How Should DeExtinction be Used? Zoos or Ecological Restoration?

Can the woolly mammoth be brought back from the dead? Scientists say it's only a matter of time.

In fact this year, the International Union for Conservation of Nature issued its first official set of guidelines on resurrecting extinct species. What's more, university research labs and non-governmental agencies have projects in motion to bring back extinct species. But is all of this a good idea?

A new paper by UC Santa Barbara researchers explores de-extinction -- the process of resurrecting an extinct species -- as a potential win for conservation and suggests how to make it so.

In an analysis in the journal Functional Ecology, UCSB ecologist Douglas McCauley and colleagues recommend several ways in which the science of de-extinction would have to evolve in order to make it maximally benefit ecological communities and ecosystems.

"The idea of de-extinction raises a fundamental and philosophical question: Are we doing it to create a zoo or recreate nature?" said co-author Benjamin Halpern, director of UCSB's National Center for Ecological Analysis and Synthesis. "Both are reasonable answers, but restoring species to a natural state will be a much, much harder endeavor. We offer guidelines for how to make ecological de-extinction more successful and how to avoid creating 'eco-zombies.' "

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St Paul Mammoths Went Extinct 5,600 Years ago

While the Minoan culture on Crete was just beginning, woolly mammoths were disappearing from St. Paul Island, Alaska, according to an international team of scientists who have dated this extinction to 5,600 years ago.

"It's amazing that everything turned out so precisely with dating of extinction at 5,600 plus or minus 100 years," said Russell Graham, professor of geosciences, Penn State."

St. Paul Island lies about 400 miles north of the Aleutian Islands and was part of the Bering Land Bridge before sea level rose when the last glacial period ended. Previous researchers radiocarbon-dated remains of five mammoths to about 6,480 years ago, but there was no way to know if these were the last five animals.

The researchers used a variety of proxies to date the demise of the mammoths on the island. Proxies are things in the environment that can be used to independently document the presence of an organism, even though they are not parts of it. In this study, three different spores from fungi that grow on large animal dung were extracted from lake cores and used to determine when the mammoths were no longer on the island. Proxies in sediments from cores from a lake near the cave were used to determine the time of the demise of the mammoth population.

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The Tools and Weapons Used to Hunt Mammoths in Poland 24,000 Years ago

Mammoth hunting – Impact traces on backed implements from a mammoth bone accumulation at Kraków Spadzista (southern Poland)
Authors:

Kufel-Diakowska et al

Abstract:

This article presents the results of use-wear analysis of the backed implements (shouldered points and backed blades) discovered at Kraków Spadzista, trench B + B1. Of the 197 examined tools, 113 specimens (55%) bear traces of use. In this group, 55 artefacts show a complete set of clear, characteristic impact traces and could be interpreted as the flint parts of thrown weapons. They were used in mammoth hunting at the Kraków Spadzista site 24 thousand years ago. The hafting method can be identified on the basis of the direction of linear traces and impact negatives. Most of these artefacts were placed at the top of wooden or bone shaft. Only single specimens were attached laterally.

Mammoth Evolution and Dispersal Across the Northern Hemisphere

Evolution and dispersal of mammoths across the Northern Hemisphere

Authors:

Lister et al

Abstract:

le of species origins and dispersal, but understanding has been impeded by taxonomic confusion, especially in North America. The Columbian mammoth Mammuthus columbi was thought to have evolved in North America from a more primitive Eurasian immigrant. The earliest American mammoths (1.5 million years ago), however, resemble the advanced Eurasian M. trogontherii that crossed the Bering land bridge around that time, giving rise directly to M. columbi. Woolly mammoth M. primigenius later evolved in Beringia and spread into Europe and North America, leading to a diversity of morphologies as it encountered endemic M. trogontherii and M. columbi, respectively. In North America, this included intermediates (“M. jeffersonii”), suggesting introgression of M. primigenius with M. columbi. The lineage illustrates the dynamic interplay of local adaptation, dispersal, and gene flow in the evolution of a widely distributed species complex.

12,000 Year Old Michigan Mammoth Likely Butchered by PaleoIndians

Paleontologists from the University of Michigan have uncovered a thrilling find only 10 miles south of Ann Arbor near the town of Chelsea, Michigan. A partial skeleton of a 12,000 year old mammoth was discovered—including parts of its skull, tusks, pelvis, and shoulder blades—but that’s not all. Dig leader and University of Michigan professor of paleontology Daniel Fisher said that the site has “excellent evidence of human activity” preserved with the mammoth remains.

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The Mammoths of Wrangel island

Evolution: The Island of Misfit Mammoths

Author:

Roca

Summary:

The genomes of two woolly mammoths have been sequenced. One of the last survivors had reduced genetic diversity. Although divergent in their mitochondrial genomes, the mammoths had similar nuclear genomes, a finding germane to elephant conservation.

