An evolutionary burst 540 million years ago filled the seas with an astonishing diversity of animals. The trigger behind that revolution is finally coming into focus , according to the journal Nature. [more inside]
“Finding the head is the main scientific result. There’s been lingering controversy about this.” - A new reconstruction of hallucigenia sparsa answers questions about the shape and orientation of the animal, something that was previously so mysterious that scientists in the 70s had it upside down.
The results of the Cambrian explosion are well documented in the fossil record, but its cause -- why and when it happened, and perhaps why nothing similar has happened since -- has been a mystery. Now a recent paper in Nature (abstract) suggests that the answer may lie in a second geological curiosity -- a dramatic boundary, known as the Great Unconformity, between ancient igneous and metamorphic rocks and younger sediments.
The cosmos is also within us, we're made of star-stuff. We are a way for the cosmos, to know itself.
Cosmos: A Personal Voyage is a thirteen-part television series of one hour shows written by Carl Sagan, Ann Druyan, and Steven Soter, that was aired at the tail end of 1980 and was - at the time - the most widely watched series in the history of American public television. It is best introduced by an audio excerpt of one of his books, The Pale Blue Dot. Inside is a complete annotated collection of the series. [more inside]
Art is seven years old and really likes life before the dinosaurs. And he thinks arthropods are really cool.
This is a subject of but small importance; and I know not whether it will interest any readers, but it has interested me.
"This is a subject of but small importance; and I know not whether it will interest any readers, but it has interested me."-C. D. Quick... what was Darwin's most popular book? If you answered The Origin of Species, you were wrong. It was his last book, published the year before he died, The Formation of Vegetable Mould Through the Action of Worms With Observation of Their Habits (illustrations [first presented 1 Nov. 1837, as noted in the record of the Royal Geological Society]). Darwin noted when he was beginning his career that worms churned up soil, causing heavier objects to sink slowly in the soil. He noted that all soil had passed through the alimentary duct of worms. It started off a fashion of cultivating worms by gardeners that continues to the present day. -We recently learned that we owe an element of our unique cerebral cortex, or pallium to our marine worm ancestors. (In amphibians, the cerebrum includes archipallium, paleopallium and some of the basal nuclei. Reptiles first developed a neopallium, which continued to develop in the brains of more recent species to become the neocortex of mammals." [&, ultimately, you and you and we]) [more inside]
"We were looking for pretty animals that have eyes, are coloured, or glow in the dark; instead, the most interesting find was the organism that was blind, brainless, and completely covered in mud." Some of the oldest fossil records may need to be reconsidered: Dr. Mikhail Matz of the University of Texas has discovered Gromia Sphaerica, a species of protist, making tracks.... [more inside]