The missing fossils argument (Introduction)
by David Turell 
, Thursday, January 20, 2022, 15:10 (1048 days ago)
Trying to explain gaps in the fossil record by hoping missing fossils will be found is a losing cause with new studies of th e Edicaran and Cambrian gap:
https://reasons.org/explore/blogs/todays-new-reason-to-believe/cambrian-explosion-becom...
"The new phyla that appeared in the Cambrian explosion (a largely marine event) included the first animals to possess skeletons, digestive tracts, circulatory systems, and complex internal and external organs. Not until the Cambrian explosion was there sufficient oxygen in Earth’s atmosphere and oceans for such animals to exist.
"Animals that suddenly appeared at the beginning of the Cambrian period included the most advanced phyla in Earth’s history. We humans belong to the chordate phylum, which is characterized by animals that possess a dorsal hollow nerve cord and a notochord. All vertebrates and many invertebrates belong to the chordate phylum. Paleontologists have discovered fossils of chordates, including some vertebrates, that date back to the very beginning of the Cambrian period.
***
"Two of the best attempts to determine an absolute date for the Cambrian explosion were undertaken by research teams led by Diazhao Chen and Can Chen, respectively. Diazhao Chen and four colleagues obtained uranium-lead zircon ages from the Ediacaran-Cambrian boundary strata, where one stratum contains fossils of Ediacaran (the period prior to the Cambrian) animals and the immediately adjacent stratum contains fossils of Cambrian animals in the Liuchapo Formation in South China.
"The fossil record reveals that the Ediacaran animals were the first to appear on Earth. Unlike the Cambrian animals, the Ediacaran fauna lacked digestive tracts, circulatory systems, skeletons, and complex organs. The record shows that the Ediacaran fauna experienced a sudden worldwide mass extinction event that was quickly followed by the appearance of the Cambrian explosion animals.
***
"They found a composite geological section in southern Namibia of the Ediacaran-Cambrian boundary that provided biostratigraphic and chemostratigraphic data that was bracketed by radiometric dating. Their measurements constrained the date for the Ediacaran-Cambrian boundary to no earlier than 538.99 ± 0.21 million years ago and no later than 538.58 ± 0.19 million years ago. Therefore, they concluded that the faunal transition from Ediacaran to Cambrian biota occurred within less than 410,000 years.
***
"A time window for the Cambrian explosion briefer than 410,000 years is far too brief for any conceivable naturalistic model for the history of life. It would be far too brief even for the appearance of just one new phylum, let alone 30+ phyla. These discoveries make paleontologist Kevin Peterson’s conclusion in his review paper on the Cambrian explosion—published a dozen years ago—all the more compelling: “Elucidating the materialistic basis for the Cambrian explosion has become more elusive, not less, the more we know about the event itself.”8 The same goes for Gregory Wray’s review published in 1992, “The Cambrian ‘explosion’ of body plans is perhaps the single most striking feature of the metazoan fossil record. The rapidity with which phyla and classes appeared during the early Paleozoic coupled with much lower rates of appearance of higher taxa since, poses an outstanding problem for macroevolution.” (my bold)
Comment: I've quoted Bechly in the past: " "The most popular attempt to resolve this discrepancy is the so-called “artifact hypothesis,” which proposes that the Cambrian animal phyla had ancestors, but that those ancestors either left no fossil record or have not yet been found, because of the incompleteness of the fossil record." Now more Bechly: "Recently, I stumbled upon a paper from 2018 that I had previously overlooked, and it proved to be dynamite. It is a study by a research group from the University of Zurich about the transition from the Ediacaran organisms to the Cambrian animal phyla in the Nama Basin of Namibia (Linnemann et al. 2018). What they found is truly mind-blowing. The window of time between the latest appearance date (LAD) of the alien Ediacaran biota and the first appearance date (FAD) of the complex Cambrian biota was only 410,000 years. You read that correctly, just 410 thousand years! This is not an educated guess but based on very precise radiometric U-Pb dating with an error margin of only plus-minus 200 thousand years. This precision is truly a remarkable achievement of modern science considering that we are talking about events 538 million years ago.
So I might add, without fossils, imagining lost fossils disappears. I've left out two supporting study descriptions. The findings are solid.
The missing fossils argument
by David Turell , Tuesday, May 17, 2022, 21:02 (931 days ago) @ David Turell
New findings in the pre-Cambrian gap period:
https://phys.org/news/2022-05-animals-complex-ecosystems-cambrian-explosion.html
"Early animals formed complex ecological communities more than 550 million years ago, setting the evolutionary stage for the Cambrian explosion, according to a study by Rebecca Eden, Emily Mitchell, and colleagues at the University of Cambridge, UK, publishing May 17th in the open-access journal PLOS Biology.
"The first animals evolved towards the end of the Ediacaran period, around 580 million years ago. However, the fossil record shows that after an initial boom, diversity declined in the run-up to the dramatic burgeoning of biodiversity in the so-called "Cambrian explosion" nearly 40 million years later. Scientists have suggested this drop in diversity is evidence of a mass extinction event roughly 550 million years ago—possibly caused by an environmental catastrophe—but previous research has not investigated the structure of these ancient ecological communities.
"To evaluate the evidence for an Ediacaran mass extinction, researchers analyzed the metacommunity structure of three fossil assemblages that span the last 32 million years of this geological period (between 575 to 543 million years ago). They used published paleoenvironmental data, such as ocean depth and rock characteristics, to look for metacommunity structure indicative of environmental specialization and interactions between species. The analysis revealed increasingly complex community structure in the later fossil assemblages, suggesting that species were becoming more specialized and engaging in more inter-species interactions towards the end of the Ediacaran era, a trend often seen during ecological succession.
