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Evolution

Evolution
Related:  Natural Selection and AdaptationBiology

The mutation that helped ancient humans survive frostbite probably gave us arthritis When humans began their slow migration out of Africa some 100,000 years ago, they carried with them the genetic seeds necessary to help survive the bitter chill of Europe and Asia. But, unknowingly, in the same genes lurked a painful burden that afflicts millions today – with a new study finding that a gene variant that helped our ancestors survive extreme climates and frostbite also increases the likelihood of developing arthritis. According to researchers at Stanford and Harvard universities, a variant of the GDF5 gene – which is associated with bone growth and joint formation – has two effects on those that carry mutations of the gene: it reduces bone length (and, subsequently, height), and it can almost double the chance of osteoarthritis. "It's clear that the genetic machinery around a gene can have a dramatic impact on how it works," says one of the researchers, human evolutionary biologist Terence Capellini, now at Harvard University. The findings are reported in Nature Genetics.

Soar | Teaching Ideas Genre(s): Adventure A young girl helps a tiny boy to fly home before it's too late! Use this delightful animated film in your classroom with our collection of cross-curricular teaching ideas and activities! English The title of this film is 'Soar'. Science Describe the forces that are involved in the flight of an object.Lucas places a star in the sky at the end of the film. Computing Make a trailer / website / poster to promote the film. Design Technology Design and build (if possible) a new flying machine for Lucas. Art Look at the storyboards and designs shown in the credits. Music Listen to the soundtrack (without watching the video). History Find out about the history of flight. OneZoom Tree of Life Explorer The tree of life gets a makeover The tree of life might seem like a stable design, appropriate for indelible ink. Plenty of people think so. An Internet search for “phylogenetic tattoos” turns up some showy skin art. But the branches are shifting. When Patrick Keeling at the University of British Columbia in Vancouver unveils a working scientist’s current diagram for his students, most have never heard the names of the major branches. In the new vision — based on increasingly sophisticated genetic analyses — people and other animals are closer cousins to single-celled choanoflagellates than to other multi­cellular organisms. Genetics-based versions of the treetop of life have inspired a new genre of tattoo, often with symbolic organisms rather than multisyllabic labels. Science Ink: Tattoos of the Science Obsessed, Carl Zimmer (Sterling). © 2011 Carl Zimmer The old tree isn’t exactly wrong. Biologists analyzing this treetop rarely use the word kingdom anymore. Story continues below graphic Old school Great idea, but

What You Can Learn About Learning Through Video Game Play Shakalaka boom! Yeah, well done! Way to hold your ground! Cool base design! Tricky strategy to draw them in! Thanks for the bombers! How do you hoard loot if they keep stealing if from you? Don't worry about trophies if you are trying to get loot. Sounds strange? I invited the cousins and nephews to get involved and we made our own clan. For those that are not familiar with the game, the point is to gather elixir, and gold to build your base to Level 11. Discoveries After playing this game, there's nine things that I have learned about education and learning: #1. #2. #3. #4. #5. #6. #7. #8. #9. How do I justify spending time on a simple game?

Case Study: How Did the Guppy Get His Color? This case study examines evolution in guppies as evidenced by color variation in populations. It is based on an iconic study performed by John Endler where he collected data on guppies by scoring the size, number, and brightness of spots. Students progress though the slides (lecture and discussion), and examine details of Endler’s study, such as where the pools were located and why natural barriers created different environments for the native guppies. The case also examine two predatory fish found in Trinidad, the killifish (Rivulus hartii) and the pike (Crenichichla alta). Students then examine real data gathered in the experiment that showed how the color and number of spots found on guppies was related to the types of predators in the stream. Students should be able to conclude that in streams with aggressive predators, natural selection favors guppies that do not have bright spots. Related Documents and Handouts: Guppy Case Study (word): Printable, can be downloaded and edited

Paleoclimatology: The Oxygen Balance : Feature Articles As air cools by rising into the atmosphere or moving toward the poles, moisture begins to condense and fall as precipitation. At first, the rain contains a higher ratio of water made of heavy oxygen, since those molecules condense more easily than water vapor containing light oxygen. The remaining moisture in the air becomes depleted of heavy oxygen as the air continues to move poleward into colder regions. As the moisture reaches the upper latitudes, the falling rain or snow is made up of more and more water molecules containing light oxygen. Ocean waters rich in heavy oxygen: During ice ages, cooler temperatures extend toward the equator, so the water vapor containing heavy oxygen rains out of the atmosphere at even lower latitudes than it does under milder conditions. The water vapor containing light oxygen moves toward the poles, eventually condenses, and falls onto the ice sheets where it stays. The concentration of 18O in precipitation decreases with temperature.

What are Dominant and Recessive? Inheritance patterns Sickle-cell disease is an inherited condition that causes pain and damage to organs and muscles. Instead of having flattened, round red blood cells, people with the disease have stiff, sickle-shaped cells. The long, pointy blood cells get caught in capillaries, where they block blood flow. Muscle and organ cells don’t get enough oxygen and nutrients, and they begin to die. The disease has a recessive pattern of inheritance: only individuals with two copies of the sickle-cell allele have the disease. In addition to causing disease, the sickle-cell allele makes people who carry it resistant to malaria, a serious illness carried by mosquitos. Now let’s look again at the shape of the blood cells. So is the sickle cell allele dominant, recessive, or co-dominant? Protein function If we look at the proteins the two alleles code for, the picture becomes a little more clear. The protist that causes malaria grows and reproduces in red blood cells.

Tree of Life Web Project Games and Learning | Through coverage of the market, research and up-to-date analysis, Games and Learning reports on the opportunities and challenges facing those seeking to unlock the educational power of games. Earth - Chicken grows face of dinosaur Sixty-five million years ago, an asteroid is believed to have crashed into Earth. The impact wiped out huge numbers of species, including almost all of the dinosaurs. One group of dinosaurs managed to survive the disaster. Today, we know them as birds. The idea that birds evolved from dinosaurs has been around since the 19th century, when scientists discovered the fossil of an early bird called Archaeopteryx. But these early birds didn't look the same as modern ones. To understand how one changed into another, a team has been tampering with the molecular processes that make up a beak in chickens. By doing so, they have managed to create a chicken embryo with a dinosaur-like snout and palate, similar to that of small feathered dinosaurs like Velociraptor. The team's aim was to understand how the bird beak evolved, because the beak is such a vital part of bird anatomy. "Whenever you examine an important evolutionary transformation, you want to learn the underlying mechanism," says Bhullar.

Related:  SimulationsBiologiEvolution