Tag Archives | Biology

Sex With Neanderthals Forever Changed Homo Sapiens

There’s now little doubt that modern day humans, homo sapiens, are partly Neanderthal. From skin disorders to the immune system, sex with archaic species changed Homo sapiens reports Nature:

Our ancestors were not a picky bunch. Overwhelming genetic evidence shows that Homo sapiens had sex with Neander­thals, Denisovans and other archaic relatives. Now researchers are using large genomics studies to unravel the decidedly mixed contributions that these ancient romps made to human biology — from the ability of H. sapiens to cope with environments outside Africa, to the tendency of modern humans to get asthma, skin diseases and maybe even depression.

Neanderthal Mother (detail of diorama)

The proportion of the human genome that comes from archaic relatives is small. The genomes of most Europeans and Asians are 2–4% Neanderthal1, with Denisovan DNA making up about 5% of the genomes of Mela­nesians2 and Aboriginal Australians3. DNA slivers from other distant relatives probably pepper a variety of human genomes4.

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The Psychology of Revenge: Biology, Evolution and Culture

Murder of Agamemnon

“Revenge is a dish best served cold…”
(Ancient Klingon Proverb)

This post originally appeared on Philosophical Disquisitions

When I was younger I longed for revenge. I remember school-companions doing unspeakably cruel things to me — stealing my lunch, laughing at my misfortune and so forth (hey, it all seemed cruel at the time). I would carefully plot my revenge. The revenge almost always consisted of performing some similarly unspeakably cruel act towards them. Occasionally, my thoughts turned to violence. Sometimes I even lashed out in response.

I’m less inclined towards revenge these days. Indeed, I am almost comically non-confrontational in all aspects of my life. But I still feel the pangs. When wronged, I’ll briefly get a bit hot under the collar and my thoughts will turn to violence once more. I’ll also empathise with the characters in the innumerable revenge narratives that permeate popular culture, willing them on and feeling a faint twinge of pleasure when they succeed.… Read the rest

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Can Pollution Help Trees Fight Infection?

Pollution may help trees fight infection. Credit: Frederic E. Pitre

Pollution may help trees fight infection.
Credit: Frederic E. Pitre

Via ScienceDaily:

Trees that can tolerate soil pollution are also better at defending themselves against pests and pathogens. “It looks like the very act of tolerating chemical pollution may give trees an advantage from biological invasion,” says Dr Frederic E. Pitre of the University of Montreal and one of the researchers behind the discovery.

Unexpectedly, whilst studying the presence of genetic information (RNA) from fungi and bacteria in the trees, the researchers found evidence of a very large amount of RNA from a very common plant pest called the two-spotted spidermite.

In fact, 99% of spidermite RNA was in higher abundance in trees without contamination, suggesting that the polluted plant’s defence mechanisms, used to protect itself against chemical contamination, improves its resistance to a biological invader.

“This higher spidermite gene expression (RNA) in non-contaminated trees suggests that tolerating contamination might ‘prime’ the trees’ defence machinery, allowing them to defend themselves better against pests, such as spidermites,” says Pitre.

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Single-celled sniper uses one eye to hunt

This single-celled organism can point its eye in different directions and it may use it to hunt prey. It also has a unique piston mechanism, but its use is still unclear.

Michael Le Page via New Scientist:

It is perhaps the most extraordinary eye in the living world – so extraordinary that no one believed the biologist who first described it more than a century ago.

Now it appears that the tiny owner of this eye uses it to catch invisible prey by detecting polarised light. This suggestion is also likely to be greeted with disbelief, for the eye belongs to a single-celled organism called Erythropsidinium. It has no nerves, let alone a brain. So how could it “see” its prey?

Fernando Gómez of the University of São Paulo, Brazil, thinks it can. “Erythropsidinium is a sniper,” he told New Scientist. “It is waiting to see the prey, and it shoots in that direction.”

Erythropsidinium belongs to a group of single-celled planktonic organisms known as dinoflagellates.

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Can We Trust Scientists’ Self-Control?

Positive-pressure biosafety suitNew biological techniques create the potential for catastrophe. The self-control of scientists is not enough to protect us, or to secure public trust. National governments must step in. Filippa Lentzos, Koos van der Bruggen and Kathryn Nixdorff argue that the US should lead the way, at the Guardian:

There is a growing convergence of concern about new technologies in the life sciences that are raising significant societal, ethical, environmental and security risks. Global public engagement must be a priority for deliberation about these technologies and for developing a set of common red lines.

The genome-editing technique CRISPR-Cas9 is the latest in a series of technologies to hit the headlines. This week Chinese scientists used the technology to genetically modify human embryos – the news coming less than a month after a prominent group of scientists had called for a moratorium on the technology. The use of ‘gene drives’ to alter the genetic composition of whole populations of insects and other life forms has also raised significant concern.