"The results point to competitive exclusion, rather than mass extinction, as the cause of the diversity drop in the late Ediacaran period, the authors say. The analysis indicates that the features of ecological and evolutionary dynamics commonly associated with the Cambrian explosion—such as specialization and niche contraction—were established by the first animal communities in the late Ediacaran.
"Mitchell adds, "We found that the factors behind that explosion, namely community complexity and niche adaptation, actually started during the Ediacaran, much earlier than previously thought. The Ediacaran was the fuse that lit the Cambrian explosion.'"
Comment: I have seen the picture of this period in the Edicaran period. They are a variety of frond-like plant-looking, but are thought to be animals. You must download the article to see it:
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001289
No complexity like in the Cambrian animals. The phenotypic gap persists, and this article is another Darwinian attempt to shrink the gap.
The missing fossils argument; a new discovery
by David Turell , Thursday, May 11, 2023, 00:50 (573 days ago) @ David Turell
In a meadow in England:
https://www.scientificamerican.com/article/462-million-year-old-fossil-trove-holds-mini...
"Hidden inside a rocky outcrop near a flock of grazing sheep, a miniature world of marine creatures—whose guts, eyes and even brains remain visible after some 462 million years—has been uncovered by researchers.
"Paleontologists Lucy Muir and Joseph Botting discovered the pint-sized fossil trove within walking distance from their home at Castle Bank Quarry in Central Wales. At the time the aquatic creatures were alive, this area was a rocky sea shelf fringing a volcanic island.
"In a new study published online on May 1 in the journal Nature Ecology and Evolution, the duo and their colleagues in England, Sweden and China describe the site’s ancient inhabitants, most of which are just a couple of millimeters long and include nozzle-mouthed worms, horseshoe crabs, starfish and early barnacles. Also in the fossil trove are tiny enigmatic holdovers from the preceding Cambrian explosion, a period that started about 540 million years ago, when a burst of diverse life-forms emerged.
***
"Over several months the paleontologists discovered the fossils of around 170 different species that likely inhabited the rocky slope along a subsiding volcano. In addition to sponges and worms were trilobites, arthropods sporting grasping appendages and a six-legged animal that looked remarkably similar to a primitive insect that did not appear until millions of years later. There was also an animal reminiscent of Opabinia, a weird wonder of the Cambrian that had five eyes and a trunklike proboscis. Many of these evolutionary oddballs were delicately etched into the ash-colored stone, where soft-body features such as gills, digestive tracts, optic nerves and neural tissue—which rarely fossilize—were easily visible.
***
"...beautifully maintained animals are much rarer in the succeeding Ordovician period. According to Alycia Stigall, a paleontologist at the University of Tennessee at Knoxville, this is potentially because of a change in ocean chemistry during the Ordovician or a rise in burrowing organisms that exposed the remains of other animals to decay. Without these remnants, scientists know little about the majority of soft-bodied organisms that lived in the aftermath of the Cambrian explosion. “Today nonbiomineralizing organisms make up [around] 70 percent of all animals,” she says, referring to soft-bodied creatures. “Snapshots into the history of nonbiomineralizing animals like the Castle Bank fauna is incredibly important for developing a fuller understanding of the history of life,” adds Stigall, who was not involved in the new study.
"The newfound fossils also offer an unparalleled glimpse into a dynamic chapter of evolution called the great Ordovician biodiversification event. “This is when life started to get really interesting,” Muir says. “As animals diversified, ecosystems became a lot more complicated.” While animal sizes stayed constant throughout the Cambrian, some ecosystems seemed to downsize during the Ordovician. Castle Bank’s fossils are generally small. Most of them measure between 1 and 5 mm.
***
"The researchers are still working to describe dozens of Castle Bank fossils in greater detail, including the tube-dwelling tentacled creature and the animal that resembles a possible marine precursor to insects. Like it was during the lockdown, their house is currently overflowing with fossils from the site. “Our spare room is so full, you can't sleep on the bed,” Botting says."
Comment: a great new find. No important gaps closed.
The missing fossils argument; all gaps are real
by David Turell , Thursday, May 11, 2023, 17:32 (572 days ago) @ David Turell
A review article:
https://evolutionnews.org/2023/05/top-scientific-problems-with-evolution-fossils-2/
"Darwin wrote this about the fossil record in On the Origin of Species:
"By the theory of natural selection all living species have been connected with the parent-species of each genus, by differences not greater than we see between the varieties of the same species at the present day; and these parent-species, now generally extinct, have in their turn been similarly connected with more ancient species; and so on backwards, always converging to the common ancestor of each great class. So that the number of intermediate and transitional links, between all living and extinct species, must have been inconceivably great.
"But the “inconceivably great” numbers of transitional links postulated by Darwin have never been found. Indeed, one of the most prominent features of the fossil record is the Cambrian explosion, in which the major groups of animals (called phyla) appeared around the same geological time in a period called the Cambrian, fully formed and without fossil evidence that they diverged from a common ancestor.
***
"In 1991, a team of paleontologists concluded that the Cambrian explosion “was even more abrupt and extensive than previously envisioned.”
