Religion, Creationism, evolution, science and politics from a centre-left atheist humanist. The blog religious frauds tell lies about.
Tuesday, 21 January 2025
Uninteligent Design - Creationism's Designer Tries Again, and Fails, Five Times
New research reveals why sabre-toothed predators evolved their deadly teeth
Creationism's designer god is nothing if not a trier - or maybe it’s just a slow learner. It tried and failed five times to create carnivores with ferocious-looking but ultimately fatal, sabre teeth.
The problem with long, curved canine teeth is that, although they are good at killing big animals quickly by tearing their throat out or stabbing them to death, because of the additional leverage on the long teeth, and the high risk of striking bone, they are prone to break, leaving their owner to starve to death.
And this has happened at least five times in evolutionary history.
The problem is there is an optimal size and shape depending in the prey species but this produces selection pressure to become more specialised in the prey which in turn produces selection pressure to produce longer, sharper teeth until the tooth shape reaches a pinnacle of shape optimised for that particular prey species. However, there is an evolutionary trade-off in that as the teeth become more specialised, the carnivore becomes more specialised and dependent on the prey species, so they are vulnerable to ecological changes that mean their prey becomes scarce of goes extinct.
How and why this occurred repeatedly due to convergent evolution is the subject of a paper in Current Biology and an open access article in The Conversation by Dr. Tahlia Pollock, Postdoctoral Research Fellow, Evans EvoMorph Laboratory, Monash University. Her article is reprinted here, reformatted for stylistic consistency:
Monday, 13 January 2025
Refuting Creationism - First Americans Were Killing Mammoths 3,000 Years Before 'Creation Week'
Study reveals mammoth as key food source for ancient Americans | UAF news and information
A good 3,000 years before creationism's small god allegedly created the little flat planet with a dome over it described in the Bible, thinking that's what a universe looked like, human beings had migrated to North America and were hunting mammoths.
This is according to a new stable isotope analysis by a team led by researchers from the University of Alaska Fairbanks (UAF). Creationists should note that a stable isotope analysis does not depend on radioactive decay rates, so the evidence-free claim that radioactive decay rates have changed isn't open to them. Stabel isotope analysis shows us what the person's diet consisted of.
The analysis was conducted by Professor Ben Potter of the University of Alaska Fairbanks and James Chatters of McMaster University, and their colleagues. Their findings are published, open access, in the journal Science Advances and is explained in a UAF new release:
Sunday, 12 January 2025
Refuting Creationism - Scientists Got The Date of the Earliest Dinosaur Wrong - It Was Even Earlier
Dinosaurs roamed the northern hemisphere millions of years earlier than previously thought, according to new analysis of the oldest North American fossils
The thing about science that distinguishes it from religion is the willingness to change its collective mind when the facts change. This is because science is led by the fact wherever they lead
Science is reasonable uncertainty religion is unreasonable certainty. Religion appeals to those who value certainty over truth, whereas science appeals to those who value truth above certainty.
And scientists have just changed their collective minds about where and when the first dinosaurs appeared.
The consensus had been that they first appeared on the southern end of the supercontinent Pangea before it split into Gondwana in the South and Laurasia in the north and only spread to Laurasia millions of years later.
What can you tell me about the ancient reptile, Ahvaytum bahndooiveche, and its place in the evolution of dinosaurs? Ahvaytum bahndooiveche is a recently identified dinosaur species from the Late Triassic period, approximately 230 million years ago, discovered in what is now Wyoming, USA. This species is notable for being the oldest known dinosaur from the ancient northern supercontinent Laurasia, challenging previous beliefs that dinosaurs originated solely in the southern supercontinent Gondwana.
Discovery and Naming
The fossil remains of Ahvaytum bahndooiveche were uncovered in 2013 at the Garrett's Surprise locality within the Popo Agie Formation in Wyoming. The genus name "Ahvaytum" translates to "long ago," and the species name "bahndooiveche" means "water's young handsome man," a term used by the Eastern Shoshone to refer to both dinosaurs and colorful native salamanders. This naming honors the Eastern Shoshone Tribe, whose ancestral lands include the discovery site, and reflects a collaborative effort between researchers and Indigenous communities.
Physical Description
Ahvaytum bahndooiveche was a small dinosaur, estimated to be about 3 feet (0.91 meters) in length and 1 foot (0.30 meters) in height, comparable in size to a modern chicken but with a notably long tail. The fossil material includes fragmentary hindlimb bones, such as an isolated left astragalus and a partial left femur, suggesting it had progressed beyond the juvenile stage and was still slowly growing.
