Tag: shorts

Evolution in Action

A fascinating study of 56,000 generations of bacteria, in 12 different populations, carefully documents how a new ability evolved in one of the populations — the ability to use citrate for food in addition to glucose.

About the key step in the process:

“It wasn’t a typical mutation at all, where just one base-pair, one letter, in the genome is changed,” he said. “Instead, part of the genome was copied so that two chunks of DNA were stitched together in a new way. One chunk encoded a protein to get citrate [for food] into the cell, and the other chunk caused that protein to be expressed.”

— Evolution is as complicated as 1-2-3 from Michigan State University.

That was the second step in a three step process:

The first stage was potentiation, when the E. coli accumulated at least two mutations that set the stage for later events. The second step, actualization, is when the bacteria first began eating citrate, but only just barely nibbling at it. The final stage, refinement, involved mutations that greatly improved the initially weak function. This allowed the citrate eaters to wolf down their new food source and to become dominant in the population.

Note

I’ve been discussing different genres of scientific writing with my middle school class, so it’s interesting to point out that the article this post refers to is just a press release about the actual research paper. These are two very distinct types of scientific writing.

Dealing with Procrastination

To avoid putting off work:

  • Change your thinking; self-motivate: Convince yourself that you’re enjoying your work, or you’re being productive.
  • Change your environment: Put barriers between you and distraction
  • Disciplined breaks: start with 25 minutes working and then take a 5 minute break. Increase the work interval over time.
  • Deadlines: costly self-imposed or even external deadlines work.

↬ The Dish

Fixing the Voting System

C.G.P.Grey lays out the problems with the U.S.A’s current “first past the post/winner take all” voting system and then explains how to fix them:

The problems:

  • Minority rule: You can win with less than half the vote (at least in the beginning).
  • Inevitable, unavoidable, two-party system evolves over time.
  • Third-parties become spoilers; the better a third-party does the worse it is for their voters because it takes away votes from the other party they would favor.

The solutions:

1. The Alternative Vote/Instant Runoff.

2. Mixed Member Proportional Representation.

Encouraging Academic Honesty

Dan Ariely concludes (video by RSA) that making people think about morality increases the likelihood that they’ll act honestly.

People try to balance the benefiting they gain from cheating against being able to feel good about themselves by being honest. While very few people tend to cheat a lot, many people cheat a little and self-rationalize their dishonesty.

Our school has adopted a short honor code that we’ll ask students to write at the top of tests and other assignments that is intended to remind them of their moral obligations.

Based on one of Ariely’s other conclusions, I’m also considering having students confess their in-class transgressions — talking out of turn; improper use of technology — every month or so, since this type of thing also seems to encourage probity.

↬ The Dish

Landing the Mars Rover: 7 Minutes of Terror

NASA gets dramatic. But the drama is oh so appropriate when you see what they have to do to land a rover on Mars. There are so many steps to the landing — heat shields, atmospheric friction, parachute, rockets — that it’ll be amazing if it works, and the video is a wonderful “strike the imagination” introduction to the physics of forces.