"The abruptness seen in the Cambrian explosion can also be seen on smaller scales throughout the fossil record. Species tend to appear abruptly in the fossil record and then persist unchanged for some period of time (a phenomenon called stasis) before they disappear. In 1972, paleontologists Niles Eldredge and Stephen Jay Gould called this pattern punctuated equilibria. According to Gould, “every paleontologist always knew” that it is the dominant pattern in the fossil record. In other words, the “inconceivably great” numbers of transitional links postulated by Darwin are missing not just in the Cambrian explosion, but throughout the fossil record. (my bold)
"Even if we did have a good fossil record, we would still need our imagination to produce narratives about ancestor-descendant relationships. Here’s why: If you found two human skeletons buried in a field, how could you know whether one was descended from the other? Without identifying marks and written records, or perhaps in some cases DNA, it would be impossible to know. Yet you would be dealing with two skeletons from the same recent, living species. With two different, ancient, extinct species — often far removed from each other in time and space — there would be no way to demonstrate an ancestor-descendant relationship.
"Decades ago, paleontologist Gareth Nelson wrote, “The idea that one can go to the fossil record and expect to empirically recover an ancestor-descendant sequence, be it of species, genera, families, or whatever, has been, and continues to be, a pernicious illusion.” In 1999, evolutionary biologist Henry Gee wrote that “it is effectively impossible to link fossils into chains of cause and effect in any valid way.” He concluded, “To take a line of fossils and claim that they represent a lineage is not a scientific hypothesis that can be tested, but an assertion that carries the same validity as a bedtime story — amusing, perhaps even instructive, but not scientific.'”
Comment: note my bold. Species appear abruptly. Last for some time and disappear. Each abrupt appearance creates a gap. Darwin was wrong in his suppositions. Where does that leave Darwin's common descent. In most cases phenotypic descent can be seen. But abrupt appearance is common. That leads to intelligent design's point. A designer fits this pattern. He can stick in a new design wherever He wishes.
The missing fossils argument; the Devonian explosion
by David Turell , Friday, May 12, 2023, 19:00 (571 days ago) @ David Turell
Another huge gap refuting Darwinian gradualism:
https://evolutionnews.org/2023/05/fossil-friday-the-devonian-nekton-revolution/
"Klug et al. (2010) described a previously overlooked radical change in the composition of the marine fauna of the Early Devonian, which they called the Devonian Nekton Revolution. Prior to this abrupt event, the marine ecosystems were dominated by organisms that lived either close to the seafloor (demersal) or passively drifting as plankton. Between 410-400 million years ago, a very sudden and enormous expansion of actively swimming (nektonic) animals occurred in the Devonian era, when groups such as ammonoid cephalopods and jawed fish made their first appearance. Within just 10 million years such active swimmers increased from only 5 percent to about 75 percent of the marine faunal biodiversity (see the chart below).
"The authors commented in a later paper that “this macroecological event corresponds to an explosive trend from planktonic and demersal marine animals toward true nekton as represented by the great diversification of jawed fish and ammonoids, reflecting a selection for swimming capabilities. It coincided with macroevolutionary transformations among various mollusc groups” (Monnet et al. 2011) and “is strongly linked with the rise of predatory jawed vertebrates, which also became more active swimmers in the same interval” (Klug et al. 2017, also see Anderson et al. 2011)".
Comment: as fully note before, species suddenly appear, last a while and then disappear. Nothing like Darwin theory of gradualism.
The missing fossils argument: Cambrian jellyfish
by David Turell , Wednesday, August 02, 2023, 14:54 (489 days ago) @ David Turell
Just found:
https://www.sciencealert.com/spectacularly-preserved-jellyfish-found-in-500-million-yea...
"Something truly and wonderfully special has been found in a 505-million-year-old Canadian fossil bed.
"There, preserved in the especially fine silt of a lagerstätte, paleontologists found more than 170 exquisite fossils of ancient jellyfish that swam Earth's waters hundreds of millions of years before the first dinosaurs trod its soil.
"The find is incredible because soft tissues are so rarely preserved in the fossil record, and these are so beautifully immortalized that even anatomical details, like their little jelly tentacles, are visible. And the newly discovered species, Burgessomedusa phasmiformis, now represents the earliest known jellyfish on the planet.
"'Although jellyfish and their relatives are thought to be one of the earliest animal groups to have evolved, they have been remarkably hard to pin down in the Cambrian fossil record," says paleontologist Joe Moysiuk of the University of Toronto and Royal Ontario Museum in Canada.
"'This discovery leaves no doubt they were swimming about at that time."
***
"Jellyfish, belonging to the phylum Cnidaria, are very soft tissue, so we don't expect them to be preserved all that often, if at all. Cnidarian preservation is not unknown, though. Cnidarians of the polyp variety – those that are anchored to rocks – have been found in fossil beds dating up to 560 million years ago.
"Polyps are the early life stage of modern jellies, but there are some polyps that remain polyps. Scientists believe that, evolutionarily, polyps came first and later transitioned into free-swimming creatures – Cnidarians of the medusa variety, otherwise known as jellyfish.
***
"The discovery of Burgessomedusa gives us a new baseline for calculating the timeline of jellyfish evolution. And it drives home the diversity of Cambrian marine ecosystems, which have the appearance of domination by hard-shelled creatures, as those are more readily preserved as fossils. Instead, they would have been rich and complex, with a range of squishy predators, too.
"'Finding such incredibly delicate animals preserved in rock layers on top of these mountains is such a wondrous discovery," says paleontologist Jean-Bernard Caron of the Royal Ontario Museum.
"'Burgessomedusa adds to the complexity of Cambrian food webs, and like Anomalocaris, which lived in the same environment, these jellyfish were efficient swimming predators. This adds yet another remarkable lineage of animals that the Burgess Shale has preserved, chronicling the evolution of life on Earth.'"
