Hardy-Weinberg The Hardy-Weinberg formulas allow scientists to determine whether evolution has occurred. Any changes in the gene frequencies in the population over time can be detected. The law essentially states that if no evolution is occurring, then an equilibrium of allele frequencies will remain in effect in each succeeding generation of sexually reproducing individuals. In order for equilibrium to remain in effect (i.e. that no evolution is occurring) then the following five conditions must be met: Obviously, the Hardy-Weinberg equilibrium cannot exist in real life. Some or all of these types of forces all act on living populations at various times and evolution at some level occurs in all living organisms. p = frequency of the dominant allele in the population q = frequency of the recessive allele in the population p2 = percentage of homozygous dominant individuals q2 = percentage of homozygous recessive individuals 2pq = percentage of heterozygous individuals PROBLEM #1.
Diseases - Manual - Activity 3, page 1 At a Glance Focus: Students investigate the growth of bacteria in the presence of antibiotics and use the results to explain a case of antibiotic-resistant tuberculosis, presented in an Internet-based interview. Major Concepts: The re-emergence of some diseases can be explained by evolution of the infectious agent (for example, mutations in bacterial genes that confer resistance to antibiotics used to treat the diseases). Objectives: After completing this activity, students will be able to explain how antibiotic treatment results in populations of bacteria that are largely resistant to the antibiotic and describe inappropriate and/or questionable uses of antibiotics. Prerequisite Knowledge: Students should be familiar with bacterial growth and with evolution by natural selection. Introduction In 1943, penicillin was introduced as the "magic bullet" for curing many infectious diseases. The primary reason for the increase in antibiotic resistance is evolution. Materials and Preparation 1.
Scientists Sample the Ocean and Find Tiny Additions to the Tree of Life Continue reading the main story Slide Show Climate change scientists have known for years that rising temperatures affect sea creatures, from the biggest fish to the microscopic plankton at the base of the ocean food chain. Now, a four-year expedition that sampled microbes from across the world’s oceans is bringing the mechanisms of that change into focus. These tiny creatures, which may be among the oldest on Earth, together absorb carbon dioxide, make oxygen, break down waste and nourish other creatures. “Temperature is the most important environmental factor determining the composition of these communities,” said Chris Bowler, an author on all five studies and a genomics expert with the Department of Biology of the École Normale Supérieure and the National Center for Scientific Research in France. “This would imply that , warming of the oceans, is going to have a strong impact on these organisms and the functions these organisms perform for the well-being of our planet,” Dr.
Five fingers of evolution - Paul Andersen In his talk, Paul Andersen explains the five causes of microevolution. Research one example for each cause in the human population. Use the following population simulator to simulate microevolution: Run the simulation using the default settings.
9-12 teachers' lounge Teaching materials : 9-12 teachers' lounge :Identify your learning goals At the end of the school year, there are certain conceptual understandings that we want our students to have. Achieving these learning goals lays the groundwork for more sophisticated understandings as students proceed through their learning experiences. The conceptual framework is aligned with the 2012 Framework for K-12 Science Education and the Next Generation Science Standards (NGSS). The Understanding Evolution Framework is divided into five strands, and a selection of teaching resources (i.e., lessons, activities, readers, and interactive online modules) targeting most concepts has been identified. Jump to: History of Life | Evidence of Evolution | Mechanisms of Evolution | Nature of Science | Studying Evolution
The driving force for molecular evolution of translation Is Most of Our DNA Garbage? Photo T. Ryan Gregory’s lab at the University of Guelph in Ontario is a sort of genomic menagerie, stocked with creatures, living and dead, waiting to have their DNA laid bare. Gregory’s investigations into all these genomes has taught him a big lesson about life: At its most fundamental level, it’s a mess. After adding a fluorescent dye that attaches to DNA, Jeffrey loaded the vial into a boxy device called a flow cytometer, which sprayed the onion juice and blood through a laser beam. One peak represented my genome, or the entirety of my DNA. “The onion wins,” Gregory said. But why? The human genome contains around 20,000 genes, that is, the stretches of DNA that encode proteins. But in the past few years, the tide has shifted within the field. In January, Francis Collins, the director of the National Institutes of Health, made a comment that revealed just how far the consensus has moved. This research led scientists to assume that the genome was mostly made up of protein-coding DNA.
stroop effect The famous "Stroop Effect" is named after J. Ridley Stroop who discovered this strange phenomenon in the 1930s. Here is your job: name the colors of the following words. Do NOT read the words...rather, say the color of the words. For example, if the word "BLUE" is printed in a red color, you should say "RED". Try this Interactive Stroop Effect Experiment. [Run Experiment] Also available: print out Stroop Test Mini Cards. Why? The words themselves have a strong influence over your ability to say the color. Speed of Processing Theory: the interference occurs because words are read faster than colors are named.Selective Attention Theory: the interference occurs because naming colors requires more attention than reading words. I think that this puzzle would be easier for a very young child than for older children or adults. My scores: Test #1 = 10.1 seconds; Test #2 = 22.4 seconds It took me more than TWICE the amount of time to read the "confusing" words. More experiments to try:
Visualizing life on Earth: data interpretation in evolution Visualizing life on Earth: data interpretation in evolution by the Understanding Evolution team This pattern might seem obvious. In this module, you will examine the same data that scientists have used to try to answer this question and can compare your own ideas to those that scientists have come up with.