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Evolutionary biology

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Original author: 
Allie Wilkinson

Lynn Tomlinson

Cooperation occurs when we act on behalf of a common benefit, often at personal cost. Everyone would be better off if an entire group cooperates, but some individual members can do better if they go it alone, so self-interest undermines cooperation. A new study indicates that your reputation—in terms of whether people are aware that you're cooperating—plays a pivotal role in your decision to cooperate.

Studies on the evolution of cooperation, or how cooperation can emerge and persist, use the Prisoner’s Dilemma as the standard example to demonstrate why people may choose not to cooperate. In the Prisoner’s Dilemma, two men are arrested and held in separate cells. Due to a lack of evidence, the prosecution plans to sentence each man to year in prison on a lesser charge. If either suspect testifies against his partner, he will go free, while his partner will be sentenced to three years in prison; if both men testify against each other, then they will each serve two years. Each man is better off if he cooperates.

The Prisoner’s Dilemma is an example of direct reciprocity, where two individuals affect one another's fate. But cooperation can also be based on indirect reciprocity, which is centered on repeated encounters between a group of individuals. In a sense, it’s the karmic approach—the belief that your good deeds toward others will come full-circle, and someone will eventually scratch your back.

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DNA strand

A group of scientists in the UK have proved that healthy human beings have a surprising amount of mutated DNA, reinforcing the old adage that "nobody's perfect." The fact that humans carry mutated DNA isn't a new concept, but a research paper just published in the American Journal of Human Genetics showed that the average person has an average of 400 defects in his or her genes, including at least a few associated with disease. "We found quite amazingly large numbers of deleterious and known disease-causing mutations," Chris Tyler-Smith of the Wellcome Trust Sanger Institute in Cambridge, England told NPR. He went on to note that previous estimates "ranged from just a handful up to 100 or more serious disease-associated mutations" —...

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The filaments created by a slime mold, along with the slime left behind on paths it discards.

Is it possible to know where you've been when you don't have a brain? Depending on your definition of "know," the answer may be yes. Researchers have shown that the slime mold, an organism without anything that resembles a nervous system (or, for that matter, individual cells), is capable of impressive feats of navigation. It can even link food sources in optimally spaced networks. Now, researchers have shown it's capable of filling its environment with indications of where it has already searched for food, allowing it to "remember" its past efforts and focus its attention on routes it hasn't explored.

And it does this all using, as the authors put it, "a thick mat of nonliving, translucent, extracellular slime." As you might expect, given the name.

Slime molds are odd creatures: organisms that have a nucleus and complex cells, but are evolutionarily distant from the multicellular animals and plants. When food is plentiful, they exist as single-celled, amoeba-like creatures that forage on the food. But once starvation sets in, the cells send out a signal that causes them to aggregate and fuse. This creates an organism that's visible to the naked eye and all a single cell, but filled with nuclei containing the genomes of many formerly individual cells. That turns out to be advantageous, because this collective can move more efficiently, and go about foraging for food. In the course of this foraging, the organism leaves behind a trail of slime.

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fitocracy founders

Brian Wang was awkwardly thin.

Richard (Dick) Talens was overweight.

The once body-conscious teenagers now have eight-pack abs and a fitness startup that's exploding, Fitocracy.

Fitocracy is a social network for fitness that was founded at the end of 2010. The site pairs Talens and Wang's love of video games with their desire to stay in shape. On Fitocracy, users can follow other members' workout schedules, comment on them, share photos, and receive points for strenuous workouts.

"Even though we started getting into all this meat-head stuff, we were still nerds at heart," Wang tells us of founding Fitocracy.  "We wanted to make people more addicted to fitness and make fitness more accessible to them. Exercising doesn't have to be daunting."

The first few months of Fitocracy were slow. Reddit sent some initial traffic to the then-invite only site and Fitocracy crept up to 30,000 users by August. 

But a cartoon marked Fitocracy's tipping point.

Fitocracy, which doesn't allow users to gain exercise points for having sex, was featured on XKCD last summer:

XKCD Fitocracy

The webcomic sent a flood of people and Fitocracy gained 20,000 new users in two weeks.

That fall, Fitocracy was accepted into Dave McClure's 500 Startups accelerator program in Mountain View, which led to a seed round of financing.  

On March 1, Fitocracy came back to New York and the traffic surge continued.

Now the startup has four employees and more than 250,000 users. Its iPhone app, which launched three weeks ago, has been downloaded 125,000 times. The free app peaked at #52 in the App Store and it's been reviewed more than 1,700 times. The average time spent on Fitocracy is over 10 minutes, says Wang.

"Dick and I believe fitness isn't some esoteric thing that only a portion of the population can do.  A lot of people don't believe they can get in shape," says Wang.  "If we can give them a perfect place, with a community, fitness knowledge and a gamified tracking experience, we can make fitness a reality for people."

Here's what both founders looked like before they got on health kicks:

Dick Talens, then and now:

fitocracy dick richard talens

Brian Wang, then and now:

brian wang fitocracy

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