Ancient Dog DNA Shows Early Spread Around the Globe

Among the other findings, Dr. Larson said he found it particularly intriguing that once dogs had become domesticated, and even while they were sometimes breeding with wolves, no new wolf DNA entered their genomes.

By contrast, pigs, for example, were brought to Europe by farmers from Anatolia. But the genes of those first domesticated pigs have been completely lost, replaced by the genes of wild European boars, even though the pigs stayed domesticated animals.

While dogs do interbreed, no new wolf genes survive over the years. One possibility, Dr. Larson said, is that “wolfiness” just doesn’t fit with an animal as close to people as a dog. Pigs can be a little wild but “if you’re a dog and you’ve got a little bit of wolf in you, that’s not a good thing and those things get knocked on the head very quickly or run away or disappear but they don’t get integrated into the dog population.”

Dr. Skoglund said another intriguing and unexplained finding from the genome data was how fast dogs spread around the globe, and diversified, so that by 11,000 years ago, not only were there five distinct lineages, but some fossil DNA also showed that those lineages had begun to recombine.

“How did that happen?” he said. “In ancient humans, we don’t really know of any human expansion that would have facilitated this, on the order of 15 to 30,000 years ago.”

In the past 11,000 years, he said, the dog genomes showed the evidence similar to that in human genomes of Anatolian farmers moving into Europe. But then there was the sudden loss of diversity in dogs starting around 4,000 years ago.

Also migrations from the steppes changed human genomes in Europe, but had almost no effect on dog genomes. Conversely, migrations from the steppes eastward left an imprint on dog genomic history, but not on humans.

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Researchers outline how marine reserves can benefit fisheries across the globe

marine reserve
Credit: CC0 Public Domain

Society will require more food in the coming years to feed a growing population, and seafood will likely make up a significant portion of it. At the same time, we need to conserve natural habitats to ensure the health of our oceans. It seems like a conflict is inevitable.

“Marine protected areas are tools commonly used to conserve marine biodiversity by closing parts of the ocean to fishing,” said Reniel Cabral, an assistant researcher at UC Santa Barbara’s Environmental Market Solutions Lab. “This creates a potential dilemma when closures cause fishers to lose access to fishing grounds.”

A new study indicates that this need not be the case. The paper outlines where the benefits of fishing restrictions could enable a fishery to become more productive, even with the closures. The research, published in the Proceedings of the National Academy of Sciences, lays the groundwork for expanding marine conservation alongside fishery catches.

The benefits of a well-considered marine protected area (MPA) can bolster the productivity of surrounding fisheries, especially when those fisheries are overexploited. The refuge enables populations to rebuild and then spill over into surrounding waters. Protecting an area from fishing also enables resident fish to grow older and larger, and scientists have found that these fish are proportionately more fertile than their smaller counterparts.

What’s more, fishing is not well regulated in many regions. The activity can be decentralized and target many different species using a variety of methods. Managing the industry can be nearly impossible, especially for agencies that are underfunded and underpowered. In this context, designating an MPA is relatively simple, especially compared to other management strategies.

“Past studies have shown that MPAs can improve catch when designed well and under the right fishery conditions,” said Cabral, the study’s lead author. “We asked how you could design a network of marine protected areas to improve fishery productivity, and what the results would be.”

Cabral and his colleagues at UC Santa Barbara, the Hawaii Institute of Marine Biology, and the National Geographic Society began constructing a model of global fisheries that would account for both biologic and economic factors. They leveraged a database of 4,000 fishery stocks, their ecological characteristics, management status and global distributions in combination with a wealth of information on fisheries catch and fisher behavior in response to marine protected areas.

The resulting bio-economic model forecasts how fish populations would respond to the creation of new MPAs based on a variety of factors such as the location and status of fisheries and species mobility and growth rates. This enabled the team to project harvest outcomes over a variety of different reserve designs. The researchers could then see where MPAs would be most beneficial.

“We found that there are a lot of places where you can get food benefits,” said coauthor Steve Gaines, dean of UCSB’s Bren School of Environmental Science & Management. “So, rather than having this traditional battle between fisheries and conservation, we can now identify the strategic places

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Satellites picture methane across the globe

Want to understand what methane is doing in our atmosphere?

Take a look at the new interactive global map produced by Montreal firm GHGSat.

Its Pulse tool allows you to move around the world to see how concentrations of the powerful greenhouse gas vary in space and time.

From the highs above oil and gas fields in the southwestern United States, to the naturally elevated levels in permafrost regions during summer.

The map shows monthly averages which, GHGSat says it will update weekly.

Pulse combines the focussed data from the company’s two small methane-detecting spacecraft with the wide-field observations from the EU and European Space Agency’s Sentinel-5P Tropomi mission.

The Canadian pair are used to “tune up” the European detections so the map can display concentrations on a 2km by 2km grid scale.

Centre the map over southern China, and you can see the effect the country’s fleet of coal-fired power stations has in raising concentrations.

Move across to northern Italy and look at how the Dolomite Mountains trap methane in the Po Valley, as they do all pollutants emanating from this industrialised sector of the nation.

Just like carbon dioxide (CO2), Methane (CH4) is increasing in the atmosphere. The globally averaged monthly trend is now above 1,876 parts per billion

Quite why methane is climbing as rapidly as it is, though, is not fully understood.

Emissions associated with fossil-fuel use are obviously a major factor, but there are many natural sources of the gas that require a more complete explanation, too.

What is certain, however, is that the rise can’t be left unchecked.

Methane’s global warming potential is 30 times that of carbon dioxide over a 100-year time period, so it’s imperative any unnecessary releases are constrained or curtailed.

GHGSat’s business is about identifying human-produced sources and working with those responsible to close off the emissions.

But company CEO, Stephane Germain, hopes the new Pulse map will initiate a much wider conversation about the methane issue.

“This is about a bunch of things for us,” he told BBC News. “First and foremost, we constantly get asked if we can make some of our data and expertise available for free, and Pulse is part of our contribution to that.

“The data and the algorithms we’ve used are open.

“But we’re also making this map available to let everyone see what methane looks like worldwide on a more granular, higher-resolution scale than has ever been available before. And we hope that’ll stimulate some conversations and some questions.”

GHGSat launched its most recent satellite, Iris, in July. This has the sharpest view of any methane-detecting spacecraft in orbit today by being able to track variations in CH4 concentration in columns of air just 25m across.

Once fully commissioned, Iris will be used to identify individual emitters, such as a leaky wellhead or landfill.

The aim of the company is to fly a constellation of Iris-like satellites, and to that end – a third platform, called Hugo, is scheduled to launch

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