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. 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. A lot of scientists wonder how all the new species that scientists are discovering are going to change the shape of this tree. References Like this:
State of the Nation Color presents an entirely different image. This is a photograph of Faro and Doris Caudill, farmers in Pietown, New Mexico. They lived in a dugout and struggled to survive on Resettlement Administration land. As the 1930s came to a close, Kodak came out with Kodachrome film – the first commercially viable color film available to the general public. Now, not just anybody could buy this film. Urban America New York City was the metropolis of America. Times Square was the happening place. Washington was a city of contrasts – the New Deal having extended its influence across the nation. But it was still very much a Southern city – especially if you were African American. Chicago was the transportation, food, and manufacturing center of the country. And the Southside was still an industrial neighborhood of steel mills and packing houses. New Orleans was the largest city in the South – not Atlanta. Rural America
The Genetic Gamesmanship of a Seven-Sexed Creature | Discoblog What could be better than two types of sexes? For one organism, the answer isn’t three, but seven! And to top it off, these seven sexes aren’t evenly distributed in a population, although researchers have now developed a mathematical model that can accurately estimate the probabilities in this crap-shoot game of sexual determination. Meet Tetrahymena thermophila, which in addition to its seven different sexes—conveniently named I, II, III, IV, V, VI, and VII—has such a complex sex life that it requires an extra nucleus. This fuzzy, single-celled critter has a larger macronucleus that takes care of most cellular functions and a smaller micronucleus dedicated to genetic conjugation. The other odd thing about this one-celled wonder is that the population of the seven sexes are skewed, leading Unversity of Houston researcher Rebecca Zufall and her colleagues to ask: What gives? Related Content: 80beats: What Makes a Boy Lizard? Image: Wikimedia Commons / Ayacop
Edheads - Activate Your Mind! The Human Body The Brain The human brain is the most complex and least understood part of the human anatomy. There may be a lot we don’t know, but here are a few interesting facts that we’ve got covered. Nerve impulses to and from the brain travel as fast as 170 miles per hour. Hair and Nails While they’re not a living part of your body, most people spend a good amount of time caring for their hair and nails. Facial hair grows faster than any other hair on the body. Internal Organs Though we may not give them much thought unless they’re bothering us, our internal organs are what allow us to go on eating, breathing and walking around. The largest internal organ is the small intestine. Bodily Functions We may not always like to talk about them, but everyone has to deal with bodily functions on a daily basis. Sneezes regularly exceed 100 mph. Sex and Reproduction As taboo as it may be in some places, sex is an important part of human life as a facet of relationships and the means to reproduce. Senses
Digital Photography Tutorials Learn how to take and edit digital photographs using visual tutorials that emphasize concept over procedure, independent of specific digital camera or lens. This is a complete listing of all tutorials on this site; click the drop-down links in the top menu to see particular topics. Photography is going through an exciting transition period as many film photographers are beginning to explore the new capabilities of digital cameras. While the fundamentals have remained similar, other aspects are markedly different. This is a great time to get involved with digital photography. These tutorials are rarely influenced by changes in image editing software and camera equipment — due to their unique concept-based approach. View in other languages: Português Русский Deutsch Français Italiano
Biologija.com.hr - Vijesti - Biologija - Zašto je nekih vrsta na Zemlji mnogo, a nekih malo? Na svijetu postoji više od 400.000 vrsta kornjaša (skupina kukaca), a samo dvije vrste tuatara ili premosnika, rođaka zmija i guštera, koji živi na sjeveru Novog Zelanda. Zašto evolucija stvara ''pobjednike',' kao što su sisavci i mnoge vrste ptica i riba, a zašto ''gubitnike'' i dalje je jedno od središnjih pitanja evolucijske biologije. Premosnici (Sphenodon) su jedini recentni rod reda Rhynchocephalia u razredu gmazova. Pored toga, jedini su recentni predstavnici porodice Sphenodontidae. Obitelj premosnika predstavljaju samo dvije vrste, Sphenodon punctatus (naslovna fotografija) i, još rjeđa, Sphenodon guntheri. Znanstvenici su pretpostavljali da je vrijeme glavni čimbenik koji utječe na broj vrsta - što su neke životinjske i biljne linije starije od ostalih, iz njih se mnogo više vrsta imalo vremena razviti. Druga teorija, da su neke skupine urođeno bolje ili lošije u proizvodnji vrsta, također ne objašnjava razlike u broju vrsta među glavnim živućim linijama biljaka i životinja.
image (bank) This is an image file databank for most of our textbook related resources. Look for the image file name in the textbook piece below to see if a high res version exists. These graphic files are protected under the creative commons licence (click icon above). Please attribute the image to “The Science Creative Quarterly”, the URL (scq.ubc.ca), and the artist responsible. We would also appreciate positive word of mouth regarding this site, and would positively gush should you send submissions (directly or indirectly) our way. Note: that we will continually update these files over the summer. *depending on computer and browser used, downloading the file may cause the occurence of additional suffixes. In Alphabetical Order (Artist in Brackets) agrobacteria (Jane Wang/Illustrator)amyloidolddeposition (Jen Philpott/JPEG)amyloidoldimportance (Jen Philpott/JPEG)antibispread (Jen Philpott/GIF)antibiotrest (Jen Philpott/GIF)applications (Jiang Long/Illustrator) hybridbreeding (Jiang Long/Illustrator)
Antique Maps, Old maps, Vintage Maps, Antique Atlases, Old Atlases Rare and Precious Moments of Animal Life How interesting can animal life be is something which we can only guess. By looking these amazing photographs it seems that they have very funny and precious moments. Would you like to be monkey, or elephant, or maybe cat sometimes? A construção costeira portuguesa revela desmazelo ou corrupção? O fotógrafo Diogo Andrade percorreu toda a costa portuguesa, desde Caminha até Vila Real de Santo António, e trouxe consigo apenas os "postais feios". Construção sobre zonas protegidas ou de altura ilegal, indústria pesada instalada sobre os areais, vias de escoamento de resíduos a céu aberto, exemplos de planeamento urbanístico e paisagístico disfuncionais constam nas imagens do projecto que o fotógrafo ironicamente intitulou de "O Jardim". A Póvoa de Varzim, a Figueira da Foz e a Quarteira foram as cidades que, devido à elevada extensão e densidade habitacionais, o impressionaram mais negativamente.