In the squirrel world, prime real estate is determined by previous owner, study reveals

In the squirrel world, prime real estate is determined by previous owner, study reveals

A young squirrel lucky enough to take over territory from an adult male squirrel is like a teenager falling into a big inheritance, according to a new University of Guelph study.

Researchers found male squirrels store more food than females, and if a young squirrel leaving the nest nabs a storage spot previously owned by a male squirrel, they will increase their lifetime pup production by 50 per cent.

“It’s like buying a home and finding a big pile of money buried in the walls,” said integrative biology professor Andrew McAdam, who worked on the study with lead author David Fisher, a former U of G post doc. “The previous owner of where you live can significantly impact how well off you are, at least in the squirrel world.”

Published in the journal Ecology Letters, the study involved hundreds of North American red squirrels.

It is part of the Kluane Red Squirrel Project, a long-term study in the Yukon investigating the ecology and evolution of red squirrels. Started by the University of Alberta in 1987, the project brings together scientists from several universities, including the University of Guelph, University of Michigan, and University of Saskatchewan to monitor behaviour and reproduction of hundreds of individually marked squirrels.

For this study, Fisher and colleagues measured the food stores and reproductive outcome of young squirrels that took over real estate previously owned by either males or females who disappeared.

Squirrels collect spruce cones in the fall and store them in the ground in a “midden” for winter. A hoard can contain more than 20,000 cones, and they can remain edible for several years, said Fisher

“Good thing too, because spruce trees produce cones in boom-bust patterns. There are more bust than boom years, so if squirrels don’t store enough in the boom years they won’t have enough food to survive the bust years.”

It’s common for squirrels to take over the territories of other squirrels after they die and in taking over another squirrel’s territory, they also inherit their food stores, added Fisher.

“We have seen a food store last as long as 31 years — as long as we have been studying these squirrels — and owned by 13 different squirrels over that time period,” said McAdam.

In this study, researchers found that if a squirrel inherits its territory from a male rather than a female, it will have around 1,300 more cones on average in its midden. This stored energy will keep the squirrel alive for an extra 17 days.

The study also revealed that squirrels at their prime, which is three to four years old, have more cones than younger and older squirrels. This difference means squirrels that inherit their territory from a squirrel that died in mid-age inherit a larger cone store than those that inherit from a young or old squirrel.

“If a female squirrel is lucky enough to take over this prime real estate, then she will have lots of food, which allows her to breed earlier,” said McAdam. “This means her offspring will leave the nest early and they will have improved survival rates. Essentially, it will improve this squirrel’s genetic contribution to the next generation.”

These finding show how the behavior of one squirrel can impact the genetic contribution to the population of another squirrel they have never met, said Fisher.

“Ultimately, the food hoarding behaviour of a squirrel you have never met, and that may have even died before you were born, can impact your chances of survival.”

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Indonesia’s devastating 2018 earthquake was a rare supershear, UCLA study finds

Indonesia’s devastating 2018 earthquake was a rare supershear, UCLA study finds

The devastating 7.5 magnitude earthquake that struck the Indonesian island of Sulawesi last September was a rare “supershear” earthquake, according to a study led by UCLA researchers.

Only a dozen supershear quakes have been identified in the past two decades, according to Lingsen Meng, UCLA’s Leon and Joanne V.C. Knopoff Professor of Physics and Geophysics and one of the report’s senior authors. The new study was published Feb. 4 in the journal Nature Geoscience.

Meng and a team of scientists from UCLA, France’s Geoazur Laboratory, the Jet Propulsion Laboratory at Caltech, and the Seismological Laboratory at Caltech analyzed the speed, timing and extent of the Palu earthquake. Using high-resolution observations of the seismic waves caused by the temblor, along with satellite radar and optical images, they found that the earthquake propagated unusually fast, which identified it as a supershear.

Supershear earthquakes are characterized by the rupture in Earth’s crust moving very fast along a fault, causing the up-and-down or side-to-side waves that shake the ground — called seismic shear waves — to intensify. Shear waves are created in standard earthquakes, too, but in supershear quakes, the rupture moving faster than the shear waves produces more energy in a shorter time, which is what makes supershears even more destructive.

“That intense shaking was responsible for the widespread landslides and liquefactions [the softening of soil caused by the shaking, which often causes buildings to sink into the mud] that followed the Palu earthquake,” Meng said.

In fact, he said, the vibrations produced by the shaking of supershear earthquakes is analogous to the sound vibrations of the sonic boom produced by supersonic jets.

UCLA graduate student Han Bao, the report’s first author, gathered publicly available ground-motion recordings from a sensor network in Australia — about 2,500 miles away from where the earthquake was centered — and used a UCLA-developed source imaging technique that tracks the growth of large earthquakes to determine its rupture speed. The technique is similar to how a smartphone user’s location can be determined by triangulating the times that phone signals arrive at cellphone antenna towers.

“Our technique uses a similar idea,” Meng said. “We measured the delays between different seismic sensors that record the seismic motions at set locations.”

The researchers could then use that to determine the location of the rupture at different times during the earthquake.

They determined that the minute-long quake moved away from the epicenter at 4.1 kilometers per second (or about 2.6 miles per second), faster than the surrounding shear-wave speed of 3.6 kilometers per second (2.3 miles per second). By comparison, non-shear earthquakes more at about 60 percent of that speed — around 2.2 kilometers per second (1.3 miles per second), Meng said.

Previous supershear earthquakes — like the magnitude 7.8 Kunlun earthquake in Tibet in 2001 and the magnitude 7.9 Denali earthquake in Alaska in 2002 — have occurred on faults that were remarkably straight, meaning that there were few obstacles to the quakes’ paths. But the researchers found on satellite images of the Palu quake that the fault line had two large bends. The temblor was so strong that the rupture was able to maintain a steady speed around these bends.

That could be an important lesson for seismologists and other scientists who assess earthquake hazards.

“If supershear earthquakes occur on nonplanar faults, as the Palu earthquake did, we have to consider the possibility of stronger shaking along California’s San Andreas fault, which has many bends, kinks and branches,” Meng said.

Supershear earthquakes typically start at sub-shear speed and then speed up as they continue. But Meng said the Palu earthquake progressed at supershear speed almost from its inception, which would imply that there was high stress in the rocks surrounding the fault — and therefore stronger shaking and more land movement in a compressed amount of time than would in standard earthquakes.

