Earth Life Is a Shadow of Its Former Greatness

Evolutionary progress? No. Look at the fossil record
to witness higher “fitness” than today.

 

 

We live in an impoverished world, with a biosphere depleted of many magnificent creatures. Today’s megafauna cannot hold a candle to their counterparts in the past, and most of the giants of the past are extinct. What happened, if evolution is a march of progress?

Giants of the Jurassic seas were twice the size of a killer whale (University of Portsmouth, 10 May 2023). Extinct marine reptiles called pliosaurs, though not as big as pictured in an old BBC animation, were nevertheless awesome sea monsters. Paleontologist David Martill got the size wrong for the BBC animators, but commented,

“It’s wonderful to prove there was indeed a truly gigantic pliosaur species in the Late Jurassic seas. Although not yet on a par with the claims made for Liopleurodon in the iconic BBC TV series Walking With Dinosaurs, it wouldn’t surprise me if one day we find some clear evidence that this monstrous species was even bigger.”

Humongous, 100-foot-long dinosaur from Argentina is so big its fossils broke the road during transport (Live Science, 21 May 2023). A well-named titanosaur was so big, its bones had to be moved inch by inch. It caused a traffic accident when it was transported, because the bones destabilized the vehicle. And this one didn’t even hold the record.

During its lifetime in the mid-Cretaceous, C. diripienda would have weighed between 30 and 40 tons (27 and 36 metric tons), Novas said. “However, it is far from being one of the largest and most colossal dinosaurs, such as Patagotitan, Argentinosaurus or Notocolossus, which would have weighed between 70 tons [63.5 metric tons].”

Study suggests differential species proliferation likely key to evolutionary increase in size of brontotheres (Phys.org, 12 May 2023). Brontotheres were giant mammals of North America, resembling rhinos but much bigger. “Over just 16 million years, some grew from dog-sized creatures to rhinoceros-looking behemoths weighing more than a metric ton.” What happened? Reporter Bob Yirka tries to explain why Cope’s Rule (“animals evolve to grow larger in size, as many advantages tend to accrue to larger species”) works except when it doesn’t (see “Looking for Laws to Make Darwinism Scientific,” 24 April 2023). Predictable answer to why brontotheres went extinct: climate change!

Ancient giant amphibians swam like crocodiles 250 million years ago (Science Daily, 30 March 2023). Today’s amphibians—those little slimy animals like salamanders, newts and frogs—look like punks compared to their extinct counterparts. In South Africa, scientists found trace fossils and tracks of amphibians two meters long, as big as crocodiles.

During the Late Permian Period, just over 250 million years ago, South Africa was home to rhinesuchid temnospondyls, large predatory amphibians with bodies similar to crocodiles or big salamanders. These extinct animals are known mainly from skeletal remains, but in this study, researchers describe an exceptional set of trace fossils which provide insight into how these animals moved through their environment.

For the open-access paper with pictures of the trackways, see Groenewald et al, Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour, PLoS One, 29 March 2023.

Quarter-ton marsupial roamed long distances across Australia’s arid interior, reveals 3D-scanning study (Flinders University via Phys.org, 31 May 2023). There are no examples of Diprotodontidae, a family of marsupials, alive today; they became extinct 40,000 Darwin Years ago, this article says, but date back to 3.5 million Darwin Years. “The largest species, Diprotodon optatum, grew to the size of a car, weighing up to 2.7 tons.” The largest marsupial alive today is the red kangaroo, weighing in at 200 pounds.

The Flinders University team believes this animal was able to walk long distances, so they named it Ambulator. Jacob van Zoelen with his green mohawk haircut attributes the beast’s giant size to its feet, but was that the cause, or the effect? He makes it sound like the creature decided to evolve its own shape.

“So, diprotodontids such as Ambulator may have evolved this morphology to traverse great distances more efficiently. This morphology also allowed for greater weight to be supported, allowing diprotodontids to get very big indeed.”