Evolutionary Significance
This discovery has significant implications for our understanding of dinosaur evolution. Prior to this find, it was believed that dinosaurs originated in Gondwana and later dispersed to Laurasia. The existence of Ahvaytum bahndooiveche in Laurasia during the same period as the earliest known southern dinosaurs indicates that dinosaurs were more widely distributed across the globe earlier than previously thought. This challenges the hypothesis of a delayed dinosaurian dispersal out of high-latitude Gondwana and suggests a more complex scenario for the early evolution and distribution of dinosaurs.
In summary, Ahvaytum bahndooiveche provides valuable insights into the early stages of dinosaur evolution, highlighting a broader and more rapid dispersal of these creatures across ancient Earth than was previously understood.
Saturday, 11 January 2025
Refuting Creationism - Oldest-Known Evolutionary Arms Race in the Cambrian
Oldest-Known Evolutionary “Arms Race” in the Cambrian | AMNH
Perhaps Creationism's designer god is just a slow learner.
Anyone with an intellect greater than that of a plank should be capable of understanding the utter futility and waste in an arms race in which the strategy is to keep running faster just to stay in the same place. Arms races only make sense as the result of a game plan in which you can't communicate with your opponent and have no way of telling what he or she is thinking and if they gain the upper-hand, you lose. The only safe choice is to up the stakes - and that goes for your opponent too.
It becomes even more incomprehensible if the person you're having the arms race with is yourself, unless you're an amnesic with multiple personality disorder, and yet, if we believe creationists, that's exactly what their putative designer god is doing constantly.
Everywhere we look in nature, organisms are competing with one another for resources, or because one is trying to exploit the other as a food source in a predator-prey relationship or as a parasite trying to live in or on another organism and even killing it or making it weak and sickly as a byproduct of its parasitism. And yet creationists insist there is only one designer designing both sides in these arms races.
For some unfathomable reason, creationists like to imagine the idea of a celestial idiot having arms races with itself in millions of relationships in nature is a much better explanation than these arms races being the inevitable result of mindless evolutionary processes where a slight improvement increases the chances of leaving descendants while reducing the chance of the opponent doing the same, so creating a selection pressure for the next twist in the spiral.
Tuesday, 10 December 2024
Refuting Creationism - Ritual Gatherings in a Cave in Israel - 25,000 Years Before 'Creation Week'
Earliest deep-cave ritual compound in Southwest Asia discovered The Daily The Daily
Clearly, the authors of the creation myths in Genesis had no knowledge of their own history let alone the history of the rest of the world, as 25,000 years before the time in which they set their 'creation week', there were people holding ritual gatherings in a cave in what is now Israel.
Before the mythical 'creation week' there was supposedly no Earth, no Universe, no living beings and only a god made of nothing which had self-assembled out of nothing according to a design it made before it existed.
Creationists reason that the Universe and life on Earth is too complex to have arisen spontaneously, and it couldn't have all come from nothing, so an even more complex god must have arisen spontaneously out of nothing first then created everything else out of nothing by magic. To a child-like creationists there is no possible flaw in that reasoning.
Sunday, 8 December 2024
Refuting Creationism - Domesticated Dogs 2000 Years Before 'Creation Week'
School of Anthropology
How did humans and dogs become friends? Connections in the Americas began 12,000 years ago | University of Arizona News
At least 2,000 years before Creationists' little god created a small flat planet with a dome over it in the Middle East, human in Alaska were feeding domesticated dogs on salmon, according to the findings of palaeontologists from the University of Arizona.
But of course, the parochial Bronze Age pastoralists from the infancy of our species who made up that myth, couldn't possibly have known anything about when dogs were domesticated, or Alaska for that matter because, as we can see from the tales they made up, they knew nothing of the world beyond a day or two's walk from their pastures and were completely ignorant of the geography, geology and history of the planet and life on it - which is why they made up such implausible origin myths in the first place.
That there were people feeding salmon to their domesticated dogs about 12,000 years ago is the subject of a paper published recently in Science Advances by the Arizona University team led by Assistant Professor François Lanoë, of the School of Anthropology in the College of Social and Behavioral Sciences. They explain their findings in an Arizona University News release
Tuesday, 26 November 2024
Transitional Form News - Precambrian Common Ancestor of Insects, Arachnids, and Nematode Worms
Tiny worm makes for big evolutionary discovery | UCR News | UC Riverside
The refutation of creationism continues today with news of another one of those 'non-existent' transitional species that turn up with monotonous regularity only to be dismissed by creationists as 'not transitional but fully formed' with now two gaps in the record where there was originally one, or by simply dismissing the dating method as unreliable and coincidentally wrong by an order of magnitude sufficient to make 6-10,000 years look like x-million years.
