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Octopuses May Be Adapting to The Rising Acidity of Our Oceans, Study Suggests

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We know that all the excess CO2 we’re pumping into the air – alongside a host of other damaging effects – is driving up the acidity of the oceans as it sinks and dissolves into the water, but it seems as though the hardy octopus can find ways to adapt to its rapidly changing environment.

 

Previous research into the impact of ocean acidification on cephalopods such as octopuses, cuttlefish, and squid has shown some indication increased carbon dioxide in the water could negatively impact this type of marine life.

However, in a new study, a group of Octopus rubescens – a species of octopus common to the west coast of North America – were observed adjusting their routine metabolic rate (RMR) over a series of weeks in response to lowering pH levels in the surrounding water.

“Challenges to an organism’s physiology are often reflected in changes in energy use and therefore can be observed as changes in aerobic metabolic rate,” write the researchers in their paper.

A total of 10 octopuses were studied under controlled lab conditions, with RMR measured immediately after exposure to acidic water, after one week, and after five weeks. Critical oxygen pressure – a measure of whether not not animals are getting enough oxygen – was monitored at the same time.

To begin with, high levels of metabolic change were detected in the creatures – a sort of shock reaction that actually conflicts with earlier research into cephalopods, which had recorded a reduction in metabolic change in similar scenarios.

 

However, RMR had returned to normal after one week, and remained the same five weeks later, suggesting some adaptation had occurred. The increased acidity did have an impact on the ability of the octopuses to function at low oxygen levels, however.

“This response in RMR suggests that O. rubescens is able to acclimate to elevated CO2 over time,” write the researchers. “The observed increase in RMR may be the result of multiple acute responses to hypercapnia [increased CO2 in the blood], possibly including both behavioural and physiological strategies.”

Those strategies could include preparing to move to find a new stretch of water to inhabit, for example, the researchers suggest (something that wasn’t possible here). The short RMR boost might also reflect the octopuses making quick adjustments to their biological processes to suit the new acid level.

The study is the first to look at both short-term (one week) and longer-term (five week) changes in metabolism rates in cephalopods in response to ocean acidification. We know these creatures are tough, and it seems they even have coping strategies that might allow them to adapt to humans destroying the natural environment all around them.

None of this means that we should be okay with the current climate crisis though, or not be trying to make major changes to reverse it. When we don’t take proper care of the planet, it’s not just ourselves that we’re potentially dooming to extinction.

Also, these tests were done in controlled laboratory conditions that don’t take into account many other interlinking factors in the animals’ natural environment. For instance, even if the octopus themselves are able to adjust, what about their food supply?

“While this species may be able to acclimate to near-term ocean acidification, compounding environmental effects of acidification and hypoxia may present a physiological challenge for this species,” write the researchers.

The research has been published in Physiological and Biochemical Zoology.

 



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Eerie ‘Tree Ring’ Lines in Our Teeth Could Indicate Life Events, Including Childbirth

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Teeth don’t just chew. The more we find out about these calcified structures inside our mouths, the more we discover how the oral environment is linked to our broader health, our mental functioning, and much more besides.

 

Even so, we may have only scratched the surface of how deep the ties go between teeth and the rest of our lives. According to new research, teeth even serve as a silent chronicler of major life events – recording significant, impactful episodes in mysterious ‘tree ring’-like bands, hidden inside the microstructure of dental tissue.

“A tooth is not a static and dead portion of the skeleton,” explains dental anthropologist Paola Cerrito from New York University. “It continuously adjusts and responds to physiological processes.”

012 teeth tree rings 1A molar of a 35-year-old female, with close-up revealing dark ‘rings’ corresponding to reproductive events. (Paola Cerrito)

In the study, Cerrito and her team analysed 47 teeth from 15 deceased individuals aged 25 to 69 at the time of their death. This cohort, drawn from a cadaveric collection of Central African Malawians of Bantu origin, was chosen because, in addition to their human remains, records exist of most of these people’s life histories, including aspects of their lifestyle information and medical history.

In terms of the dental remains, what the researchers wanted to examine in particular was the cementum preserved in the teeth. Like other mineralised tissues such as bone, enamel, and dentine, cementum – a calcified substance that covers the root of each tooth – can record subtle, observable growth lines linked to physiological stressors that impact normal tissue formation.

 

Unlike enamel and dentine, though, cementum grows throughout our lives, not only while we are young. Because of this longevity, cementum abnormalities can be used as markers indicative of physiological stressors throughout an individual’s entire life.

In the case of many mammal species, observations of this phenomenon have helped scientists identify the histological signature of things like pregnancy and lactation – physiologically demanding events in the lifetime of an animal, resulting in narrower cementum growth layers.

What Cerrito and her colleagues wanted to know was whether the same changes in human teeth would correlate with major life events in people’s lives, leaving identifiable traces of things like childbirth and menopause.

