stasis

Interesting, because 300 million years ago, harvestmen (like spiders) were much the same as today. Said one researcher, “It is absolutely remarkable how little harvestmen have changed in appearance since before the dinosaurs.” Yet changes do happen. From ScienceDaily: Called after Tolkien’s character from the “Lord of the Rings” series, a new eyeless harvestman species was found to crawl in a humid cave in southeastern Brazil. Never getting out of its subterranean home, the new daddy longlegs species is the most highly modified representative among its close relatives and only the second one with no eyes living in Brazil. While there are cave dwellers that can easily survive above the ground and even regularly go out in order to feed Read More ›

From National Geographic: Which Animals Have Barely Evolved? That said, two mammals that have undergone the fewest evolutionary shifts are the platypus and the opossum, says Samantha Hopkins, associate professor of geology at the University of Oregon. You could say the platypus is a survivor: It’s one of the few living descendants of an ancestor that diverged from all the other mammals about 150 million years ago, Hopkins says. The platypus has “a number of primitive features,” Ibrahim says, “both from what we know from fossils and from what we can see in their [modern-day] anatomy.” More. What does “primitive” mean in the context? Maybe we should call it a “durable species”? Oh, and the opossum, A 2009 study published Read More ›

From the University of Edinburgh: Until now, the oldest evidence of complex animals – which succeeded more primitive creatures that often resembled sponges or coral – came from the Cambrian Period, which began around 541 million years ago. Scientists had long suspected that complex animals had existed before then but, until now, they had no proof. … Genetic family tree data suggested that complex animals – known as bilaterians – evolved prior to the Cambrian Period. The finding suggests that bilaterians may have lived as early as 550 million years ago, during the late Ediacaran Period. … The team studied fossils of an extinct marine animal – known as Namacalathus hermanastes – which was widespread during the Ediacaran Period. The Read More ›

Some have. And they are said to “turn paleontology on its head.” F. protensa is 520 mya or so. (They had brains back then?) From Eurekalert: Science has long dictated that brains don’t fossilize, so when Nicholas Strausfeld co-authored the first ever report of a fossilized brain in a 2012 edition of Nature, it was met with “a lot of flack.” … His latest paper in Current Biology addresses these doubts head-on, with definitive evidence that, indeed, brains do fossilize. … The only way to become fossilized is, first, to get rapidly buried. Hungry scavengers can’t eat a carcass if it’s buried, and as long as the water is anoxic enough – that is, lacking in oxygen – a buried Read More ›

From ScienceDaily: A team from USC found the Eotiaris guadalupensis in the collections of the Smithsonian Institution from the Glass Mountains of west Texas, where it had been buried in a rock formation that dates back to 268.8 million years at its youngest.”This fossil pushes the evolution of this type of sea urchin from the Wuchiapingian age all the way back to the Roadian age,” said David Bottjer, professor at the USC Dornsife College of Letters, Arts and Sciences, and senior author of a paper announcing the find that appeared in Nature Scientific Reports on October 21. … Eotiaris guadalupensis is a cidaroid, one of the two main types of sea urchins found in today’s oceans. The other group, the Read More ›

From ScienceDaily: “We now know what the plumage looked like on the tail, and that from the mid-femur down, it had bare skin,” says Aaron van der Reest. This is the first report of such preserved skin forming a web from the femoral shaft to the abdomen, never before seen in non-avian dinosaurs. “Ostriches use bare skin to thermoregulate. Because the plumage on this specimen is virtually identical to that of an ostrich, we can infer that Ornithomimus was likely doing the same thing, using feathered regions on their body to maintain body temperature. It would’ve looked a lot like an ostrich.” In fact, this group of animals–referred to as ornithomimids–is commonly referred to as “ostrich mimics.” The find is Read More ›

Recently, a reader wrote to me concerning Stasis: Life goes on but evolution does not happen. Reader asked, Concerning horseshoe crabs and coelecanths, could it be possible that marine-environment organisms are under less pressure to change/evolve than terrestrial organisms? I replied, — Thank you very much for your thoughts! You could of course be correct. And then we face several conceptual tasks prior to research: 1. Specifying testable hypotheses as to why the longest-conserved marine life forms were under less pressure to change/evolve. We must not fall into the trap of assuming that they must be under less pressure because they didn’t evolve. We don’t know for sure that pressure has much to do with it. That is, we assume Read More ›