“Geometrically irregular rock fragments along the fault plane usually act as barriers preventing earthquakes,” Meng said. “However, if the pressure accumulates for a long time — for decades or even hundreds of years — an earthquake will eventually overcome the barriers and will go supershear right away.”

Among the paper’s other authors are Tian Feng, a UCLA graduate student, and Hui Huang, a UCLA postdoctoral scholar. The UCLA researchers were supported by the National Science Foundation and the Leon and Joanne V.C. Knopoff Foundation. The other authors are Cunren Liang of the Seismological Laboratory at Caltech; Eric Fielding and Christopher Milliner of JPL at Caltech and Jean-Paul Ampuero of Geoazur.

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Why too much DNA repair can injure tissue: Overactive repair system promotes cell death following DNA damage by certain toxins, study shows

Why too much DNA repair can injure tissue: Overactive repair system promotes cell death following DNA damage by certain toxins, study shows

DNA-repair enzymes help cells survive damage to their genomes, which arises as a normal byproduct of cell activity and can also be caused by environmental toxins. However, in certain situations, DNA repair can become harmful to cells, provoking an inflammatory response that produces severe tissue damage.

MIT Professor Leona Samson has now determined that inflammation is a key component of the way this damage occurs in photoreceptor cells in the retinas of mice. About 10 years ago, she and her colleagues discovered that overactive initiation of DNA-repair systems can lead to retinal damage and blindness in mice. The key enzyme in this process, known as Aag glycosylase, can also cause harm in other tissues when it becomes hyperactive.

“It’s another case where despite the fact that inflammation is there to protect you, in some circumstances it can actually be harmful, when it’s overactive,” says Samson, a professor emerita of biology and biological engineering and the senior author of the study.

Aag glycosylase helps to repair DNA damage caused by a class of drugs known as alkylating agents, which are commonly used as chemotherapy drugs and are also found in pollutants such as tobacco smoke and fuel exhaust. Retinal damage from these drugs has not been seen in human patients, but alkylating agents may produce similar damage in other human tissues, Samson says. The new study, which reveals how Aag overactivity leads to cell death, suggest possible targets for drugs that could prevent such damage.

Mariacarmela Allocca, a former MIT postdoc, is the lead author of the study, which appears in the Feb. 12 issue of Science Signaling. MIT technical assistant Joshua Corrigan, former postdoc Aprotim Mazumder, and former technical assistant Kimberly Fake are also authors of the paper.

A vicious cycle

In a 2009 study, Samson and her colleagues found that a relatively low level of exposure to an alkylating agent led to very high rates of retinal damage in mice. Alkylating agents produce specific types of DNA damage, and Aag glycosylase normally initiates repair of such damage. However, in certain types of cells that have higher levels of Aag, such as mouse photoreceptors, the enzyme’s overactivity sets off a chain of events that eventually leads to cell death.

In the new study, the researchers wanted to find exactly out how this happens. They knew that Aag was overactive in the affected cells, but they didn’t know exactly how it was leading to cell death or what type of cell death was occurring. The researchers initially suspected it was apoptosis, a type of programmed cell death in which a dying cell is gradually broken down and absorbed by other cells.

However, they soon found evidence that another type of cell death called necrosis accounts for most of the damage. When Aag begins trying to repair the DNA damage caused by the alkylating agent, it cuts out so many damaged DNA bases that it hyperactivates an enzyme called PARP, which induces necrosis. During this type of cell death, cells break apart and spill out their contents, which alerts the immune system that something is wrong.

One of the proteins secreted by the dying cells, known as HMGB1, stimulates production of chemicals that attract immune cells called macrophages, which specifically penetrate the photoreceptor layer of the retina. These macrophages produce highly reactive oxygen species — molecules that create more damage and make the environment even more inflammatory. This in turn causes more DNA damage, which is recognized by Aag.

“That makes the situation worse, because the Aag glycosylase will act on the lesions produced from the inflammation, so you get a vicious cycle, and the DNA repair drives more and more degeneration and necrosis in the photoreceptor layer,” Samson says.

None of this happens in mice that lack Aag or PARP, and it does not occur in other cells of the eye or in most other body tissues.

“It amazes me how segmented this is. The other cells in the retina are not affected at all, and they must experience the same amount of DNA damage. So, one possibility is maybe they don’t express Aag, while the photoreceptor cells do,” Samson says.

“These molecular studies are exciting, as they have helped define the underlying pathophysiology associated with retinal damage,” says Ben Van Houten, a professor of pharmacology and chemical biology at the University of Pittsburgh, who was not involved in the study. “DNA repair is essential for the faithful inheritance of a cell’s genetic material. However, the very action of some DNA repair enzymes can result in the production of toxic intermediates that exacerbate exposures to genotoxic agents.”

Varying effects

The researchers also found that retinal inflammation and necrosis were more severe in male mice than in female mice. They suspect that estrogen, which can interfere with PARP activity, may help to suppress the pathway that leads to inflammation and cell death.

Samson’s lab has previously found that Aag activity can also exacerbate damage to the brain during a stroke, in mice. The same study revealed that Aag activity also worsens inflammation and tissue damage in the liver and kidney following oxygen deprivation. Aag-driven cell death has also been seen in the mouse cerebellum and some pancreatic and bone marrow cells.

The effects of Aag overactivity have been little studied in humans, but there is evidence that healthy individuals have widely varying levels of the enzyme, suggesting that it could have different effects in different people.

“Presumably there are some cell types in the human body that would respond the same way as the mouse photoreceptors,” Samson says. “They may just not be the same set of cells.”

The research was funded by the National Institutes of Health.

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Indonesia’s devastating 2018 earthquake was a rare supershear, UCLA study finds

Indonesia’s devastating 2018 earthquake was a rare supershear, UCLA study finds

The devastating 7.5 magnitude earthquake that struck the Indonesian island of Sulawesi last September was a rare “supershear” earthquake, according to a study led by UCLA researchers.

Only a dozen supershear quakes have been identified in the past two decades, according to Lingsen Meng, UCLA’s Leon and Joanne V.C. Knopoff Professor of Physics and Geophysics and one of the report’s senior authors. The new study was published Feb. 4 in the journal Nature Geoscience.

Meng and a team of scientists from UCLA, France’s Geoazur Laboratory, the Jet Propulsion Laboratory at Caltech, and the Seismological Laboratory at Caltech analyzed the speed, timing and extent of the Palu earthquake. Using high-resolution observations of the seismic waves caused by the temblor, along with satellite radar and optical images, they found that the earthquake propagated unusually fast, which identified it as a supershear.

