Back to the future: Mastodon extends the time limit on DNA sequencing

July 24, 2007

In a new paper in the open access journal PLoS Biology, Michael Hofreiter from the Max Planck Institute for Evolutionary Anthropology in Germany, and colleagues from Switzerland and the United States, announce the sequencing of the complete mitochondrial genome of the mastodon (Mammut americanum), a recently extinct relative of the living elephants that diverged about 26 million years ago.

The sequence was obtained from a tooth dated to 50,000–130,000 years ago, increasing the specimen age for which such palaeogenomic analyses have been done by almost a complete glacial cycle.

The mastodon becomes only the third extinct taxon for which the complete mitochondrial genome is known, joining the superficially similar looking woolly mammoth, and several species of Moa, the giant flightless Australasian bird.

Using the mitochondrial genome sequence, together with sequences from two African elephants, two Asian elephants, and two woolly mammoths (obtained from previous work), it was shown that mammoths are more closely related to Asian than to African elephants. This shows the power of genetic data to clarify interrelationships, even in the case of well studied taxa.

Moreover, the researchers used the mastodon data as a calibration point, lying outside the Elephantidae radiation (elephants and mammoths), which enabled them to estimate accurately the time of divergence of African elephants from Asian elephants and mammoths (about 7.6 million years ago) and the time of divergence between mammoths and Asian elephants (about 6.7 million years ago).

These dates are strikingly similar to the divergence time for humans, chimpanzees, and gorillas, and raise the possibility that the speciation of mammoths and elephants and of humans and African great apes had a comm on cause. Despite the similarity in divergence times, the substitution rate within primates is more than twice as high as in proboscideans, showing that the molecular clock ticks differently for different taxa.

Citation: Rohland N, Malaspinas AS, Pollack JL, Slatkin M, Matheus P, et al. (2007) Proboscidean mitogenomics: Chronology and mode of elephant evolution using mastodon as outgroup. PLoS Biol 5(8): e207. doi:10.1371/journal.pbio.0050207.

Source: Public Library of Science

4.5 /5 (22 votes)  

Rank 4.5 /5 (22 votes)
Tags

Relevant PhysicsForums posts

More news stories

Big Society could threaten biodiversity conservation

A study of the Moray Firth Seal Management Plan (MFSMP), in north-east Scotland, identified four key conditions for long-term success, three of which pointed to the importance of direct government involvement.

Biology / Ecology

created 10 minutes ago | popularity not rated yet | comments 0

Biobased approaches examined in fight against zebra chip

Thanks to investigations by scientists-turned-detectives with the U.S. Department of Agriculture (USDA) and other agencies, potato growers in the western United States and abroad now know the identities of ...

Biology / Ecology

created 30 minutes ago | popularity not rated yet | comments 0

New molecule has potential to help treat genetic diseases and HIV

(PhysOrg.com) -- Chemists at The University of Texas at Austin have created a molecule that's so good at tangling itself inside the double helix of a DNA sequence that it can stay there for up to 16 days before ...

Biology / Plants & Animals

created 2 hours ago | popularity 5 / 5 (2) | comments 0 | with audio podcast

Integrated pest management recommendations for the southern pine beetle

The southern pine beetle, Dendroctonus frontalis Zimmermann, is a chronic insect pest within pine forests in the southeastern United States. Under favorable environmental and host conditions, it is an agg ...

Biology / Ecology

created 5 hours ago | popularity not rated yet | comments 0

Germination of Bacillus species which can lead to food poisoning

Some bacteria can form spores (survival capsules) that are particularly resistant to heat. Since sporogenous bacteria can also cause food poisoning and a reduction in food quality, they constitute a significant ...

Biology / Cell & Microbiology

created 1 hour ago | popularity not rated yet | comments 0


Transforming galaxies

(PhysOrg.com) -- Many of the Universe's galaxies are like our own, displaying beautiful spiral arms wrapping around a bright nucleus. Examples in this stunning image, taken with the Wide Field Camera 3 on ...

'Smart' microcapsules in a single step

(PhysOrg.com) -- A new, single-step method of fabricating microcapsules, which have potential commercial applications in industries including medicine, agriculture and diagnostics, has been developed by researchers ...

New ability to regrow blood vessels holds promise for treatment of heart disease

(Medical Xpress) -- University of Texas at Austin researchers have demonstrated a new and more effective method for regrowing blood vessels in the heart and limbs — a research advancement that could have ...

A continent ablaze in auroral and manmade light

The North American continent is literally set ablaze in a confluence of Auroral and Manmade light captured in spectacular new videos snapped by the astronauts serving aboard the International Space Station ...

Ethanol mandate not the best option

Many people are willing to pay a premium for ethanol, but not enough to justify the government mandate for the corn-based fuel, a Michigan State University economist argues.

Nanostructured electrodes for rechargeable sodium-Ion batteries

Highly efficient 3V cathodes for rechargeable sodium-ion batteries have been developed by users from Argonne National Laboratory's Materials Science, Chemical Sciences & Engineering, and X-ray Sciences Divisions, ...