Postcards from the Planet

Another shuttle mission ended today — but this one was the last for Space Shuttle Atlantis. Its final planned mission was to deliver an Integrated Cargo Carrier and a Russian-built Mini Research Module to the International Space Station. STS-132 was the 32nd mission for Atlantis. Despite the success of the shuttle missions in helping to build and re-supply the International Space Station, there are no new shuttles planned by NASA, due to changes in US government plans for NASA. You can read more about Atlantis’ final mission: Atlantis.

As the space shuttle Discovery circles the earth this week , the Obama administration is proposing a 60% rise in funding for NASA to study the earth. One particular focus of study will be carbon dioxide and its effects on the atmosphere — part of the money would pay for a new Orbiting Carbon Observatory. The GRACE satellites, which study gravity, will also be replaced. You can listen to the NPR story here: NASA Slated to Receive Billions of Dollars to Study Earth.

For updates on the Discovery mission, the astronauts, and to find out when Discovery is passing overhead, visit NASA Shuttle and Space Station.

Researchers led by Eske Willerslev at the University of Copenhagen this week announced the first completed sequencing of the genome of an ancient human. The genetic material came from an ancient clump of hair, collected in Greenland by Danish archeologists in the 1980’s. “From the DNA, we can tell a lot about the individual,” says Willerslev. “He had brown eyes, brown skin, a tendency to baldness, dry earwax, and shovel-shaped front teeth.” The researchers have named him “Inuk,” which means “man” or “human” in Greenlandic. To see a drawing of Inuk and read more about the research, check out this article: Ancient Human Sequenced for First Time.

“The borna virus is at once obscure and grotesque,” starts this New York Times article: Hunting Fossil Viruses in Human DNA. The article continues by describing the effects of the virus: “horses sometimes kill themselves by smashing in their skulls.”

The borna virus is only one fossil virus found in the DNA of every human. Other viruses are retroviruses, which are viruses uses RNA to make DNA, like the HIV virus.

Scientists have only begun to research these fossil viruses, buried deep in our DNA.

Last week I wrote about snakes in Asia, and how they are evolving to take advantage of the local snails. This week it’s birds in Europe.

Blackcap warblers in central Europe have a genetically determined migration route that takes them to the Mediterranean when the weather cools in the fall. Well, it used to take them to Spain… now some populations go to England instead.

Why England? Bird feeders. People feed birds during the winter in England, and the birds evolved to take advantage of that. 30% of blackcap warblers now migrate to England.

Since food is readily available during the winter in England, and it’s a shorter route back to their summer home in Germany and Austria, the birds get to summer nesting sites earlier, and the English-winter birds mate with each other and not with the Spanish-winter birds.

This is called “reproductive isolation” and it’s one of the first steps in creating new species. The warblers are still the same species–they can still mate and produce fertile children–but they’re beginning to look different, fly differently, and eat a different diet.

More details, and some excellent photos here: Feeding Birds Could Create New Species.

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.

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.

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!

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.

Spiders are carnivores. We all know that. But a Mexican jumping spider turns out to be an omnivore that prefers leaf tips to meat. In an article in last week’s New York Times , Jumping Spider Prefers Green Leaves to Meat, scientists explain how the spider takes advantage of the mutualistic relationship between acacia trees and ants.

Acacia trees provide shelter and food for ants by secreting a sweet nectar that the ants eat; thorns protect the trees from most herbivores and the ants sting other herbivores that approach. But this particular spider–Bagheera kiplingi–dodges the ants and eats the leaf tips of the acacia.

Bagheera is the name of a black panther–a particularly stealthy predator–in Rudyard Kipling’s Mowgli stories, part of The Jungle Book, first published in 1894. The person who first describes and names a new species of plant or animal gets to choose the name. The two people who named this spider–George and Elizabeth Peckham, who described the spider in 1896–must have liked the book!