Supershear earthquakes are characterized by the rupture in Earth’s crust moving very fast along a fault, causing the up-and-down or side-to-side waves that shake the ground — called seismic shear waves — to intensify. Shear waves are created in standard earthquakes, too, but in supershear quakes, the rupture moving faster than the shear waves produces more energy in a shorter time, which is what makes supershears even more destructive.

“That intense shaking was responsible for the widespread landslides and liquefactions [the softening of soil caused by the shaking, which often causes buildings to sink into the mud] that followed the Palu earthquake,” Meng said.

In fact, he said, the vibrations produced by the shaking of supershear earthquakes is analogous to the sound vibrations of the sonic boom produced by supersonic jets.

UCLA graduate student Han Bao, the report’s first author, gathered publicly available ground-motion recordings from a sensor network in Australia — about 2,500 miles away from where the earthquake was centered — and used a UCLA-developed source imaging technique that tracks the growth of large earthquakes to determine its rupture speed. The technique is similar to how a smartphone user’s location can be determined by triangulating the times that phone signals arrive at cellphone antenna towers.

“Our technique uses a similar idea,” Meng said. “We measured the delays between different seismic sensors that record the seismic motions at set locations.”

The researchers could then use that to determine the location of the rupture at different times during the earthquake.

They determined that the minute-long quake moved away from the epicenter at 4.1 kilometers per second (or about 2.6 miles per second), faster than the surrounding shear-wave speed of 3.6 kilometers per second (2.3 miles per second). By comparison, non-shear earthquakes more at about 60 percent of that speed — around 2.2 kilometers per second (1.3 miles per second), Meng said.

Previous supershear earthquakes — like the magnitude 7.8 Kunlun earthquake in Tibet in 2001 and the magnitude 7.9 Denali earthquake in Alaska in 2002 — have occurred on faults that were remarkably straight, meaning that there were few obstacles to the quakes’ paths. But the researchers found on satellite images of the Palu quake that the fault line had two large bends. The temblor was so strong that the rupture was able to maintain a steady speed around these bends.

That could be an important lesson for seismologists and other scientists who assess earthquake hazards.

“If supershear earthquakes occur on nonplanar faults, as the Palu earthquake did, we have to consider the possibility of stronger shaking along California’s San Andreas fault, which has many bends, kinks and branches,” Meng said.

Supershear earthquakes typically start at sub-shear speed and then speed up as they continue. But Meng said the Palu earthquake progressed at supershear speed almost from its inception, which would imply that there was high stress in the rocks surrounding the fault — and therefore stronger shaking and more land movement in a compressed amount of time than would in standard earthquakes.

“Geometrically irregular rock fragments along the fault plane usually act as barriers preventing earthquakes,” Meng said. “However, if the pressure accumulates for a long time — for decades or even hundreds of years — an earthquake will eventually overcome the barriers and will go supershear right away.”

Among the paper’s other authors are Tian Feng, a UCLA graduate student, and Hui Huang, a UCLA postdoctoral scholar. The UCLA researchers were supported by the National Science Foundation and the Leon and Joanne V.C. Knopoff Foundation. The other authors are Cunren Liang of the Seismological Laboratory at Caltech; Eric Fielding and Christopher Milliner of JPL at Caltech and Jean-Paul Ampuero of Geoazur.

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Why too much DNA repair can injure tissue: Overactive repair system promotes cell death following DNA damage by certain toxins, study shows

Why too much DNA repair can injure tissue: Overactive repair system promotes cell death following DNA damage by certain toxins, study shows

DNA-repair enzymes help cells survive damage to their genomes, which arises as a normal byproduct of cell activity and can also be caused by environmental toxins. However, in certain situations, DNA repair can become harmful to cells, provoking an inflammatory response that produces severe tissue damage.

MIT Professor Leona Samson has now determined that inflammation is a key component of the way this damage occurs in photoreceptor cells in the retinas of mice. About 10 years ago, she and her colleagues discovered that overactive initiation of DNA-repair systems can lead to retinal damage and blindness in mice. The key enzyme in this process, known as Aag glycosylase, can also cause harm in other tissues when it becomes hyperactive.

“It’s another case where despite the fact that inflammation is there to protect you, in some circumstances it can actually be harmful, when it’s overactive,” says Samson, a professor emerita of biology and biological engineering and the senior author of the study.

Aag glycosylase helps to repair DNA damage caused by a class of drugs known as alkylating agents, which are commonly used as chemotherapy drugs and are also found in pollutants such as tobacco smoke and fuel exhaust. Retinal damage from these drugs has not been seen in human patients, but alkylating agents may produce similar damage in other human tissues, Samson says. The new study, which reveals how Aag overactivity leads to cell death, suggest possible targets for drugs that could prevent such damage.

Mariacarmela Allocca, a former MIT postdoc, is the lead author of the study, which appears in the Feb. 12 issue of Science Signaling. MIT technical assistant Joshua Corrigan, former postdoc Aprotim Mazumder, and former technical assistant Kimberly Fake are also authors of the paper.

A vicious cycle

In a 2009 study, Samson and her colleagues found that a relatively low level of exposure to an alkylating agent led to very high rates of retinal damage in mice. Alkylating agents produce specific types of DNA damage, and Aag glycosylase normally initiates repair of such damage. However, in certain types of cells that have higher levels of Aag, such as mouse photoreceptors, the enzyme’s overactivity sets off a chain of events that eventually leads to cell death.

In the new study, the researchers wanted to find exactly out how this happens. They knew that Aag was overactive in the affected cells, but they didn’t know exactly how it was leading to cell death or what type of cell death was occurring. The researchers initially suspected it was apoptosis, a type of programmed cell death in which a dying cell is gradually broken down and absorbed by other cells.

However, they soon found evidence that another type of cell death called necrosis accounts for most of the damage. When Aag begins trying to repair the DNA damage caused by the alkylating agent, it cuts out so many damaged DNA bases that it hyperactivates an enzyme called PARP, which induces necrosis. During this type of cell death, cells break apart and spill out their contents, which alerts the immune system that something is wrong.

One of the proteins secreted by the dying cells, known as HMGB1, stimulates production of chemicals that attract immune cells called macrophages, which specifically penetrate the photoreceptor layer of the retina. These macrophages produce highly reactive oxygen species — molecules that create more damage and make the environment even more inflammatory. This in turn causes more DNA damage, which is recognized by Aag.

