Tag: evolution
Long Lives Made Humans Human
The fundamental structure of human populations has changed exactly twice in evolutionary history. The second time was in the past 150 years, when the average lifespan doubled in most parts of the world. The first time was in the Paleolithic, probably around 30,000 years ago. That’s when old people were basically invented.
Throughout hominid history, it was exceedingly rare for individuals to live more than 30 years. Paleoanthropologists can examine teeth to estimate how old a hominid was when it died, based on which teeth are erupted, how worn down they are, and the amount of a tissue called dentin. Anthropologist Rachel Caspari of Central Michigan University used teeth to identify the ratio of old to young people in Australopithecenes from 3 million to 1.5 million years ago, early Homo species from 2 million to 500,000 years ago, and Neanderthals from 130,000 years ago. Old people—old here means older than 30 (sorry)—were a vanishingly small part of the population. When she looked at modern humans from the Upper Paleolithic, about 30,000 years ago, though, she found the ratio reversed—there were twice as many adults who died after age 30 as those who died young.
Excerpt from an article written by Laura Helmuth at Slate. Continue THERE
What Cannibals Could Teach Us About Evolution
In the past few decades, scientists studying the eating habits of Earth’s creatures have noticed something strange: the babies of several species, from tiger sand sharks to fruit flies, are eating each other.
Thing is, they aren’t freaks of nature. And in fact, the mechanisms behind animal cannibalism are helping scientists ask–and answer–some important evolutionary questions. These three recent studies provide a glimpse into this gruesome diet and what it means for evolution.
Why paternity might still matter after fertilization
Sand tiger sharks have been known to have cannibalistic embryos since the 1980s, when detailed autopsies revealed embryos in the stomachs of other shark embryos. But a new study published in Biological Letters could give some clues as to why.
Female sand tiger sharks aren’t the most faithful–they tend to mate with multiple male partners. And if you’re a male sand tiger shark trying to further your lineage, it’s not just about the speed and strength of sperm. The competition continues even after the eggs turn to embryos. After about five months of gestation, the embryo to first hatch from its egg in utero (the female sand tiger shark has two uteri) begins to feed on its smaller siblings–specifically those fathered by a different male. Some litters may start at 12 but this alpha embryo will eat all but one, leaving its brother or sister from the same mister alive. So despite the litters starting out with various fathers, the offspring that make it through the gestational massacre tend to be from the same father–and they’re large and strong enough to survive potential predators after birth. “It’s exactly the same sort of DNA testing that you might see on Maury Povich to figure out how many dads there are,” Stony Brook University marine biologist and study author Demian Chapman told LiveScience.
Text and Image via POPSci. Continue THERE
How A Virus Hid In Our Genome For Six Million Years
In the mid-2000s, David Markovitz, a scientist at the University of Michigan, and his colleagues took a look at the blood of people infected with HIV. Human immunodeficiency viruses kill their hosts by exhausting the immune system, allowing all sorts of pathogens to sweep into their host’s body. So it wasn’t a huge surprise for Markovitz and his colleagues to find other viruses in the blood of the HIV patients. What was surprising was where those other viruses had come from: from within the patients’ own DNA.
HIV belongs to a class of viruses called retroviruses. They all share three genes in common. One, called gag, gives rise to the inner shell where the virus’s genes are stored. Another, called env, makes knobs on the outer surface of the virus, that allow it to latch onto cells and invade them. And a third, called pol, makes an enzyme that inserts the virus’s genes into its host cell’s DNA.
It turns out that the human genome contains segments of DNA that match pol, env, and gag. Lots of them. Scientists have identified 100,000 pieces of retrovirus DNA in our genes, making up eight percent of the human genome. That’s a huge portion of our DNA when you consider that protein coding genes make up just over one percent of the genome.
Excerpt form an article written by Carl Zimmer. Continue HERE
Russian billionaire reveals real-life ‘avatar’ plan – and says he will upload his brain to a hologram and become immortal by 2045
32 year-old Dmitry Itskov believes technology will allow him to live forever in a hologram body. His ‘2045 initiative’ is described as the next step in evolution, and over 20,000 people have signed up on Facebook to follow its progress, with global conferences planned to explore the technology needed.
