Home » Evolution (Page 7)

  • Harvest of the Seasons – Jacob Bronowski (1973)

    Harvest of the Seasons – Jacob Bronowski (1973)

    Harvest of the Seasons is the second episode of a thirteen-part documentary series called The Ascent of Man written and presented by Jacob Bronowski. The series reached wide audiences for Bronowski’s highly intellectual but simple and convincing analysis. Much of his long monologues were unscripted and were a source of inspiration for creating a template for Carl Sagan’s hugely sucessful Cosmos series. The motto used by Bronowski “A personal view” became “A personal voyage” in Sagan’s. The episode provides an […]

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  • Is Picture Wing Fly a Predatory Jumping Spider Mimic?

    Is Picture Wing Fly a Predatory Jumping Spider Mimic?

    The video of this picture wing fly (Delphinia picta) was recorded on April 24th 2011 in Athens, GA. It has a curious wing pattern which resembles a jumping spider but is it really? Mimicry is a type of species interaction that evolves in response to prey, predators and parasites. Examples of mimicry is abundant in nature and provide compelling cases for natural selection. A classic example is Heliconius butterflies living in tropical America. Some Heliconius species show Batesian mimicry. Wing […]

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  • A Tour of a Section of Human Chromosome 11

    A Tour of a Section of Human Chromosome 11

    This video produced by Cold Spring Harbor Laboratories takes us on a tour of about 650,000 nucleotides from the tip of the short arm of human chromosome 11. From a distance we can discern 28 genes, denoted by red and yellow blocks. The red exons carry the DNA code for protein, while the yellow introns are noncoding. Also prominent are more than 500 transposons, or jumping genes, denoted by blue and purple blocks. If we zoom in, we can take […]

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  • Nice Guys Finish First – Richard Dawkins (1987)

    Nice Guys Finish First – Richard Dawkins (1987)

    In this BBC documentary Richard Dawkins explores the evolution of cooperation. The problem has been discussed intensely since Darwin’s time and is still being investigated scientifically. Cooperative species are quite successful but rare. Social insects (ants, wasps, bees and termites) make up only 3 percent of animal diversity yet they may constitute up to 50 percent of the total animal biomass in land habitats. Among 43,678 known species of spiders cooperative behavior evolved in only a few. How could a […]

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  • An Illustrated Introduction to Natural Selection & Sexual Selection – Cornell Lab of Ornithology (2013)

    An Illustrated Introduction to Natural Selection & Sexual Selection – Cornell Lab of Ornithology (2013)

    Cornell Bird Lab produced a series of quite informative teaching materials to provide scientific explanation for how new species have evolved (and are evolving). Evolution is not only a struggle for existence, it is also an effort to pass on genes to next generation. Modern biology has described mechanisms of evolution with fine details and this video effectively tells how natural selection works with three cartoonified traits in an island setting at the first few minutes. In many animals females […]

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  • Revealing the Origins of Life – PBS (2011)

    Revealing the Origins of Life – PBS (2011)

    How life began is a very fundamental question. This short documentary is an outstanding primer for scientific explanation of the origin of life. Featuring Nobel prize winner Jack Szostack of Harvard University and John Sutherland of University of Manchester, it explains the chemical evolution leading to the formation of RNA. Scientists all agree that formation of basic building blocks of life is suprisingly very easy. The burning question is how do they react to form complex molecules? RNA world hypothesis […]

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  • Hummingbirds: Magic in the Air – PBS (2010)

    Hummingbirds: Magic in the Air – PBS (2010)

    Hummingbirds. Today they are strictly found on American continent but there are hummingbird-like fossil specimens from Germany hinting that this group might have been more widespread in its evolutionary past. More than 8000 species of plants have evolved to get their pollination services from hummingbirds. In 2013 a 50 million year old fossil showed the earliest ancestor of hummingbirds. With a heart beating at 600 beats per minute hummingbirds are champions of survival. The PBS documentary explores a rich repertoire […]

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  • Carolina Cranesbill (Geranium carolinianum) Flower Self-pollination

    Carolina Cranesbill (Geranium carolinianum) Flower Self-pollination

    Dr. Rebecca Shirk has studied genetic diversity and adaptation in native and invasive populations of Carolina cranesbill (Geranium carolinianum) during her PhD project in Department of Plant Biology at the University of Georgia in Athens. Flowers of this genus has a quite diverse pollination strategy. Flowers come in a staggering diversity of forms. There are huge flowers; tiny flowers; flowers that never open; flowers with patterns that can’t be seen by the human eye; and extremely specialized flowers that are […]