One Small Step to a Woolly Mammoth: Genome Fully Sequence, Cold Adaptions IDed

Elephantid Genomes Reveal the Molecular Bases of Woolly Mammoth Adaptations to the Arctic

Authors:

Lynch et al

Abstract:

Woolly mammoths and living elephants are characterized by major phenotypic differences that have allowed them to live in very different environments. To identify the genetic changes that underlie the suite of woolly mammoth adaptations to extreme cold, we sequenced the nuclear genome from three Asian elephants and two woolly mammoths, and we identified and functionally annotated genetic changes unique to woolly mammoths. We found that genes with mammoth-specific amino acid changes are enriched in functions related to circadian biology, skin and hair development and physiology, lipid metabolism, adipose development and physiology, and temperature sensation. Finally, we resurrected and functionally tested the mammoth and ancestral elephant TRPV3 gene, which encodes a temperature-sensitive transient receptor potential (thermoTRP) channel involved in thermal sensation and hair growth, and we show that a single mammoth-specific amino acid substitution in an otherwise highly conserved region of the TRPV3 channel strongly affects its temperature sensitivity.

The Last Woolly Mammoths on Wrangel Island Circa 2,300 BC Were Very Inbred

Before the world's last woolly mammoth took its final breath, the iconic animals had already suffered from a considerable loss of genetic diversity. These findings, based on a comparison of the first complete genome sequences isolated from two ancient mammoth specimens, are reported in the Cell Press journal Current Biology on April 23.

One of those mammoths, representing the last population on Russia's Wrangel Island, is estimated to have lived about 4,300 years ago. The other specimen, from northeastern Siberia, is about 44,800 years old. The younger of the two specimens showed much lower genetic variation, including large stretches of DNA with no variation whatsoever - the mark of living in a very small population in which related individuals unavoidably mate with each other.

"We found that the genome from one of the world's last mammoths displayed low genetic variation and a signature consistent with inbreeding, likely due to the small number of mammoths that managed to survive on Wrangel Island during the last 5,000 years of the species' existence," says Love Dalén of the Swedish Museum of Natural History.

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Harvard Geneticist Inserts Woolly Mammoth Genes Into Elephant Cells Using CRISPR

Researchers from Harvard University have successfully inserted genes from a woolly mammoth into living cells from an Asian elephant, the extinct giant's closest remaining relative.

Harvard geneticist George Church used DNA from Arctic permafrost woolly mammoth samples to copy 14 mammoth genes -- emphasizing those related to its chilly lifestyle.

"We prioritized genes associated with cold resistance including hairiness, ear size, subcutaneous fat and, especially, hemoglobin," Church told The Sunday Times.

Then, using a kind of DNA cut/paste system called CRISPR (clustered regularly interspaced short palindromic repeat), Church dropped the genes into Asian elephant skin cells.

The result? A petri dish of elephant cells functioning normally with mammoth DNA in them, marking the first time mammoth genes have been on the job since the creature went extinct some 4,000 years ago, as Sarah Fecht, from Popular Science, noted.

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15 Sites are Considered Undisputed Examples of Clovis Era Human Predation of Megafauna

Revisiting Paleoindian Exploitation of Extinct North American Mammals

Authors:

Grayson et al

Abstract:

In 2002, we assessed all sites known to us that had been suggested to provide evidence for the association of Clovis-era archaeological material with the remains of extinct Pleistocene mammals in North America. We concluded that, of the 76 sites we assessed, 14 provided compelling evidence for human involvement in the death and/or dismemberment of such mammals. Of these sites, 12 involved mammoth (Mammuthus), the remaining two mastodon (Mammut). Here, we update that assessment. We examine Clovis-era, and earlier, sites reported since 2002, as well as sites examined previously but for which additional information has become available. Our assessment leads us to exclude Hebior (Wisconsin) from the list of accepted sites, and to add El Fin del Mundo (Sonora) and Wally’s Beach (Alberta). There are now 15 sites on our list, providing what we find to be compelling evidence for human involvement in the death and/or dismemberment of five genera of now-extinct late Pleistocene mammals: Equus, Camelops, Cuvieronius, Mammut, and Mammuthus. As in 2002, however, we note this is a small fraction of the 37 genera that disappeared at the end of the Pleistocene, and for this and other reasons we remain highly skeptical that human overkill was responsible for their extinction.

Using Magnesium Isotopes to Determine Paleodiets

Magnesium stable isotope ecology using mammal tooth enamel

Authors:

Martin et al

Abstract:

Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (δ13C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (δ44Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (δ26Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for δ26Mg, δ13C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that δ26Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this 26Mg enrichment up the trophic chain is due to a 26Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using δ26Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel δ26Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages.

