Cambrian explosion

From Jasmin Fox Skelly at New Scientist: A 520-million-year-old fossil shows an ancient shrimp-like creature caring for its four offspring. It is the oldest ever example of a parent actively looking after its young after they hatch. More. (paywall) The arthropod may be the ancestor of insects and spiders (or maybe not). We have one “snapshot” and that’s from billions of lives. What it mainly shows is that, contrary to what we might expect, there seems to have been little evolution of animal psychology since then. See also: The cancer theory of the Cambrian explosion of life 541 million years ago

No really. From Evolution News: You thought you’d heard it all? All the desperate materialist theories seeking to explain the burst of biological novelty some 530 million years ago that Meyer writes about in Darwin’s Doubt? You were wrong. Along comes Lund University in Sweden with a “Novel hypothesis on why animals diversified on Earth.” Get ready for the cancer theory of the Cambrian explosion. Can tumors teach us about animal evolution on Earth? Researchers believe so and now present a novel hypothesis of why animal diversity increased dramatically on Earth about half a billion years ago. A biological innovation may have been key. [Emphasis added.] Not many of us who have seen friends suffer or die from cancer would Read More ›

From ScienceDaily: Researchers at the Royal Ontario Museum and the University of Toronto have described an exceptionally well-preserved new fossil species of bristle worm called Kootenayscolex barbarensis. Discovered from the 508-million-year-old Marble Canyon fossil site in the Burgess Shale in Kootenay National Park, British Columbia, the new species helps rewrite our understanding of the origin of the head in annelids, a highly diverse group of animals which includes today’s leeches and earthworms. This research was published today in the journal Current Biology in the article “A New Burgess Shale Polychaete and the Origin of the Annelid Head Revisited.” … One key feature of the new Burgess Shale worm Kootenayscolex barbarensis is the presence of hair-sized bristles called chaetae on the Read More ›

From ScienceDaily: A team of palaeontologists from Uppsala (Ben Slater, Sebastian Willman, Graham Budd and John Peel) used a low-manipulation acid extraction procedure to dissolve some of these less intensively cooked mudrocks. To their astonishment, this simple preparation technique revealed a wealth of previously unknown microscopic animal fossils preserved in spectacular detail. Most of the fossils were less than a millimetre long and had to be studied under the microscope. Fossils at the nearby Sirius Passet site typically preserve much larger animals, so the new finds fill an important gap in our knowledge of the small-scale animals that probably made up the majority of these ecosystems. Among the discoveries were the tiny spines and teeth of priapulid worms — small Read More ›

From Annalee Newitz at Ars Technica: The Cambrian Explosion gets a lot of play because it was the first time multicellular creatures ruled the planet. What few people (other than geologists and paleontologists) realize is that there was an even crazier time for early life. It came during the Ordovician period, right after the Cambrian came to a close 485 million years ago. The Ordovician Radiation, also called the Great Ordovician Biodiversification Event (GOBE), saw a quadrupling of diversity at the genus level (that’s the category one step above species). Life also started occupying new ecological niches, clinging to plants floating in the ocean’s water column and burrowing deep into the seabed. More. All life, so far as is known, Read More ›

From ScienceDaily: Oxygen has provided a breath of fresh air to the study of the Earth’s evolution some 400-plus million years ago. A team of researchers, including a faculty member and postdoctoral fellow from Washington University in St. Louis, found that oxygen levels appear to increase at about the same time as a three-fold increase in biodiversity during the Ordovician Period, between 445 and 485 million years ago, according to a study published Nov. 20 in Nature Geoscience. … This explosion of diversity, recognized as the Great Ordovician Biodiversification Event, brought about the rise of various marine life, tremendous change across species families and types, as well as changes to the Earth, starting at the bottom of the ocean floors. Read More ›

A tulip-shaped feeder. From ScienceDaily: “This was the earliest specimen of a stalked filter feeder that has been found in North America,” said lead author Julien Kimmig, collections manager for Invertebrate Paleontology at the Biodiversity Institute. “This animal lived in soft sediment and anchored into the sediment. The upper part of the tulip was the organism itself. It had a stem attached to the ground and an upper part, called the calyx, that had everything from the digestive tract to the feeding mechanism. It was fairly primitive and weird.” … “The Spence Shale gives us soft-tissue preservation, so we get a much more complete biota in these environments,” he said. “This gives us a better idea of what the early Read More ›

