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Sunday, December 15, 2013

Standing Up for Sex by Henry Gee

Humans evolved the ability to walk on two legs because it allowed them to more accurately size up prospective mates. Or did they?
 
By | December 1, 2013
UNIVERSITY OF CHICAGO PRESS, OCTOBER 2013It happened years ago, but the event was so traumatic that I remember it as if it were yesterday: an elderly professor physically pinned me against a wall and berated me for rejecting his paper on why human ancestors got up on their hind legs and walked. “The reason,” frothed the empurpled sage, “was to make it easier for mothers to carry babies close to their chests.” See? So blindingly obvious that anyone, even I, could understand it.

Manuscripts seeking to explain the evolutionary roots of human bipedalism land in my in-box at Nature with monotonous regularity. We became bipeds so that we could carry food, or tools; so we could see farther; so we wouldn’t expose so much of our skin to the Sun; so we could wade better in rivers and lakes. They all make good stories, but they all share the same error—they are explanations after the fact, and, as such, betray a fundamental misunderstanding of how evolution works.

Natural selection, the mechanism of evolution, operates without memory or foresight. It has no intention. It is we who choose to interpret evolutionary purposes as such later on. The features of living things, therefore, do not evolve for any preconceived purpose that we can discern. I explain how such misunderstandings color our understanding of human evolution in my latest book, The Accidental Species: Misunderstandings of Human Evolution.

But none of this stops me having my own go at understanding why humans came to walk on two legs. In my view, it all happened by accident.

Bipedalism is just one of the many peculiarities of human anatomy and behavior that set us apart from our closest relatives, the great apes. We are also much more social than they are, we have unusually large brains, we have much more body fat, and we are much less hairy. The differential distribution of fat and hair happens to be strongly correlated with sexual dimorphism.

On the subject of sex, women’s furless breasts are prominent at all times, not just when women are lactating. Unlike female chimpanzees, our closest living primate relatives, women do not advertise estrus—the time of maximum fertility—by the swelling of the sexual organs. And while we’re talking about advertisement, men have the largest penises, relative to body mass, of any ape. A male gorilla might weigh twice as much as an adult human, but he’s lucky if he ever gets an erection more than inch long.

But if humans’ prominent breasts and big penises are made obvious by hairlessness, they are made more so by bipedalism, which displays everything for all to see. In which case, standing upright could be a by-product of sexual selection, in which mates choose one another on the basis of features that might represent outward signs of inward genetic health.

Some sexually selected features, though, appear have been chosen at random when, by chance, a trait in one sex becomes associated with the preference for that trait in the other, leading to runaway positive feedback, survival value be damned. The massive train of the peacock is a good example. It looks flashy and attracts mates, but costs a great deal of energy to make and maintain, and hobbles a peacock trying to flee from predators. The transition to bipedalism might be seen in the same way: it was selected because it better advertised our sexual wares, but hobbled us in other ways.

The imposition of walking upright on a fundamentally quadrupedal design has prompted a thorough reworking of the entire human body, making back pain one of the single biggest causes of worker absenteeism in the world. Rather than an adaptation, bipedalism could be a dreadful kludge, forced on us by sexual selection in defiance of gravity and common sense.

Now, I advance the above more than half in jest. It’s possibly no better or worse than any other idea, but I’m not going to pin anyone against a wall and shout about it.

Henry Gee is a senior editor at Nature, and the author of Jacob’s Ladder: The History of the Human Genome, In Search of Deep Time, and The Science of Middle-earth. Read an excerpt of The Accidental Species.

Splitting water into hydrogen and oxygen using light, nanoparticles

Splitting water into hydrogen and oxygen using light, nanoparticles

Pseudoscience and psychopathy

hunting pseudoscience in the internet jungle

Guest post on Skeptical Raptor by Matthew Facciani
psychopath-lecter
There has been a news story creating some buzz lately regarding recent claims made by neuroscientist James Fallon, a Professor of Psychiatry at the University of California-Irvine School of Medicine. Dr. Fallon studied the brains of psychopaths for a few years and later saw that his brain was just like those of the psychopaths he studied. Many news outlets are picking up on this story as Dr. Fallon has just released a new book about it as well.