‘We are in the process of creating focus groups of experts,’ said Itskov. ‘Along with these teams, we will prepare goal statements and research programs schedules.’ The foundation has already planned out its timeline for getting to a fully holographic human, and claims it will be ready to upload a mind into a computer by 2015, a timeline even Itskov says is ‘optimistic’.
‘The four tracks and their suggested deadlines are optimistic but feasible,’ he said of the foundation’s site.
‘This is our program for the next 35 years, and we will do our best to complete it.’
The ultimate aim is for a hologram body.
‘The fourth development track seems the most futuristic one,’ said Itskov.
‘It’s intent is to create a holographic body. Indeed, its creation is going to be the most complicated task, but at the same time could be the most thrilling problem in the whole of human evolution.’
Continue HERE
Evolution of the New York Driver’s License
New York State first began issuing paper licenses to chauffeurs in 1910, and the shape, form and style have changed over the past century, adapting to new laws and technologies. The following is a sampling of how the license has evolved. See More HERE
Our Former Faces
To put a human face on our ancestors, scientists from the Senckenberg Research Institute used sophisticated methods to form 27 model heads based on tiny bone fragments, teeth and skulls collected from across the globe. The heads are on display for the first time together at the Senckenberg Natural History Museum in Frankfurt, Germany. Continue HERE
Text and Images via Discovery.
Sorry, vegans: Eating meat and cooking food is how humans got their big brains (Perhaps bigger brains are the problem)
Vegetarian, vegan and raw diets can be healthful, probably far more healthful than the typical American diet. But to call these diets “natural” for humans is a bit of a stretch in terms of evolution, according to two recent studies.
Eating meat and cooking food made us human, the studies suggest, enabling the brains of our pre-human ancestors to grow dramatically over a few million years.
Although this isn’t the first such assertion from archaeologists and evolutionary biologists, the new studies demonstrate that it would have been biologically implausible for humans to evolve such a large brain on a raw, vegan diet and that meat-eating was a crucial element of human evolution at least a million years before the dawn of humankind.
Excerpt from an article written by Christopher Wanjek in the Washington Post. Continue HERE
How the Beetle Got His Handles
This little beetle has evolved a handle on its back, allowing it to be carried around by termites. Learn More HERE
Anything But Human
The very idea of an “ought” is foreign to evolutionary theory. It makes no sense for a biologist to say that some particular animal should be more cooperative, much less to claim that an entire species ought to aim for some degree of altruism. If we decide that we should neither “dissolve society” through extreme selfishness, as Wilson puts it, nor become “angelic robots” like ants, we are making an ethical judgment, not a biological one. Likewise, from a biological perspective it has no significance to claim that I should be more generous than I usually am, or that a tyrant ought to be deposed and tried. In short, a purely evolutionary ethics makes ethical discourse meaningless.
Excerpt from an article written by RICHARD POLT, NYT. Continue HERE
Life in Code and Software: Mediated Life in a Complex Computational Ecology
This book explores the relationship between living, code and software. Technologies of code and software increasingly make up an important part of our urban environment. Indeed, their reach stretches to even quite remote areas of the world. Life in Code and Software introduces and explores the way in which code and software are becoming the conditions of possibility for human living, crucially forming a computational ecology, made up of disparate software ecologies, that we inhabit. As such we need to take account of this new computational environment and think about how today we live in a highly mediated, code-based world. That is, we live in a world where computational concepts and ideas are foundational, or ontological, which I call computationality, and within which, code and software become the paradigmatic forms of knowing and doing. Such that other candidates for this role, such as: air, the economy, evolution, the environment, satellites, etc., are understood and explained through computational concepts and categories.
Introduction: What is Code and Software?
Thinking Software
Code Literacy (‘iteracy’)
Decoding Code
Software Ecologies
Attributions
Text and Image via Life in Code and Software. Content edited by David M. Berry
Science Geneticists evolve fruit flies with the ability to count
A team of geneticists has announced that they have successfully bred fruit flies with the capacity to count.