Another big disappointment for creationists is the fact that this one is from before the Cambrian when their traditional disinformation claims lots of species popped into existence without ancestors by magic in a single event called the 'Cambrian explosion'. The Cambrian 'explosion' was of course a period of some 6-10 million years during which many of the basic body plans of multicellular organisms evolved.
This fossil however was before then and was clearly the ancestral stem species from which a whole range of Cambrian organism, collectively known as Ecdysozoa evolved. These are a group of organisms with an outer cuticle which is shed periodically as the organism grows. The vast group includes nematode worms and arthropods such as insects, spiders, crustaceans like crabs, shrimps, lobsters, and the horseshow crab. So, this discovery, which the palaeontologists have named Uncus dzaugisi sits at the base of this branch of the evolutionary tree. It resembled a nematode worm.
Tell me all about the Ecdysozoa, please. Ecdysozoa is a major clade of animals within the larger group known as Protostomia, distinguished by their unique mode of growth, which involves periodic moulting of an external cuticle. The term "ecdysozoa" comes from the Greek word ecdysis, meaning "to strip off" or "to shed," referring to this moulting process.The discovery was made by a team from University of California, Riverside (UCR), led by Professor Mary Droser a distinguished professor of geology. The have explained their findings in the journal, Current Biology, and in a UCR press release:
Characteristics of Ecdysozoa
- Moulting (Ecdysis):
- The defining feature of Ecdysozoans is the shedding of their cuticle—a tough, non-living outer layer made of proteins, polysaccharides (like chitin), or collagen. This process allows them to grow, as the rigid cuticle limits continuous size increase.
- After moulting, a new, larger cuticle is secreted, which hardens over time.
- Body Structure:
- Many have a hydrostatic skeleton, relying on fluid pressure in their body cavity for movement and structure.
- Most lack cilia or flagella in their adult form, distinguishing them from other protostomes.
- Diversity:
- The group includes some of the most diverse and abundant organisms on Earth, ranging from microscopic species to large, visible ones.
- Nervous System:
- Typically, they have a ventral nerve cord and a dorsal brain, with varied sensory adaptations.
Major Groups Within Ecdysozoa
Ecdysozoa includes eight phyla, with two of the most well-known being Arthropoda and Nematoda:
- Arthropoda
- The largest and most diverse group of animals, including insects, arachnids, crustaceans, and myriapods.
- They have segmented bodies, jointed appendages, and a hard exoskeleton.
- Examples: Butterflies, crabs, spiders, centipedes.
- Nematoda (Roundworms)
- Microscopic to macroscopic worms with a cylindrical, unsegmented body.
- Found in nearly every habitat on Earth, often as parasites in plants and animals.
- Examples: Caenorhabditis elegans (a model organism), Ascaris (a human intestinal parasite).
- Tardigrada (Water Bears)
- Microscopic, water-dwelling animals known for their extreme resilience to harsh environments.
- They can survive desiccation, radiation, and even the vacuum of space.
- Onychophora (Velvet Worms)
- Segmented, soft-bodied terrestrial animals with slime glands used for capturing prey.
- Priapulida
- Marine worms with a tubular body, often found burrowing in sediment.
- Kinorhyncha
- Tiny, segmented marine animals often referred to as "mud dragons."
- Loricifera
- Microscopic animals inhabiting marine sediment, with a complex, retractable body.
- Nematomorpha (Horsehair Worms)
- Parasites as larvae, often controlling the behaviour of their insect hosts.
Evolution and Phylogeny
- Ecdysozoa was proposed as a clade in 1997, based on molecular evidence (notably studies of ribosomal RNA).
- They share a common ancestor with other protostomes but diverged early to adopt their unique moulting strategy.
- Their evolutionary success is evident in their sheer numbers and adaptability, especially in arthropods.
Ecological and Economic Importance
- Ecological Roles:
- Many ecdysozoans are key components of ecosystems as decomposers, predators, prey, and parasites.
- Insects, a subgroup of arthropods, are critical for pollination and nutrient cycling.
- Economic Impact:
- Beneficial: Insects (e.g., bees) aid in agriculture, while nematodes play a role in soil health.
- Harmful: Some ecdysozoans are pests or parasites causing diseases in humans, animals, and crops.
Fun Facts
- Tardigrades can enter a state called cryptobiosis, surviving for decades without water or food.
- Arthropods are the most successful phylum, with over a million described species, and likely many more undiscovered.
- Nematodes may account for about 80% of individual animals on Earth.