“Eventually, this led to the evolution of the giant and relatively well-known Diprotodon.”

A predatory dinosaur from Brazil and its surprising anatomy (Phys.org, 18 May 2023). This is about the giant dinosaur Spinosaurus, entering the debate about whether it was semi-aquatic or terrestrial. Either way, it was a record holder living in a rich ecosystem.

Spinosaurids are among the largest land-dwelling predators to have ever lived on Earth. Their peculiar anatomy and sparse fossil record make spinosaurids mysterious in comparison to other large-bodied carnivorous dinosaurs. Spinosaurids bear relatively long and slender snouts with numerous near-conical teeth, sturdy arms with impressive claws and very long processes on their spines.

The most complete fossil skull of a spinosaurid is represented by Irritator challengeri found in approx. 115 Ma old sedimentary rocks from eastern Brazil. While the species, being estimated to have reached some 6.5 m in body length, represents the largest animal in its ecosystem, paleontologists also found fossils from other dinosaurs, pterosaurs, relatives of crocodiles, turtles and diverse fish species there.

Paleontology: All dinosaurs big and small (Stephen Brusatte, Current Biology, 22 May 2023). Renowned dinosaur paleontologist Stephen Brusatte weighs in on the lightweight and heavyweight dinosaurs. This paper is behind a paywall.

Evolutionary Explanations, Anyone?

Developmental strategies underlying gigantism and miniaturization in non-avialan theropod dinosaurs (D’Emic et al., Science Magazine, 23 Feb 2023). The summary on “How to Get Big” starts with a grotesque question-begging sentence:

Over evolutionary history, many different taxa have evolved very large body sizes. The general consensus has been that an animal grows to a large size based on an increase in growth rate. However, very few studies have explored this question across many species within a comparative phylogenetic framework. D’Emic et al. looked across a large dataset of non-avialan theropod dinosaurs, which had an array of body sizes. They found evidence supporting changes in growth rate contributing to body size change, but also found that changes in the duration of growth played a large role.

The paper confuses causation with correlation. If it were a law of nature that animals that grow cells more rapidly also get bigger, then it would apply everywhere, and would also “explain” cancer. The authors’ central diagram is a mess: four “mechanisms” of growth in size vary incoherently across the theropod dinosaurs. This commits the explanatory nightmare of multiple causation, leaving the reader wondering which one is predominant, and how it fits with other mechanisms. Is gigantism due to acceleration, deceleration, truncation, or prolongation? Was it one of these or more of them in combination? Different dinosaurs seem to have grown large with different mechanisms. Such “explanations” allow for any number of explanations for any particular case. It’s too hard, so the team says they may figure it out in futureware.

Just as broad, phylogenetic comparative studies have repeatedly failed to find support for directional evolution in body size [i.e., Cope’s Rule], with increased scrutiny the developmental mechanisms underlying body size evolution may be found to be equally prevalent across Amniota as a whole.

Evolution of the largest of the large dinosaurs (Phys.org, 8 May 2023). This press release from Adelphi University summarizes the paper by D’Emic above. It counts three dozen independent instances of gigantism among dinosaurs, and admits that it violates the only known rule of size evolution—Cope’s Rule—instead, giving up explanation to the Stuff Happens Law.

D’Emic’s findings contradict Cope’s rule, the popular 19th-century theory that animals’ size evolves over time. Instead, the new study sees animals achieving different body sizes depending on their ecological context and whatever niches happened to be available—which can appear random when looked at from a large scale.

Starting small and simple – key to success for evolution of mammals (University of Birmingham, 14 April 2023). This press release repeats the questionable claim that early mammals were tiny, but evolved to be bigger over time after the dinosaurs went extinct.

The ancestors of modern mammals managed to evolve into one of the most successful animal lineages – the key was to start out small and simple, a new study reveals.