Comment: the Cambrian had its own ecosystem. A new discovery but the gap remains.
The missing fossils argument; all gaps are real
by David Turell , Tuesday, August 29, 2023, 14:46 (462 days ago) @ David Turell
New discoveries in a known Cambrian animal:
https://www.cell.com/current-biology/fulltext/S0960-9822(23)01065-5?dgcid=raven_jbs_aip...
"Highlights:
"CT imaging clarifies head structure in the Cambrian stem-group euarthropod Kylinxia
"Kylinxia has three eyes and four pairs of biramous head limbs
"The six-segmented head of living arthropods dates to shared ancestry with Kylinixia
"Phylogeny supports homology of frontal appendages across stem-group arthropods (my bold)
"The early Cambrian Kylinxia zhangi occupies a pivotal position in arthropod evolution, branching from the euarthropod stem lineage between radiodonts (Anomalocaris and relatives) and “great-appendage” arthropods. Its combination of appendage and exoskeletal features is viewed as uniquely bridging the morphologies of so-called “lower” and “upper” stem-group euarthropods. Microtomographic study of new specimens of Kylinxia refines and corrects previous interpretation of head structures in this species. Phylogenetic analyses incorporating new data reinforce the placement of Kylinxia in the euarthropod stem group but support new hypotheses of head evolution. The head of Kylinxia is composed of six segments, as in extant mandibulates, e.g., insects. In Kylinxia, these are an anterior sclerite associated with an unpaired median eye and paired lateral eyes (thus three rather than five eyes as was previously described ), deutocerebral frontal-most appendages, and four pairs of biramous appendages (rather than two pairs of uniramous appendages). Phylogenetic trees suggest that a six-segmented head in the euarthropod crown group was already acquired by a common ancestor with Kylinxia. The segmental alignment and homology of spinose frontal-most appendages between radiodonts and upper stem-group euarthropods is bolstered by morphological similarities and inferred phylogenetic continuity between Kylinxia and other stem-group euarthropods."[/b] (my bold)
Comment: An early stem group is further described with three eyes. Such complexity with no precursors is typical of the Cambrian Explosion.
The missing fossils argument; all gaps are real
by David Turell , Saturday, September 23, 2023, 18:40 (437 days ago) @ David Turell
First jellyfish in th2 Cambrian:
https://evolutionnews.org/2023/09/fossil-friday-jellyfish-body-plan-and-life-cycle-orig...
"The Cambrian Explosion certainly represents the best-known example of abrupt appearances in the history of life. Most of the body plans of bilaterian animal phyla appeared on the scene without known precursors that would document the incremental and gradual evolution predicted by the modern neo-Darwinian paradigm. However, the abrupt appearances in the Cambrian Explosion are not restricted to bilaterian animals. In a previous article I meticulously elaborated that unequivocal sponges also first show up in the Lower Cambrian (Bechly 2020), and Precambrian evidence for cnidarians is at least controversial (Bechly 2022).
"Now a new study by Moon et al. (2023) suggests that the distinctive medusoid body plan of jellyfish and their complex life cycle with sessile polyp stage and free-swimming medusa stage also originated during the Cambrian Explosion (News Staff 2023), adding to the enormous biological importance of this crucial event. The scientists examined 182 exceptionally well-preserved fossil jellyfish from the Lower Cambrian of the famous Burgess Shale in the Canadian Rocky Mountains, which is quite remarkable considering that jellyfish are roughly 95 percent water and therefore not the most likely candidates for well-preserved fossils. The animals were named Burgessomedusa phasmiformis and had a cuboidal umbrella of up to 8 inch size with over 90 very short and finger-like tentacles.
'Remarkably, these animals can already be placed within the crown group of the living cnidarian clade Medusozoa, which is not exactly what Darwinists should expect to find as the very first and oldest fossil record of a group. The new study also clarifies that “previously described macrofossils, putatively representing medusa stages of crown-group medusozoans from the Cambrian of Utah and South China, are here reinterpreted as ctenophore-grade organisms.” This shows that such identifications should always be taken with a grain of salt.
Comment: Darwin's expectation that intermediate forms would be found has not happened during the 170+ years that followed. All the gaps are real.
The missing fossils argument; gaps everywhere
by David Turell , Saturday, November 18, 2023, 19:46 (381 days ago) @ David Turell
From evolution news:
https://evolutionnews.org/2023/11/fossil-friday-protists-add-to-the-cambrian-explosion/
"When talking about the Cambrian Explosion, the focus is usually on the abrupt appearance of bilaterian animal phyla with their distinct body plans, which has been called a Big Bang of life. However, the Cambrian Explosion is not restricted to these animals. As I have shown in previous articles, non-bilaterian animals like true sponges and jellyfish also first appeared in the Lower Cambrian. Today we will have a look at a largely ignored part of the Cambrian Explosion. That is the abrupt appearance of several major groups of protists.
"Radiolarians represent an important group of marine zooplankton with beautiful siliceous mineral skeletons that were famously featured in wonderful drawings by the German pioneer Darwinist Ernst Haeckel. Their oldest fossil record is from the Earliest Cambrian (Ediacaran-Cambrian boundary) to Middle Cambrian of China. Thus, they appear right together with the Cambrian Explosion of animal phyla.