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DNA Can’t Explain All Inherited Biological Traits, Research Shows

A histone is a protein that provides structural support to a chromosome. In order for very long DNA molecules to fit into the cell nucleus, they wrap around complexes of histone proteins, giving the chromosome a more compact shape. Some variants of histones are associated with the regulation of gene expression. Credit: Darryl Leja, NHGRI

A histone is a protein that provides structural support to a chromosome. In order for very long DNA molecules to fit into the cell nucleus, they wrap around complexes of histone proteins, giving the chromosome a more compact shape. Some variants of histones are associated with the regulation of gene expression.
Credit: Darryl Leja, NHGRI

Via ScienceDaily:

Characteristics passed between generations are not decided solely by DNA, but can be brought about by other material in cells, new research shows.

Scientists studied proteins found in cells, known as histones, which are not part of the genetic code, but act as spools around which DNA is wound. Histones are known to control whether or not genes are switched on.

Researchers found that naturally occurring changes to these proteins, which affect how they control genes, can be sustained from one generation to the next and so influence which traits are passed on.

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Scan Allows Scientists to Determine Biological Age From the Face Alone

You know how there’s always some ancient person emerging from a formerly “hidden” culture who’s supposed to be hundreds of years old? Well now we can just scan them to find out their real age. That’s assuming the software’s any good, mind. From the Guardian:

Scientists have created a 3D imaging system they claim can reliably predict a person’s biological age from the look of their face alone.

These 3D images are a composite of two sets of female faces, showing the average facial structure for each age group in the study. The left image shows the average of the 17-29 year-old women, the right 60-77 year-old women. Composite: Chinese Academy of Sciences

These 3D images are a composite of two sets of female faces, showing the average facial structure for each age group in the study. The left image shows the average of the 17-29 year-old women, the right 60-77 year-old women. Composite: Chinese Academy of Sciences

 

The researchers believe the technology could be used to judge whether proposed anti-ageing treatments have any effect, and to help doctors fine-tune advice and therapies for their patients.

They developed the technology after scanning the faces of more than 300 people aged 17 to 77 and building up a map that reveals how the human face changes over a lifetime.

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You Are More Bug Than Human

Yup, that’s right, you have so many disgusting creatures living on and in your body that you’re more bug than human (per BBC Future). Deal with it.

We hate to break it you, but you’re not totally human. It’s nothing about you personally. It’s just that more than 90% of the cells in the human body are actually parasites. You might feel like a single being, but you’re really more of a bug city, teeming with different species.

Every square centimetre of your face houses one or two tiny spiders. — Don’t panic – they keep you clean.

Or as Greg Foot from BritLab puts it in the above video: “In a rather gross way, you are practically a walking petri dish, a home for more bugs and bacteria than you’d care think about.”

Consider the skin on your face. As smooth and peachy as it may look, every square centimetre houses around one or two “demodex spiders”.

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DARPA’s Solution to Ebola (and all other Infectious Diseases)

It’s tempting to think of DARPA as the US Government’s evil technology agency, but Alexis Madrigal has discovered one DARPA program that might just be an incredible solution to infectious diseases, reporting for Fusion:

Saving the world from Ebola suddenly sounds so simple, as the solution spills from Colonel Dan Wattendorf’s mouth, up on the stage in the windowless banquet hall of this Marriott hotel south of San Francisco.

“We’re going to take the genetic code and put it into a format where you go to your drug store or doctor and get a shot in the arm,” Wattendorf told a room full of medical researchers and technologists. “There’s a low-cost of goods, no cold chain, and we would produce the correct antibody in [any] individual directly.”

DARPA

Wattendorf, a clean-cut, angular triathlete, is a program manager for the Defense Advance Research Projects Agency (DARPA), the military’s far-out research wing. On this day, he’s speaking at a DARPA-sponsored conference called Biology Is Technology.

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Ending Aging with Dr. Aubrey de Grey | Midwest Real

aubrey de grey

Via Midwest Real

Dr. Aubrey de Grey is Co-Founder and Chief Science Officer at the SENS Research Foundation, a nonprofit dedicated to ending aging. 

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The march of time spares none, neither rich, famous nor powerful. The deep, existential angst that comes part and parcel with that knowledge has, no doubt, haunted mankind from the very first moment we became self-aware. It’s also the one obstacle we’ve encountered as a species we just take for granted as the unassailable natural order of things.

It’s incredible really- we’ve walked the moon, we fly across the world and we transmit words through the air as if it’s trivial. Yet, for some reason when it comes to aging, we yield. Even the most brilliant men among us don’t consider the possibility that we might be able to circumvent becoming old and dying.

Actually, some brilliant men do.

Ending aging has become the life’s work of our guest, Dr.Read the rest

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