To summarize, Dr. Fallon had received a PET scan of his brain in conjunction with an Alzheimer’s disease study, and subsequently noticed that his PET scan image was eerily similar to PET scan images from those of the psychopaths he researched. These articles then reported how both the psychopaths and  Dr. Fallon had less activity in the frontal and temporal lobes which he claimed are linked to empathy, self-control, and morality. Beyond the PET scan results, Dr. Fallon mentions how he his family has the “Warrior Gene” which is associated with aggressive behavior.

Additionally, he admitted to some history of violence in his family. Despite all of these observations, Dr. Fallon claimed that he has led a normal life without violence. He argued that despite having genes which can promote aggression, a psychopathic brain, and a history of family violence, he did not turn into a psychopath because he did not have a traumatic childhood which could trigger psychopathic tendencies. Of course, his book will probably be a best seller as it brings up interesting questions and discussions about free will and criminal behavior.

As a neuroscientist myself, I was curious about the particular details about the specifics of Dr. Fallon’s brain imaging research. I searched through several news articles, listened to his NPR interview, and watched a talk he gave on the subject and was always left puzzled over the lack of details. I searched for ANY details regarding the PET scans Dr. Fallon mentioned, but every article simply had a pretty brain picture with little information. I was curious as to how a single brain scan from an unrelated study could predict psychopathic behavior.

Why didn’t anyone mention the details or link to an article that did? Specifically, I was confused on why Dr. Fallon was comparing his brain scan from an Alzheimer’s study to an unrelated study about psychopaths. Did they do the same task in each study? PET scans measure real time brain activity, so these brain activations seen in the pretty pictures reflect activity from some task. Despite this empirical data being crucial to make any sort of scientific inference, no article mentioned what the individuals being scanned were actually doing during the PET scan. Dr. Fallon argues that his own brain activity in the regions of the frontal and temporal cortex is lacking, similar to psychopaths, but fails to mention anything more specific in these interviews.

Morality, like any other high level cognition, is terribly difficult to study in the brain and there are a significant number of scientific articles trying to tease apart morality’s functional neuroanatomy. Higher-level cognitive processes are often derived from a complicated network of neural activation which requires careful experimental design to tease apart. A crucial issue with Dr. Fallon’s story is that we can’t even critique such an experimental design because he wasn’t even doing any sort of morality study! So to say that less frontal and temporal activity equals less morality is a gross oversimplification to begin with and there isn’t even any details to support such a claim.

Furthermore, even if Dr. Fallon’s was identical to a group of psychopathic brains, it would only prove association, not causation. There could be many factors which create differences in neural activity and a third variable (exposure to violence for example) could be the cause. Finally, neuroimaging studies are often based on the results of group analysis. Rarely is a single brain scan discussed in the results. Thus, comparing a single brain scan from one study to an aggregate of brain scans from an entirely different study isn’t just wrong, it’s unethical.

This is a classic example of poor scientific journalism and I believe it became so popular due to widespread deficits in scientific literacy. You don’t have to be a neuroscientist to see that there are huge problems with his story. You simply have view this story objectively have a healthy dose of skepticism without quickly deferring to the authority figure. There are simple questions which are never addressed here. What experiment was being done during each PET scan? If the psychopaths and Dr. Fallon were both completing a morality task and they both had low activity in certain regions, THEN that would be something more tangible. This is simply showing a brain picture and not asking questions. We know that people are much more likely to believe something if there is a brain picture associated with it and this is further proof.

My intention is not to claim that Dr. Fallon is lying and purposefully simplifying science to make a profit. I would need much more evidence for that. However, I am arguing that the news articles covering his story do not provide enough details to support his claims. I find it rather troubling that no one is even addressing this so I wanted to blog about it. It is also troubling that Dr. Fallon has not been more explicit about the limitations of his findings as he should surely be aware of them as an accomplished neuroscientist. America often ranks pretty poorly in scientific literacy and this is an example of the result. People should at least have a working understanding of the scientific method and not blindly believe an authority figure with an interesting story.

Matthew Facciani is a 3rd year Ph.D. candidate focused on cognitive neuroscience at a major Southern US research university. If you have questions for Mr. Facciani and his critiques, please drop a comment. 
Key citations:

Higgs Boson Gets Nobel Prize, But Physicists Still Don’t Know What It Means

By Adam Mann.  "Adam is a Wired Science staff writer. He lives in Oakland, Ca near a lake and enjoys space, physics, and other sciency things."

