Tag: Max Planck Institute

The diaspora of modern humans across Eurasia — update and revision

1 Comment


Migration routes — Click to enlarge

❝ Most people are now familiar with the traditional “Out of Africa” model: modern humans evolved in Africa and then dispersed across Asia and reached Australia in a single wave about 60,000 years ago. However, technological advances in DNA analysis and other fossil identification techniques, as well as an emphasis on multidisciplinary research, are revising this story. Recent discoveries show that humans left Africa multiple times prior to 60,000 years ago, and that they interbred with other hominins in many locations across Eurasia.

❝ A review of recent research on dispersals by early modern humans from Africa to Asia by researchers from the Max Planck Institute for the Science of Human History and the University of Hawai’i at Manoa confirms that the traditional view of a single dispersal of anatomically modern humans out of Africa around 60,000 years ago can no longer be seen as the full story. The analysis, published in the journal Science, reviews the plethora of new discoveries being reported from Asia over the past decade, which were made possible by technological advances and interdisciplinary collaborations, and shows that Homo sapiens reached distant parts of the Asian continent, as well as Near Oceania, much earlier than previously thought. Additionally, evidence that modern humans interbred with other hominins already present in Asia, such as Neanderthals and Denisovans, complicates the evolutionary history of our species.

The Max Planck Institute is the gold standard for research into the evolutionary biology of homo sapiens. When original discussions stretched around the world at the turn of the 21st Century, debate and discussion took over a great deal of public and non-institutional dialogue on the latest discussions of evolution. Scuence readers and writers as well as core researchers were all involved.

I spent about 2 years getting my head around the results of the first DNA analysis providing deeper genetic and chronological analysis previously impossible. While spirited debate was often the order of the day – well above the perpetual attempts to educate superstitious folk stuck into biblical fiction – I have rarely so enjoyed the weekly expansion of knowledge rolling out the doors of the Max Planck Institute like tides changing the face of the intellectual Earth after an Ice Age.

Oh, yeah. Between 3 and 4% of my overall DNA is Neanderthal. Never was one of those straight-up white guys. 🙂

Evidence that birds sleep while flying

Leave a comment

❝ We already know that some birds can fly for weeks or even months at a time without landing, but this remarkable ability has raised a few questions about how, if at all, these creatures find the time to sleep. In the first study of its kind, scientists have monitored the brain activity of seabirds in flight and discovered that they regularly squeeze in some shut-eye while out searching for food, though how they perform on such little rest remains a little unclear.

❝ If there was ever a bird well-suited to sleeping on the job, it might be the frigatebird, a large seabird that scans the ocean surface for flying fish and squid. Recent research has shown that these elite gliders can stay aloft for months by hitching rides on clouds and are among the longest-flying creatures in the seabird world. But even frigatebirds need their sleep, so scientists have been perplexed as to how they maintain performance without regularly coming down for rest…

❝ To find some conclusive answers, an international team of scientists hooked up frigatebirds nesting on the Galápagos Island to a device to monitor electroencephalographic (EEG) activity and head movement during flight. This recorder was carted along for 10-day flights across 3,000 km (1,864 mi) with a GPS module on the bird’s back to monitor their position and altitude.

The data showed that during the day, the birds remained awake while searching for food, so business as usual. But when the sun went down and the birds soared, the awake EEG pattern changed to a slow-wave sleep pattern, sometimes for minutes at a time. This SWS often occurred in one half of the brain, but interestingly, sometimes in both hemispheres at the same time, suggesting that unihemispheric sleep isn’t critical to maintaining aerodynamic control.

❝ Compared to how frigatebirds sleep on land, however, the SWS sleep mode was more frequent. By tracking the head movements of the birds, the researchers found that as they circle on rising air currents while sleeping in this way, it allowed them to keep one eye open in the direction they were turning.

The big surprise was that the frigatebirds were only sleeping for 42 minutes per day — compared to the usual 12 hours a day on land. Working out comparisons with what we know about sleep and sleep deprivation in other species – like us – will be part of where these studies will be going next.

Armed conflict: bad for humanity, great for reducing air pollution!