After repeatedly subjecting fruit flies to a stimulus designed to teach numerical skills, the evolutionary geneticists finally hit on a generation of flies that could count — it took 40 tries before the species’ evolution occurred. The findings, announced at the First Joint Congress on Evolutionary Biology in Canada, could lead to a better understanding of how we process numbers and the genetics behind dyscalculia — a learning disability that affects a person’s ability to count and do basic arithmetic.
Text and Image via Wired. Continue article HERE
Scientists place 500-million-year-old gene in modern organism
Using a process called paleo-experimental evolution, Georgia Tech researchers have resurrected a 500-million-year-old gene from bacteria and inserted it into modern-day Escherichia coli(E. coli) bacteria. This bacterium has now been growing for more than 1,000 generations, giving the scientists a front row seat to observe evolution in action.
“This is as close as we can get to rewinding and replaying the molecular tape of life,” said scientist Betül Kaçar, a NASA astrobiology postdoctoral fellow in Georgia Tech’s NASA Center for Ribosomal Origins and Evolution. “The ability to observe an ancient gene in a modern organism as it evolves within a modern cell allows us to see whether the evolutionary trajectory once taken will repeat itself or whether a life will adapt following a different path.”
Excerpt of an article via PhysOrg. Continue HERE
Are there human races?
One of the touchiest subjects in human evolutionary biology—or human biology in general—is the question of whether there are human races. Back in the bad old days, it was taken for granted that the answer was not only “yes,” but that there was a ranking of races (invariably done by white biologists), with Caucasians on top, Asians a bit lower, and blacks invariably on the bottom. The sad history of biologically based racism has been documented in many places, including Steve Gould’s book The Mismeasure of Man (yes, I know it’s flawed).
But from that sordid scientific past has come a backlash: the subject of human races, or even the idea that they exist, has become taboo. And this despite the palpable morphological differences between human groups—differences that must be based on genetic differences and would, if seen in other species, lead to their classification as either races or subspecies (the terms are pretty interchangeable in biology). Racial delimitation could, critics say, lead to a resurgence of racism, racial profiling, or even eugenics.
Excerpt of a text via Why Evolution is True. Continue HERE
Previously on Wanderlust: What is Race? Bodies with Histories: The New Search for the Biology of Race
The disadvantage of smarts
What, if any, evolutionary advantage does intelligence give us?
Actually, less intelligent people are better at doing most things. In the ancestral environment general intelligence was helpful only for solving a handful of evolutionarily novel problems.
Suggested reading: “The Bell Curve: Intelligence and Class Structure in American Life” by Herrnstein, Richard J. and Charles Murray (1994)
You mean our ancestors did not really have to reason?
Evolution equipped humans with solutions for a whole range of problems of survival and reproduction. All they had to do was to behave in the ways in which evolution had designed them to behave—eat food that tastes good, have sex with the most attractive mates. However, for a few evolutionarily novel problems, evolution equipped us with general intelligence so that our ancestors could reason in order to solve them. These evolutionarily novel problems were few and far between. Basically, dealing with any type of major natural disaster that is very infrequent in occurrence would require general intelligence.
Suggested reading: “Evolutionary Psychology and Intelligence Research” by Satoshi Kanazawa, in American Psychologist; 65: 279-289 (2010)
Excerpt of an interview with Satoshi Kanazawa on intelligence. Continue HERE
SATOSHI KANAZAWA is Reader in Management at the London School of Economics and Political Science, and Honorary Research Fellow in the Department of Psychology at Birkbeck College, University of London. He has written over 80 articles across the fields of psychology, sociology, political science, economics, anthropology and biology. One such was his widely reported article “Why Liberals and Atheists Are More Intelligent” (2010). His latest book is called “The Intelligence Paradox: Why the Intelligent Choice Isn’t Always the Smart One” (2012).