“That makes the situation worse, because the Aag glycosylase will act on the lesions produced from the inflammation, so you get a vicious cycle, and the DNA repair drives more and more degeneration and necrosis in the photoreceptor layer,” Samson says.

None of this happens in mice that lack Aag or PARP, and it does not occur in other cells of the eye or in most other body tissues.

“It amazes me how segmented this is. The other cells in the retina are not affected at all, and they must experience the same amount of DNA damage. So, one possibility is maybe they don’t express Aag, while the photoreceptor cells do,” Samson says.

“These molecular studies are exciting, as they have helped define the underlying pathophysiology associated with retinal damage,” says Ben Van Houten, a professor of pharmacology and chemical biology at the University of Pittsburgh, who was not involved in the study. “DNA repair is essential for the faithful inheritance of a cell’s genetic material. However, the very action of some DNA repair enzymes can result in the production of toxic intermediates that exacerbate exposures to genotoxic agents.”

Varying effects

The researchers also found that retinal inflammation and necrosis were more severe in male mice than in female mice. They suspect that estrogen, which can interfere with PARP activity, may help to suppress the pathway that leads to inflammation and cell death.

Samson’s lab has previously found that Aag activity can also exacerbate damage to the brain during a stroke, in mice. The same study revealed that Aag activity also worsens inflammation and tissue damage in the liver and kidney following oxygen deprivation. Aag-driven cell death has also been seen in the mouse cerebellum and some pancreatic and bone marrow cells.

The effects of Aag overactivity have been little studied in humans, but there is evidence that healthy individuals have widely varying levels of the enzyme, suggesting that it could have different effects in different people.

“Presumably there are some cell types in the human body that would respond the same way as the mouse photoreceptors,” Samson says. “They may just not be the same set of cells.”

The research was funded by the National Institutes of Health.

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Arctic sea ice loss in the past linked to abrupt climate events

Arctic sea ice loss in the past linked to abrupt climate events

A new study on ice cores shows that reductions in sea ice in the Arctic in the period between 30-100,000 years ago led to major climate events. During this period, Greenland temperatures rose by as much as 16 degrees Celsius. The results are published today (Monday 11 February) in Proceedings of the National Academy of Sciences (PNAS).

A team from British Antarctic Survey (BAS), University of Cambridge and University of Birmingham studied data from ice cores drilled in Greenland. They looked at oxygen isotopes and compared them to climate models run on the ARCHER supercomputer1. From this they determined that sea ice changes were massively significant in past climate change events in the North Atlantic. These periods, called Dansgaard-Oeschger events2, are some of the fastest and largest abrupt climate changes ever recorded. During some of these events, Greenland temperatures are likely to have increased by 16 degrees Celsius in less than a decade.

Lead author, Dr Louise Sime, a climate scientist at BAS says:

“For years scientists have been puzzled about the correlation between Arctic sea ice loss and the extreme climate events found in the ice core record. There were at least four theories being mooted and for two years we’ve been investigating this problem. I’m delighted that we have proven the critical importance of sea ice using our numerical model simulations.

“The summer time sea ice in the Arctic has experienced a 40% decline in the last few decades, but we know that about two thirds of that reduction is caused by human-induced climate change. What we now need to determine is, what can be learnt from these past sea ice losses to enable us to understand what might happen next to our climate3.”

Dr Rachael Rhodes, an ice core scientist from Northumbria University says:

“Now that we better understand how sea ice loss is imprinted on Greenland ice cores, we move closer to deciphering between different theories about what triggered these remarkable climate events.”

This work confirms a major significance of sea ice for past abrupt warming events. This is important because changes in sea ice have profound consequences on both global and local scales, including impacts on global climate and local ecosystems. Accurate forecasts of Arctic sea ice over the coming decades to centuries are crucial to understanding how the earth will respond to any changes.

Impact of abrupt sea ice loss on Greenland water isotopes during the last glacial period by Louise C. Sime, Peter O. Hopcroft, Rachael H. Rhodes is published in the Proceedings of the National Academy of Sciences.

Notes:

1.The researchers’ numerical model simulations were run on the large ARCHER supercomputer. ARCHER is based around a Cray XC30 supercomputer and is provided by EPSRC, NERC, EPCC, Cray Inc. and The University of Edinburgh. The simulations were run over the course of two years and were compared to ice core data that has been collected over the last twenty to thirty years.

2. Dansgaard-Oeschger events are rapid climate fluctuations that occurred about 25 times during the last glacial period. They are named after Willi Dansgaard who was a Danish paleoclimatologist (1922-2011) and Hans Oeschger (1927-1998), another paleoclimatologist, who jointly identified them in Greenland ice core records.

3.Following on from this work, Dr Sime alongside her European partners, have now won an 8 million EUR grant from the EU to develop our understanding of risk from abrupt climate change events. They will develop the underpinning science for safe operation of the Earth system. This will help us understand the risk of crossing climate tipping points, particularly due to Arctic and Antarctic sea ice loss.

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Connection between home energy efficiency and respiratory health in low-income homes: New study finds people living in drafty homes in low-income, urban communities are at a higher risk of respiratory health issues

Connection between home energy efficiency and respiratory health in low-income homes: New study finds people living in drafty homes in low-income, urban communities are at a higher risk of respiratory health issues

A team of investigators from the Colorado School of Public Health at the CU Anschutz Medical Campus and the University of Colorado Boulder has identified that people living in homes with high ventilation are more likely to suffer from respiratory health issues such as asthma.

The findings are published in the February issue of Environmental Research.

The Colorado Home Energy Efficiency and Respiratory Health (CHEER) study evaluated the impact of air-exchange rates on respiratory health in low-income, urban homes in the cities of Denver, Aurora, Boulder, Loveland and Fort Collins. The study revealed that many homes had high ventilation rates, also known as air-exchange rates — the rate at which outdoor air replaces indoor air within a room (median 0.54 air changes per hour; range 0.10 to 2.17).

The findings show that residents in drafty homes with higher air-exchange rates were more likely to report a chronic cough, asthma and asthma-like symptoms.

Notably, people in homes with the highest air-exchange rates were approximately four times more likely to report a chronic cough than people living in households with the lowest air-exchange rates.

Similarly, people were two to four times more likely to report asthma or asthma-like symptoms if they lived in households with the highest ventilation rates versus the lowest.

