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This lecture is available from Howard Hughes' Bio Interactive website.
Evo in the news: What has the head of a crocodile and the gills of a fish?
This article is located within History of Evolutionary Thought.
Webcast: Fossils, genes, and embryos In lecture three of a four part series, evolutionary biologist David Kingsley examines the original objections to Darwin's theory and shows how modern evidence supports the theory.
This article appears at Springer Link.15 evolutionary gems This succinct briefing describes 15 examples drawn from recent research that demonstrate evolutionary theory’s power to explain natural phenomena, along with some of their supporting lines of evidence--from whale fossils to the latest in genetics. Wallace and Wegener: Biogeography Alfred Russel Wallace's studies of species ranges and Alfred Wegener's conception of continental drift provide compelling evidence that much of a species’ present distribution can be explained by its evolutionary history.
The following formula can be used to calculate half-life (t1/2): t1/2 = (t ln 1/2)/(ln mf / mi) t = time that has passed mf = the final or remaining mass of undecayed sample mi = the initial or original mass of undecayed sample (The fraction mf / mi is of course equivalent to the fraction of undecayed sample remaining, in case you are given the fraction remaining rather than specific masses.) Note: You can also use base-10 logarithms instead of natural logarithms.
This news brief, from May 2006, reviews what is likely to be the most important fossil find of the year: Tiktaalik helps us understand how our own ancestors crawled out of the water and began to walk on dry land. Darwin used the words "extreme imperfection" to describe the gappy nature of the fossil record - but is this really such a problem?
This article delves into the topic of transitional fossils and explores what we have learned about them since Darwin's time.
Creeds and schools in abeyance, Retiring back a while sufficed at what they are, but never forgotten, I harbor for good or bad, I permit to speak at every hazard, Nature without check with original energy.
The proportions of the copper and zinc are varied to yield many different kinds of brass. However, the amount of copper may range from 55% to 95% by weight, with the amount of zinc varying from 5% to 40%.
Lead commonly is added to brass at a concentration of around 2%.
Uses of brass include musical instruments, firearm cartridge casing, radiators, architectural trim, pipes and tubing, screws, and decorative items. Wrought brasses, which are suitable for mechanical forming, begin with 1 through 7.
Common names for brass alloys may be misleading, so the Unified Numbering System for metals and alloys is the best way to know the composition of the metal and predict its applications. Cast brasses, which may be formed from molded molten metal, are indicated using an 8 or 9.
The half-lives of radioactive isotopes vary between a tiny fraction of a second, and more than 1015 years.