Because it’s stuffed with unexamined evidence. From Christopher Kemp at New Scientist: As he read the beetle’s yellowed, handwritten label, he realised the specimen had been collected in 1832 in Argentina by Charles Darwin during the voyage of the Beagle. Somehow it had never been described. It was stored away unnamed, then disappeared into the museum’s vast beetle collection. Finally, after 180 years in limbo, Chatzimanolis gave it a name: Darwinilus sedarisi, in honour of Darwin and the writer David Sedaris, whose audiobooks he listened to while writing the description in his office at the University of Tennessee. Yes, this reads like a novel (film option?) but it isn’t. The rediscovery of Darwin’s long-lost beetle was a remarkable stroke of Read More ›

Maybe Darwin and Steve Meyer aren’t the only ones who claim the right to honest doubt. Amazon Best Sellers Rank: #25,107 in Books (See Top 100 in Books) #6 in Books > Science & Math > Evolution > Organic #6 in Books > Science & Math > Biological Sciences > Paleontology #8 in Books > Christian Books & Bibles > Theology > Creationism

. . . here (at 194) in his amazing engineering thread as he responds to Dionisio: >>Dionisio: Thank you for summarizing that interesting discussion. I will summarize it even more. 1) Nobody knows how morphogenesis is controlled and guided. 2) Moran is no exception to that. 3) “Experts” are no exception to that. 4) However, according to Moran (and, unfortunately, he is probably quite right): “experts do not see a need to encode body plans and brain in our genome” 5) You and I, and probably some more sensible people, do see that need. 6) So, it seems, the problem is not about what we know, but about what we see as a need. Now, I notice that Moran says: Read More ›

And considered “remarkable” for exploring a specialized niche so early in their evolution. From ScienceDaily: Loriciferans are a group of miniscule animals, always less than a millimetre long, which live among grains of sediment on the seabed. They are easy to overlook: the first examples were described from modern environments as recently as the 1980s. Dr Harvey added: “As well as being very small, loriciferans lack hard parts (they have no shell), so no-one expected them ever to be found as fossils — but here they are! The fossils represent a new genus and species, which we name Eolorica deadwoodensis, loosely meaning the “ancient corset-animal from rocks of the Deadwood Formation.” “It’s remarkable that so early in their evolution, animals Read More ›

In Greenland. From Tia Ghose at LiveScience: The species, dubbed Tamisiocaris borealis, used large, bristly appendages on its body to rake in tiny shrimplike creatures from the sea, and likely evolved from the top predators of the day to take advantage of a bloom in new foods in its ecosystem, said study co-author Jakob Vinther, a paleobiologist at the University of Bristol in England. More. This is tremendous, but let’s all revise our expectations about “gigantic”: These ancient sea monsters grew to about 70 centimeters (2.7 feet) long and “looked like something completely out of this planet,” with massive frontal appendages for grasping prey, huge eyes on stalks, and a mouth shaped like a piece of canned pineapple, Vinther told Read More ›

From ScienceDirect: Life was limited for most of Earth’s history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life? Early life was dominated by Archaea and Bacteria, which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with Read More ›

Seems like a bold claim re this 520 mya fossil, from Rasmus Kragh Jakobsen at ScienceNordic: A new study has described the mouth apparatus of a half billion year old fossilised carnivore, the Pambdelurion, in fine detail for the first time. In doing so, scientists have discovered that this primitive animal, discovered in Sirius Passet in Greenland, is the common ancestor of all living arthropod animals today. Arthropods make up 90 per cent of all living animals and include insects, scorpions, mites, and crustaceans. … In the new study, Vinther and colleagues describe Pambdelurion’s mouth apparatus as a circle of needle sharp parts arranged around a central hole, which is similar to that of the present-day penis worm. More. We Read More ›

It was multicellular, not unicellular, a predicted. From Nature News: A mysterious deep-ocean seaweed diverged from the rest of the green-plant family around 540 million years ago, developing a large body with a complex structure independently from all other sea or land plants. All of the seaweed’s close relatives are unicellular plankton. The finding, published today in Scientific Reports, upends conventional wisdom about the early evolution of the plant kingdom. “People have always assumed that within the green-plant lineage, all the early branches were unicellular,” says Frederik Leliaert, an evolutionary biologist at Ghent University in Belgium. “It is quite surprising that among those, a macroscopic seaweed pops up.” … “We still need to do a lot more sampling of those Read More ›