stasis

From George Dvorsky at Gizmodo: Scientists working in Myanmar have uncovered a nearly 100-million-year-old baby snake encased in amber. Dating back to the Late Cretaceous, it’s the oldest known baby snake in the fossil record, and the first snake known to have lived in a forested environment. … The discovery of a baby snake fossilized in amber shows that early snakes had spread beyond swamps and sea shores, finding their way into forested environments. What’s more, these ancient snakes bore a startling resemblance to those living today—a classic case of evolution not having to fix something that ain’t broke. These findings were published today in Science Advances. More. “a classic case of evolution not having to fix something that ain’t Read More ›

From at ScienceDaily: The 240-million-year-old fossil, Megachirella wachtleri, is the most ancient ancestor of all modern lizards and snakes, known as squamates, the new study, published today in the journal Nature, shows. The fossil, along with data from both living and extinct reptiles — which involved anatomical data drawn from CT scans and DNA — suggests the origin of squamates is even older, taking place in the late Permian period, more than 250 million years ago. Tiago Simões, lead author and PhD student from the University of Alberta in Canada, said: “The specimen is 75 million years older than what we thought were the oldest fossil lizards in the entire world and provides valuable information for understanding the evolution of Read More ›

From David Klinghoffer at ENST: If you ever encounter a horseshoe crab on the beach, you are a looking at a creature that would not have appeared out of place hundreds of millions of years ago. Arthropods breathtakingly similar to this, says paleontologist Günter Bechly, go back “almost a half billion years without significant morphological change. And you really have to let this number sink in.” Some want to get rid of the category. At the Guardian, Mark Carnall says, Although the idea of living fossils flourished after Darwin introduces the idea, it was never formally defined and was used as a catch all for apparently any organism that has an interesting fossil record. In a paper on rates of Read More ›

From Laurel Hamers at Science News: Tiny light-scattering structures that give today’s butterflies and moths their brilliant hues date back to the days of the dinosaurs. Fossilized mothlike insects from the Jurassic Period bear textured scales on their forewings that could display iridescent colors, researchers report April 11 in Science Advances. The fossils are the earliest known examples of insects displaying structural color — that is, color produced by light bending around microscopic structures, rather than light being absorbed and reflected as with a pigment or a dye. Structural color is common in bird feathers and butterfly wings today, but finding such features in the fossil record can be tricky.More. Anyone want to bet against finding color displays meant to Read More ›

Earth’s history, our planet’s continents would have been devoid of all life except microbes. All of this changed with the origin of land plants from their pond scum relatives, greening the continents and creating habitats that animals would later invade. The timing of this episode has previously relied on the oldest fossil plants which are about 420 million years old. New research, published today in the journal Proceedings of the National Academy of Sciences, indicates that these events actually occurred a hundred million years earlier, changing perceptions of the evolution of the Earth’s biosphere. The researchers were using molecular clock technology. Co-lead author Mark Puttick described the team’s approach to produce the timescale. He said: “The fossil record is too Read More ›

From ScienceDaily: While it is largely believed that horses simply evolved with fewer digits, researchers pose a new theory that suggests remnants of all five toes are still present within the hooves of the horse. For the first time, as published in the January 24 issue of Royal Society Open Science, NYITCOM researcher, Nikos Solounias, Ph.D., paleontologist and anatomy professor, and a team of researchers propose that the reduction in the number of digits is not a matter of simple attrition; instead, they believe that all five digits have merged to form the compacted forelimbs with hooves that we know today. Currently, scientists accept that splints, small bones found along the outer sides of the metacarpal in modern horses, are Read More ›

From ScienceDaily: Paleontologists at the University of Toronto (U of T) and the Royal Ontario Museum (ROM) in Toronto have entirely revisited a tiny yet exceptionally fierce ancient sea creature called Habelia optata that has confounded scientists since it was first discovered more than a century ago. In those days, we had it all sewn up except for a few outliers. Then… The researchers argue that this difference in anatomy allowed Habelia to evolve an especially complex head that makes this fossil species even more peculiar compared to known chelicerates. The head of Habelia contained a series of five appendages made of a large plate with teeth for mastication, a leg-like branch with stiff bristle-like spines for grasping, and an Read More ›

From Lorna Siggins at the Irish Times: Though this species of brittle star (which are closely related to starfish) first developed nearly half a billion years ago, its modern day descendants are remarkably similar.  … According to Doyle, this brittle star is incredibly resilient — it was around during the Silurian period, when the first land plants evolved. More. Well, everything new is old again, right? And when we are talking about evolution, that matters. See also: “Confounding”: Moths and butterflies predate flowering plants by millions of years and Stasis: Life goes on but evolution does not happen

