Sandwalk: The Adaptation Assessment Probe I'm taking a MOOC on evolution that's designed for educators [Evolution: A Course for Educators]. One of the things that was covered in the first lecture was a test on "adpatation" taken from a book called "Uncovering Student Ideas in Science, Volume 4: 25 New Formative Assessment Probes. The book is published by the National Science Teachers Association (NSTA). Let's take the test ... Adaptation Three friends were arguing about what would happen if a population of rabbits from a warm, southern climate were moved to a cold, northern climate.1 This is what they said:Bernie: "I think all of the rabbits will try to adapt to the change." Cell Size and Scale Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an ameoba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny. Smaller cells are easily visible under a light microscope.
Teaching Evolution through Human Examples The "Teaching Evolution through Human Examples" (TEtHE) three-year exploratory research and development project was funded by National Science Foundation Discovery Research K-12 grant #1119468. The project has created four curriculum units for Advanced Placement (AP) Biology classes, aligned to the learning objectives, using human case studies to teach core evolutionary principles. The curriculum units are: (1) Adaptation to Altitude, (2) Malaria, (3) Evolution of Human Skin Color, and (4) What Does It Mean To Be Human?.
Genetics and the tree of life We traditionally think about the tree of life in terms of Kingdoms: plants, animals, fungi, bacteria, etc. Genetics has really revolutionized the way we think about the tree of life and, because our classifications should reflect ancestry (that is, who is more closely related to whom), it has actually called into question a lot of our traditional classifications. Most biologists split up life into three domains: Archaea, Bacteria, and Eucarya (the last of which includes animals, plants, fungi, etc.). The three domains of life.
Rare Dinosaur-Era Bird Wings Found Trapped in Amber Two tiny wings entombed in amber reveal that plumage (the layering, patterning, coloring, and arrangement of feathers) seen in birds today already existed in at least some of their predecessors nearly a hundred million years ago. A study of the mummified wings, published in the June 28 issue of Nature Communications and funded in part by the National Geographic Society's Expeditions Council, indicated they most likely belonged to enantiornithes , a group of avian dinosaurs that became extinct at the end of the Cretaceous period. (Read more about the evolution from dinosaurs to modern birds.) Genes and Geography Photo Credit: NASA Our early human ancestors began migrating across the globe tens of thousands of years ago. Some left behind archaeological evidence of their travels. But as you'll hear in this Science Update, another record of where we come from and where we've been might be found right in our DNA. Transcript
Genetic Science Learning Center Launch Tool The Genetic Science Learning Center is a great place to visit to explore and learn about cells, heredity, DNA, genes, natural selection, etc. The Learn.Genetics part of the site is geared to students, teachers, and the general public. It delivers educational materials on genetics, bioscience, and health topics. The homepage is divided into three main sections: Basics, New & Popular, and a section that highlights a variety of topics, from genetic technology to the new science of addiction.
Under the Sea, a Missing Link in the Evolution of Complex Cells Photo Unlike bacteria, humans have big, complex cells, packed with nuclei containing DNA and mitochondria that produce energy. All so-called eukaryotes share our cellular complexity: animals, plants, fungi, even single-celled protozoans like amoebae. Scientists estimate that the first eukaryotes evolved about 2 billion years ago, in one of the greatest transitions in the history of life.
All 2.3 Million Species Are Mapped into a Single Circle of Life Since Charles Darwin's day, biologists have depicted how new organisms evolve from old ones by adding branches to numerous trees that represent portions of the animal, plant and microbial kingdoms. Researchers from a dozen institutions recently completed a three-year effort to combine tens of thousands of trees into one diagram, most readable as a circle (below). The lines inside the circle represent all 2.3 million species that have been named. Biologists have genetic sequences for only about 5 percent of them, however; as more are finished, the relationships within and across groups of species may change. Experts estimate that up to 8.7 million species may inhabit the planet (about 15,000 are discovered every year).
Lesson: evolution mini-lesson: A Step in Speciation Time: Two 50-minute periods Preparation: 1. Make color copies of the salamander sheets (one per team of 2-4); place these in non-glare transparent plastic notebook sleeves to protect from wear and tear as they are re-used every period and year. 2. Make copies of Grid Map of California. Tree of Life : Exhibits : Yale Peabody Museum of Natural History Phylogenetic trees predict the characteristics of species that have not yet been carefully studied. This can guide the search for useful natural products, including “bioprospecting” for new drugs. For example, the drug “taxol,” which is used to treat breast cancer, was first isolated from the Pacific yew plant. A focus on related plants turned up a similar chemical in a more widespread species, which greatly enabled the production of the drug. Treating Snake Bites
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.