"Foraminiferans are amoeboid marine protists, which mostly live in the seafloor sediment and have a calcium carbonate skeleton. Their oldest uncontroversial fossil record is again from the Early Cambrian. Pawlowski et al. (2003) therefore concluded that “Fossil Foraminifera appear in the Early Cambrian, at about the same time as the first skeletonized metazoans.” More recent evidence for late Ediacaran foraminiferans suggests that this group may have originated already with the Avalon Explosion rather than the Cambrian Explosion, but even Hua et al. (2010) admitted that “the oldest unambiguous foraminifers are from Early Cambrian Atdabanian Stage strata.” Possible testate amoebae and possible foraminiferans (Rhizaria) have even been reported from 716-635 million-year-old carbonate rocks in Namibia and Mongolia, which date to a time right after the Sturtian glaciation of the Cryogenian “Snowball Earth”. However, these determinations are only tentative and far from established. At least the tintinnid determinations in the same work have been strongly disputed by Lipps et al. (2012).
***
"Other groups of protists appeared at other periods in Earth history, but they also originated abruptly without gradual transition from assumed precursors. For example, diatoms suddenly appear in the fossil record of the Early Jurassic about 182 million years ago. Coccolithophores (Hapotophyta), which form the chalk of the famous White Cliffs of Dover, appear at the Norian-Rhaetian boundary about 208.5 million years ago.
***
" Darwin’s dilemma of the lack of fossils for this ancient age therefore still holds for at least the ciliates. If there are tintinnid fossils from this ancient time, they have yet to be discovered.”
"Not even the tiniest and most abundant organisms seem to confirm the gradualist predictions of Darwinian evolution. Whenever empirical data from the actual fossil record are used to test this crucial part of the theory, it simply fails. Since gradualism is strongly refuted by the evidence, the theory must be false, because even Richard Dawkins, arguably the most ardent modern popularizer of Darwinism, clearly stated in his bestselling book The Greatest Show on Earth (Dawkins 2009) that “evolution not only is a gradual process as a matter of fact; it has to be gradual if it is to do any explanatory work.” Clinging to a refuted paradigm, in spite of the accumulated conflicting evidence, is not science but rather irrational dogmatic belief." (my bold)
Comment: this is Gould's vindication of his statement gaps are everywhere. I hope this removes dhw's irrational clinging to stepwise evolution as a dogmatic belief. Gaps mean new organism require design because new irreducible complexity is required.
The missing fossils argument; Bechly on finding ancestors
by David Turell , Monday, March 11, 2024, 21:47 (267 days ago) @ David Turell
A hard task:
https://evolutionnews.org/2024/03/fossil-friday-direct-fossil-ancestors-of-living-species/
"It is the often posed obvious question of whether there are any known fossil species that are believed to be the direct ancestors of living species, thus not just cousins on side branches of the stem group but actual stem species on the stem lineage.
"Given that there are millions of living species and each of them must have had numerous successive ancestral species in their stem lineage, we might expect to find a lot of examples in the technical literature. However, actually there are only very few cases, where such direct ancestor-descendant relationships have been proposed. All these cases are only weakly supported and not uncontroversial. They are generally restricted to groups with a rich Plio-Pleistocene fossil record.
"Among the few examples for mammalian species would be the extinct European canids Canis etruscus and Canis mosbachensis as assumed ancestors of modern wolves, or the extinct Bison antiquus and Bison occidentalis as assumed ancestors of the modern American bison, or the extinct Elephas hysudricus as ancestor of the modern Asian elephant . Another example might be the steppe mammoth Mammuthus trogontherii as ancestor of the woolly mammoth Mammuthus primigenius, which only went extinct about 4,000 years ago on Wrangel Island and thus may count as modern species. Some paleoanthropologists suggested that the Eurasian archaic human Homo heidelbergensis was via Homo steinheimensis the direct ancestor of Neanderthals, and the African archaic human Homo rhodesiensis could be the direct ancestor of later Homo sapiens in north-eastern Africa, but this is quite controversial, as is the valid taxonomic status of these fossil human species themselves.
"More examples for assumed direct ancestors of living species are found in Pliocene and Pleistocene marine protists among the foraminiferans and radiolarians, mainly because we have a long-lasting undisturbed microfossil record of these unicellular organisms in deep sea sediments. But of course, this raises the fuzzy question of chronospecies and whether we are only seeing microevolution within a species rather than speciation (which arguably could be an arbitrary distinction).
"Overall, it looks like the evidence for direct fossil ancestors is extremely slim to say the least. Why is that? Of course, one possibility would be that common descent is wrong, but even young earth creationists affirm that speciation does occur and that wolves or bisons had ancestral species respectively. So, could there be another explanation?
Indeed, there are two general problems concerning the recognition of direct ancestors in the fossil record:
"1.) Even though the fossil record is pretty complete on the macroevolutionary level of higher taxa (family and above), the fossil record will always be highly incomplete on the lower taxonomic levels because it was estimated that less than 1% of all species were preserved as fossils (not to speak of having been discovered). This seems to make it very unlikely to find exactly the direct ancestor of a particular living species. However, renowned expert Mike Foote (1996) estimated the probability of ancestors in the fossil record and found the probability to find ancestor-descendant pairs not negligible and likely underestimated.
"2.) There is a general methodological impossibility to diagnose a direct ancestor species based on morphological characters, because all of its primitive characters are shared with other stem group representatives and outgroup taxa, while all of its derived characters are inherited by its descendant species. There is no diagnostic character that would label an ancestor as such. We should expect an ancestor to lack any autapomorphies that would indicate its position on a side branch, but given the incomplete preservation of fossils we can never know if such characters were just not preserved or even have not been preservable at all (e.g., soft tissue, genetic, behavioral, physiological characters). The only theoretical case where a stem species could possess a unique diagnostic character, would be the esoteric case when it developed a derived trait that then immediately got lost in the descendent species. However I don’t know of a single example, and such a case would also not be empirically distinguishable from a side branch autapomorphy. So overall, fossil ancestors can in principle not be recognized as such based on their characters. Therefore, there can always only be plausibility arguments, based on a continuous preservation and certain criteria such as occurrence older but in the same region as the descendant species. (my bold)
"...Therefore, modern paleobiologists generally do not even look for ancestor-descendant relationships but only for sister group relationships in terms of more recent common descent.