According to the results, it does. Under the microscope, the team found that cementum markers correlating to reproductive events and menopause were identifiable in the teeth of all the women in the study who had experienced such events – but that’s not all they found.

When they compared the documented life histories (largely provided by next of kin) against the dental remains, they discovered other kinds of events also appeared to leave indelible marks in the teeth: systemic illnesses, incarceration, and even moving from a rural environment to an urban centre.

 

“This tells us something about the ‘sensitivity’ of cementum as a recording structure: episodic events are not recorded, while prolonged systemic ones are,” Cerrito told The Guardian.

Of course, so far, these cementum-based markers have only been demonstrated in a small number of individuals. Before we get too carried away with the potential of the technique, we should wait to see if accurate results can be replicated in a larger group.

There are also limitations to consider in the absence of known life histories. Precisely what might distinguish an event that should have a systemic impact on the body also isn’t clear. What could this actually tell us about a John Doe from hundreds of years ago, or even a Neanderthal, if we can’t join the dots to any documented chapters of their lives?

For now, there are still plenty of questions, but this could be a discovery set to have a major impact on future research, ranging from archaeology to medicine.

After all, inscribed in each of us, there seems to be a hidden time capsule of life’s major moments, preserved in our teeth, and never tapped before now.

“This study provides the first evidence in humans of histological markers corresponding not only to parturitions and menopause, but also illnesses and drastic changes in lifestyle,” the team writes.

“Our results demonstrate that dental cementum constitutes a chronologically faithful biological archive of an individual, from which life history milestones, thus far not inferable from other mineralised tissues, can be detected and accurately timed.”

The findings are reported in Scientific Reports.

 



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NASA Just Announced More Strange Results From Its Ambitious ‘Twin Study’

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Long-duration spaceflight does weird things to the human body, even at the molecular level, but so far there’s no reason to think humans couldn’t survive a two-and-a-half-year round-trip journey to Mars.

 

That was the bottom-line message Friday from a NASA official and two scientists as they revealed more results from the agency’s “Twins Study,” which examined physiological changes in astronaut Scott Kelly during his nearly year-long sojourn in space while his twin brother, Mark Kelly, stayed on Earth.

The full report has not yet been published, but reporters got a summary at a news conference at the annual meeting of the American Association for the Advancement of Science, in Washington.

Among the highlights: Scott Kelly’s bloodwork showed that his immune system quickly ramped up when he went into space, as if, at the cellular level, his body felt under attack.

“It’s almost as if the body’s on high alert,” said Christopher Mason, associate professor of computational genomics at Weill Cornell Medicine.

Some of the physiological effects of microgravity have long been known, such as impaired vision, bone loss, muscle loss and disruption to the wake-sleep cycle. The new research shows changes at the cellular level, including changes in gene expression.

“It’s mostly really good news,” Mason said. “The body has extraordinary plasticity and adaptation to being in zero gravity, at least for a year.”

 

That was echoed by Craig Kundrot, director of NASA’s space life and physical sciences division. He said so far the NASA research has found nothing that would make a Mars mission impossible. The biggest concern is radiation: Such a mission would expose astronauts to levels of radiation greater than permitted under current guidelines. That wouldn’t necessarily prevent a mission, but it remains a concern.

He cautioned that the twins study has a very small study sample: two people.

“We don’t regard any of this as conclusive, but on the whole it’s encouraging,” he said. “There are no new major warning signs.”

NASA under President Trump has renewed its vow to put human beings on the moon again, and on Thursday produced a provisional plan that envisioned astronauts on the lunar surface in 2028 as part of an international effort that would include commercial partners.

The agency says that, unlike the Apollo program, the new moon program would be sustained and not merely a “flags and footprints” mission.

Any human mission beyond low Earth orbit presents a suite of health risks for astronauts because of the radiation in deep space. The technological challenges associated with a human mission to Mars are obvious, but the physiological challenges are potentially just as significant.

 

Kundrot said Friday that NASA envisions a Mars mission that would require a six-month flight each way plus 18 months on the Martian surface.

Such a mission might involve four to six astronauts, likely an international team. The psychological stresses of such a mission would be considerable.

“It’s the ICE conditions — isolated, confined, extreme,” said Steve Kozlowski, a professor of organizational psychology at Michigan State University who will make a presentation at the AAAS convention on Sunday. Kozlowski has been researching technologies that could help astronauts monitor the quality of team dynamics.

“You’re going to be in a little tiny space, you’re not going to have virtually any privacy,” he said. The time delay in communication across millions of miles of space will make conversations with people back home essentially impossible, he said.

“Your social world is going to be you and this small group of people for a really, really long time.”

2019 © The Washington Post

This article was originally published by The Washington Post.

 



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