“The goal of this study was to understand the health impacts of home weatherization practices. Many of these practices focus on reducing air exchange rates between the building interior and outdoor environment,” said Elizabeth Carlton, PhD, assistant professor in Environmental and Occupational Health at the Colorado School of Public Health. “We found people in the homes with the highest air-exchange rates — the leakiest homes — were considerably more likely to report chronic cough, asthma or asthma-like symptoms. It is possible that in homes with high air-exchange rates, outdoor pollutants are entering the home and affecting health. If true, home-energy efficiency measures may be an effective way to protect health in areas with high pollution such as homes located near major roads.”

Carlton adds, “The health effects of high-exchange rates in urban areas are not well-documented, and since Americans spend approximately 90 percent of their time indoors, it’s crucial to have a better understanding of the impact of leaky homes.”

While prior studies have highlighted the potential hazards of low ventilation rates in residences, this study reveals high ventilation rates in many urban-area homes and that these high air-exchange rates may have a negative impact on respiratory health. Based on the findings, the infiltration of outdoor pollutants into leaky homes, such as traffic-related pollutants, could be a significant cause of chronic respiratory issues and an array of health outcomes.

The (CHEER) research is a cross-sectional study that enrolled 302 people in 216 non-smoking, low-income homes. A blower door test was conducted and the annual average air-exchange rate (AAER) was estimated for each house. Respiratory health was assessed using a structured questionnaire based on standard instruments. The researchers evaluated the association between AAER and respiratory symptoms, adjusting for relevant variants such as age, sex, location and both indoor and outdoor pollution.

“This study was a one-of-a-kind opportunity to combine engineering, geography and public health expertise,” said Shelly Miller, PhD, professor in Mechanical Engineering at the University of Colorado Boulder. “We hope that the results of our research will help rethink how we expend energy in homes for heating and cooling and how we best ventilate homes, especially in under-resourced communities that often live in polluted urban areas.”

This study was developed under an assistance agreement awarded by the U.S. Environmental Protection Agency.

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Seafood mislabelling persistent throughout supply chain, study finds

Seafood mislabelling persistent throughout supply chain, study finds

Not only does Canada continue to have a problem with fish mislabelling, but that problem persists throughout the supply chain, according to a first-ever study by University of Guelph researchers.

In a new study, U of G researchers found 32 per cent of fish were mislabelled and the number of incorrectly identified samples became compounded as the samples moved through the food system.

“We’ve been doing seafood fraud studies for a decade,” said Prof. Robert Hanner, lead author and associate director for the Canadian Barcode of Life Network. “We know there are problems. But this is the first study to move beyond that and look at where the problems are happening throughout the food supply chain.”

The findings reveal that mislabelling happens before fish are imported into Canada, as well as throughout the supply chain, Hanner added.

“It seems it’s not isolated to foreign markets, but it’s also happening at home. The Canadian Food Inspection Agency (CFIA) has partnered with us to actively find solutions to this persistent problem,” said Hanner.

Published recently in the journal Food Research International, the study was conducted in collaboration with the Canadian Food Inspection Agency (CFIA).

Hanner is the associate Director for the Canadian Barcode of Life Network, headquartered at the Biodiversity Institute of Ontario, University of Guelph.

“As a science-based regulator, the CFIA works with an array of partners to address mislabelling and promote compliance within industry,” said the CFIA’s Deputy Chief Food Safety Office, Dr. Aline Dimitri. “It is only through our collective efforts that we will be able to tackle this global issue.”

U of G researchers examined 203 samples from 12 key targeted species collected from various importers, processing plants and retailers in Ontario. Of the samples, 141 (69.5 per cent) were from retailers, 51 (25 per cent) from importers and 11 (5.5 per cent) from processing plants.

Researchers identified the samples using DNA barcoding. Developed at U of G, DNA barcoding allows scientists to determine species of organisms using a short, standardized region of genetic material.

The findings revealed 32 per cent of the samples overall were mislabelled. The mislabelling rate was 17.6 per cent at the import stage, 27.3 per cent at processing plants and 38.1 per cent at retailers.

“The higher mislabelling rate in samples collected from retailers, compared to that for samples collected from importers, indicates the role of distribution and repackaging in seafood mislabelling,” said Hanner.

He points to a few reasons for the problem.

“It’s either economically motivated, meaning cheaper fish are being purposely mislabelled as more expensive fish. Or it’s inconsistent labelling regulations between countries and the use of broader common names being used to label fish instead of scientific species names that are leading to mislabelling.”

In both Canada and the U.S., fish are labelled using a common name rather than a specific scientific name. For example, a variety of species may be sold as tuna, although different species can significantly vary in price.

“It creates ambiguity and opens the door for fraud or honest mistakes,” he said. “It also makes it more difficult to track species at risk or indicate if a fish is a species that has higher mercury content. At the end of the day, Canadian consumers don’t really know what type of fish they are eating.”

European countries that recently included species names along with common names have seen less fraud, he added.

That might help curb the problem with fish imports, Hanner said, but this new study shows a need for verification testing at multiple points along the supply chain.

“The next step would be to follow one package from import to wholesale to retail and see what happens.”

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Insects crave salt and search grasslands for the limiting nutrient

Insects crave salt and search grasslands for the limiting nutrient

A University of Oklahoma team from the Geographical Ecology Group has published a new study in the journal Ecology on the nutritional preferences of diverse insect communities from Texas to Minnesota. The OU team conducted 54 experiments in both grazed and ungrazed grasslands to determine the salt cravings of insects and the types of insects that crave salt. The OU team found that insects not only crave salt, but will search for it in their grassland habitats.

“Sodium is relatively unique among the elements in that it is required by all animals, but not used by plant life,” said Ellen Welti, lead author on the study and postdoctoral researcher in the OU Department of Biology. “Sodium is a critical nutrient for animal cell membrane functions while sodium is generally a stressor for plants. In other words, plants don’t need salt and plant eaters do.”

OU team members conducted a simple experiment containing plots receiving water only and the other half of the plots receiving a solution of table salt or simulated cow urine. This experiment was repeated at 54 grassland sites across the United States. Two days after setting up each experiment, a team member would literally vacuum the bugs from the plots. The bugs captured in the bag would then be frozen, sorted, counted and compared between salted and unsalted plots. At each site, plant and soil samples were taken to characterize the spectrum of grasslands from ‘bland to salty.’