Mammoths, Mastodons From Ohio did *NOT* Migrate

Their scruffy beards weren't ironic, but there are reasons mammoths and mastodons could have been the hipsters of the Ice Age.

According to research from the University of Cincinnati, the famously fuzzy relatives of elephants liked living in Greater Cincinnati long before it was trendy – at the end of the last ice age. A study led by Brooke Crowley, an assistant professor of geology and anthropology, shows the ancient proboscideans enjoyed the area so much they likely were year-round residents and not nomadic migrants as previously thought.

They even had their own preferred hangouts. Crowley's findings indicate each species kept to separate areas based on availability of favored foods here at the southern edge of the Last Glacial Maximum's major ice sheet.

"I suspect that this was a pretty nice place to live, relatively speaking," Crowley says. "Our data suggest that animals probably had what they needed to survive here year-round."

[...]

Mammoths ate more grasses and sedges than mastodons, which favored leaves from trees or shrubs.

Strontium from all of the animals (except one mastodon) matched local water samples, meaning they likely were less mobile and migratory than previously thought.

Differences in strontium and carbon between mammoths and mastodons suggest they didn't inhabit the same localities.

Mammoths preferred to be closer to the retreating ice sheet where grasses were more abundant, whereas mastodons fed farther from the ice sheet in more forested habitat.

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DeExtinction: Efforts at Harvard are Underway to "Bring Back" the Woolly Mammoth

There's a mission to bring back one of history's most famous animals, it's already underway, and it's closer to becoming a reality than even some of the most forward-looking minds think it is.

For all the talk and attention it gets, de-extincting an animal isn't exactly easy—it's difficult to clone cells from an animal that has been dead for thousands of years, tougher to turn it into a viable embryo, and, most importantly, more difficult still to find a closely-related animal that can serve as a surrogate mother to give birth to the cloned animal. There's certainly work still being done in that area, but, increasingly, researchers are working to hybridize existing animals with extinct ones in order to create what Brand calls a "2.0" version of the animal.

That's what Harvard synthetic biologist George Church is doing with woolly mammoths. Using a genome editing technique known as CRISPR, Church is working on inserting three key genes from woolly mammoths into Asian elephant cells, with the hope of eventually creating a hybrid between the two that will ideally be more mammoth-like than elephant-like.

The project and technology has been touched on before, most notably in a lengthy New York Times Magazine article from February, but Church tells me that the team has now successfully migrated the three genes, which gave the woolly mammoth its furry appearance, extra layer of fat, and cold-resistant blood. In theory, given what we know about both the woolly mammoth genome and the Asian elephant genome, the final product will be something that more closely resembles the former than the latter.

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(more info)

Wooly Mammoth Blood Extracted?

Read it here and here.

Wooly-Columbian Mammoth Hybrid Found?

Mammoths were a diverse genus that roamed across Eurasia and North America during the Pleistocene era. In continental North America, at least two highly divergent species have long been recognized – woolly mammoths (Mammuthus primigenius) and Columbian mammoths (M. columbi). But new genetic evidence published in BioMed Central's open access journal Genome Biology suggests that these species may have been closely related enough to mate when they had the chance.

Remains of woolly mammoths have been found across the glacial tundra-steppe of Eurasia and northern North America, while the much physically larger Columbian mammoths inhabited the savannah environments of temperate southern and central North America. The differences between the species have long been considered as unique adaptations to the environments where they evolved. But by piecing together trace fragments of DNA from an 11 thousand year-old Columbian mammoth from Fairview, Utah, a team of Canadian, American and French researchers found that surprisingly the mitochondrial genome from this mammoth was nearly indiscernible from that of its northern woolly counterparts.

But the group does not suspect that this requires a re-write of North American mammoth evolution. "We think this individual may have been a woolly-Columbian hybrid," says Jacob Enk of the McMaster Ancient DNA Centre, the group that led the research. "Living African elephant species interbreed where their ranges adjoin, with males of the bigger species out-competing the smaller for mates. This results in mitochondrial genomes from the smaller species showing up in populations of the larger. Since woolly and Columbian ranges periodically overlapped in time and space, it's likely that they engaged in similar behaviour and left a similar genetic signal." The team goes on to suggest that interbreeding may explain some mammoth fossils that have intermediate physical characteristics, between woollies and Columbians, sometimes assigned to the species M. jeffersonii.

They do not rule out other explanations however, and note that the only way to know for sure whether their mammoth was a hybrid is to sequence nuclear DNA from it and other mammoths. For poorly-preserved remains like those of southern-ranging Columbians, this will be a challenge. But they expect that by exploiting new cutting-edge sequencing technologies, the nuclear genomes of these amazing animals are within reach.

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