Darwin’s ‘clumsy’ prose
Reading Charles Darwin’s On the Origin of Species straight after publication, Friedrich Engels wrote to tell Karl Marx that it was quite splendid. Excepting, that is, its “clumsy English method”. Turning to it on his sickbed a year later, Marx responded that “although it is developed in the crude English style, this is the book which contains the natural history basis for my view”. Closer to home, Darwin’s readers were not always more enamoured of his style. Within weeks of its appearance, George Eliot wrote that she thought the book “ill-written”, and that she didn’t think it would be very popular. But few could doubt its significance, and writers were among the first to see this. Hitting the bookshops in November 1859, it sold out on the first day, Darwin’s publisher John Murray told him. Eliot said “it will have a great effect in the scientific world . . . . So the world gets on step by step towards brave clearness and honesty!”, and Thomas Hardy, who read it as a teenager, declared himself to be one of its first champions. Rereading the Origin (“slowly again for the nth time, with the view of picking out the essentials of the argument for the obituary notice”), T. H. Huxley remarked that “nothing entertains me more than to hear people call it easy reading”. “Exposition”, he insisted, “was not Darwin’s forte – and his English is sometimes wonderful.” This wonderful English, the extraordinary prose that could puzzle Darwin’s Victorian readers, is the subject of George Levine’s new book, from which Darwin emerges as an artist as well as a scientist, a master of argument, analogical reasoning, hypothesis and anecdote.
Excerpt fro a review by Angelique Richardson, at TLS. Continue HERE
Image above: Darwin’s 1837 sketch of an evolutionary tree. Courtesy of Darwin Online. Via
Did Humans Invent Music?
Did Neanderthals sing? Is there a “music gene”? Two scientists debate whether our capacity to make and enjoy songs comes from biological evolution or from the advent of civilization.
Music is everywhere, but it remains an evolutionary enigma. In recent years, archaeologists have dug up prehistoric instruments, neuroscientists have uncovered brain areas that are involved in improvisation, and geneticists have identified genes that might help in the learning of music. Yet basic questions persist: Is music a deep biological adaptation in its own right, or is it a cultural invention based mostly on our other capacities for language, learning, and emotion? And if music is an adaptation, did it really evolve to promote mating success as Darwin thought, or other for benefits such as group cooperation or mother-infant bonding?
Excerpt of an article written by Gary Marcus and Geoffrey Miller, at The Atlantic. Continue HERE
Image above: A neanderthal instrument. A 40,000 year old flute at Divje Babe, Slovenia. Via Glen Morton.
Evolution has given humans a huge advantage over most other animals: middle age
As a 42-year-old man born in England, I can expect to live for about another 38 years. In other words, I can no longer claim to be young. I am, without doubt, middle-aged.
To some people that is a depressing realization. We are used to dismissing our fifth and sixth decades as a negative chapter in our lives, perhaps even a cause for crisis. But recent scientific findings have shown just how important middle age is for every one of us, and how crucial it has been to the success of our species. Middle age is not just about wrinkles and worry. It is not about getting old. It is an ancient, pivotal episode in the human life span, preprogrammed into us by natural selection, an exceptional characteristic of an exceptional species.
Compared with other animals, humans have a very unusual pattern to our lives. We take a very long time to grow up, we are long-lived, and most of us stop reproducing halfway through our life span. A few other species have some elements of this pattern, but only humans have distorted the course of their lives in such a dramatic way. Most of that distortion is caused by the evolution of middle age, which adds two decades that most other animals simply do not get.
Excerpt of an article written by David Bainbridge, WP. Continue HERE
Lessons From Ants to Grasp Humanity
To the biologist Edward O. Wilson, the Metropolitan Museum of Art encapsulates some of the conflicting impulses natural selection has instilled in humans: the innate drive for expression that spurs some of us to make art, the selfishness that motivates others to earn the riches needed to collect it, and the altruism that compels the donation of collections for the public good — as long as the donors’ names are inscribed on the walls too.
But asked to imagine the museum from the perspective of ants, whose intricate social world he has built a towering reputation by studying, Dr. Wilson painted a scene that was less a lesson in evolution than a chaotic free-for-all.
“To them the crowds would just be a flank-to-flank herd of enormous elephants you have to dodge around,” he said with a boyish giggle from the museum’s teeming steps during a recent visit to New York to promote his 27th book, “The Social Conquest of Earth,” which is being published Monday by Liveright. “I don’t think ants would have any aesthetic or intellectual interest in the museum, though they would certainly find a happy home in Central Park.”
Excerpt of an article by JENNIFER SCHUESSLER at NYT. Continue HERE
Unreasonable Atheist? Robert Wright on Richard Dawkins
Robert Wright : “…But is Dawkins really pursuing our common goal in a reasonable way? At the Reason Rally he encouraged people not just to take issue with religious teachings, but to “ridicule” religious belief and show “contempt” for it.”