Tiny worm makes for big evolutionary discovery
UC Riverside scientists have described ‘Uncus,’ the oldest ecdysozoan and the first from the Precambrian period
Everyone has a past. That includes the millions of species of insects, arachnids, and nematode worms that make up a major animal group called the Ecdysozoa. Until recently, details about this group’s most distant past have been elusive. But a UC Riverside-led team has now identified the oldest known ecdysozoan in the fossil record and the only one from the Precambrian period. Their discovery of Uncus dzaugisi, a worm-like creature rarely over a few centimeters in length, is described in a paper published today in Current Biology.
Scientists have hypothesized for decades that this group must be older than the Cambrian, but until now its origins have remained enigmatic. This discovery reconciles a major gap between predictions based on molecular data and the lack of described ecdysozoans prior to the rich Cambrian fossils record and adds to our understanding of the evolution of animal life.
Mary L. Droser, co-author Earth and Planetary Sciences University of California, Riverside
Riverside, CA , USA.
The ecdysozoans are the largest and most species-rich animal group on Earth, encompassing more than half of all animals. Characterized by their cuticle — a tough external skeleton that is periodically shed — the group comprises three subgroups: nematodes, which are microscopic worms; arthropods, which include insects, spiders, and crustaceans; and scalidophora, an eclectic group of small, scaly marine creatures.Like many modern-day animal groups, ecdysozoans were prevalent in the Cambrian fossil record and we can see evidence of all three subgroups right at the beginning of this period, about 540 million years ago. We know they didn’t just appear out of nowhere, and so the ancestors of all ecdysozoans must have been present during the preceding Ediacaran period.
Ian V. Hughes, first author
Organismic and Evolutionary Biology
Harvard University, Cambridge, MA, USA.
DNA-based analyses, used to predict the age of animal groups by comparing them with their closest living relatives, have corroborated this hypothesis. Yet ecdysozoan fossil animals have remained hidden among scores of animal fossils paleontologists have discovered from the Ediacaran Period.
Ediacaran animals, which lived 635-538 million years ago, were ocean dwellers; their remains preserved as cast-like impressions on the seabed that later hardened to rock. Hughes said uncovering them is a labor-intensive, delicate process that involves peeling back rock layers, flipping them over, dusting them off, and piecing them back together to get “a really nice snapshot of the sea floor.”
This excavation process has only been done at Nilpena Ediacara National Park in South Australia, a site Droser and her team have been working at for 25 years that is known for its beautifully preserved Ediacaran fossils.
Nilpena is perhaps the best fossil site for understanding early animal evolution in the world because the fossils occur during a period of heightened diversity and we are able to excavate extensive layers of rock that preserve these snapshots. The layer where we found Uncus is particularly exciting because the sediment grains are so small that we really see all the details of the fossils preserved there.
Assistant Professor Scott Evans, co-author
Earth, Ocean, and Atmospheric Sciences
Florida State University, Tallahassee, FL, USA.
While the team didn’t set out to find an early ecdysozoan during their 2018 excavation, they were drawn to a mysterious worm-like impression that they dubbed “fishhook.”
Sometimes we make dramatic discoveries and sometimes we excavate an entire bed and say ‘hmmm, I’ve been looking at that thing, what do you think?’ That’s what happened here. We had all sort of noticed this fishhook squiggle on the rock. It was pretty prominent because it was really, really deep.
Because it was deep, we knew it wasn’t smooshed easily so it must have had a pretty rigid body. At this point we knew this was a new fossil animal and it belong to the Ecdysozoa.
Ian V. Hughes
After seeing more of the worm-like squiggles the team paid closer attention, taking note of fishhook’s characteristics. Other defining characteristics include its distinct curvature and the fact that it could move around — seen by trace fossils in the surrounding area. Paul De Ley, an associate professor of nematology at UCR, confirmed its fit as an early nematode and ruled out other worm types.
The team called the new animal Uncus, which means “hook” in Latin, noting in the paper its similarities to modern-day nematodes. Hughes said the team was excited to find evidence of what scientists had long predicted; that ecdysozoans existed in the Ediacaran Period.
It’s also really important for our understanding of what these early animal groups would have looked like and their lifestyle, especially as the ecdysozoans would really come to dominate the marine ecosystem in the Cambrian.
Ian V. Hughes
The paper is titled “An Ediacaran bilateran with an ecdysozoan affinity from South Australia.” Funding for the research came from NASA.
HighlightsI think my favourite quote from one of the scientists is "We know they didn’t just appear out of nowhere, and so the ancestors of all ecdysozoans must have been present during the preceding Ediacaran period", which just about describes the difference between someone who knows the Theory of Evolution is correct because he understands the evidence for it, and a creationists who believes in fully formed living organisms made from nothing, magically popping into existence from nowhere, with magic spells cast by an unproven supernatural deity their mummy and daddy told them about.
