Author Archives: Attention to the Unseen

Babies have more acute powers of perception than adults

Science News reports: Six-month-old babies can spot subtle differences between two monkey faces easy as pie. But 9-month-olds — and adults — are blind to the differences. In a 2002 study of facial recognition, scientists pitted 30 6-month-old babies against 30 9-month-olds and 11 adults. First, the groups got familiar with a series of monkey and human faces that flashed on a screen. Then new faces showed up, interspersed with already familiar faces. The idea is that the babies would spend more time looking at new faces than ones they had already seen.

When viewing human faces, all of the observers, babies and adults alike, did indeed spend more time looking at the new people, showing that they could easily pick out familiar human faces. But when it came to recognizing monkey faces, the youngsters blew the competition out of the water. Six-month-old babies recognized familiar monkey faces and stared at the newcomers longer. But both adults and 9-month-old babies were flummoxed, and looked at the new and familiar monkey faces for about the same amount of time.

Superior visual skills don’t apply to just faces, either. Three- to 4-month-old babies can see differences in lighting that are undetectable to adults. This ephemeral superskill evaporates just months later, scientists reported in December in Current Biology. To test babies’ visual acuity, researchers led by Jiale Yang of Chuo University in Tokyo first generated a series of 3-D pictures of snails. The shiny snails were made to look as though light was hitting them from different places. Like adults, 5- to 6-month-old babies couldn’t spot the lighting differences. But younger babies could, the team found. [Continue reading…]

Facebooktwittermail

Dawn of the Anthropocene: Five ways we know humans have triggered a new geological epoch

By Jan A. Zalasiewicz, University of Leicester and Mark Williams, University of Leicester

Is the Anthropocene real? That is, the vigorously debated concept of a new geological epoch driven by humans.

Our environmental impact is indeed profound – there is little debate about that – but is it significant on a geological timescale, measured over millions of years? And will humans leave a distinctive mark upon the layers of rocks that geologists of 100,000,000AD might use to investigate the present day?

Together with other members of the Anthropocene Working Group we’ve just published a study in Science that pulls much of the evidence together.

The case for the Anthropocene might be distilled into five strands:

1. Carbon in the atmosphere

Carbon is important, both due to its growing impact on global warming and because it leaves long-lived geological traces. The increased levels of carbon dioxide in the atmosphere – now higher than at any time in at least the past few million years – can be found as fossil bubbles in the geologically short-lived “rock” that is polar ice.

But there are wider and more long-lived traces too, in the form of changed patterns of carbon isotopes (absorbed by every living thing) and in tiny, virtually indestructible particles of fly ash released from furnaces and chimneys. These are leaving an indelible signal in rock and soil strata now accumulating.

Continue reading →

Facebooktwittermail

Why wealth hasn’t brought health: The body isn’t built to be an exclusive neighborhood

microbiome

Matt Ridley writes: As Stewart Brand acutely says, most of the things that dominate the news are not really new: love, scandal, crime, and war come round again and again. Only science and invention deliver truly new stuff, like double helixes and search engines. In this respect, the new news from recent science that most intrigues me is that we may have a way to explain why certain diseases are getting worse as we get richer. We are defeating infectious diseases, slowing or managing many diseases of ageing like heart disease and cancer, but we are faced with a growing epidemic of allergy, auto-immunity, and things like autism. Some of it is due to more diagnosis, some of it is no doubt hypochondria, but there does seem to be a real increase in these kinds of problems.

Take hay fever. It is plainly a modern disease, far more common in urban, middle-class people than it used to be in peasants in the past, or still is in subsistence farmers in Africa today. There’s really good timeline data on this, chronicling the appearance of allergies as civilization advances, province by province or village by village. And there’s really good evidence that what causes this is the suppression of parasites. You can see this happen in eastern Europe and in Africa in real time: get rid of worms and a few years later children start getting hay fever. Moises Velasquez-Manoff chronicles this in glorious detail in his fine book An Epidemic of Absence.

This makes perfect sense. In the arms race with parasites, immune systems evolved to “expect” to be down-regulated by parasites, so they over-react in their absence. A good balance is reached when parasites try down-regulating the immune system, but it turns rogue when there are no parasites. [Continue reading…]

Nina Jablonski writes: The taxonomic diversity and census of our resident bacteria are more than just subjects of scientific curiosity; they matter greatly to our health. The normal bacteria on our skin, for instance, are essential to maintaining the integrity of the skin’s barrier functions. Many diseases, from psoriasis to obesity, inflammatory bowel disease, some cancers, and even cardiovascular disease, are associated with shifts in our microbiota.

