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. Smaller cells are easily visible under a light microscope. To see anything smaller than 500 nm, you will need an electron microscope. Adenine The label on the nucleotide is not quite accurate. How can an X chromosome be nearly as big as the head of the sperm cell? No, this isn't a mistake. The X chromosome is shown here in a condensed state, as it would appear in a cell that's going through mitosis. A chromosome is made up of genetic material (one long piece of DNA) wrapped around structural support proteins (histones). Carbon The size of the carbon atom is based on its van der Waals radius.
Scale of the Universe 2012 Credits: Scale of the Universe 2 was created by Cary and Michael Huang. Drag the scrollbar or use your mouse-wheel to zoom in and out of the universe. Prepare to have your mind blown! OML has thousands of free addictive Flash and HTML5 Games like Scale of the Universe 2012. Credits: Scale of the Universe 2 was created by Cary and Michael Huang. Drag the scrollbar or use your mouse-wheel to zoom in and out of the universe. OML has thousands of free addictive Flash and HTML5 Games like Scale of the Universe 2012. Charles Darwin Spotlight | Learn Science at Scitable Like so many great scientists, Charles Darwin was first drawn to science as a young boy by his intense interest in the diverse animals and plants that filled his surroundings. Later, despite his father's urgings to pursue a career in medicine, young Darwin found himself drawn to careful, empirical observation of nature, particularly through his cherished hobby of collecting beetles. His empirical instincts were further developed at the University of Cambridge through deep study under contemporary naturalists, such as John Stevens Henslow, founder of the Cambridge University Botanic Garden (1831), and through reading progressive philosophers, such as William Paley, author of Natural Theology (1802). By the time he was serendipitously invited to accompany Captain Robert FitzRoy on a voyage of the HMS Beagle, Darwin had become an astute and insatiable scientist, primed for significant discoveries. Who could have imagined how significant his discoveries would be?
The History of Life on Earth by Robert Patierno on Prezi Biodiversity Heritage Library Current Book List General Index Search Charles Darwin's Library Charles Darwin’s Library is a digital edition and virtual reconstruction of the surviving books owned by Charles Darwin. This BHL special collection draws on original copies and surrogates from other libraries. It also provides full transcriptions of his annotations and marks. In this first release (2011) we provide 330 of the 1480 titles in his library, concentrating on the most heavily annotated books. more... How to use Charles Darwin's Library A Darwin’s Library transcription pane faces each page that Darwin marked or wrote notes on. Entries in the pane have line numbers, such as lines 5-7. In books scanned from Darwin’s personal copies you will see his writing. Click the banner to reach the Current Book List and the General Index. The pane uses a very few specialized terms and symbols: The transcription pane uses special characters to represent some elements of Darwin's annotations. Support United Kingdom United States
History of Life by Jesse Brunner on Prezi The Beagle Project Blog: Pics in space One of the most exciting science projects we plan to do aboard the new Beagle is to correlate ocean surface biological surveys with images of our position taken at the same time by our astronaut friends aboard the International Space Station. The premise of such a study got a big boost this week when Nature published special News Features and Commentaries on earth monitoring. The issue includes an essay by Stewart Brand of the Long Now Foundation. Way back in 1966 Brand promoted 'the idea of photographing the "whole Earth" from space, hoping that it would stimulate humanity's interest in its mega-habitat.' And oh, how it did. On Christmas Eve, they transmitted the first images of the whole Earth that anyone had ever seen. Stewart Brand was right in 1966, so let's listen carefully to him now. Throw in a charismatic tall ship with a scientific legacy like the Beagle's and we might find ourselves even closer to achieving Brand's vision.
Time Tree :: The Timescale of Life Origins by Lucas Laursen Charles Darwin may have had his biggest impact on biology, but he began his scientific career as a geologist. So it’s appropriate that earlier this year, retired geologist John Ramsay, who had long studied the famed biologist’s life, accepted a commission to compose a Darwin-themed string quartet. Darwin “did some pretty fundamental geological mapping," says Ramsay, drawing a parallel to his own geological career, during which he has drawn maps of the Scottish Highlands, South Africa, and the Swiss Alps. At the beginning of the piece, a disorganized Earth takes shape, with the core, mantle, and crust emerging into distinct musical themes. Performed by the Fitzwilliam String Quartet, Ramsay’s composition premiered in Cambridge, U.K., during the Darwin Festival (Ramsay pictured above and Quartet playing pictured below) on 7 July 2009. When his tour was over, Ramsay had to decide between pursuing music or geology. And what would Darwin have thought of the composition?
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. From Carl Zimmer's blog The Loom. Science writer Carl Zimmer has an interesting post on his blog about how the newest genetic data may even call this classification into question by adding a fourth domain. There’s a lot of debate about whether eukaryotes actually split off from within the archaea, or just branched off from a common ancestor. New research is looking at tons of genes from these sorts of organisms. References Wu, D., et al. (2011). Like this:
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