stasis

In “Yukon fossils reveal oldest armoured organism” (CBC News, Jun 13, 2011), we learn, … 800 million-year-old fossilized evidence that organisms were trying to protect themselves by forming their own shield-like plates.It is the oldest evidence ever of biomineralization, the use of minerals by a living thing to form a hard shell, similar to the way clams or lobsters form their own protection. The tiny fossils date back between 717 and 812 million years. [ … ] Until now the oldest evidence from similar organisms biomineralizing was found in Africa and dates back to about 550 million years ago, Cohen said. The fossils are microscopic, of course. Do they raise questions one doesn’t ask nowadays? See also “Spider in amber Read More ›

Which shows how number sense evolved? Forget them. In “Geometry skills are innate, Amazon tribe study suggests,” (BBC News , 24 May 2011), Jason Palmer reports ,

Tests given to an Amazonian tribe called the Mundurucu suggest that our intuitions about geometry are innate.Researchers examined how the Mundurucu think about lines, points and angles, comparing the results with equivalent tests on French and US schoolchildren.

The Mundurucu showed comparable understanding, and even outperformed the students on tasks that asked about forms on spherical surfaces.

It got better: Read More ›

At MSNBC (5/25/20), Charles Q. Choi tells us “Bizarre shrimp-like predators grew larger and survived longer than thought”:

The creatures, known as anomalocaridids, were giant predators (ranging from 2 to possibly 6 feet in length) with soft-jointed bodies and toothy maws with spiny limbs in front to snag worms and other prey.

[ … ]

Past research showed they dominated the seas during the early and middle Cambrian period 542 million to 501 million years ago, a span of time known for the “Cambrian Explosion” that saw the appearance of all the major animal groups and the establishment of complex ecosystems. Read More ›

In “Birch Mouse Ancestor Discovered in Inner Mongolia Is New Species of Rare ‘Living Fossil’”, we learn that tiny fossil teeth (ScienceDaily May 25, 2011)” found in Inner Mongolia are “a new species of birch mouse, indicating that ancestors of the small rodent are much older than previously reported”:17 million years old as opposed to the previous estimate of eight. Kimura identified Sicista primus from 17 tiny teeth, whose size makes them difficult to find. A single molar is about the size of half a grain of rice. The teeth, however, are distinctive among the various genera of rodents known as Dipodidae. Cusps, valleys, ridges and other distinguishing characteristics on the surface of the teeth are identifiable through a microscope. “We are Read More ›

Further to “Recent Uncommon Descent posts reveal starkly different standards of evidence out there” (Uncommon Descent, 18 May 2011), this ScienceDaily story (May 18, 2011) about a trapped spider is instructive:

Imaging Technology Reveals Intricate Details of 49-Million-Year-Old SpiderScientists have used the latest computer-imaging technology to produce stunning three-dimensional pictures of a 49 million-year-old spider trapped inside an opaque piece of fossilized amber resin.

Writing in the international journal Naturwissenschaften, the scientists showed that the amber fossil — housed in the Berlin Natural History Museum — is a member of a living genus of the Huntsman spiders (Sparassidae), a group of often large, active, free-living spiders that are hardly ever trapped in amber.

The amber had grown dark so until they tried X-ray computed tomography, they couldn’t get a good image, but then, especially through a short film revealing astounding details, the scientists showed that even specimens in historical pieces of amber, which at first look very bad, can yield vital data when studied by computed tomography.

So we know it can’t be a huntsman spider because they “hardly ever” get trapped in amber: Read More ›

This blast from the past is still a source of ruinous commercial fish losses. Because lampreys do not have bone or any substantial cartilage, they are extremely rare as fossils. This fossil not only reveals a nearly complete soft tissue impression, but it also pushes back their fossil record another 35 million years. File under: Someone contact the guy who says “Evolution must happen.