"So, even if Darwinism were true, we would not expect to find a lot of direct fossil ancestors of living species. But on the other hand, there is certainly no positive support for Darwinism from such elusive ancestors either. I would consider this to be a draw." (my bold)
Comment: I would remind the reader Bechly also points out the very high completeness rate of the fossil record and many more small new findings may appear, but the present gaps are real and not likely to be erased.
The missing fossils argument; new fossils support 'gap'
by David Turell , Saturday, May 04, 2024, 17:15 (213 days ago) @ David Turell
New Cambrian forms, some more complex than their current forms:
https://evolutionnews.org/2024/05/fossil-friday-kinorhyncha-yet-another-animal-body-pla...
"This Fossil Friday we will look at an obscure group of animals from a clade of molting invertebrate animals called Ecdysozoa that include the roundworm phyla (Nematoda, Nematomorpha, Priapulida, Loricifera, and Kinorhyncha) as well as tardigrades, velvet worms (Onychophora), extinct lobopods, and arthropods. Almost all of these ecdysozoan phyla have been recorded from the Lower Cambrian and thus clearly originated with the burst of biological creativity in the Cambrian Explosion, which brought forth all the different animal body plans.
***
"Indeed, apart from some dubious trace fossils and microfossils from the terminal Ediacaran ...unequivocal body fossils of the ecdysozoan phyla (i.e., Priapulida and Loricifera) are first appearing in the Early to Middle Cambrian. The extinct Palaeoscolecida (Early Cambrian – Silurian) are considered to be either stem nematomorphs or rather stem priapulids. Maas et al. (2010) described a possible stem Nematoida (Nematoda+Nematomorpha) from the Middle Cambrian of Australia, but its closer affinities remain unknown. A notable gap in our knowledge of ecdysozoan history was the phylum Kinorhyncha, which until recently had no known fossil record at all. These animals are small marine invertebrates that are also called mud dragons because of their spiny body.
"Hardly a decade ago, Chinese scientists described “three dimensionally phosphatized worm-like fossils from the early Cambrian rocks, approximately 535 million years old, in northern Sichuan and southern Shaanxi provinces” of South China. They were interpreted as early kinorhynchs and therefore named Eokinorhynchus rarus (featured above). The 2 mm long animals only differed from their living relatives in having more body segments and more distinct spines. In other words: the earliest kinorhynchs were more complex than modern ones. So much for the evolutionary narrative from simple to complex. (my bold)
"Five years later, Shao et al. (2020) described Zhongpingscolex qinensis from the Early Cambrian (Fortunian Stage) of South China. Their phylogenetic analysis resolved this new taxon as closest relative (sister group) of Eokinorhynchus in the stem group of Kinorhyncha.The authors did not mention three undescribed taxa of fossil kinorynchs with up to 40 mm length from the Middle Cambrian Qingjiang biota in China.
"Based on these findings we can safely count Kinorhyncha among the large number of animal phyla that originated abruptly in the Cambrian Explosion. The more we learn about the fossil record the more the Cambrian Explosion is confirmed as a key event in the history of life, which defies Darwinian explanations.'
Comment: Note my bold. we generally assume life evolves to the more complex, but some forms are seen to devolve to simpler type. This article is part of a continuing event, the discovery of new fossils in China whose shale beds ae rich in fossils. These new fossils constantly enforce the 'gap' as a real explosion of new forms without predecessors.
The missing fossils argument; new fossils found
by David Turell , Wednesday, May 15, 2024, 00:29 (203 days ago) @ David Turell
The source of spiders, scorpions and horseshoe crabs:
https://phys.org/news/2024-05-discovery-ancestors-scorpions-spiders-horseshoe.html
"Who were the earliest ancestors of scorpions, spiders and horseshoe crabs? A Ph.D. student from the University of Lausanne (Switzerland), with the support of a CNRS researcher, has identified a fossil that fills the gap between modern species and those from the Cambrian period (505 million years ago), solving a long paleontological mystery.
"Modern scorpions, spiders and horseshoe crabs belong to the vast lineage of arthropods, which appeared on Earth nearly 540 million years ago. More precisely, they belong to a subphylum that includes organisms equipped with pincers used notably for biting, grasping prey, or injecting venom—the chelicerae, hence their name chelicerates. But what are the ancestors of this very specific group?
"This question has puzzled paleontologists ever since the study of ancient fossils began. It was impossible to identify with certainty any forms among early arthropods that shared enough similarities with modern species to be considered ancestors. The mystery was further compounded by the lack of fossils available for the key period between -505 and -430 million years ago, which would have facilitated genealogical investigation.
"Lorenzo Lustri, then a Ph.D. student at the University of Lausanne (UNIL)'s Faculty of Geosciences and Environment, provided the missing piece of the puzzle. Together with his supervisors, he studied a hundred fossils dating back 478 million years from the Fezouata Shale of Morocco and identified the candidate that links modern organisms to those of the Cambrian (505 million years ago).
