Post Tagged with: "evolutionary biology"

Cult Of The Caveman: Paleofantasies

Cult Of The Caveman: Paleofantasies

Atossa Araxia Abrahamian on Paleofantasy by Marlene Zuk and the assumptions of the paleo lifestyle set, noting that it has become a popular diet amongst libertarians:

Charges of hypocrisy, however amusing, are facile. Paleo is an improvement on a diet of processed, sugary junk. It’s not the first diet to banish starches, and it certainly won’t be the last. In fact, by any other name, the Paleo diet would be just that — a diet.

But more substantial problems lurk in the reasoning behind Paleo principles. By assuming that all that was once natural is now good, militant Paleo leans on biological determinism to back up its theories. While it may not advocate for a complete reversion to cave-dwelling, it accepts that we evolved in a certain way to do certain things and not others, and that advances in technology, civilization, and culture can do little to change that. This logic, however seductive, is incomplete. You can’t get an ought from a was. [...]

Incomplete or flawed interpretations of our biology have long been used to marginalize women, racial groups, even entire civilizations, and nutrition may well become the next variant in this pattern of discrimination. If rice isn’t “natural,” does that make those entire continents with highly developed cultures who eat it “un-natural”? Doesn’t agriculture, however flawed it may be in certain societies, support billions of people? Let’s not forget that for centuries women were considered ineligible to participate in most professions, sports, and diversions on the basis of their supposed female “nature.” Are modern bread-eaters somehow less human than those carrying out “primal” urges by sprinting, lifting, and eating meat?

These troubling questions are probably not the point of an apparently well-meaning lifestyle program. Many adopters of the Paleo diet do so for no reason other than weight loss, or vanity, or ailments caused by certain foods; others are simply curious about how so-called “ancestral” nutrition will affect them, or how certain types of foods affect their bodies. If their giddy testimonials are to be believed, the Paleo diet can cure everything from diabetes to anxiety attacks, which sounds wonderful. Still, the social and political implications of Paleo reasoning ought to be more closely examined, especially as the lifestyle gains adherents.

Full Story: The New Inquiry: Natural’s Not In It

Previously: Hardwired to Nurture: What the New Testosterone Study Really Says About Men

January 2, 2013 0 comments
Researchers Say Humans Didn’t Wipe Out the Neanderthals

Researchers Say Humans Didn’t Wipe Out the Neanderthals

new xmen neanderthals

I thought the idea that humans killed off the Neanderthals was already losing currency. And now a paper published in the journal Molecular Biology and Evolution casts more doubt on that particular hypothesis.

i09′s Alasdair Wilkins summarizes:

A team of Spanish and Swedish researchers say that new DNA evidence paints a far grimmer view of the state of Neanderthals. Their analysis suggests the Neanderthal population had crashed 50,000 years ago, and a relatively small band of survivors then recolonized central and western Europe before their final end 20,000 years later. In a statement, Love Dalén of the Swedish Museum of Natural History explained what they discovered:

Instead the paper’s authors suggest climate change had a greater impact on neanderthals than previously thought.

Alasdair Wilkins writes: “This also raises the question of just how humans would have really fared against a Neanderthal population at full strength. I’m sensing some pretty serious alternate history fodder here…”

i09: The extinction of Neanderthals had nothing to do with us

Image from New X-Men

February 28, 2012 1 comment
NASA Discovers New Life on Earth: Bacteria with Arsenic-Based DNA

NASA Discovers New Life on Earth: Bacteria with Arsenic-Based DNA

Arsenic

Update: Please see this update on how, although this research is significant, it doesn’t necessarily indicate that there is arsenic-based bacteria in the wild.

Evidence that the toxic element arsenic can replace the essential nutrient phosphorus in biomolecules of a naturally occurring bacterium expands the scope of the search for life beyond Earth, according to Arizona State University scientists who are part of a NASA-funded research team reporting findings in the Dec. 2 online Science Express.

It is well established that all known life requires phosphorus, usually in the form of inorganic phosphate. In recent years, however, astrobiologists, including Arizona State University professors Ariel Anbar and Paul Davies, have stepped up conversations about alternative forms of life. [...]

