biology

“Mammoth species interbred, perhaps extensively”

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A new study of mammoth DNA suggests that mammoths mated outside of their species. Mammoth tissue specimens reveal that woolly mammoths of cold regions in North America bred with temperate climate Columbian mammoths. The news is surprising to me given the social cohesion of mammoth herds. I would have thought that herds would have resisted advances by bull mammoths with distinctive phenomes.

Phys.org sums up the study:

…By using differences in the size and shape of their fossilized teeth, a number of North American mammoth species have been identified. But, some scientists are not confident this method of species categorization tells the whole story.

“Species boundaries can be very blurry. We might find differences in features of the teeth or skeleton that closely correspond to what we think are real species boundaries. But other features may not correspond to those boundaries, suggesting that what we formerly regarded as separate species are in fact not at all,” explains Hendrik Poinar, a Professor at McMaster University in Canada, who co-led the new study with his former graduate student Jake Enk and collaborator Ross MacPhee, a Professor at the American Museum of Natural History.

Professor Poinar and his co-authors used cutting-edge methods to distinguish species of North American mammoths. Tiny samples of fossilized mammoth bone, teeth and faeces, were generously donated by a number of museums across America and Canada. DNA was extracted from these samples in a specialized laboratory of the Ancient DNA centre at the McMaster University, and used to create a family tree of their evolution. The results proved to be very interesting.

North American mammoths such as the Columbian and Woolly Mammoths were historically thought to originate from two separate primitive species. However, this latest DNA analysis agrees with a more recent idea that all North American mammoths originated from a single primitive species, the Steppe Mammoth.

“Individuals of the Woolly and Columbian mammoths look like they represent different species in terms of their molar teeth, but their genetics say that they were not completely separate in the evolutionary sense and could successfully interbreed,” says Professor MacPhee.

Professor Poinar continues, “Mammoths were much better at adapting to new habitats than we first thought—we suspect that subgroups of mammoths evolved to deal with local conditions, but maintained genetic continuity by encountering and potentially interbreeding with each other where their two different habitats met, such as at the edge of glaciers and ice sheets.”

So, while mammoths clearly evolved differences in their physical appearance to deal with different environments, it did not prohibit them from cross-breeding and producing healthy offspring…

Lab seeks artificial womb for mammoths

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asian elephant calf in the womb

It would be too controversial to implant a woolly mammoth embryo in an endangered Asian elephant surrogate.  Therefore, an artificial mammoth womb must be created.  So says Dr. George Church, the Harvard biologist on a mission to resurrect the mammoths.

Scientific American reports that “editing, birthing and then raising mammoth-like elephants is a huge undertaking. Church says that it would be unethical to implant gene-edited embryos into endangered elephants as part of an experiment. So his lab is looking into ways to build an artificial womb; so far, no such device has ever been shown to work.”

The creation of a mammoth-like uterus would be quite the scientific accomplishment since scientists have yet to master that with existing animals…

Scientist: Mammoths can live again in 7 years

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woolly-mammoth-with-Asian-elephant-shape

In five years, scientists could create a “cold-resistant elephant” (mammoth) embryo.  Gestation in the womb of an Asian elephant surrogate would take another two years.  So says Dr. George Church, a Harvard University biologist.

The mammoth midwives would use CRISPR technology, a breakthrough in DNA sequencing, to mirror Asian elephant genes to the genome of the woolly mammoth.  Church makes it sound simple:  “We could easily make tens of thousands of these elephants.”

Although the genetic basis for the cold-resistant elephants would be the mammoth, Church says that the goals are to protect Asian elephants and to stabilize Arctic habitats.  The Asian elephant population is dwindling for deforestation and herpes.  Having elephants graze in the tundra would reduce carbon emissions by keeping soil temperatures low.

Here’s an excerpt of what Church said in an interview with the Huffington Post:

CRISPR turned out to be easier than expected. The growing of embryos is harder to predict. I would say it will probably take us five years to work out the embryo development part, and then it takes at least two years to go through full gestation. So we might be seeing the first new baby elephants in seven years. Maybe a decade. That’s pretty soon…

I call them cold-resistant Asian elephants. What are unambiguously woolly mammoths are the DNA we’re drawing inspiration from and literally moving from the computer back into Asian elephants. What the hybrid will be called will be up to popular decision making that’s outside of my realm. I’m not going to call them mammoths unless somebody insists. They’re elephants with mammoth DNA.