While it’s too early to tell if the changing bacteria are the cause or the result of these problems, the discovery of robust associations between bacterial profiles and disease states opens the door for new treatments and targeted preventive measures. The body’s microbiota also affects and is affected by the body’s epigenome, the chemical factors influencing gene expression. Thus, the bugs on us and in us are controlling the normal action of genes in the cells of our bodies, and changes in the proportions or overall numbers of bacterial affect how our cells work and respond to stress.

Let’s stop thinking about our bodies as temples of sinew and cerebrum, and instead as evolving and sloshing ecosystems full of bacteria, which are regulating our health in more ways than we could ever imagine. As we learn more about our single-celled companions in the coming years, we will take probiotics for curing acute and chronic diseases, we’ll undertake affirmative action to maintain diversity of our gut microflora as we age, and we’ll receive prescriptions for increasingly narrow-spectrum antibiotics to exterminate only the nastiest of the nasties when we have a serious acute infection. Hand sanitizers and colon cleansing will probably be with us for some time, but it’s best just to get used to it now: Bugs R us. [Continue reading…]

Facebooktwittermail

Mapping the Earth from the surface to the core

Steve LeVine writes: This was the defining tension underlying the half-century-long study of the supercontinents: That, unlike in other fields that deal in the very old, the scientists had no time machine. Astronomers, by looking through telescopes at galaxies billions of light years away, are transported back to the early universe. Paleontologists, by stumbling on ancient fossils, can look directly at remnants of prehistoric life. But no instrument or evidence had ever similarly teleported their paleogeologist comrades back to the age of supercontinents.

Instead, paleogeologists painstakingly pieced together their theories using disparate fragments of clues, mainly from the magnetic signatures in old rocks. At first, to give their field a face, they translated these clues into cut-out shapes on paper or in Adobe Illustrator, and strung them together into mosaic-like animations still found today on Google.

But while pretty good as far as they went, most such depictions were faulty in important ways. Among the unavoidable imperfections was their typical reliance on a “flat Earth,” two-dimensional illustrations that distorted the appearance and movement of the continents. In addition, they provided plate movements, but ignored the inextricable system that penetrates thousands of miles into the bowels of the Earth, linked all the way to the core. [Continue reading…]

Facebooktwittermail

How plants fight to stay alive

lichen8

Mike Newland writes: Compared to the hectic rush of our bipedal world, a plant’s life may appear an oasis of tranquility. But look a little closer. The voracious appetites of pests put plants under constant stress: They have to fight just to stay alive.

And fight they do. Far from being passive victims, plants have evolved potent defenses: chemical compounds that serve as toxins, signal an escalating attack, and solicit help from unlikely allies.

However, all of this security comes at a cost: energy and other resources that plants could otherwise use for growth and repair. So to balance the budget, plants have to be selective about how and when to deploy their chemical arsenal. Here are five tactics they’ve developed to ward off their insect foes without sacrificing their own wellbeing. [Continue reading…]

Facebooktwittermail

The volcano that shrouded the Earth and gave birth to Frankenstein

Gillen D’Arcy Wood writes: wo hundred years ago, the greatest eruption in Earth’s recorded history took place. Mount Tambora — located on Sumbawa Island in the East Indies — blew itself up with apocalyptic force in April 1815.

After perhaps 1,000 years’ dormancy, the devastating evacuation and collapse required only a few days. It was the concentrated energy of this event that was to have the greatest human impact. By shooting its contents into the stratosphere with biblical force, Tambora ensured its volcanic gases reached sufficient height to disable the seasonal rhythms of the global climate system, throwing human communities worldwide into chaos. The sun-dimming stratospheric aerosols produced by Tambora’s eruption in 1815 spawned the most devastating, sustained period of extreme weather seen on our planet in perhaps thousands of years.

Within weeks, Tambora’s stratospheric ash cloud circled the planet at the equator, from where it embarked on a slow-moving sabotage of the global climate system at all latitudes. [Continue reading…]

Facebooktwittermail

Poachers using science papers to target newly discovered species

The Guardian reports: Academic journals have begun withholding the geographical locations of newly discovered species after poachers used the information in peer-reviewed papers to collect previously unknown lizards, frogs and snakes from the wild, the Guardian has learned.

In an age of extinctions, scientists usually love to trumpet the discovery of new species, revealing biological and geographical data that sheds new light on the mysteries of evolution.

But earlier this year, an announcement in the Zootaxa academic journal that two new species of large gecko had been found in southern China contained a strange omission: the species’ whereabouts.

