BioNumbers - The Database of Useful Biological Numbers Storia della Scienza per ragazzi La storia della scienza raccontata ai ragazzi Giovanni Di Gregorio Sciamani, filosofi e vecchie comari nella medicina classica Il mistico Keplero e le leggi dell’astronomia Bussola, portolani e polvere da sparo: l’esplorazione dei nuovi mondi Magia, alchimia e la trasformazione delle sostanze La sconfitta di Aristotele e la nascita della scienza moderna La riscoperta dell’anatomia tra autopsie e stampe illustrate La rivincita del microscopio e la scoperta di nuovi mondi Una mela, Saturno e leggi universali di Newton Linneo e il grande catalogo della Natura Ossa di drago e rocce dalla forma curiosa: la lenta nascita della geologia I fringuelli delle Galapagos e il mistero dell’origine della specie Louis Pasteur e l’evoluzione della ricerca medica Una piccola raccolta di immagini su ... Darwin, le Galapagos, i fringuelli, l'origine della specie ... e altre cose
Tree of Life Web Project The Tree of Life Web Project (ToL) is a collaborative effort of biologists and nature enthusiasts from around the world. On more than 10,000 World Wide Web pages, the project provides information about biodiversity, the characteristics of different groups of organisms, and their evolutionary history (phylogeny). Each page contains information about a particular group, e.g., salamanders, segmented worms, phlox flowers, tyrannosaurs, euglenids, Heliconius butterflies, club fungi, or the vampire squid. ToL pages are linked one to another hierarchically, in the form of the evolutionary tree of life. Starting with the root of all Life on Earth and moving out along diverging branches to individual species, the structure of the ToL project thus illustrates the genetic connections between all living things.
The Biology Project Erbe medicinali What Darwin Never Knew | NOVA Skip to Main Content Use one of the services below to sign in to PBS: You've just tried to add this video to My List. But first, we need you to sign in to PBS using one of the services below. You've just tried to add this show to My List. By creating an account, you acknowledge that PBS may share your information with our member stations and our respective service providers, and that you have read and understand the Privacy Policy(opens in new window) and Terms of Use(opens in new window). You have the maximum of 100 videos in My List. We can remove the first video in the list to add this one. Edit My List You have the maximum of 100 shows in My List. We can remove the first show in the list to add this one. Edit My List
Yes, We Should Clone Neanderthals | discussion | ethics 30,000 years ago a Neanderthal woman died in what would become Croatia’s Vindija cave. Five years ago, 454 Life Sciences and the Max Planck Institute started working together on the tedious and time-consuming task of piecing her fossilized DNA back together. Just over a month ago, they succeeded and, in the process, revealed that most of us are between 1% and 4% Neanderthal. Knowing where Neanderthals fit, however, also creates a problem. The problem is, of course, that we don’t have a cloned Neanderthal. The argument may seem absurd and offensive at first. As the bioethicist Bernard Rollin points out in the Archaeology piece, there’s more to worry about than the law. Not so. Unlike examples found in science fiction, be it Mary Shelley’s Frankenstein or the more recent sci-horror flick Splice, it’s not as if our only options are to send the neo-Neanderthal into the world on its own or to trap it in a laboratory where it would be poked and prodded to death.
Dipartimento di Botanica dell'Università di Catania Neanderthals on Trial | Tracing Ancestry with MtDNA by Rick Groleau In 1987, three scientists announced in the journal Nature that they had found a common ancestor to us all, a woman who lived in Africa 200,000 years ago. She was given the name "Eve," which was great for capturing attention, though somewhat misleading, as the name at once brought to mind the biblical Eve, and with it the mistaken notion that the ancestor was the first of our species—the woman from whom all humankind descended. The "Eve" in question was actually the most recent common ancestor through matrilineal descent of all humans living today. That is, all people alive today can trace some of their genetic heritage through their mothers back to this one woman. Nuclear DNA vs mitochondrial DNA When someone mentions human DNA, what do you think of? Outside the nucleus, but still within the cell, lie mitochondria. Inheriting mtDNA If you went back six generations in your own family tree, you'd see that your nuclear DNA is inherited from 32 men and 32 women[1]. Final note
Tree of Life Web Project Tavola periodica interattiva, descrizione aanche audio dei singoli elementi e video Lanthanum: the essentials Lanthanum is silvery white, malleable, ductile, and soft enough to be cut with a knife. It is one of the most reactive of the rare-earth metals. It oxidises rapidly when exposed to air. Cold water attacks lanthanum slowly, and hot water attacks it much more rapidly. The metal reacts directly with elemental carbon, nitrogen, boron, selenium, silicon, phosphorus, sulphur, and with halogens. Lanthanum: historical information Lanthanum was discovered by Carl Gustaf Mosander at 1839 in Sweden. Carl Gustav Mosander recognized the element lanthanum in impure cerium nitrate in 1839. Lanthanum: physical properties Melting point: 1193 [or 920 °C (1688 °F)] KBoiling point: 3743 [or 3470 °C (6278 °F)] KDensity of solid: 6146 kg m-3 Read more » » Lanthanum: orbital properties Read more » » Isolation For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. 2LaF3 + 3Ca → 2La + 3CaF2
Ten Recent Advances in Evolution By Carl Zimmer Posted 10.26.09 NOVA To celebrate the 150th anniversary of the Origin of Species, here's a list—by no means exhaustive—of some of the biggest advances in evolutionary biology over the past decade. These advances include not just a better understanding of how this or that group of species first evolved, but insights into the evolutionary process itself. In some cases those insights would have given Darwin himself a pleasant jolt of surprise. Ten significant leaps forward in evolution research in the past decade, as chosen and described by noted science writer Carl Zimmer Enlarge Photo credit: (Earth) © NASA; (text) © WGBH Educational Foundation Darwin envisioned natural selection acting so slowly that its effects would be imperceptible in a human lifetime. If he were alive today, Darwin would be astonished at the pace and nature of discoveries being made in evolutionary biology, including the witnessing of evolution in action.