A total of 32,430 insects were identified from 120 taxa. Naturally, grasslands near the Gulf of Mexico tended to have saltier plants, but surprisingly had less salty soils, likely due to their sandy composition. The experimental plots splashed with the simulated cow urine attracted an average of 70 percent more bugs than those splashed with water. Additionally, the study found that grasslands were less salty hosted insects with keener cravings for salt.

“This study highlights the knowledge gap in understanding nutrient limitation for animal communities and the importance of sodium,” said Welti. “While sodium attraction across a broad geographic gradient suggest widespread sodium limitation, it is not known how long-term changes in sodium levels translate into changes in animal abundances and shifts in community composition.”

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How landscape plants have an impact on the carbon footprint: Activities and inputs in landscape plant production that can be modified to reduce carbon footprint

How landscape plants have an impact on the carbon footprint: Activities and inputs in landscape plant production that can be modified to reduce carbon footprint

A study out of the University of Kentucky provides a base of understanding of carbon footprint terminology and illustrates carbon footprint analyses using data from previous research that modeled nursery and greenhouse crop production systems and their life-cycle impact. Dewayne Ingram, Charles Hall, and Joshua Knight present the science underlying the determination of carbon footprint and the degree to which it is important in minimizing the negative impacts of new product development and assessing the positive or negative cradle-to-grave life-cycle impacts.

Their research is in the article “Understanding Carbon Footprint in Production and Use of Landscape Plants” in HortTechnology.

Carbon footprint relates to the efflux of greenhouse gases in the environment. The greenhouse gas emissions of primary interest or concern are carbon dioxide, nitrous oxide, and methane, and result from human and environmental activities. These warm the earth by absorbing energy and decreasing the rate at which energy escapes the earth’s atmosphere to space. In other words, greenhouse gases increase the effectiveness of the atmosphere to act as a blanket that insulates the earth. Therefore, greenhouse gases have a measurable potential for trapping energy in the earth’s atmosphere.

Life cycle assessment, with tools used to estimate greenhouse gases during the life cycle of a targeted product or activity, has been used to characterize representative field-grown and container-grown landscape plants. The dominant contributor to the carbon footprint and variable costs of field-grown trees is equipment use, or, more specifically, the combustion of fossil fuels.

Most of that impact is at harvest, when heavy equipment is used to dig and move individual trees. Transport of these trees to customers and subsequent transplantation in the landscape are also carbon-intense activities.

Greenhouse heating also can also have an impact on the carbon footprint of plants, depending on the location of the greenhouse or nursery and the length and season of production. Knowing the input products and activities that contribute most toward the carbon footprint and costs during plant production allows nursery and greenhouse managers to consider protocol modifications that are more beneficial to profit potential and environment impact.

Greenhouse gases differ in their effectiveness to absorb energy in specific wavelengths, primarily infrared. This is referred to as their radiative efficiency. They also differ in terms of how long they stay in the atmosphere, or their lifetime. Global warming potential was developed to categorize greenhouse gases based on their radiative efficiency and lifetime in the atmosphere.

The impact of landscape plants on atmospheric carbon dioxide during the production and use phases contributes to the life-cycle benefits. Although greenhouse gases are emitted during the production phase, carbon dioxide is sequestered from the air and is stored in the wood of plants, having an impact on atmospheric carbon dioxide levels for decades. The carbon will eventually be emitted when the tree is removed from the landscape at the end of its life cycle.

As the green industry continues to mature, differentiation is an increasingly important business strategy for green industry businesses. One such way to accomplish this is by adopting environmentally friendly behavior and/or selling products that offer environmental benefits.

Ingram adds, “Our research over the last decade has revealed activities and inputs in landscape plant production that can be modified to reduce carbon footprint. The analyses also documented the many beneficial life-cycle environmental impacts, including carbon sequestration from the atmosphere, of landscape plants.”

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A very small number of crops are dominating globally: That’s bad news for sustainable agriculture

A very small number of crops are dominating globally: That’s bad news for sustainable agriculture

A new U of T study suggests that globally we’re growing more of the same kinds of crops, and this presents major challenges for agricultural sustainability on a global scale.

The study, done by an international team of researchers led by U of T assistant professor Adam Martin, used data from the U.N.’s Food and Agricultural Organization (FAO) to look at which crops were grown where on large-scale industrial farmlands from 1961 to 2014.

They found that within regions crop diversity has actually increased — in North America for example, 93 different crops are now grown compared to 80 back in the 1960s. The problem, Martin says, is that on a global scale we’re now seeing more of the same kinds of crops being grown on much larger scales.

In other words, large industrial-sized farms in Asia, Europe, North and South America are beginning to look the same.

“What we’re seeing is large monocultures of crops that are commercially valuable being grown in greater numbers around the world,” says Martin, who is an ecologist in the Department of Physical and Environmental Sciences at U of T Scarborough.

“So large industrial farms are often growing one crop species, which are usually just a single genotype, across thousands of hectares of land.”

Soybeans, wheat, rice and corn are prime examples. These four crops alone occupy just shy of 50 per cent of the world’s entire agricultural lands, while the remaining 152 crops cover the rest.

It’s widely assumed that the biggest change in global agricultural diversity took part during the so-called Columbia exchange of the 15th and 16th centuries where commercially important plant species were being transported to different parts of the world.

But the authors found that in the 1980s there was a massive increase in global crop diversity as different types of crops were being grown in new places on an industrial scale for the first time. By the 1990s that diversity flattened out, and what’s happened since is that diversity across regions began to decline.

The lack of genetic diversity within individual crops is pretty obvious, says Martin. For example, in North America, six individual genotypes comprise about 50 per cent of all maize (corn) crops.

This decline in global crop diversity is an issue for a number of reasons. For one, it affects regional food sovereignty. “If regional crop diversity is threatened, it really cuts into people’s ability to eat or afford food that is culturally significant to them,” says Martin.

There is also an ecological issue; think potato famine, but on a global scale. Martin says if there’s increasing dominance by a few genetic lineages of crops, then the global agricultural system becomes increasingly susceptible to pests or diseases. He points to a deadly fungus that continues to devastate banana plantations around the world as an example.

He hopes to apply the same global-scale analysis to look at national patterns of crop diversity as a next step for the research. Martin adds that there’s a policy angle to consider, since government decisions that favour growing certain kinds of crops may contribute to a lack of diversity.

“It will be important to look at what governments are doing to promote more different types of crops being grown, or at a policy-level, are they favouring farms to grow certain types of cash crops,” he says.