- A new, motile bilaterian is described from the Ediacaran of South Australia
- Features including morphology and movement suggest an ecdysozoan affinity
- This discovery firmly places ecdysozoans in the Precambrian
Summary
Molecular clocks and Cambrian-derived metazoans strongly suggest a Neoproterozoic origin of many animal clades.1,2,3,4 However, fossil bilaterians are rare in the Ediacaran, and no definitive ecdysozoan body fossils are known from the Precambrian. Notably, the base of the Cambrian is characterized by an abundance of trace fossils attributed to priapulid worms,5,6 suggesting that major divisions among ecdysozoan groups occurred prior to this time. This is supported by ichnofossils from the latest Ediacaran or early Cambrian left by a plausible nematoid,7,8,9 although definitively attributing this inferred behavior to crown-Nematoida remains contentious in the absence of body fossils.10 Given the high probability of the evolution of Ecdysozoa in the Proterozoic, the otherwise prolific fossil record of the Ecdysozoa, and the identification of more than 100 distinct Ediacaran genera, it is striking that no Ediacaran body fossils have been confidently assigned to this group. Here, we describe Uncus dzaugisi gen. et. sp. nov. from the Ediacara Member (South Australia), a smooth, vermiform organism with distinct curvature and anterior-posterior differentiation. The depth of relief of Uncus is unique among Ediacara fossils and consistent with a rigid outer cuticle. Ecological relationships and associated trace fossils demonstrate that Uncus was motile. Body morphology and the inferred style of movement are consistent with Nematoida, providing strong evidence for at least an ecdysozoan affinity. This validates the Precambrian origin of Ecdysozoa, reconciling a major gap between predicted patterns of animal evolution and the fossil record.4
Hughes, Ian V.; Evans, Scott D.; Droser, Mary L.
An Ediacaran bilaterian with an ecdysozoan affinity from South Australia
Current Biology, DOI: 10.1016/j.cub.2024.10.030
© 2024 Elsevier.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
The ancestral form, the transitional species, was in exactly for rock formation of exactly the right age which the theory of evolutionary decent with modifiction from a common ancester predicted.
And in case a creationist is tempted to try the 'radiometric dating is flawed/wrong/faked fallacy. The Ediacaran rock formation these fossils were found in was independently dated several different ways that all converged on a 98-million-year span from 635 to 538 million years ago known as the Ediacaran. The Most important being the Uranium-Lead (U-Pb) dating of zircons found in the layers of volcanic ash sandwiched within the rocks. To compress 600 million years of radioactive decay into less than 6-10,000 years would have caused Earth's rocks to melt and the seas to boil away. And the weak nuclear force would have been so weak that atoms could not have formed, let alone life, and there would have been no planet and no universe to fine tune for it either.
Refuting Creationism: Why Creationism Fails In Both Its Science And Its Theology
The Failure of Creationism: The Theory That Never Was
Sunday, 24 November 2024
Refuting Creationism - How Pterosaurs Evolved
New fossil discovery reveals key step in the evolution of flying reptiles - Queen Mary University of London
Although creationists insist dinosaurs coexisted with humans before their god launched his genocidal flood, and even twist words like 'behemoth' in the Bible to try to show how the authors of genesis were familiar with dinosaurs (as though there was only one species) what they never explain is why the same authors said nothing at all about the pterodactyls that were contemporaneous with dinosaurs.
The real reason is of course that pterodactyls and dinosaurs lived in that vast expanse of time before 'Creation Week' when 99.9975% of everything that happened on Earth happened.
The evidence for this can be found in any palaeontological article that deals with the evolution of these first flying vertebrates, like this one about the discovery of a new species, Skiphosoura bavarica, which is also helping to understand how these reptiles evolved. It was identified by a team led by Dr David Hone, a palaeontologist from Queen Mary University of London. Early pterosaurs had a wingspan of about 2 meters (6 feet) but they evolved into massive creatures with wing spans up to 10 meters (30 feet). On the ground, some of them may have been at tall as a giraffe!
Pterosaurs, their evolution, and their relationship to dinosaurs. Pterosaurs were a group of flying reptiles that lived during the Mesozoic Era, from the late Triassic (about 228 million years ago) to the end of the Cretaceous (66 million years ago). They were the first vertebrates to achieve powered flight and were remarkable for their diversity in size, morphology, and ecological niches. Here's a detailed overview of pterosaurs, their evolution, and their relationship to dinosaurs:Dr Hone's team have published their findings in the journal Current Biology and describe it in a Queen Mary University news release:
- Evolutionary Origins
- Pterosaurs belonged to the clade Pterosauria, which is part of the larger group Archosauria, making them close relatives of dinosaurs and crocodilians.
