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How did feathers evolve? - Carl Zimmer

How did feathers evolve? - Carl Zimmer
Dinosaurs are a diverse group of animals. They first appeared during the Triassic period, approximately 230 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the beginning of the Jurassic (about 201 million years ago) until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups at the close of the Mesozoic Era. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic Period and, consequently, they are considered a subgroup of dinosaurs by many paleontologists. Some birds survived the extinction event that occurred 66 million years ago, and their descendants continue the dinosaur lineage to the present day. Archaeopteryx (ar-kee-OP-ter-iks) is considered by most to be a true flying dinosaur. It has feathers, and only birds have feathers; therefore, Archaeopteryx is usually considered a bird.

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The game theory of life Original story reprinted with permission from Quanta magazine, an editorially independent division of SimonsFoundation.org, whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences. In what appears to be the first study of its kind, computer scientists report that an algorithm discovered more than 50 years ago in game theory and now widely used in machine learning is mathematically identical to the equations used to describe the distribution of genes within a population of organisms. Researchers may be able to use the algorithm, which is surprisingly simple and powerful, to better understand how natural selection works and how populations maintain their genetic diversity. By viewing evolution as a repeated game, in which individual players, in this case genes, try to find a strategy that creates the fittest population, researchers found that evolution values both diversity and fitness.

Five fingers of evolution - Paul Andersen In his talk, Paul Andersen explains the five causes of microevolution. Research one example for each cause in the human population. Use the following population simulator to simulate microevolution: Run the simulation using the default settings. Note the change in gene frequencies due to chance. Reset the simulation and increase the population size to 200.

100 Years of Breed “Improvement” For the sake of honest disclosure, I will admit to owning “purebreds” (the ‘pureness’ of purebreeds is a discussion for another time) but I also have mutts. All the dogs I’ve had since childhood had a few things in common, they were friendly, prey driven, ball-crazy, intense, motivated, athletic (crazy dogs are easier to train) and none had intentionally bred defects. I would never buy/adopt a dog whose breed characteristics exacted a health burden.

Meet Your Inner Fish—and a few other animals left inside you Neil Shubin's day job consists of two apparently unrelated tasks. He teaches anatomy to medical students at the University of Chicago, and he studies evolution by looking at fossils of ancient fish (he also runs a lab that experiments on modern ones). But the work he does while moonlighting as a popularizer of science neatly ties these two things together. The human anatomy has deep roots in the evolutionary past, and some of our key features date back to an odd-looking fish called Tiktaalik that Shubin found high in the Canadian Arctic. That find seems to have been what launched Shubin's career as a communicator.

Diseases - Manual - Activity 3, page 1 At a Glance Focus: Students investigate the growth of bacteria in the presence of antibiotics and use the results to explain a case of antibiotic-resistant tuberculosis, presented in an Internet-based interview. Major Concepts: The re-emergence of some diseases can be explained by evolution of the infectious agent (for example, mutations in bacterial genes that confer resistance to antibiotics used to treat the diseases). Objectives: After completing this activity, students will Male Chromosomes Are Not Dying Soon, Study Finds : News Update Date: Jan 11, 2014 05:31 PM EST A new study has challenged the notion that Y chromosomes are largely unimportant and will no longer exist in the next 5 million years. (Photo : Image Editor/Flickr)

Origin of organs: Thank viruses for your skin and bone - life - 27 February 2014 NEXT time you have a cold, rather than cursing, maybe you should thank the virus for making your skin. Genes borrowed from viruses seem to give cells the ability to grow into tissues and organs, and even reproduce sexually. Without these genes, animals could not have evolved beyond simple blobs of cells. Our cells often need to fuse with other cells, making big cells with multiple nuclei. They do this with the help of proteins on their outer surfaces that stick the cell's walls together and then break them open, so the insides can mix. This mixing is essential for the production of most organs – such as muscles, skin and bone – and even for reproduction, when eggs and sperm fuse.

Life Science Learning Goals Which skull is a lizard and which is a snake? During this session, you will have an opportunity to build understandings to help you: Bed bugs bite back thanks to evolution Resource library : Evo in the news : Bed bugs bite back thanks to evolutionSeptember 2010 Where's the evolution? What's to be done if you wind up the unhappy bunkmate to a nest of these pests? Rise of Animals: David Attenborough explores evolution of vertebrates The first episode of David Attenborough's two-part documentary, Rise of Animals: Triumph of the vertebrates, airs tonight at 9pm on BBC 2Sir David explores the origins of the backbone by studying a tiny prehistoric animal and a living fossil living in the south of EnglandThe documentary uses CGI animation to bring long-dead creatures to life such as the Tiktaalik and famous feathered dinosaur It sees Sir David filming for the first time in China, where he sees the fossils that are changing the face of palaeontology By Sarah Griffiths Published: 11:16 GMT, 20 September 2013 | Updated: 12:49 GMT, 20 September 2013 David Attenborough has visited new paleontological hotspots to fill in evolutionary gaps of how vertebrates came to rule the Earth and how their evolution defines our own human bodies.

Transitional forms Transitional forms Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants are referred to as transitional forms. There are numerous examples of transitional forms in the fossil record, providing an abundance of evidence for change over time. Pakicetus (below left), is described as an early ancestor to modern whales. Although pakicetids were land mammals, it is clear that they are related to whales and dolphins based on a number of specializations of the ear, relating to hearing.

Epigenetic Feedback Regulation Accelerates Adaptation and Evolution A simple cell model consisting of a gene regulatory network with epigenetic feedback regulation is studied to evaluate the effect of epigenetic dynamics on adaptation and evolution. We find that, the type of epigenetic dynamics considered enables a cell to adapt to unfamiliar environmental changes, for which no regulatory program has been prepared, through noise-driven selection of a cellular state with a high growth rate. Furthermore, we demonstrate that the inclusion of epigenetic regulation promotes evolutionary development of a regulatory network that can respond to environmental changes in a fast and precise manner. These results strongly suggest that epigenetic feedback regulation in gene expression dynamics provides a significant increase in fitness by engendering an increase in cellular plasticity during adaptation and evolution. Figures Citation: Furusawa C, Kaneko K (2013) Epigenetic Feedback Regulation Accelerates Adaptation and Evolution.

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