Davies has previously speculated that forms of life different from our own, dubbed “weird life,” might even exist side-by-side with known life on Earth, in a sort of “shadow biosphere.” The particular idea that arsenic, which lies directly below phosphorous on the periodic table, might substitute for phosphorus in life on Earth, was proposed by Wolfe-Simon and developed into a collaboration with Davies and Anbar. Their hypothesis was published in January 2009, in a paper titled “Did nature also choose arsenic?” in the International Journal of Astrobiology.

PhysOrg: Deadly arsenic breathes life into organisms

December 2, 2010 0 comments
Culture Is More Important Than Genes To Altruistic Behavior In Large-scale Societies

Culture Is More Important Than Genes To Altruistic Behavior In Large-scale Societies

Socially learned behavior and belief are much better candidates than genetics to explain the self-sacrificing behavior we see among strangers in societies, from soldiers to blood donors to those who contribute to food banks.

This is the conclusion of a study by Adrian V. Bell and colleagues from the University of California Davis in the Oct. 12 edition of Proceedings of the National Academy of Sciences.

Altruism has long been a subject of interest to evolutionary social scientists. Altruism presents them with a difficult line to argue: behaviors that help unrelated people while being costly to the individual and creating a risk for genetic descendants could not likely be favored by evolution: at least by common evolutionary arguments.

The researchers used a mathematical equation, called the Price equation, that describes the conditions for altruism to evolve. This equation motivated the researchers to compare the genetic and the cultural differentiation between neighboring social groups. Using previously calculated estimates of genetic differences, they used the World Values Survey (whose questions are likely to be heavily influenced by culture in a large number of countries) as a source of data to compute the cultural differentiation between the same neighboring groups. When compared they found that the role of culture had a much greater scope for explaining our pro-social behavior than genetics.

Science Daily: Culture Is More Important Than Genes To Altruistic Behavior In Large-scale Societies

November 3, 2009 2 comments
Depression’s Evolutionary Roots

Depression’s Evolutionary Roots

Depression seems to pose an evolutionary paradox. Research in the US and other countries estimates that between 30 to 50 percent of people have met current psychiatric diagnostic criteria for major depressive disorder sometime in their lives. But the brain plays crucial roles in promoting survival and reproduction, so the pressures of evolution should have left our brains resistant to such high rates of malfunction. Mental disorders should generally be rare — why isn’t depression? [...]

In an article recently published in Psychological Review, we argue that depression is in fact an adaptation, a state of mind which brings real costs, but also brings real benefits. [...]

So what could be so useful about depression? Depressed people often think intensely about their problems. These thoughts are called ruminations; they are persistent and depressed people have difficulty thinking about anything else. Numerous studies have also shown that this thinking style is often highly analytical. They dwell on a complex problem, breaking it down into smaller components, which are considered one at a time.

This analytical style of thought, of course, can be very productive. Each component is not as difficult, so the problem becomes more tractable. Indeed, when you are faced with a difficult problem, such as a math problem, feeling depressed is often a useful response that may help you analyze and solve it. For instance, in some of our research, we have found evidence that people who get more depressed while they are working on complex problems in an intelligence test tend to score higher on the test. [...]

Depression is nature’s way of telling you that you’ve got complex social problems that the mind is intent on solving. Therapies should try to encourage depressive rumination rather than try to stop it, and they should focus on trying to help people solve the problems that trigger their bouts of depression. (There are several effective therapies that focus on just this.) It is also essential, in instances where there is resistance to discussing ruminations, that the therapist try to identify and dismantle those barriers.

For those who think modernity or civilization or technology is the problem:

Or, perhaps, depression might be like obesity — a problem that arises because modern conditions are so different from those in which we evolved. Homo sapiens did not evolve with cookies and soda at the fingertips. Yet this is not a satisfactory explanation either. The symptoms of depression have been found in every culture which has been carefully examined, including small-scale societies, such as the Ache of Paraguay and the !Kung of southern Africa — societies where people are thought to live in environments similar to those that prevailed in our evolutionary past.

Scientific American: Depression’s Evolutionary Roots

(via Theoretick)

September 28, 2009 0 comments