species (like Asian elephants and band-tailed pigeons), to get a hybrid species that can (perhaps) fill the ecological niches vacated by the extinct species.  That is, we can’t get the original mammoths back, but we may be able to create a mammoth-like elephant that looks like a mammoth and can survive in the cold the way mammoths did.

She makes a good case for the environmental benefits for reintroducing some species to habitats that have lost them—particularly large herbivores like mammoths and giant tortoises, but she also presents the case against reintroduction fairly clearly (though her position is clear).

I highly recommend the book for high-school biology students, particularly home-schooled students, who have time to ponder some of the difficult ethical questions involved in de-extinction.

2015 April 19

How to clone a mammoth

Filed under: Uncategorized — gasstationwithoutpumps @ 21:42
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One of my most popular blog posts was a tongue-in-cheek one, Bring back the mammoth!, which has had almost 3000 views since I wrote it. Now a UCSC assistant professor has written a serious book on the subject:

Biologist Beth Shapiro explains the science of ‘de-extinction’ in new book

A leading expert on ancient DNA, Shapiro aims to separate science from science fiction in her new book ‘How to Clone a Mammoth’

April 13, 2015

By Tim Stephens

Tired of answering questions about cloning mammoths, Beth Shapiro, a professor of ecology and evolutionary biology at UC Santa Cruz, wrote a book called How to Clone a Mammoth. (Spoiler Alert: You can’t actually clone a mammoth.)

See Biologist Beth Shapiro explains the science of ‘de-extinction’ in new book for the rest of the press release.

Maybe this summer I’ll have time to read the book.

2011 January 18

Bring back the mammoth!

Filed under: Uncategorized — gasstationwithoutpumps @ 16:46
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According to Daily Yomiuri Online, scientists aim to bring mammoth back to life.

The plan is to extract mammoth DNA from frozen mammoth cells and put it into elephant eggs. I wonder how much damage the DNA of the mammoth cells has taken. Does the genome need to be repaired before putting it into elephant egg cells? They claim “Iritani’s team devised a technique to extract the nuclei of eggs—only 2 percent to 3 percent are in good condition—without damaging them.”

I wonder how well growing a mammoth fetus in an African elephant will work. Have they even managed to clone an elephant? Can they get successful gestation between different extant elephant species?

According to Cristian Capelli, Ross D.E. MacPhee, Alfred L. Roca, Francesca Brisighelli, Nicholas Georgiadis, Stephen J. O’Brien, Alex D. Greenwood, A nuclear DNA phylogeny of the woolly mammoth (Mammuthus primigenius), Molecular Phylogenetics and Evolution, Volume 40, Issue 2, August 2006, Pages 620-627, ISSN 1055-7903, DOI:10.1016/j.ympev.2006.03.015, mammoths are more closely related to Asian elephants than to either Savannah African or Forest African elephants.  So why are they planning to use an African (presumably Savannah African) elephant as the egg donor and host mother?  Availability of donor eggs from a dead zoo elephant perhaps?  In fact, the phylogeny given in that paper suggests that mammoths are closer to Asian elephants than either is to the African species, so choosing an African elephant as the host and egg donor makes even less sense to me.

I think that they need to do a bit more experimenting with existing elephant genomes before they try mammoths.

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