Passage 1
Why Is it So Difficult to Swat a Fly?
The brains of flies are wired to avoid the swatter, US researcherssaid on Thursday.
At the mere hint of a threat, the insects adjust their preflightstance to flee in the opposite direction, en-suring a cleangetaway, they said in a finding that helps explain why flies can soeasily evade swipes fromtheir human foes.
"These movements are made very rapidly, within about 200milliseconds, but within that time the ani-mal determines where thethreat is coming and activates a set of movements to position itslegs and wings,"Michael Dickinson of the California Institute ofTechnology said in a statement.
"This illustrates how rapidly the fly's brain can process sensoryinformation into an appropriate motorresponse," said Dickinson,whose research appears in the journal Current Biology.
Dickinson's team studies this process in fruit flies usinghigh-speed digital imaging equipment and afancy fly swatter.
In response to a threat from the front, the fly moves its middlelegs forward, leans back and raises itsback legs for a backwardtakeoff. If the threat is from the side, the fly leans the otherway before takeoff.
The findings offer new insight into the nervous system of the fly,and lends a few clues on how to out-smart them.
Dickinson, a bioengineer, has devoted his life's work to the studyof insect flight. He has built a tiny ro-botic fly called Roboflyand a 3-D visual flight simulator called Fly-O-Vision.
Passage 2
The Truth about the Environment
For many environmentalists, the world seems to be getting worse.They have developed a hit-list of ourmain fears: that naturalresources are running out; that the population is ever growing,leaving less and less toeat; that species are becoming extinct invast numbers, and that the planet's air and water are becomingevermore polluted.
But a quick look at the facts shows a different picture. First,energy and other natural resources havebecome more abundant, notless so, since the book The Limits to Growth was published in 1972by a group ofscientists. Second, more food is now produced per headof the world's population than at any time in history.Fewer peopleare starving.