- Their exact evolutionary origins are debated, but they likely evolved from small, ground-dwelling or arboreal reptiles within the clade Avemetatarsalia, which also includes dinosaurs and birds.
- Early pterosaurs, such as Eudimorphodon and Dimorphodon, appeared in the late Triassic and already exhibited the characteristic wing structure.
- Anatomy and Adaptations for Flight
- Pterosaurs' wings were formed by a membrane of skin, muscle, and other tissues stretched along an elongated fourth finger, which supported the main wing structure.
- Other adaptations included:
- Lightweight skeletons with hollow bones to reduce weight.
- Keel-like breastbones to anchor powerful flight muscles.
- Complex cranial crests in some species, possibly for display or aerodynamic purposes.
- Unique respiratory adaptations with air sacs similar to those in modern birds.
- Relationship to Dinosaurs
- Pterosaurs and dinosaurs share a common ancestor, but they are distinct groups within Archosauria. Pterosaurs are not considered dinosaurs.
- The distinction lies in their lineage: dinosaurs belong to the clade Dinosauria, while pterosaurs form their own separate clade.
- Diversity and Evolutionary Trends
- Pterosaurs diversified into two main groups:
- Rhamphorhynchoids (Early Pterosaurs):
- Typically small to medium-sized.
- Long tails with a vane or rudder-like structure at the tip.
- Examples: Rhamphorhynchus, Dimorphodon.
- Lived during the Triassic and Jurassic periods.
- Pterodactyloids (Advanced Pterosaurs):
- Larger body sizes, including giants like Quetzalcoatlus with wingspans exceeding 10 meters.
- Short tails or no tails.
- Adapted to various ecological roles, such as fish-eating, filter-feeding, and scavenging.
- Examples: Pteranodon, Istiodactylus, Quetzalcoatlus.
- Dominated the skies during the Jurassic and Cretaceous periods.
Ecological Roles
- Pterosaurs occupied diverse ecological niches:
- Some were piscivores, using long, pointed jaws to catch fish.
- Others were filter feeders, like Pterodaustro, which had bristle-like teeth.
- Large pterosaurs may have been scavengers or predators of small terrestrial animals.
- Their crests may have been used for sexual selection, thermoregulation, or species recognition.
Extinction
- Pterosaurs went extinct at the end of the Cretaceous period during the mass extinction event 66 million years ago, likely caused by the asteroid impact and subsequent environmental changes.
- Birds, which evolved from theropod dinosaurs, survived and continued to dominate the skies, taking over many of the ecological niches once held by pterosaurs.
Fossil Evidence
- Pterosaur fossils are relatively rare due to their fragile skeletons, but significant discoveries have been made worldwide, revealing exquisite details of their anatomy and even soft tissues like wing membranes and pycnofibers (hair-like structures covering their bodies).
Key Distinctions from Dinosaurs
- Dinosaurs were primarily terrestrial, with a diverse range of locomotion and body plans, whereas pterosaurs were adapted for flight.
- Birds are considered modern-day dinosaurs (descendants of theropods), but they are not descended from pterosaurs.
Pterosaurs are an incredible example of evolutionary innovation, showcasing how vertebrates conquered the skies long before birds. Their fossils continue to provide insights into the complexity of prehistoric life and the adaptive potential of ancient reptiles.
New fossil discovery reveals key step in the evolution of flying reptiles
A remarkable new fossil discovery is shedding light on how flying reptiles, known as pterosaurs, evolved from their early forms into the later giants that ruled prehistoric skies.
The new species, named Skiphosoura bavarica, was identified by a team led by Dr David Hone, a palaeontologist from Queen Mary University of London. Their findings were published today in the journal Current Biology.
The pterosaurs, close relatives of dinosaurs, were the first vertebrates to achieve powered flight. While early species typically had wingspans of about 2 metres, later pterosaurs evolved into enormous forms with wingspans reaching 10 metres. The discovery of Skiphosoura bavarica provides critical insights into how these transformations occurred.