From ScienceDaily: They predate the Createous period, moths and butterflies existed earlier than the Cretaceous period, which began 145 million years ago. A team of scientists report on new evidence that primitive moths and butterflies existed during the Jurassic period, approximately 50 million years earlier than the first flowering plants, shedding new light on one of the most confounding cases of co-evolution. … The slides of rock samples drilled in the German countryside included some material that looked familiar to Strother, a Department of Earth and Environmental Sciences researcher at Boston College’s Weston Observatory, who studies the origin and early evolution of land plants. What he saw were features similar to those found in insect wings. The wrinkle was that Read More ›

Past time, really. From ScienceDaily: Maybe the ‘Boring Billion’ wasn’t so boring, after all The world’s oldest algae fossils are a billion years old, according to a new analysis by earth scientists at McGill University. Based on this finding, the researchers also estimate that the basis for photosynthesis in today’s plants was set in place 1.25 billion years ago. … The new findings also add to recent evidence that an interval of Earth’s history often referred to as the Boring Billion may not have been so boring, after all. From 1.8 to 0.8 billion years ago, archaea, bacteria and a handful of complex organisms that have since gone extinct milled about the planet’s oceans, with little biological or environmental change Read More ›

This is a complex and long-running dispute. From ScienceDaily: Commenting on the breakthrough research, Professor Pisani said: “The fact is, hypotheses about whether sponges or comb jellies came first suggest entirely different evolutionary histories for key animal organ systems like the nervous and the digestive systems. Therefore, knowing the correct branching order at the root of the animal tree is fundamental to understanding our own evolution, and the origin of key features of the animal anatomy.” In the new study, Professor Pisani and colleagues used cutting edge statistical techniques (Posterior Predictive Analyses) to test whether the evolutionary models routinely used in phylogenetics can adequately describe the genomic datasets used to study early animal evolution. They found that, for the same Read More ›

So do they think that we humans will evolve into separate species as a result of migration and founder effects? If not, what does “evolution” mean? From David Warmflash at the Genetic Literacy Project: The goblin shark, duck-billed platypus, lungfish, tadpole shrimp, cockroach, coelacanths and the horseshoe crab — these creatures are famous in the world of biology, because they look as though they stopped evolving long ago. To use a term introduced by Charles Darwin in 1859, they are “living fossils”. And to their ranks, some have added humans, based on the idea that technology and modern medicine has, for all intents and purposes, eliminated natural selection by allowing most infants to live to reproductive age and pass on their Read More ›

From Will Dunham at Reuters, Genetic data from the skeletal remains of seven people who lived centuries ago in South Africa’s KwaZulu-Natal Province is offering intriguing new evidence that our species, Homo sapiens, is older than previously believed. Scientists said on Thursday they sequenced the genomes of the seven individuals including a boy who lived as a hunter-gatherer at Ballito Bay roughly 2,000 years ago. In doing so, they were able to estimate that the evolutionary split between Homo sapiens and ancestral human groups occurred 260,000 to 350,000 years ago. Until recently, the prevailing belief was that Homo sapiens arose a bit before 200,000 years ago. The new study and fossil discoveries from Morocco announced in June indicate a much Read More ›

From ScienceDaily: Exceptionally preserved trilobite fossils from China, dating back to more than 500 million years ago, have revealed new insights into the extinct marine animal’s digestive system. Published today in the journal PLOS ONE, the new study shows that at least two trilobite species evolved a stomach structure 20 million years earlier than previously thought. “Trilobites are one of the first types of animals to show up in large numbers in the fossil record,” said lead author Melanie Hopkins, an assistant curator in the Division of Paleontology at the American Museum of Natural History. “Their exoskeletons were heavy in minerals, and so they preserved really well. But like all fossils, it’s very rare to see the preservation of soft Read More ›

From ScienceDaily: The fossils were discovered in sediment in the Corumbá region of western Brazil, near the border with Bolivia. The burrows measure from under 50 to 600 micrometres or microns (?m) in diameter, meaning the creatures that made them were similar in size to a human hair which can range from 40 to 300 microns in width. One micrometre is just one thousandth of a millimeter. Dr Russell Garwood, from Manchester’s School of Earth and Environmental Sciences, said: ‘This is an especially exciting find due to the age of the rocks — these fossils are found in rock layers which actually pre-date the oldest fossils of complex animals — at least that is what all current fossil records would Read More ›