Leave a comment

NM Ozymandias

Air pollution has decreased dramatically in parts of the Middle East in the past five years – partly due to armed conflicts since the Arab Spring.

A new study suggests the improvement is the result of the conflicts, economic recessions and human displacement suffered across the region.

The findings state: “A combination of air quality control and political factors, including economical crisis and armed conflict, has drastically altered the emission landscape of nitrogen oxides in the Middle East.”

Jos Lelieveld of the Max Planck Institute for Chemistry in Mainz, Germany, was the lead author of the study, which was published in Science Advances.

Between 2005 and 2010, the Middle East had the world’s fastest-rising air pollution emission levels.

A similar increase took place in East Asia, most likely due to economic and industrial growth.

“However, [the Middle East] is the only region where this pollution trajectory was interrupted around 2010 and followed by a strong decline,” Professor Lelieveld said…

In Syria, the level of nitrogen dioxide over Damascus has fallen by 50 per cent since the start of the civil war in 2011.

“It’s proportional to people, so if emissions have gone down in Syria by 50 per cent, I’d expect that 50 per cent of the people might have been displaced, as indeed they have,” Prof Lelieveld said.

The findings “disagree with scenarios used in prediction of air pollution and climate change for the future,” he added.

Yes, yes. Unless you’re one of the delightful nation-states which carries around the occasional nuclear weapon and threatens other lands with an opportunity to glow in the dark for several thousand years.

I admit, though, it is tempting to consider reducing the number of human beings in any location because of generally positive results. I would prefer doing so in a manner equally beneficial to the human species – as it is to those others, animal and vegetable, occupying the same landscape.

I suggest providing a basic scientific education including knowledge of birth control. In general, everywhere that happens the birth rate diminishes and tends to produce the same result. No fighter-bombers or helicopters required.

Awareness of thinking – awareness of dreaming

1 Comment

metacognition

To control one’s dreams and to live out there what is impossible in real life – a truly tempting idea. Some persons – so-called lucid dreamers –can do this. Researchers from the Max Planck Institute for Human Development in Berlin and the Max Planck Institute of Psychiatry in Munich have discovered that the brain area which enables self-reflection is larger in lucid dreamers. Thus, lucid dreamers are possibly also more self-reflecting when being awake.

Lucid dreamers are aware of dreaming while dreaming. Sometimes, they can even play an active role in their dreams. Most of them, however, have this experience only several times a year and just very few almost every night. Internet forums and blogs are full of instructions and tips on lucid dreaming. Possibly, lucid dreaming is closely related to the human capability of self-reflection – the so-called metacognition…

The differences in volumes in the anterior prefrontal cortex between lucid dreamers and non-lucid dreamers suggest that lucid dreaming and metacognition are indeed closely connected. This theory is supported by brain images taken when test persons were solving metacognitive tests while being awake. Those images show that the brain activity in the prefrontal cortex was higher in lucid dreamers…

The researchers further want to know whether metacognitive skills can be trained. In a follow-up study, they intend to train volunteers in lucid dreaming to examine whether this improves the capability of self-reflection.

You, too, can join the ranks of Sartre and Camus. 🙂

It is especially interesting to me – to see these attributes often referred to in the Existential offshoots from Materialist Dialectics getting special attention from one of the leading researchers in the world.

In the expanse of free time accrued since retirement, I have found myself from time to time wandering back to questions like these for the first time in decades. I’ve been aware of being a lucid dreamer since childhood. Metacognitive processes have always been equally provocative, equally challenging.

Fascinating as ever.

FANTASTIC VOYAGE is closer to reality — with scallop microbots

Leave a comment

In the 1960s science fiction film Fantastic Voyage, audiences thrilled to the idea of shrinking a submarine and the people inside it to microscopic dimensions and injecting it into a person’s bloodstream. At the time it was just fantasy and as fantastic an idea as its title suggested. Today, however, micro-miniature travelers in your body have come one step closer to reality. Researchers from the Max Planck Institute have been experimenting with real micro-sized robots that literally swim through your bodily fluids and could be used to deliver drugs or other medical relief in a highly-targeted way…

The microrobots being designed by the team literally are swimmers; they are scallop-like devices designed to paddle through non-Newtonian fluids like blood and plasma (even water behaves in this way at a microscopic level). This means that, unlike swimming in water at a macro-level, these microbots need to move through fluid that has a changing viscosity depending on how much force is exerted upon it.