Read at The Atlantic
Part 1
Part 2
Of course, they didn’t even touch any of the muffins and pastries.
The evolution of the moon
From year to year, the moon never seems to change. Craters and other formations appear to be permanent now, but the moon didn’t always look like this. Thanks to NASA’s Lunar Reconnaissance Orbiter, we now have a better look at some of the moon’s history.
Via NASA
On Silence
“A young monk came to live in the monastery where Ajahn Chah was practicing. The people who lived in the town outside the monastery were holding a series of festivals in which they sang and danced all night long. When the monks would rise at three thirty in the morning to begin their meditation, the parties from the night before would still be going strong. At last, one morning the young monk cried out to Ajahn Chah, ‘Venerable One, the noise is interrupting my practice — I can’t meditate with all this noise!; ‘The noise isn’t bothering you, ‘ Ajahn responded. ‘You are bothering the noise.’ As Lushtak put it to me, ‘Silence is not a function of what we think of as silence. It’s when my reaction is quiet. What’s silent is my protest against the way things are.”
Excerpt from “In Pursuit of Silence: Listening for Meaning in a World of Noise” by George Prochnik
PROSTHETIC AESTHETICS at SCIENCE GALLERY DUBLIN
PROSTHETIC AESTHETICS: WITH STELARC, BERTOLT MEYER, LIZBETH GOODMAN AND RACHEL ARMSTRONG
Will people equipped with prosthetic technologies soon outperform “natural” abilities? How are we blurring the boundaries between human enhancement and body augmentation? How does the realm of prosthetics merge aesthetics and technology, in transforming the form and capabilities of the human body? How are artists, designers and scientists joining forces to push the boundaries of prosthetic technologies?
Join us for a panel discussion where we hope to address many issues raised in Science Gallery’s HUMAN+ exhibition with legendary Australian performance artist Stelarc (who has had a lab-grown “third ear” implanted in his left arm), medic and TED fellow Rachel Armstrong and SmartLab Founder Lizbeth Goodman, hosted by Science Gallery director Michael John Gorman
Also joining the panel will be Dr. Bertolt Meyer of Universität Zürich, equipped with a state-of-the-art i-Limb Pulse bionic hand.
Text via SCIENCE GALLERY
Image above: Prosthetic aesthetics arm by spiraltwist on flickr.jpg
Susan Oyama: Development and evolution in a world without labels
Susan Oyama
John Jay College of Criminal Justice
The Graduate School and University Center, CUNY, USA
Accounts of development and evolution typically involve complementary notions of prespecification–organismic and environmental ‘labeling,’ if you will. In the case of development these can take the form of genetic programs or instructions and the like, while descriptions of evolution often invoke preexisting environmental demands or problems that organisms must meet.
The traditions of thought informing The Embodied Mind and Developmental Systems Theory (DST) both challenge such ways of conceiving life processes. Yet these traditions sprang from different grounds, and they bring distinctive sensibilities to their overlapping projects. I describe the systemic contingencies of self-organizing systems in DST, pointing out the importance of alternative pathways, both in biological processes and the theorizing they inspire.
Spelunking for Genes: A bone and a molar hold clues to a new branch of our family tree
ANCIENT HISTORY: The layers of sediment excavated in Denisova Cave (top left) and its surroundings have yielded such artifacts as chipping tools (top right), a fragment of a pinky bone, and a molar. DNA in the bone and molar led to the identification of a new hominin group, the Denisovans.Photos: Courtesy of David Reich (top left, top right, bottom right); Courtesy of the Max Planck Institute for Evolutionary Anthropology (bottom left, middle right)
Perched in the Altai Mountains of southern Siberia, and overlooking the Anui River and its surrounding forest, is the Denisova Cave. It is not a particularly large natural structure, but its high ceilings, central limestone chimney, and location near abundant food sources have made it an inviting shelter for humans and animals for tens of thousands of years.