Hailing from southern Germany, Skiphosoura boasts a rare, nearly complete skeleton preserved in three dimensions—a significant contrast to the often-flattened fossils of its relatives. Measuring about 2 metres in wingspan, the new species’ most striking feature is its short, stiff, sword-like tail, which inspired its name: “sword tail from Bavaria.”For two centuries, scientists divided pterosaurs into two major groups: early non-pterodactyloids, characterised by short heads, long tails, and specific wing and toe structures, and the later pterodactyloids, which had larger heads, shorter tails, and other adaptations for efficient flight. Intermediate species, like the Darwinopterus discovered in the 2010s, showed how the head and neck evolved first. Skiphosoura represents a critical step beyond the Darwinopterus. Its head and neck resemble the more advanced pterodactyloids, while its wrist, tail, and foot show transitional features. These traits help trace the gradual adaptations that allowed later pterosaurs to grow to massive sizes. The study also reconstructed the evolutionary family tree of pterosaurs, placing Skiphosoura between Darwinopterus and true pterodactyloids. Additionally, a Scottish pterosaur named Dearc was identified as a key intermediate between early pterosaurs and Darwinopterus. Together, these findings form a near-complete evolutionary sequence for pterosaurs, detailing how their anatomy changed over time. The discovery was made possible through the efforts of an international team. Adam Fitch, from the University of Wisconsin-Madison, highlighted the significance of Skiphosoura:This is an incredible find. It really helps us piece together how these amazing flying animals lived and evolved. Hopefully, this study will inspire more research into this important evolutionary transition.
Dr. David William Elliott Hone, lead author, School of Biological and Behavioural Sciences
Queen Mary University of London, UK.
Pterosaurs have long been symbols of the unique life of the past. Skiphosoura represents an important new form for working out pterosaur evolutionary relationships and how this lineage arose and changed.
Adam Fitch, co-author
University of Wisconsin-Madison UW Geology Museum, Madison, WI, USA.Having worked on over 60 pterosaurs from the Solnhofen limestone, it became clear during preparation that this fossil displayed features from both major groups of pterosaurs, with the shortened tail being a crucial diagnostic trait.
Stefan Selzer, co-author
Grabenäcker 12, Hemhofen, Germany.
Bruce and René Lauer of the Lauer Foundation, who contributed to the project, underscored the importance of modern techniques such as UV photography in uncovering fine details of the specimen.
We are proud to bring this important specimen to science and further the understanding of pterosaur evolution.
Bruce Lauer, co-author
Lauer Foundation for Paleontology, Science and Education
Wheaton, IL, USA.
With its blend of cutting-edge research, meticulous preparation, and international collaboration, the study of Skiphosoura bavarica offers a significant leap forward in understanding the evolutionary journey of these extraordinary flying reptiles.
HighlightsAs Though to rub salt into creationist wounds, not only is this pterosaur from the Lower Tithonian (i.e. 148-150.8 million years old) but as the palaeontologist explain, it forms part of a transitional sequence of fossils showing how this group of reptiles evolved.Summary For over a century, there was a major gap in our understanding of the evolution of the flying Mesozoic reptiles, the pterosaurs, with a major morphological gap between the early forms and the derived pterodactyloids.1 Recent discoveries have found a cluster of intermediate forms that have the head and neck of the pterodactyloids but the body of the early grade,2 yet this still leaves fundamental gaps between these intermediates and both earlier and more derived pterosaurs. Here, we describe a new and large Jurassic pterosaur, Skiphosoura bavarica gen. et sp. nov., preserved in three dimensions, that helps bridge the gap between current intermediate pterosaurs and the pterodactyloids. A new phylogeny shows that there is a general progression of key characteristics of increasing head size, increasing length of neck and wing metacarpal, modification to the fifth toe that supports the rear wing membrane, and gradual reduction in tail length and complexity from earlier pterosaurs into the first pterodactyloids. This also shows a clear evolution of the increasing terrestrial competence of derived pterosaurs. Furthermore, this closes gaps between the intermediates and their ancestors and descendants, and it firmly marks the rhamphorhynchines and ctenochasmatid clades as, respectively, being the closest earliest and latest groups to this succession of transitional forms.
- A new pterosaur, Skiphosoura bavarica, is named from the Jurassic of Germany
- The specimen is much larger than other known forms and is preserved in three dimensions
- The Skiphosoura helps document the transition from early pterosaurs to the pterodactyloids
- The tail is short but retains the supporting structures of earlier forms
Hone, David William Elliott; Fitch, Adam; Selzer, Stefan; Lauer, René; Lauer, Bruce
A new and large monofenestratan reveals the evolutionary transition to the pterodactyloid pterosaurs Current Biology (2024) Doi: 10.1016/j.cub.2024.10.023
Copyright: © 2024 The authors.
Published by Elsevier Inc. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
Saturday, 9 November 2024
Refuting Creationism - What Did The Denisovans Ever Do For Us?