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  • One Voice in the Cosmic Fugue – Carl Sagan (1980)

    One Voice in the Cosmic Fugue – Carl Sagan (1980)

    The Cosmos, is a thirteen part documentary produced written and presented by Carl Sagan aiming to expand public understanding of science. It is one of the most successful series and is perhaps the best one for telling the fascinating history of science reaching audiences in 60 countries since it has been aired. It inspired generations to become scientists from all over the world. It was written with such poetic vigor that in title of every episode there is an attractive […]

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  • Kozmik Bestede Bir Nota – Carl Sagan (1980)

    Kozmik Bestede Bir Nota – Carl Sagan (1980)

    Carl Sagan 1980’li yıllarda televizyonu olan pek çok evin salonuna misafir olmuş Amerika’lı bir astronomdur. Onüç bölümden oluşan Kozmoz dizisi 6.3 milyon dolarlık bir bütçe ile hazırlanarak 60’dan fazla ülke televizyonunda yayınlandı. Gelmiş geçmiş en başarılı bilim belgeselinin tarzı öylesine şiirseldir ki, bölümlerin başlıkları bile işlenen konuyu kavramada yardımcı derin benzetmeler içeren özenle seçilmiş kelimelerden oluşur. Carl Sagan, “kişisel bir yolculuk” olarak nitelediği eserinde bizleri yolculuğuna yoldaş eder. Bilim tarihinde nefes kesici bir gezintiye çıkarız birlikte. Dizi içinde bir biyolog […]

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  • Sinister Cannibals or Nurturing Fathers?

    Sinister Cannibals or Nurturing Fathers?

    In majority of sexually reproducing species females are the choosy ones. Generally, females invest more in offspring during pregnancy and post-natal care. Males try many tricks (fighting with other males, making elaborate dances, providing nuptial gifts, carrying showy and difficult to maintain body ornaments etc.) to prevent being filtered out in female preferences. Parental investment is a determinant in choosiness. In this post we will take a look at a spectrum of male behavior in parental care. Pipefishes and mudskippers […]

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  • After Death: Fossil Carrion Beetles

    After Death: Fossil Carrion Beetles

    Until very recently the oldest known carrion beetle fossils were 50 million years old. The fossil discoveries coming from Daohugou and Jehol rock deposits in Northeastern China extended our knowledge further back till 160 million years ago. During Jurassic period dinosaur abundance had a cascading influence on animal world. When a dinosaur died its carcass became a protein rich multi-generational feeding island. Insects including carrion beetles most certainly exploited this opportunity. Therefore carrion beetle evolution took a new turn leading […]

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  • What is A Species? Christina Choate (2011)

    What is A Species? Christina Choate (2011)

    How did diversity of life on our planet form? How does it maintain itself? Species concept is most certainly a very convenient construct for biologists who are trying to understand life. Rightly so, Charles R. Darwin titled his masterpiece as On the Origin of Species for the concept was crucial in developing a theory that is central to biology. The species argument is quite parallel to that of transitional fossils. Both terms are plastic and represent data points along a […]

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  • When and Why We Lost Hair?

    When and Why We Lost Hair?

    When and why our ancestors began to wear clothing is a curious story. Clothing may have emerged for insulation of body heat. Similarly it also have provided a means to carry things and improve mobility. Cold snaps engulfed the earth many times. Using ice cores from Antarctica scientists identified 8 glacial cycles within the last 800 thousand years alone. An archaelogical site from Israel provides the earliest evidence of controlled fire by humans spanning the same time period. We know […]

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  • The Botany of Desire – Michael Pollan – PBS (2009)

    The Botany of Desire – Michael Pollan – PBS (2009)

    Domestication is a defining feature of recent human evolution. In animals first trait selected by humans was behavior. In plants harvestability through selection of non-shattering seeds was the first trait of domestication. Plant domestication paved the way to agriculture which enabled highly specialized sedentary human societies. Domesticated plants differ from their wild ancestors in distinct ways that can be categorized under a term called as the domestication syndrome. Domestication syndrome includes reduced shattering of seeds (seeds don’t separate from the […]

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