“It’s kind of a magical cave,” says David Reich, an HMS professor of genetics who traveled to the site this past summer. It was a rugged trip, covering 5,500 miles on a 48-hour journey that began in Boston, touched London and Moscow, and finished with a bumpy 10-hour van ride to the Denisova Cave, near Russia’s border with Kazakhstan. But Reich, whose affiliation with the Broad Institute of MIT and Harvard means he’s more often surrounded by gene sequencers than Stone Age tools, took the opportunity to step inside this remote refuge to witness the resting spot of ancient DNA that had been preserved in bone fragments buried deep in cave sediments.
For the past year, Reich and an international team of evolutionary geneticists have been coaxing information from that DNA. What they’ve found has changed our understanding of human history.
DOWN TO EARTH: Excavation of Denisova Cave, a site overseen by the Russian Academy of Sciences, is an ongoing venture involving international teams of researchers. Photo: Courtesy of David Reich
Text and Images via Harvard Medicine. Continue HERE
The Elements of ExoPlanets
By looking at the wavelengths of light from nearby stars, researchers have determined the abundance of certain elements for more than a hundred stars. Trace elements in such stars may influence their habitable zones, where planets with life might dwell.
A star’s energy comes from the combining of light elements into heavier elements in a process known as fusion. Our Sun is currently burning, or fusing, hydrogen to helium. After the hydrogen in the star’s core is exhausted, the star can burn helium to form progressively heavier elements, carbon and oxygen and so on, until iron and nickel are formed. Supernova explosions result when the cores of massive stars have exhausted their fuel supplies and burned everything into iron and nickel. Credit: NASA
Trace elements in stars may influence the evolution of habitable zones around them where life as we know it might dwell, scientists now find.
Stars are made nearly entirely from hydrogen and helium gas. Still, traces of heavier elements — which astronomers call metals, even if they are not what one normally think of as metals — can be found in stars as well, either inherited from the remains of older stars or forged via nuclear fusion.
Scientists can detect what elements a star possesses by looking at its light, which comes in a wide variety of wavelengths, some visible, many invisible. The wavelengths of light that matter emits often comes in specific clumps or lines, which can act like a fingerprint, revealing the identity of the material in question.
By looking at the wavelengths or spectra of light from nearby dwarf stars as part of searches for alien worlds, or exoplanets, researchers have with high precision determined the abundance of certain elements for more than a hundred of these stars, with more to come. Now researchers suggest variations in the compositions of these stars could impact the habitable zones around them.
Text and Images via Physorg. Continue HERE
BRAINTRUST: What Neuroscience Tells Us about Morality
BRAINTRUST: What Neuroscience Tells Us about Morality. Patricia S. Churchland. xii + 273 pp. Princeton University Press, 2011.
Robert J. Richards at American Scientis: In Braintrust, Patricia Churchland, a philosopher at the University of California at San Diego, seems intent on advancing a project comparable to Darwin’s through the application of the most recent science, as the subtitle of her book suggests: What Neuroscience Tells Us about Morality. Readers may, however, decide instead to stick with that old-time evolution.
Churchland does not think that moral behavior can be reduced to any special kind of activity, as Darwin believed; rather, in her view, the term “moral” hovers over a variety of social behaviors, behaviors that might attract the same term but vary considerably across different cultures and individuals. Such behaviors, she argues, are not usually governed or motivated by explicit rules but are constituted by habits and emotionally guided decisions. She seeks to understand those habits and emotionally fed values as consequences of our neurobiology. She thus undertakes in several chapters to lay out the terrain of the brain, its regions and functions, and the kinds of hormones important for fertilizing the flowering of social relationships.
Churchland investigates other neurological features that might plausibly be offered as part of the scaffolding of moral behavior. She considers, for example, the possibility that there is an innate and heritable impulse to behave morally (Darwin’s view) and the hypothesis that moral behavior is grounded in mirror neurons, so that we might effortlessly imitate empathetic behaviors. Churchland chips away at these as possible neural structures for moral behavior. For instance, she attempts to undermine the concept of innate behavior generally by requiring a specification of the relevant genes and their relation to brain circuitry—a criterion beyond reach even for highly heritable traits, such as height. Indeed, by that criterion Darwin’s general theory of heritable adaptations, for which he had no reliable genetic foundation, would be but a passing fancy for the delectation of Intelligent Designers. Continue review HERE
WANDERLUST 