“Due to the popularity of this genus as novelty pets, and recurring cases of scientific descriptions driving herpetofauna to near-extinction by commercial collectors, we do not disclose the collecting localities of these restricted-range species in this publication,” the paper said. [Continue reading…]

Facebooktwittermail

New human species may rewrite history

New Scientist reports: We may have lived alongside an archaic human species just 10,500 years ago in China. Controversial bone discoveries suggest we even interbred with and cannibalised these mystery hominins.

Some think the findings could overturn our understanding of what it means to be human. “If true, this would be rather spectacular and it would make the finds of truly global importance,” says Michael Petraglia at the University of Oxford, who wasn’t involved in the discoveries.

One of the most exciting finds is a hominin femur found in Muladong cave in south-west China, alongside other human and animal bones. It shows evidence of having been burned in a fire that was used for cooking other meat, and has marks consistent with it being butchered. It has also been broken in a way that is used to access bone marrow. Unusually, it has been painted with a red clay called ochre, associated with burial rituals (PLoS One, doi.org/97c).

Things got more interesting when the team tried to identify the bone. “Our work shows clearly that the femur resembles archaic humans,” says Darren Curnoe of the University of New South Wales in Sydney, Australia, who led the team behind the discoveries. Yet the sediment the bone was found in dates to just 14,000 years ago. This would make it the most recent human species to go extinct. [Continue reading…]

Facebooktwittermail

Will we ever understand the beginning of the universe?

blakes-rock2

Ross Andersen writes: One crisp day last March, Harvard professor John Kovac walked out of his office and into a taxicab that whisked him across town, to a building on the edge of the MIT campus. People were paying attention to Kovac’s comings and goings that week. He was the subject of a fast-spreading rumour. Kovac is an experimental cosmologist midway through the prime of a charmed career. He did his doctoral work at the University of Chicago and a postdoc at Caltech before landing a professorship at Harvard. He is a blue chip. And since 2009, he has been principal investigator of BICEP2, an ingenious scientific experiment at the South Pole.

Kovac had come to MIT to visit Alan Guth, a world-renowned theoretical cosmologist, who made his name more than 30 years ago when he devised the theory of inflation. Guth told Kovac to take the back steps up to his office, to avoid being seen. If Guth’s colleagues caught a glimpse of the two men talking, the whispers swirling around Kovac would have swelled to a roar.

The science of cosmology has achieved wonders in recent centuries. It has enlarged the world we can see and think about by ontological orders of magnitude. Cosmology wrenched the Earth from the centre of the Universe, and heaved it, like a discus, into its whirling orbit around one unremarkable star among the billions that speed around the black-hole centre of our galaxy, a galaxy that floats in deep space with billions of others, all of them colliding and combining, before they fly apart from each other for all eternity. Art, literature, religion and philosophy ignore cosmology at their peril.

But cosmology’s hot streak has stalled. Cosmologists have looked deep into time, almost all the way back to the Big Bang itself, but they don’t know what came before it. They don’t know whether the Big Bang was the beginning, or merely one of many beginnings. Something entirely unimaginable might have preceded it. Cosmologists don’t know if the world we see around us is spatially infinite, or if there are other kinds of worlds beyond our horizon, or in other dimensions. And then the big mystery, the one that keeps the priests and the physicists up at night: no cosmologist has a clue why there is something rather than nothing. [Continue reading…]

Facebooktwittermail

The migrant roots of ancient European ancestry

University of Cambridge

The first sequencing of ancient genomes extracted from human remains that date back to the Late Upper Palaeolithic period over 13,000 years ago has revealed a previously unknown “fourth strand” of ancient European ancestry.

This new lineage stems from populations of hunter-gatherers that split from western hunter-gatherers shortly after the ‘out of Africa’ expansion some 45,000 years ago and went on to settle in the Caucasus region, where southern Russia meets Georgia today.

Here these hunter-gatherers largely remained for millennia, becoming increasingly isolated as the Ice Age culminated in the last ‘Glacial Maximum’ some 25,000 years ago, which they weathered in the relative shelter of the Caucasus mountains until eventual thawing allowed movement and brought them into contact with other populations, likely from further east.

This led to a genetic mixture that resulted in the Yamnaya culture: horse-borne Steppe herders that swept into Western Europe around 5,000 years ago, arguably heralding the start of the Bronze Age and bringing with them metallurgy and animal herding skills, along with the Caucasus hunter-gatherer strand of ancestral DNA – now present in almost all populations from the European continent.

The research was conducted by an international team led by scientists from Cambridge University, Trinity College Dublin and University College Dublin. The findings were published last month in the journal Nature Communications.

Continue reading →

Facebooktwittermail