Archive for November, 2009

Published by Diana on 26 Nov 2009

Changes in organisms from natural selection

Over time, new kinds of organisms develop as a result of mutations and changes to existing organisms. Bacteria evolve resistance to antibiotics; the bacteria that aren’t resistant to antibiotics die off–and the very few that have a gene that makes them less likely to die are the only ones that live to reproduce. This process, in which better adapted organisms survive to reproduce and less adapted organisms die before reproducing (or have fewer offspring), is called natural selection and is the key concept of Charles Darwin’s theory of evolution.

Darwin published the first edition of his book on the evolution of species one hundred and fifty years ago, in November of 1859.

Darwin was curious about many things, and was interested in how land snails–like the European snail that ends up being eaten in the French dish escargot–could get to islands, because they don’t survive in salt water. After discovering that a short bath in salt water didn’t kill them, he decided that perhaps they got there on floating logs.

But more modern scientists have discovered that land snails come in right-handed and left-handed versions. The right-handed versions are more common, but there are more left-handed snails in Asia than elsewhere. Why? Well, it turns out that some snakes have evolved jaws that work better on the right-handed snails than on the left-handed ones. So as the right-handed snails get eaten more often, the left-handed snails are more likely to survive and reproduce, so there are more left-handed snails where there are more snakes that eat right-handed snails. Evolution and natural selection in action!

Read all about it here: In Snails and Snakes, Features to Delight Darwin.

Published by Rosalind on 24 Nov 2009

Butterflies in Space!

The Space Shuttle Atlantis was launched on November 16, carrying not only spare parts for the International Space Station but also two kinds of butterfly larvae — Painted Lady and Monarch caterpillars. The butterflies are going to live in special habitats on the Space Station, and they’re part of an experiment in finding out how living in different gravity affects the development of the larvae. Students across the US will be raising butterflies and comparing them to the ones in space. For updates, photos or video, visit Butterflies in Space.

Published by Diana on 20 Nov 2009

Galileo’s middle finger

Galileo Galilei, the famous astronomer who “”perhaps more than any other single person, was responsible for the birth of modern science” (according to Stephen Hawking, who should know, being a physicist himself) died in 1642, while under house arrest near Florence, Italy. (He was put under house arrest by the Catholic Church, which then ruled what later become Italy, because he believed in a sun-centered Solar System, which was considered heresy at the time.)

95 years after his death, his body was moved to Florence to a special tomb near Michelangelo’s, in Florence. At that time, a tooth, his right thumb, and his right middle finger were kept by an admirer, and the relics were passed down through the family.

But now they’ve been given to the Museum of the History of Science in Florence and will soon be on display there. This is true. Read about it here: Galileo’s fingers, tooth are found.

Published by Diana on 18 Nov 2009

“Everyone talks about the weather but no one does anything about it….”*

Ben Franklin, an astute observer of the weather, believed that the settling of North America had changed the weather: “cleared land absorbs more heat and melts snow quicker.” He also thought that volcanoes led to cool weather. In both of these observations, he has been proven to be correct.

In today’s New York Times, this article: Ben Franklin on Global Warming talks about the writings of our founding fathers on weather and climate.

*Quotation from Mark Twain

Published by Rosalind on 14 Nov 2009

An Amazing Discovery

Craters are clearly visible in this NASA photo of the Earth's Moon.

Craters are clearly visible in this NASA photo of the Earth's Moon.

People have always said that the moon is dry and barren – no ice caps, no water. But recently scientists began to think that might not be true. So NASA researchers came up with the idea of crashing a spacecraft into a lunar crater and then analyzing the dust from the impact. The crash  took place October 9th, 2009. Now NASA has  announced that there is definitely water (in the form of ice) on the moon! Check out the story here: Water on the Moon!

Published by Diana on 12 Nov 2009

Oceans of Trash

There is a garbage patch in the middle of the Pacific Ocean, and it’s getting bigger and bigger. Made of little pieces of plastic, it’s created by the currents in the Pacific sweeping the plastic into one area. You can read more about it here: Afloat in the Ocean, Expanding Islands of Trash.

Published by Rosalind on 07 Nov 2009

See the Space Station!

International Space Station Using this link, you can figure out when the International Space Station will be passing over your area. Don’t miss the chance to see it go over you some dark evening! Then you can run back inside to your computer and see the live camera footage from the Space Station — just click here: Space Station camera.