363 lecture 5-2008 - Mass extinctions 1

363 lecture 5-2008 - Mass extinctions 1 - Fossils passed...

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Fossils passed around in class: Horse teeth (Pliocene) 4-5 million years old Molluscs and sharks teeth from Calvert Cliffs, about 15 my old Dinosaur bone, 70 my old?? Trilobite, 230 my old (Permian-Triassic extinction
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“Pseudo-extinction” Cladogenesis Anagenesis Cladogenesis = branching of lineages during phylogeny Anagenesis = directional evolution of a feature over an arbitrarily short
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Feel it in your bones SUMMARY: Deciding whether our ancestors evolved as a single lineage may depend more on philosophy than fossils. Rex Dalton reports. Nature 440, 1100 - 1101 (27 Apr 2006) News http://www.nature.com/nature/journal/v440/n7088/f ull/4401100a.html
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Scientific Description Can Imperil Species Scientists are racing to discover and describe new species in the face of a global biodiversity crisis. Ironically, in cases of commercially valuable taxa, publishing new species descriptions may inadvertently facilitate their extinctions. These descriptions advertise "novelties" for hobbyists and drive new markets. Most modern descriptions provide detailed information on the locality and habitat where the new species occurs, turning a scientific article into a treasure map for commercial collectors. Researchers in fields with application to bioterrorism are debating codes of conduct to ensure that their findings do not fall into the wrong hands, the so-called "dual-use dilemma". Taxonomists describing new species that have the potential to become commercially valuable are also faced with a dual-use dilemma. Chinese gecko: $1500-2000 per lizard, now $40
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Neurobiology: After the bomb NATL NUCLEAR SECURITY ADMIN./NEVADA SITE OFFICE Proc. Natl Acad. Sci. USA 103 12564–12568 (2006) A legacy of nuclear-bomb tests is helping to settle controversy about whether new neurons are born in the brain's neocortex throughout our lives. The level of carbon-14 in the atmosphere (and thus the human body) was more or less doubled by Cold War bomb tests, then dropped after the 1963 Test Ban Treaty. A team led by Peter Eriksson of Gothenburg University and Jonas Frisén of the Karolinska Institute, Stockholm, Sweden, measured carbon-14 in autopsy tissue of people born before and after the bomb tests. Levels of the isotope in neocortex neurons corresponded to atmospheric levels at the time of the person's birth, suggesting that almost all neurons are born at that time. This supports Frisén's earlier work.
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Raccoon dogs, indigenous to some Asian countries, supplied some coats' fur. It is illegal to import dog and cat hair to the United States. (Courtesy Of The Humane Society Of The United States)
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Md. Bill Seeks to End Mislabeling of Fur Coats By Philip Rucker Washington Post Staff Writer Tuesday, February 5, 2008; Page B01 Imagine discovering that the trim on your designer coat, labeled as faux fur, actually was rabbit. Or raccoon. Or even dog hair. Some of the biggest names in retail -- Bloomingdale's, Saks Fifth Avenue and
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This note was uploaded on 10/22/2008 for the course BSCI 363 taught by Professor Staff during the Spring '08 term at Maryland.

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363 lecture 5-2008 - Mass extinctions 1 - Fossils passed...

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