More than a year ago, scientists found the Higgs boson. This morning, two physicists who 50 years ago theorized the existence of this particle, which is responsible for conferring mass to all other known particles in the universe, got the Nobel, the highest prize in science.

For all the excitement the award has already generated, finding the Higgs — arguably the most important discovery in more than a generation — has left physicists without a clear roadmap of where to go next. While popular articles often describe how the Higgs might help theorists investigating the weird worlds of string theory, multiple universes, or supersymmetry, the truth is that evidence for these ideas is scant to nonexistent.

No one is sure which of these models, if any, will eventually describe reality. The current picture of the universe, the Standard Model, is supposed to account for all known particles and their interactions. But scientists know that it’s incomplete. Its problems need fixing, and researchers could use some help figuring out how. Some of them look at the data and say that we need to throw out speculative ideas such as supersymmetry and the multiverse, models that look elegant mathematically but are unprovable from an experimental perspective. Others look at the exact same data and come to the opposite conclusion.

“Physics is at a crossroads,” said cosmologist Neil Turok, speaking to a class of young scientists in September at the Perimeter Institute, which he directs. “In a sense we’ve entered a very deep crisis.”

The word “crisis” is a charged one within the physics community, invoking eras such as the early 20th century, when new observations were overturning long-held beliefs about how the universe works. Eventually, a group of young researchers showed that quantum mechanics was the best way to describe reality. Now, as then, many troubling observations leave physicists scratching their heads. Chief among them is the “Hierarchy Problem,” which in its simplest form asks why gravity is approximately 10 quadrillion times weaker than the three other fundamental forces in the universe. Another issue is the existence of dark matter, the unseen, mysterious mass thought to be responsible for strange observations in the rotation of galaxies.

The solution to both these problems might come from the discovery of new particles beyond the Higgs. One theory, supersymmetry, goes beyond the Standard Model to say that every subatomic particle — quarks, electrons, neutrinos, and so on — also has a heavier twin. Some of these new particles might have the right characteristics to account for the influence of dark matter. Engineers built the Large Hadron Collider to see if such new particles exist (and may yet see them once it reaches higher energy in 2014), but so far it hasn’t turned up anything other than the Higgs.

In fact, the Higgs itself has turned out to be part of the issue. The particle was the final piece in the Standard Model puzzle. When scientists discovered it at the LHC, it had a mass of 125 GeV, about 125 times heavier than a proton — exactly what standard physics expected. That was kind of a buzzkill. Though happy to know the Higgs was there, many scientists had hoped it would turn out to be strange, to defy their predictions in some way and give a hint as to which models beyond the Standard Model were correct. Instead, it’s ordinary, perhaps even boring.

All this means that confidence in supersymmetry is dropping like a stone, according to Tommaso Dorigo, a particle physicist at the LHC. In one blog post, he shared a rather pornographic plot showing how the findings of the LHC eliminated part of the evidence for supersymmetry. Later, he wrote that many physicists would have previously bet their reproductive organs on the idea that supersymmetric particles would appear at the LHC. That the accelerator’s experiments have failed to find anything yet “has significantly cooled everybody down,” he wrote.

In fact, when the organizers of a Higgs workshop in Madrid last month asked physicists there if they thought the LHC would eventually find new physics other than the Higgs boson, 41 percent said no. As to how to solve the known problems of the Standard Model, respondents were all over the map. String theory fared the worst, with three-quarters of those polled saying they did not think it is the ultimate answer to a unified physics.

One possibility has been brought up that even physicists don’t like to think about. Maybe the universe is even stranger than they think. Like, so strange that even post-Standard Model models can’t account for it. Some physicists are starting to question whether or not our universe is natural. This cuts to the heart of why our reality has the features that it does: that is, full of quarks and electricity and a particular speed of light.

This problem, the naturalness or unnaturalness of our universe, can be likened to a weird thought experiment. Suppose you walk into a room and find a pencil balanced perfectly vertical on its sharp tip. That would be a fairly unnatural state for the pencil to be in because any small deviation would have caused it to fall down. This is how physicists have found the universe: a bunch of rather well-tuned fundamental constants have been discovered that produce the reality that we see.