"Fossils from the Fezouata Shale were discovered in the early 2000s and have undergone extensive analysis. However, the fossil illustrated in the publication, one of the most abundant in the deposit, had never been described before. Measuring between 5 and 10 millimeters in size, it has been named Setapedites abundantis. This animal makes it possible, for the first time, to trace the entire lineage of chelicerates, from the appearance of the earliest arthropods to modern spiders, scorpions and horseshoe crabs.
"...the fossil has yet to reveal all its secrets. In fact, some of its anatomical features allow for a deeper understanding of the early evolution of the chelicerate group, and perhaps even link to this group other fossil forms whose affinities remain highly debated.
***
"To obtain these results, the scientists studied a hundred fossils and used an X-ray scanner to reconstruct their anatomy in detail and in 3D. They were then able to draw comparisons with numerous fossil chelicerates from other sites, as well as with their more ancient relatives.
"Finally, the importance of the Fezouata fossil became clear with the help of phylogenetic analyses, which mathematically reconstruct the family tree of different species based on the "coding" of all their anatomical traits."
Comment: Yes, a new helpful fossil is found, but the main gap remains, and most likely will remain. The missing fossil argument is a prayer to save Darwinism a theory filled with multiple gaps in the record and multiple saltations of new species.
The missing fossils argument; new fossils found
by David Turell , Friday, August 02, 2024, 15:55 (123 days ago) @ David Turell
Another discovery of an early form:
https://www.science.org/doi/10.1126/science.ado0059?utm_source=sfmc&utm_medium=emai...
"Modern molluscs vary widely in form and size—including everything from giant squids to itty bitty snails. This intense variation evolved rapidly during the Cambrian “explosion” some 500 million years ago. However, there’s a bias in the fossil record, as shelled species are much more likely to fossilize than soft ones like slugs.
"But recently, a team of researchers unearthed a breakthrough find: a new species of mollusc that slimed the Earth 514 million years ago. Shishania aculeata, as the authors of a paper in the most recent issue of Science dubbed the creature, suggests that the world’s earliest molluscs were flat slugs with spiny armor instead of shells.
"The exquisitely preserved treasure, discovered in the Yunnan Province of southern China, reveals that the slug built its spines—spiky cones made of chitin—from a sophisticated secretion system shared by annelids like earthworms. An internal system of canals less than a hundredth of a millimeter in diameter indicate the cones were secreted at their base by soft microvilli in a process reminiscent of 3D printing. Meanwhile, underneath the animal was a muscular foot—a trait characteristic of mollusks.
“'Trying to unravel what the common ancestor of animals as different as a squid and oyster looked like is a major challenge,” said co-author Luke Parry in a statement. “The new fossil is an extra piece of the puzzle as it shows us what molluscs looked like before they evolved a shell ,” he told The Guardian."
Comment: The site for the full paper is above. This is a summary:
https://mail.google.com/mail/u/0/#inbox/FMfcgzQVxtmfvDZtcdqzXtxLRzTrHpTn
As usual the Cambrian Gap is reinforced by this new early form. The recent new discoveries all consistently add to evidence the gap is real. A regular disappointment for staunch Darwinians.
The missing fossils argument; the Avalon explosion
by David Turell , Friday, October 11, 2024, 18:01 (53 days ago) @ David Turell
In the Ediacaran period before the Cambrian:
https://evolutionnews.org/2024/10/fossil-friday-the-avalon-explosion-and-the-power-of-m...
"This Fossil Friday features the 569-556-million-year-old frond-like fossil Charnia from Charnwood Forest in Leicestershire (UK), an example of the abrupt appearance of the so-called Ediacaran biota in the latest Precambrian. During this event, which has been called the Avalon Explosion and preceded the famous Cambrian Explosion, we find in three distinct assemblages the emergence of strange organisms that looked like aliens from a remote planet. They were very much unlike any of the organisms that roamed our planet after the Cambrian Explosion and certainly did not represent the ancestors of the Cambrian bilaterian animal phyla. The Ediacaran organisms generally exhibited a quilted body like an air mattress, a glide symmetry, a fractal growth pattern, and lacked any visible organs for feeding or locomotion or any internal structure. A genuine enigma for biologists and paleontologists.
***
"...the authors simply suggest that “major transgressions would therefore both increase habitable shallow marine shelf area and also drive long-term increases in environmental oxygen levels, which culminated in the appearance of the Avalon, White Sea, and Cambrian assemblages.” As I have often said, these are at best describing necessary conditions for the appearance of new organisms but certainly not sufficient conditions. There is zero causal explanation for the astonishing culmination in the appearance of the totally new types of organisms that characterize these assemblages. The new study was published in the prestigious journal Science Advances, but did it really advance our understanding of the mechanisms responsible for the sudden origin of the Ediacaran biota? The answer must be a resounding no, not even a single bit. While evolutionary biology has no explanation even according to the authors themselves, intelligent design theory does uniquely provide a causally adequate explanation and therefore should be preferred over the blind acceptance of Darwinian magic as an imposed default explanation."
Comment: firstly, clear gaps that have never been filled in. Secondly, his other point is quite clear, that favorable conditions are not drivers of innovations. That is the province of DNA actions
The missing fossils argument; new very early Ediacaran
by David Turell , Monday, October 21, 2024, 16:25 (43 days ago) @ David Turell
Lived in a mat of algae and bacteria:
https://www.sciencealert.com/this-strange-fleshy-blob-is-one-of-earths-earliest-animals...
"The traces of one of these early complex creatures has just been unearthed in the South Australian outback, and its intricate design rivals all other fossils before it.