To do this, the microbots need a method of propulsion that can fit in their tiny bodies as well as take advantage of the non-Newtonian fluid in which they are moving. Importantly, the team is using a reciprocal method of movement to propel their microscallops; but generally this doesn’t work in such fluids, which is why organisms that move around in a biological system use non-reciprocating devices like flagella or cilia to get about.

However these robotic microswimmers actually take advantage of this property and use a scallop swimming motion to move around. The researchers call this process “modulation of the fluid viscosity upon varying the shear rate.” In simple terms, the micro scallops open and close their “shells” to compress the fluid and force it out behind them, which then propels them along.

The fact that the microrobot scallop has no motor to drag around contributes to its exceptionally small size – around 800 microns. This makes it miniscule enough to make its way through your bloodstream, around your lymphatic system, or across the slippery goo on the surface of your eyeballs…

The first and most obvious use would be delivery of medication. The authors are otherwise laid back about suggestions for the future. They’re confident today’s medical researchers are technically hip enough that there will be more potential uses for these microbots than any one team might ever invent.

Experiment will attempt to create matter from light

Leave a comment

In what could be a landmark moment in the history of science, a team of physicists working at the Blackett Physics Laboratory in Imperial College London has designed an experiment to validate one of the most tantalizing hypotheses in quantum electrodynamics: the theory that matter could be created using nothing more than pure light.

Premised on a discussion that they had over one day and a few cups of coffee, the three physicists – two from Imperial College and one visiting from the Max Planck Institute in Heidelberg, Germany – recognized that their work on fusion energy also offered possibilities in the theory of light to matter creation, suggested in a theory 80 years ago by two American physicists, Breit and Wheeler. These two physicists had premised the idea that because annihilating electron-positron pairs produce two or more photons, then colliding photons should, in turn, produce electron-positron or “Breit-Wheeler” pairs…

Given the potential to open up a relatively low-energy, simple way to investigate a cornerstone of quantum electrodynamics, this proposal should allow many more researchers access to this field. As a result, this could help add to our knowledge of the processes that took place in the first 100 seconds of the universe and possibly shed more light on those mysterious denizens of deep-space: gamma-ray bursts emanating from exploding massive stars.

Lastly, validating the Breit-Wheeler theory would also provide the seventh and final in the line theories describing the simplest ways in which light and matter interact. These include Dirac’s 1930 theory on the annihilation of electrons and positrons, Einstein’s 1905 theory on the photoelectric effect, and Blackett and Occhialini’s single-photon annihilation. Those theories are all associated with Nobel Prize-winning research.

A delightful comment on the expanding universe of scientific hardware and software in recent decades. Twenty years ago this experiment would have been a pipe dream. It still may come to nothing; but, the point is that we’re now capable of reaching out into this particular realm of darkness and literally attempt to bring light to our knowledge.

RTFA for the means these researchers intend to invoke for their experiment. Hang on. It could be a bumpy ride.

Cold plasma demonstrates clean doom for bacteria

Leave a comment

Researchers have demonstrated a prototype device that can rid hands, feet, or even underarms of bacteria, including the hospital superbug MRSA.

The device works by creating something called a plasma, which produces a cocktail of chemicals in air that kill bacteria but are harmless to skin. A related approach could see the use of plasmas to speed the healing of wounds…

Plasmas are known as the fourth state of matter, after solid, liquid, and gas. They are a soup of atoms that have had their electrons stripped off by, for example, a high voltage.

The new research focuses on so-called cold atmospheric plasmas.

Rather than turning a whole group of atoms into plasma, a more delicate approach strips the electrons off just a few, sending them flying…

The resulting plasma is harmful to bacteria, viruses, and fungi – the approach is already used to disinfect surgical tools…

Professor Gregor Morfill said that more testing of the devices is necessary before they end up in widespread use, but he said that there is already significant interest from industry.

RTFA. The systems have been miniaturized enough to be battery-operated and portable.

Cripes, I can see them supplanting underarm deodorant sticks someday.