This point is apparently made in Cameron M. Smith’s The Fact of Evolution: Walking the reader through the steps in the evolutionary process, Cameron uses plenty of real-world examples to show that not only does evolution happen, it must happen. Cameron analyzes evolution as the unintended consequence of three independent facts of the natural world that we can observe every day: (1) the fact of the replication of life forms (producing offspring); (2) the fact that offspring are not identical (variation); and (3) the fact that not all offspring survive (selection). Viewed in terms of this analysis, evolution is no longer debatable; in fact it has to occur. It is simply the inevitable consequence of three obvious, observable, factual natural Read More ›

From ScienceDaily (May 5, 2011),we learn more about “if it ain’t broke, don’t …” Horsetail grass decidedly ain’t broke: “Horsetail Plant Developed Successful Set of Tools for Extreme Environments – For Millions of Years” The authors discovered that in many ways the morphology and anatomy of this fossilized Equisetum is indistinguishable from those of species living today in two subgenera, Equisetum and Hippochaete. For example, it was evergreen, grew upright in a single straight stem, and had a double endodermis. Yet, there were some features that did not fit with any extant or fossil species of Equisetum — thus justifying the erection of a new species: Equisetum thermale.”Equisetum thermale appears to be the oldest record of the genus Equisetum and Read More ›

In “A golden orb-weaver spider from the Middle Jurassic” (4/21/11), David Tyler at manchester U comments on a recent find:

The golden orb-weaver spider features in newly reported research and provides an exciting insight into past ecosystems. Today, these animals adorn tropical rainforests, with giant females of Nephila maculate (legs spanning up to 20 cm), and small males (just a few centimetres across). However, the fossil record of the Nephilidae family is meagre. The earliest example of the genus Nephila comes from the Eocene (considered to be about 34 Ma) and the earliest example of the family Nephilidae is a male from the Cretaceous (considered to be 130 Ma). The newly reported fossil golden orb-weaver spider is a giant female with a leg span of about 15 cm.

and observes

So this particular living fossil exhibits stasis at the genus level and raises again the issue of what can be learned from the phenomenon of stasis. A previous blog expressed some frustration at Neodarwinian evolutionists who file stasis in a box that says: no environmental change, no selection pressures, no evolution. The problem with Read More ›

Following up his comments on the stunning half billion years of changelessness (stasis) demonstrated by the pterobranch, David Tyler now addresses the unchanging cricket, one of whose fossils was found from 100 million years ago: He comments on howthe fact that many life forms seem motionless in time is handled in the science literature: It is of interest to note how living fossils are described. Sometimes, they are “some of evolution’s greatest survivors”, and the splay-footed cricket is “obviously doing something right”. The Economist reporter says that the insect illustrates the “first rule of natural selection”: “If it ain’t broke, don’t fix it.” LiveScience took a different view, making the point that the animal has been “stuck in time for the Read More ›

David Tyler reports that “The earliest pterobranch reveals stasis”: A modern-day pterobranch genus is Rhabdopleura. An informative description is provided here. Comparing the new fossil and Rhabdopleura leads to the exclamation: “You don’t look a day over 500 million years. You and Rhabdopleura could be sisters”. The detail has led to comments such as this from co-author Professor David Siveter: “Amazingly, it has exceptionally preserved soft tissues — including arms and tentacles used for feeding — giving unrivalled insight into the ancient biology of the group.” The significant finding is that the earliest fossil hemichordate zooid looks remarkably similar to Rhabdopleura.”Galeaplumosus abilus demonstrates stasis in pterobranch morphology, mode of coenecium construction, and probable feeding mechanism over 525 million years.” The Read More ›

File under this one under: If it ain’t broke … In Current Biology (Volume 21, Issue 7, 612-616, 24 March 2011), we read that A 525 million year old fossil hemichordate with preserved soft tissues is the earliest and largest fossil hemichordate zooid and offers unmatched insight into the fossil anatomy and evolution of the group. Abstract: Hemichordates are known as fossils from at least the earliest mid-Cambrian Period (ca. 510 Ma) and are well represented in the fossil record by the graptolithinid pterobranchs (“graptolites”), which include the most abundantly preserved component of Paleozoic macroplankton [1]. However, records of the soft tissues of fossil hemichordates are exceedingly rare and lack clear anatomical details [2]. Galeaplumosus abilus gen. et sp. nov. Read More ›