New insights into the Denisovans – the new hominin group that interbred with modern day humans - News & Events | Trinity College Dublin
In marked contrast to the childish creationist notion of a single founder couple being magically created without ancestors 6-10,000 years ago, evidence is growing that one ancestral species that contributes some of its DNA to modern non-African humans, the Denisovans, were once widespread especially in Southeast Asia and may have reached South America, or at least people carrying some Denisovan DNA may have done, but not via the traditional route - Siberia, Beringia and Alaska - followed by later Homo sapiens.
My understanding is that they and Neanderthals were most likely direct descendants of H. erectus that migrated out of Africa some 2 million years ago and gave rise to the Denisovans in Eastern Eurasia and Neanderthals in Western Eurasia. These two then interbreed with the H. sapiens migrants as they came up out of Africa and spread throughout Eurasia and down to Melanesia, Austronesia and Oceania.
So, rather than a single ancestral couple magically created out of dirt, without ancestors, as creationists believe, modern non-African humans don't have an ancestral couple, they don't even have a single ancestral species but are the result of hybridization between at least three ancestral species.
There is also evidence, according to two researchers from Trinity College, Dublin, Ireland, that there may have been several regional populations of Denisovans, each of which contributed to the Homo sapiens genome at different times. As with other hominin species, they were diversifying as they spread in what may have been the beginnings of classical allopatric speciation.
The Denisovan DNA that was retained by H. sapiens as they migrated into the different environments in Asia was that which gave them an advantage, such as the ability to survive in the low oxygen partial pressure of the Tibetan Plateau - something that the Tibetans have inherited - immunity to certain endemic pathogens and an improved ability to keep their body temperature up during cold weather by burning stored body fats - something that Innuits have inherited.
Friday, 8 November 2024
Refuting Creationism - How Bird's and Bat's Wings Evolved
Bats’ and birds’ evolutionary paths are vastly different | Cornell Chronicle
Unlike an intelligent designer, the process of evolution can't go back to basic and start again. It is normally an additive process that has no control over what it has to work with and simply refines and improves on what is there. That's not to say new structures can't evolve but they do so by enlarging or remodelling something that was already there - the membrane of a bat's wing, for example is the webbing that exists in the tetrapod embryo between the fingers and toes, while the feathers of a bird's wing are highly modified scales. Both those structures evolved out of tissues that were already there. It would have been impossible for a bat to grow wing feathers instead of a membrane, for example, because the earliest mammals had lost their scales and evolved fur.
But of course, that would not have been a problem for an omnipotent intelligent designer who, having designed one wing would not need to set about designing another way to do the same thing.
So, constrained as evolution was by what it could use, it's not really surprising that birds and bats evolved on two different trajectories, with the only thing in common being flight (and of course the basic vertebrate skeletal body plan).
Thursday, 7 November 2024
Refuting Creationism - Domestication of Sheep Long Before 'Creation Week'
male near Agios Epiphanios, Cyprus
Population History of Domestic Sheep Revealed by Paleogenomes | Molecular Biology and Evolution | Oxford Academic
I've previously noted how almost all our domestic animals have been selectively bred to improve upon their wild ancestors, sometimes to the extent that the wild ancestor is hardly recognisable as the same species. Indeed, in some instances, the genetic isolation of the wild and domestic varieties is so wide that they are regarded as different species.
And Bible-literalist creationists believe all animals were magically create out of dirt without ancestors, specifically for the use of man - which begs the question, why have we had to improve on them to make them fit for purpose? Did an omnipotent creator god not know what we would use them for?
In a recent post I describes the domestication of modern cattle from their wild auroch ancestors, which, because of their size and aggressive nature, were too dangerous for herding and milking, and the domestic breeds have evolved from a very small founder population, probably because of that difficulty so animals placid enough were only rarely found.
All that took place thousands of years before creationists believe there was an Earth with life on it, as is usual with almost all of Earth's and human history.
Now, as an added embarrassment to creationists, palaeogeneticists have managed to trace the ancestors (wild mouflons) of modern domestic sheep to discover where they were domesticated and how long ago. It goes without saying that it happened long before creationists believe the god magicked sheep out of dirt, in common with almost all of Earth's history.
Wednesday, 6 November 2024
Common Origins - Stem Species of Horseshoe Crab's Scorpions & Spiders From 450 Million Years Before 'Creation Week'
The Megacheiran candidate: Fossil hunters strike gold with new species | YaleNews
It's another of those 'non-existent' transitional fossils days that come round several times a month, as scientists find yet another fossil which is clearly of an intermediate species between two different taxons.
Today's example is of an intermediate or stem species from which horseshoe crabs, spiders and scorpions evolved. It lived about 450 million years before there was an Earth for it to live on, according to creationists superstition, which believe Earth was created by magic as a small flat planet with a dome over it between 6 and 10,000 years ago.