The study, which is published in the journal PLOS ONE, received funding from the Natural Sciences and Engineering Research Council of Canada (NSERC).

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Underwater forests threatened by future climate change, new study finds: Fisheries potentially at risk if global kelp forests decline

Underwater forests threatened by future climate change, new study finds: Fisheries potentially at risk if global kelp forests decline

Researchers at the University of Sydney and the Sydney Institute of Marine Science have found that climate change could lead to declines of underwater kelp forests through impacts on their microbiome.

In humans, it has been observed that changes in the microbes in the gut can result in poor health. A similar process happens in kelp. Predicted ocean warming and acidification can change microbes on the kelp surface, leading to disease and potentially putting fisheries at risk.

Climate change is affecting biodiversity at a global scale. In the marine realm, ocean warming and acidification are pushing dominant habitat-forming species, such as corals and large seaweeds, into decline, affecting biodiversity.

New research shows these two processes can cause changes in the microbiome on the surface of large brown seaweed leading to disease-like symptoms. Blistering, bleaching and eventually degradation of the kelp’s surface is impacting the species’ ability to photosynthesise and potentially survive.

This could impact kelp forests around the world.

For example, it could contribute to further declines of the 8000km long kelp forests that dominate the bottom half of Australia — known as the Great Southern Reef — potentially affecting all the associated ecosystems, including many species of fish, shellfish, lobster and abalone.

“If we lose the kelp forests, we also lose our two biggest fisheries,” said Dr Ziggy Marzinelli, lecturer in Marine Temperate Reef Ecology in the School of Life and Environmental Sciences.

The cooler water kelp forests support a significant component of Australia’s fisheries and is estimated to be worth over $10bn to the Australian economy.

Published today in Proceedings of The Royal Society B, the study tested the independent and interactive effects of ocean warming and acidification on the associated microbiome and condition of the dominant kelp Ecklonia, which is already in steep decline in Australian waters.

“Our study shows the effects of climate change can be complex, driven by changes in tiny organisms — microbes — that cannot be seen,” Dr Marzinelli said. “Changes in the microbiome impacts the life of the host. When you have disruption to the microbiome in the human gut, it affects your health. It’s the same for seaweed. One of the consequences you see is clusters of blisters on the surface of the kelp.”

The study has implications for the health and resilience of entire marine ecosystems, said Professor Peter Steinberg, director of Sydney Institute of Marine Science, who co-authored the study. “The impact of losing the kelp forests would be the same as cutting down all the trees on the land. All the animals would be affected. It is the same in the oceans. If we lose the physical structure of the habitat, we lose the ecosystems.”

One surprising aspect of the research showed the microbiome reverted to a healthier state when it was exposed to the most extreme scenarios. “When we tested under warming and acidification conditions predicted in 50 years time, the microbiome reverted to what it was at the start with healthy hosts,” said Professor Steinberg. “This was a surprise. It means it is hard to predict what might happen in the most extreme future ocean conditions.”

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Prehistoric food globalization spanned three millennia: Peasant farmers began transforming diets across the Old World 7,000 years ago, study finds

Prehistoric food globalization spanned three millennia: Peasant farmers began transforming diets across the Old World 7,000 years ago, study finds

Since the beginning of archaeology, researchers have combed the globe searching for evidence of the first domesticated crops. Painstakingly extracting charred bits of barley, wheat, millet and rice from the remains of ancient hearths and campfires, they’ve published studies contending that a particular region or country was among the first to bring some ancient grain into cultivation.

Now, an international team of scientists, led by Xinyi Liu of Washington University in St. Louis, has consolidated findings from hundreds of these studies to plot a detailed map of how ancient cereal crops spread from isolated pockets of first cultivation to become dietary staples in civilizations across the Old World.

“The very fact that the ‘food globalization’ in prehistory spanned more than three thousand years indicates perhaps a major driver of the process was the perpetual needs of the poor rather than more ephemeral cultural choices of the powerful in the Neolithic and Bronze Age,” said Liu, assistant professor of anthropology in Arts & Sciences.

Forthcoming Feb. 15 in the journal Quaternary Science Reviews, the study illustrates the current scientific consensus on the prehistoric food globalization process that transformed diets across Eurasia and Northern Africa between 7,000 and 3,500 years ago.

Co-authors include researchers from the University of Cambridge in the United Kingdom; Zheijiang University in China; the Lithuanian Institute of History; the Smithsonian Institution; and the Chinese Academy of Social Sciences in Beijing.

The study suggests that food globalization in prehistoric times was driven not by exotic appetities of ruling elites, but by the relentless, season-to-season ingenuity of poor peasant farmers looking for new ways to put just a little more food on their tables.

“Recent research developments shift the focus from chronology and routes to the drivers of the ‘food globalization’ process and considers the context in which agricultural and dietary innovations arose and what agents were involved,” Liu said. “These studies emphasize the role played by the primary agents of agricultural production, the ordinary farmers in the past.”

By trying new types of seed, plowing fields a little further up or down the mountain or shifting planting and harvest times, peasant farmers used a trial-and-error approach to overcome climatic challenges and expand the geographic boundaries of where certain grains could be planted. Gradually, this experimentation led to vastly improved yields as farmers learned to extend the growing season by planting both spring and fall crops in the same fields.

While many people are familiar with the global spread of food crops following the exploration of the New World — a process known as the Columbian Exchange — Liu contends that the prehistoric food globalization process had an equally dramatic impact on food cultivation in the Old World.

Wheat and barley moved from southwest Asia to Europe, India and China, while broom and foxtail millet moved in the other direction: from China to the West. Rice traveled across East, South and Southeast Asia; African millets and sorghum moved across sub-Saharan Africa and across the Indian Ocean, Liu said.

“While much of the exotic foods we enjoy today are the results of modern trade networks, the food globalization process clearly has its roots in prehistory,” Liu said. “Food globalization was well underway before the Columbia Exchange and the Islamic Agricultural Revolution. It predates even the earliest material evidence of trans-Eurasian contact, such as the Silk Route, by millennia.”

Liu’s study traces the farm-to-table journeys of mainstay cereal crops as they criss-crossed continents of the Old World in three distinct waves:

Before 5000 B.C., early farming communities sprang up in isolated pockets of fertile foothills and stream drainage basins where conditions were optimal for cultivating wild grains that originated nearby. Crop dispersals are generally limited to neighboring regions that are broadly compatible in terms of climate and seasonality.