The statement makes no sense in Darwinian theory. Did the small mammals hold a committee meeting and vote on how they might manage to evolve? Did they decide to reduce the number of bones in their skulls so that they could grow bigger? Dr Stephan Lautenschlager, Senior Lecturer for Palaeobiology at the University of Birmingham, confuses allowing with causing:

Reducing the number of bones led to a redistribution of stresses in the skull of early mammals. Stress was redirected from the part of the skull housing the brain to the margins of the skull during feeding, which may have allowed for an increase in brain size.

It “may have allowed”? That’s ridiculous. You can allow the Publisher’s Clearing House to give you a million dollars till the cows come home. You can lay out the red carpet and offer the representative milk and cookies. You’ll likely wait a long, long time. Evolution works by chance, by unguided, aimless, purposeless processes: the Stuff Happens Law. Why doesn’t Lautenschlager do the experiment? Let him breed mice with less skull stress, allowing their brain sizes to increase, and see if they evolve into mega-mice as big as brontotheres..

Earth prefers to serve life in XXS and XXL sizes: UBC research (University of British Columbia, 29 Mar 2023). Dr Eden Tekwa at UBC explains why creatures evolve to be very large except when they evolve to be very small. She and her colleague don’t explain why so few really large animals remain today.

“Life constantly amazes us, including the incredible range of sizes that it comes in,” says senior author Dr. Malin Pinsky, associate professor in the department of ecology, evolution, and natural resources at Rutgers University. “If the tiniest microbe was the size of the period at the end of this sentence, the largest living organism, a sequoia tree, would be the size of the Panama Canal.”

This press release was echoed by McGill University: “Nature favours creatures in largest and smallest sizes,” McGill U, 10 May 2023.

The sizes of life (Tekwa, Pinsky et al., PLoS One, 29 March 2023). This is the paper by the above authors. They calculated mean biomass for different groups, and found a rough bimodal distribution (two peaks on the size scale, very large and very small). But they did not explain why Earth is impoverished of megafauna today. Once again: futureware will be required to solve this evolutionary conundrum.

Our results provide a first crude roadmap for what patterns may exist, but they will likely drastically change if size-biomass spectra become targets for research programs. Moving forward, macroecology should embrace taxonomic inclusivity and unexplored scales that defy existing explanations.

None of these sources could explain why so many animal groups had bigger representatives in the past.

See also these previous CEH articles on this topic:

• 20 March 2023: Life Is Devolving from a Past World of Giants
• 21 June 2021: Extinct Animals Were Bigger

We note that bigger is not always better, and not a sole measure of “fitness” (however one wants to define that subjective word). Miniaturization can be a good design strategy, as shown by progress in more powerful computers using less space. Still, support for a giant creature as big as a Titanosaur implies not only the ability for the huge beast to live and survive under gravity and climate, but to be part of an ecosystem that can support giants. On almost every continent, there used to be animals much bigger than those alive today: giant penguins in South America, giant lions, camels and sloths in North America, giant therapsids in Africa, giant beavers, giant armadillos, giant dragonflies, giant mammoths in Siberia, giant everything. Why are they all gone?

Dr Matt McLain, paleontologist at The Master’s College, spoke recently to the Bible-Science Association about therapsids, the so-called “mammal-like reptiles” in the fossil record. Therapsids like glyptodon used to be considered transitional forms between reptiles and mammals, but not any more. He demonstrated from his own research on digits from these animals, which are well known from fossils, that there are five groups of therapsids that cluster among themselves, but do not fit on any evolutionary sequence. Some resembled crocodiles, some resembled VW beetles and were as big as tanks, and some well-known ones like Dimetrodon were unlike anything else. They appeared, and went extinct. They came in all sizes; many of them were giants. Dr McLain agrees that today’s world is depleted of many magnificent creatures that only left traces in the rocks.

If most animals went extinct during a global flood, it implies not all representatives of animal clades were on the ark, and of those that were, many of them could not survive in a radically changed world after the flood.