A natural explanation would show why the pencil is standing on its end. Perhaps there is a very thin string holding the pencil to the ceiling that you never noticed until you got up close. Supersymmetry is a natural explanation in this regard – it explains the structure of universe through as-yet-unseen particles.

But suppose that infinite rooms exist with infinite numbers of pencils. While most of the rooms would have pencils that have fallen over, it is almost certain that in at least one room, the pencil would be perfectly balanced. This is the idea behind the multiverse. Our universe is but one of many and it happens to be the one where the laws of physics happen to be in the right state to make stars burn hydrogen, planets form round spheres, and creatures like us evolve on their surface.

The multiverse idea has two strikes against it, though. First, physicists would refer to it as an unnatural explanation because it simply happened by chance. And second, no real evidence for it exists and we have no experiment that could currently test for it.

As of yet, physicists are still in the dark. We can see vague outlines ahead of us but no one knows what form they will take when we reach them. Finding the Higgs has provided the tiniest bit of light. But until more data appears, it won’t be enough.

I Had to Repost Jerry Coyne's Blog (with apologies if I'm not supposed to)

The good and bad of humanity

It is a truism of both religion and biology that humans are simultaneously selfish and altruistic.  The faithful say the selfishness comes from original sin and the goodness from God, while the biologist imputes our selfishness to evolution (for how better can you ensure propagation of your genes than by taking care of yourself and your kin first?); and, as for altruism, cooperation and kindness, they’re probably partly derived from adaptive reciprocal altruism evolved when we lived in small social groups, and partly from  a cultural overlay of expanded cooperation derived from reason (we now see that we don’t occupy any privileged position relative to others in society).
Regardless, I saw both traits demonstrated this week.  Last Saturday afternoon I parked my car in front of my building at work; I usually use it on the weekends and then leave it at work in case I need to use it during the week.  On Wednesday I looked out the window of my lab (I can overlook the car, which is nice) to see a huge dent in the front fender on the driver’s side. Going down to investigate, I saw that it was indeed a large, fresh dent, but I also found a note stuck in my door handle.
The note said this (I’ve redacted names and phone numbers):
“Hi,
I saw the guy hit your left front fender in the snow. It was a [model and make of car redacted], with the Illinois plate [license plate number redacted].   Best of luck.
—name redacted
[phone number of person who wrote note redacted]. That’s all I saw, but feel free to call if you want.”
So while I was enormously peeved that someone had dinged me and run off, I was touched that a passerby took the time to take down the license number and description of the car and leave it for me, along with his phone number.
I called the number, which turned out to belong to a medical student here at the University. He reported that he say the guy hit my car while backing out in the snow, and then get out of his car and inspect the damage to both his SUV and mine. At that time the student told him, “You know, you should leave a note for the owner.” The dinger said, “Yeah, I guess I should,” but the student suspected he wouldn’t.  So he took out a pen and wrote all the information down on a piece of paper, which he later on my car when he returned and found no note from the malefactor.
I reported it to my insurance company and the University police, which ran the plates of the car that hit me and identified the owner. They also filed a formal report with the state of Illinois (I guess hit and run, even if it doesn’t hurt someone, violates some law or other).  My insurance company will fix the damage for nearly free, (I have to pay a small deductable). I don’t know what will happen to the miscreant who hit me and ran: probably nothing except that my insurance company will force his to pony up for the damage to my car.
This is about the fourth time this has happened to me in my life, and only once has someone left a note—a woman visiting from California, and the damage was so minor that I didn’t do anything about it. But it’s a truly vile act to damage someone’s property and then abscond without taking responsibility.  They do it because, of course, they think they can get away with it.  But this guy didn’t, thanks to a kind and observant student.
It’s a slow news day, so I’m reporting this, but it does show what we all know: some people are jerks and others go out of their way to be helpful. The next time you’re on the bus and an old person gets on, don’t be one of those who keeps your sit or pretends not to notice. Stand up and let the older person sit down.
If you’ve had experiences with really nice strangers, report them below (car-bashing jerks or others can also be reported).

Proto-metabolism

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wi...