"...it's a flattened, circular blob with a mysterious question mark shape for a butt crack.
***
"They know it's an animal because of the features it shares with living members of the kingdom: multiple cells, the ability to move, and a body plan organized into different halves.
"And they found not one, but more than a dozen of these things, along with trace fossils – the imprints of their blobby bodies preserved forever in the now-petrified mat of microscopic algae and bacteria that Quaestio once lurked in.
"Some of these impressions show slightly offset outlines distinct from the harder edges of the animal's imprint, evidence that these were among the first animals capable of moving on their own.
"'One of the most exciting moments… was when we flipped over a rock, brushed it off, and spotted what was obviously a trace fossil behind a Quaestio specimen – a clear sign that the organism was motile; it could move," Harvard University evolutionary biologist Ian Hughes says.
"A little smaller than the size of a human palm, the Quaestio's distinctive question-mark shape – for which it was named – distinguishes a left and right side, a sign of bilateral symmetry, along with a crucial asymmetrical twist.
"'There aren't other fossils from this time that have shown this type of organization so definitively," Florida State University geologist Scott Evans says.
"Asymmetry is a component of modern-day animals, including humans, and Quaestio might just be the first to evolve this mathematically complicated quirk.
Comment: the appearance of animals had to happen at some point. Note that it looks nothing like later forms.
The missing fossils argument; new very early Ediacaran
by David Turell , Friday, November 08, 2024, 20:01 (25 days ago) @ David Turell
Bechly says much of the hype is unsupported:
https://evolutionnews.org/2024/11/fossil-friday-an-edicaran-animal-with-a-question-mark/
"This Fossil Friday discusses Quaestio simpsonorum from the Late Precambrian of the Ediacaran biota in Australia, which is, well, actually I have no idea what it really is, and neither does anyone else, which makes its genus name very fitting indeed. Here is the backstory of these fossils that were discovered in the 555-million-year-old sandstones of Nilpena Ediacara National Park in the South Australian outback, and were reconstructed as inflated disc-shaped organisms that were floating over microbial mats on the ancient seafloor like a Roomba.
***
"It was boldly celebrated as “oldest evidence for complex, macroscopic animals” (de Lazaro 2024) and “the earliest moving animals” (Luntz 2024). Wow, that surely sounds like something important.
***
"Yes, you heard that right. All we know about this fossil is the shape, which is nothing more than a few-inch-large round impression with a question-mark-like fold in the middle that originates from a kind of notch. Are any organs visible that suggest that it was a multicellular animal? No. Any bilateral symmetry? No, but this does not prevent the scientists from speculating that in spite of the external asymmetry, it might have been a pioneer bilaterian ancestor, because humans are bilaterian animals and internally asymmetrical (authors quoted in de Lazaro 2024). You can’t make this stuff up: They seriously compare a Precambrian blob of jello with a highly derived modern human and claim that external asymmetry in the former and internal asymmetry in the latter could somehow correspond, even though the internal asymmetry of humans does not belong to the ground plan of vertebrate animals even according to mainstream evolutionary biology. This is ridiculous junk science, based on almost useless fossil evidence. Actually, there are even inorganic pseudofossils like salt pseudomorphs that look quite similar to this stuff. All the elaborate hypotheses in the new study are based on the simple circumstance that the structures in the stone seem to show some polarity. Here is news: almost every organism does show some polarity including most protists and plants. This is much ado about nothing.
***
"There are also similarities between Quaestio and the trilobozoan Ediacaran fossils like Tribrachidium that were initially misidentified as echinoderms, or to other circular Ediacaran fossils like Cyclomedusa (featured above) that were initially misidentified as jellyfish, but later reinterpreted as holdfasts or microbial colonies. We have no clue what all these Ediacaran biota organisms really were. To claim that such undefinable blobs in sandstone represent fossils of the oldest motile animals is massively overselling the evidence to say the least."
Comment: my previous presentation is fully refuted.
The missing fossils argument; new very early Ediacaran
BECHLY: To claim that such undefinable blobs in sandstone represent fossils of the oldest motile animals is massively overselling the evidence to say the least.
DAVID: My previous presentation is fully refuted.
We shall just have to leave it to the experts to fight it out among themselves.
The missing fossils argument; new very early Ediacaran
by David Turell , Saturday, November 09, 2024, 19:12 (24 days ago) @ dhw
BECHLY: To claim that such undefinable blobs in sandstone represent fossils of the oldest motile animals is massively overselling the evidence to say the least.
DAVID: My previous presentation is fully refuted.
dhw: We shall just have to leave it to the experts to fight it out among themselves.
Yes. Back to elevating.
The missing fossils argument; new very early Ediacaran
by David Turell , Monday, November 18, 2024, 21:43 (15 days ago) @ David Turell
A worm with an external skeleton:
https://www.sciencedaily.com/releases/2024/11/241118125212.htm
"The history of a major animal group, composed of millions of species of insects, arachnids, and nemotodes, has been elusive -- until now. A team has now identified the oldest known ecdysozoan in the fossil record and the only one from the Precambrian period.
"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.
***
"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," said Mary Droser, a distinguished professor of geology at UCR, who led the study.
"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.
***
"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.
***
"'Because it was deep, we knew it wasn't smooshed easily so it must have had a pretty rigid body," Hughes said. 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.
"'At this point we knew this was a new fossil animal and it belong to the Ecdysozoa," Hughes said.
"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."
Comment: this is the first animal like Ediacaran fossil I've seen. Non e of the others seemed to be mobile. Also it appears de novo as do the Cambrian animals.