Between 5000 and 2500 B.C., farmers found ways to push cultivation of various grains across wide regions where crop-compatible weather systems were contained within and separated by major mountain systems, such as those associated with the Tibetan Plateau and the Tianshan Mountains.

Between 2500 and 1500 B.C., farmers found ways to move beyond natural and climatic barriers that had long separated east and west, north and south — mastering the cultivation of grains that had evolved to flourish in the extreme elevations of the Tibetan Plateau or the drenching rains of Asian monsoons. Previously isolated agricultural systems were brought together, ushering in a new kind of agriculture in which the planting of both local and exotic crops enables multiple cropping and extended growing seasons.

“The whole process is not only about adoption but also about ‘rejection,’ reflect a range of choices that different communities made, sometimes driven by ecological expediency in novel environments, sometimes by culinary conservatism,” Liu said. “As the old Chinese saying goes: For what has been long united, it will fall apart, and for what has been long divided, it will come together eventually.”

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Scientists study organization of life on a planetary scale

Scientists study organization of life on a planetary scale

When we think of life on Earth, we might think of individual examples ranging from animals to bacteria. When astrobiologists study life, however, they have to consider not only individual organisms, but also ecosystems, and the biosphere as a whole.

In astrobiology, there is an increasing interest in whether life as we know it is a quirk of the particular evolutionary history of the Earth or, instead, if life might be governed by more general organizing principles.

If general principles exist that can explain properties common to all life on Earth, scientists hypothesize, then they may be universal to all life, even life on other planets. If a “universal biology” exists, it would have important implications for the search for life beyond Earth, for engineering synthetic life in the lab, and for solving the origin of life, enabling scientists to predict at least some properties of alien life.

Previous research in this area has primarily focused on specific levels of organization within biology such as individual organisms or ecological communities. These levels form a hierarchy where individuals are composed of interacting molecules and ecosystems are composed of interacting individuals.

An interdisciplinary team of researchers at Arizona State University (ASU) has gone beyond focusing on individual levels in this hierarchy to study the hierarchy itself, focusing on the biosphere as a whole. The results of their study have been recently published Science Advances.

“To understand the general principles governing biology, we must understand how living systems organize across levels, not just within a given level,” says lead author Hyunju Kim of ASU’s Beyond Center and the School of Earth and Space Exploration.

Through this study, the team found that biochemistry, both at the level of organisms and ecosystems, is governed by general organizing principles. “This means there is a logic to the planetary-scale organization of biochemistry,” says co-lead author Harrison Smith of ASU’s School of Earth and Space Exploration. “Scientists have talked about this type of logic for a long time, but until now they have struggled to quantify it. Quantifying it can help us constrain the way that life arises on a planet.”

For this research, the team constructed biochemical networks using a global database of 28,146 annotated genomes and metagenomes and 8,658 catalogued biochemical reactions. In so doing, they uncovered scaling laws governing biochemical diversity and network structure that are shared across levels of organization from individuals to ecosystems, to the biosphere as a whole.

“Quantifying general principles of life — not restricted to a domain on the tree of life, or a particular ecosystem — is a challenge,” says Smith. “We were able to do that by combining tools from network science and scaling theory, while simultaneously leveraging large genomic datasets that researchers have been cataloging.”

The research team, led by Kim and Smith under supervision of Sara Walker of the ASU School of Earth and Space Exploration and the Beyond Center, also includes Cole Mathis of the Beyond Center and the ASU Department of Physics (now at the University of Glasgow), and Jason Raymond of the School of Earth and Space Exploration.

“Understanding the organizing principles of biochemistry at a global scale better enables us to understand how life operates as a planetary process,” says Walker. “The ability to more rigorously identify universal properties of life on Earth will also provide astrobiologists with new quantitative tools to guide our search for alien life — both in the lab on other worlds.”

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New islands, happy feet: Study reveals island formation a key driver of penguin speciation

New islands, happy feet: Study reveals island formation a key driver of penguin speciation

Ever since Darwin first set foot on the Galapagos, evolutionary biologists have long known that the geographic isolation of archipelogos has helped spur the formation of new species.

Now, an international research team led by Theresa Cole at the University of Otago, New Zealand, has found the same holds true for penguins. They have found the first compelling evidence that modern penguin diversity is driven by islands, despite spending the majority of their lives at sea.

“We propose that this diversification pulse was tied to the emergence of islands, which created new opportunities for isolation and speciation,” said Cole.

Over the last 5 million years, during the Miocene period, (particularly within the last 2 million years), island emergence in the Southern Hemisphere has driven several branches on the penguin evolutionary tree, and also drove the more recent influence of human-caused extinctions of two recently extinct penguin species from New Zealand’s Chatham Islands.

“Our findings suggest that these taxa were extirpated shortly after human settlement on the Chatham Islands,” said Cole. “These findings thus potentially represent important new examples of human-driven, Holocene extinction in the Pacific.”

“While our results reinforce the importance of islands in generating biodiversity, they also underscore the role of humans as agents of biodiversity loss, especially via the extinction of island-endemic taxa,” said Cole. As many of the bones were from middens, our results provide direct evidence that our newly discovered extinct taxa was hunted by humans.”

The publication appears in the advanced online edition of the journal Molecular Biology and Evolution.

About 20 modern penguin species exist, from the Antarctic emperor penguin, the forest dwelling Fiordland penguin and the tropical Galapagos penguin. A fossil record of more than 50 species can trace back penguin history to more than 60 million years ago — indicating that penguin diversity may have once been much higher than today.

Using historical skin samples and subfossils from natural history museums, along with blood samples, the researchers performed the largest survey to date, across all penguin taxa.

The team tested their island hypotheses using 41 near-complete mitochondrial genomes, representing all extant and recently extinct penguin taxa. They calibrated their mitogenomic evolution to make an evolutionary clock based on the fossil record.

“By using well-justified fossil calibrations, we resolve the timing and mechanisms of modern penguin diversification,” said Cole.

They found that the two largest-bodied and most polar-adapted penguins are sister to all other living penguins. The DNA evidence also showed that genetically similar penguin species may be at the earlies stages of diversification.

The study provides important new data and perspectives to the debate on the origins of penguin diversity. It will also help better understand the role of islands as drivers of speciation to other animals and marine life.

The new taxa have been named Eudyptes warhami and Megadyptes antipodes richdalei after John Warham and Lance Richdale, pioneers in penguin biology.

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