From the Guardian: Prehistoric rat-like mammal fossil is earliest showing fur, skin and organs The remains, unearthed in a quarry near Cuenca in central Spain, are more than 60m years older than other fossils that record the soft tissues of prehistoric mammals. The animal’s ear lobe, lung and liver are all fossilised, along with its furry pelt and tiny hedgehog-like spines on its lower back that likely protected it from predators. Researchers even found evidence of a fungal skin infection in the remains. Named Spinolestes xenarthrosus, the insect-eating furball was discovered in 2011 when fossil hunters at the Autonomous University of Madrid, were prising apart thin leaves of fine limestone sediment in the Las Hoyas Quarry. “The preservation of its Read More ›

If we go by the fact that they survive tens or hundreds of millions of years pretty much unchanged: That wasn’t what Darwin told us to expect. Darwin explained clearly and eloquently the pattern we should find in the fossil record if his theory was correct, let alone the juggernaut that his present day supporters insist: It may be said that natural selection is daily and hourly scrutinizing, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, wherever and whenever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life. However, it hasn’t turned out Read More ›

From ScienceDaily: Bacteria in ancient flea may be ancestor of the Black Death About 20 million years ago a single flea became entombed in amber with tiny bacteria attached to it, providing what researchers believe may be the oldest evidence on Earth of a dreaded and historic killer — an ancient strain of the bubonic plague. If indeed the fossil bacteria are related to plague bacteria, Yersinia pestis, the discovery would show that this scourge, which killed more than half the population of Europe in the 14th century, actually had been around for millions of years before that, traveled around much of the world, and predates the human race. Talk about stasis. One wonders what it was doing in the Read More ›

From Eurekalert: Giant ‘sea scorpion’ fossil discovered The fossil of a previously unknown species of ‘sea scorpion’, measuring over 1.5 meters long, has been discovered in Iowa, USA, and described in the open access journal BMC Evolutionary Biology. Dating back 460 million years, it is the oldest known species of eurypterid (sea scorpion) – extinct monster-like predators that swam the seas in ancient times and are related to modern arachnids. Lead author, James Lamsdell from Yale University, USA, said: “The new species is incredibly bizarre. The shape of the paddle – the leg which it would use to swim – is unique, as is the shape of the head. It’s also big – over a meter and a half long!” Read More ›

From ScienceDaily: More than 20 million years ago, a short struggle took place in what is now the Dominican Republic, resulting in one animal getting its leg bitten off by a predator just before it escaped. But in the confusion, it fell into a gooey resin deposit, to be fossilized and entombed forever in amber. The fossil record of that event has revealed something not known before — that salamanders once lived on an island in the Caribbean Sea. Today, they are nowhere to be found in the entire Caribbean area. … “There are very few salamander fossils of any type, and no one has ever found a salamander preserved in amber,” Poinar said. “And finding it in Dominican amber Read More ›

Montsechia/Oscard Sanisidro From Indiana University, Indiana University paleobotanist David Dilcher and colleagues in Europe have identified a 125 million- to 130 million-year-old freshwater plant as one of earliest flowering plants on Earth. The finding, reported today in the Proceedings of the National Academy of Sciences, represents a major change in the presumed form of one of the planet’s earliest flowers, known as angiosperms. “This discovery raises significant questions about the early evolutionary history of flowering plants, as well as the role of these plants in the evolution of other plant and animal life,” said Dilcher, an emeritus professor in the IU Bloomington College of Arts and Sciences’ Department of Geological Sciences. … “Montsechia possesses no obvious ‘flower parts,’ such as Read More ›

Shouldn’t we be used to this “no change in 20 million years” stuff by now? Here: A community of lizards from the Caribbean, preserved for 20 million years in amber, have been found to be identical to their modern cousins, say researchers. … “Most of ours had full skeletons, and details of the skin were impressed on the amber, providing very detailed images of tiny scales on the body and on the sticky toe pads,” she adds. More. What if we just changed our default assumption? Change doesn’t usually or randomly happen. Most of the time it doesn’t happen at all. And when it does happen, Darwinblather doesn’t explain it. Who knows, a science could come out of all this. Read More ›

Butt heads like deer? Further to Oldest animal sperm to date, from ScienceDaily: “It is incredible to think that features found in deer such as the water deer, musk deer and muntjacs today were already represented 270 million years ago,” says Cisneros. The researchers found the Tiarajudens’ marginal teeth are also located in a bone from the palate called epipterygoid. “This is an extraordinary condition as no other animal in the lineage leading to mammals show marginal dentition in a bone from the palate,” says Abdala. In another group of mammal fossil relatives, dinocephalians — that lived at the same time as anomodonts, some of the bones in their foreheads were massively thickened. This can be interpreted as being used Read More ›