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.
Deep Time : A History of the Earth - Interactive Infographic Life on the planet started astonishingly early. The first living organisms, in the current model of evolution, are thought to be Prokaryotes1. The oldest known fossilised prokaryotes have been dated to approximately 3.5 billion years ago, only 1 billion years after the formation of the Earth's crust. Antibiotic Overuse May Increase Superbug Evolution Rate Multiple drug-resistant Staphylococcus aureus bacteria seen under an electron microscope. Photo: CDC By flooding our environment with antibiotics, people may alter a little-appreciated but profound aspect of bacterial evolution: the very pace at which it occurs.
Rediscovering Biology - Case Studies: The Genetics of Resistance to HIV Infection This case uses the example of HIV, to explore the relationships between viruses, cells and the immune system, and the role of genes in disease resistance. An animation explains PCR (polymerase chain reaction) and electrophoresis and their practical use as a genetic test. We will see how mutations in an HIV receptor confer relative reslstance to infection. 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.
Mother nature network These bizarre locations may seem like a series of elaborate movie sets, but they are real destinations that you might want to see for yourself. Photo: Greg Mote/Flickr The Wave, Arizona, U.S. Photo: Shutterstock The pace of evolution The pace of evolution Does evolution occur in rapid bursts or gradually? This question is difficult to answer because we can't replay the past with a stopwatch in hand. Male Chromosomes Are Not Dying Soon, Study Finds : News Update Date: Jan 11, 2014 05:31 PM EST A new study has challenged the notion that Y chromosomes are largely unimportant and will no longer exist in the next 5 million years. (Photo : Image Editor/Flickr) A new study has challenged the notion that Y chromosomes are largely unimportant and will no longer exist in the next 5 million years.
The evolution of the human eye - Joshua Harvey The evolution of the human eye has long been regarded as a contentious issue. It was believed to be an example of irreducible complexity – that is something that could not have evolved, because any precursor to the fully evolved form would be non-functioning. Wikipedia gives a good overview of the concept. This lesson shows that not only do evolutionary precursors to the eye exist, but that there is a huge diversity in the structure and function of eyes in the animal kingdom.
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.
Myrmedrome - A real ant colony simulator MYRMEDROME is an ant colony simulator which tries to imitate the ants’ life as well as possible without introducing artificial effects. The simulation is based on the fundamental principle that each ant is not enough intelligent to understand it lives in a complex community, nor it is able to organize tasks in its colony. Therefore, each ant lives and works following some simple rules interacting (unaware of it) with the others by chemical signals. These thousands of connections rise a self-organization of the whole colony, which leads an observer to believe that someone imposed some kind of strategy. This Someone is named... Transitional forms Transitional forms Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants are referred to as transitional forms. There are numerous examples of transitional forms in the fossil record, providing an abundance of evidence for change over time. Pakicetus (below left), is described as an early ancestor to modern whales. Although pakicetids were land mammals, it is clear that they are related to whales and dolphins based on a number of specializations of the ear, relating to hearing. The skull shown here displays nostrils at the front of the skull.
100 Years of Breed “Improvement” For the sake of honest disclosure, I will admit to owning “purebreds” (the ‘pureness’ of purebreeds is a discussion for another time) but I also have mutts. All the dogs I’ve had since childhood had a few things in common, they were friendly, prey driven, ball-crazy, intense, motivated, athletic (crazy dogs are easier to train) and none had intentionally bred defects. I would never buy/adopt a dog whose breed characteristics exacted a health burden.(Asher 2009).