Archive for the ‘biology’ tag

#  Why Zebras Have Stripes →

April 16th, 2014 at 11:00 // In Worth Knowing 

I’d heard the answer — in short, flies seem to disliked landing on striped surfaces, and so stripes horses are less likely to be bitten — but it wasn’t ‘til I read this little explanation of the study from Michael Lemonick that I thought it worth a note. The reason? There method was interesting:

So Caro and his colleagues tried a different approach. They took all twenty known species and subspecies of wild equids, including zebras, horses, and wild asses, and looked at how much striping each group has and where on the body it appears. Then they matched the range of the animals to the various factors that have been suggested as evolutionary reasons stripes might have appeared—the presence of large predators, for example, climate, or the kind of vegetation that is prevalent where zebras live.

Almost none of these factors correlated strongly with whether a species or subspecies was boldly striped, subtly striped, or stripeless—except for the prevalence of biting flies.

#  “Law of Urination” →

November 1st, 2013 at 18:34 // In Worth Knowing 

Some scientists are claiming that all mammals pee for exactly 21 seconds. I don’t know that I believe it, but it’s an interesting idea.

Combining this with data on mass, bladder pressure and urethra size, they were able to create a mathematical model of urinary systems to show why mammals take the same time to empty their bladder, despite the difference in bladder size.

#  Rat Park & Addiction →

September 28th, 2013 at 18:27 // In Worth Considering 

A really interesting compilation of anecdotes by Garry Tan about someone who questioned this old story:

We all learned this in DARE class. About the rats in a cage who can self-administer morphine who get addicted to the stuff, and then just hit that lever until they die. A seemingly keystone argument in the war against drugs.

Turns out, the story it tells about addiction isn’t all that scientifically sound.

#  The Peril of Jellyfish →

September 9th, 2013 at 18:26 // In Worth Reading 

When I came across this in the NYRB — an august politics and culture institution — I though, jellyfish!? And then I greedily thought, “This far outside the norm means this will be fantastic.” And it is. By turns amazing and terrifying, you’re almost guaranteed to learn something:

On the night of December 10, 1999, 40 million Filipinos suffered a sudden power blackout. President Joseph Estrada was unpopular, and many assumed that a coup was underway. Indeed, news reports around the world carried stories of Estrada’s fall. It was twenty-four hours before the real enemy was recognized: jellyfish. Fifty truckloads of the creatures had been sucked into the cooling system of a major coal-fired power plant, forcing an abrupt shutdown.

#  r-/K-selection in the Economy →

August 24th, 2013 at 15:27 // In Worth Considering 

Building on his idea of three capitalisms (LB), I really liked this piece from Michael O. Church about how we can understand the economy in terms of the biological idea of breeding strategies. It won’t blow up your head, but it’s a really interesting lens to apply.

An r-strategist doesn’t care about social stability, because the general assumption is that with a few hundred offspring, some will thrive no matter how damaged the environment becomes. K-strategists, on the other hand, want social progress because a fair, reasonable, predictable, and progressively improving society is the one in which quality offspring have the best chances.

#  Octopus Intelligence →

April 16th, 2012 at 6:55 // In Worth Reading 

Very interesting story of the peculiar kind of intelligence we’re still learning to perceive in octopi. For example:

One octopus Mather was watching had just returned home and was cleaning the front of the den with its arms. Then, suddenly, it left the den, crawled a meter away, picked up one particular rock and placed the rock in front of the den. Two minutes later, the octopus ventured forth to select a second rock. Then it chose a third. Attaching suckers to all the rocks, the octopus carried the load home, slid through the den opening, and carefully arranged the three objects in front. Then it went to sleep. What the octopus was thinking seemed obvious: “Three rocks are enough. Good night!”

(via Kottke)

#  Making Multicellular Life →

January 20th, 2012 at 7:45 // In Worth Knowing 

We made a group of single-celled organism start cooperating in a lab. This was one of those things that people were struggling to prove, but now it’s been done. I thought I’d let you know.

(via Justin Wehr Knows Stuff You Don’t)

#  Internal Ecology →

April 3rd, 2011 at 11:34 // In Worth Reading 

This piece from Carl Zimmer about how you’re body is like a lake is wide-ranging and massively informative (even if you already realize how many microbes live in and on you). Highly recommended.

(via The Browser)

#  Why Women Have Breasts →

May 14th, 2010 at 15:39 // In Worth Considering 

This had never crossed my mind:

The full, plump bosom seen in the human ape is an anomaly. No other primate has a permanent breast.

I would extend the article’s evolutionary point to say that we’re probably the only species that has ever been successful enough to select so strongly for aesthetic preferences of members of the species. A quick look couldn’t find anything about this, but I’d be interested to know that I’m wrong.

(via Reddit, whose comments offer this visual of the topic, and the male version)

#  Monkeys Do It Too →

July 12th, 2008 at 17:47 // In Worth Knowing 

This is rather old, but it was news to me: when taught to use currency, monkeys pay for sex.

(via Wired Science)