Sauropod sojourns or enamel of evacuation?
Dinosaur migration, like other dinosaur behavior, can only be guessed at. Geochemist Henry Fricke’s group at Colorado College has been scraping up some clues. They have scraped the enamel from sauropod teeth and analyzed the oxygen isotopes in it. Oxygen isotope ratios matching those of drinking water are typically incorporated into vertebrate tooth enamel. Their findings, published in Nature, are believed to be the first proof that sauropods were migratory.
“The common occurrence of sauropods in this basin [Morrison Basin in Wyoming and Utah] has remained a paradox,” the researchers write, because “in the Late Jurassic-aged Morrison depositional basin . . . these animals occupied lowland river-floodplain settings characterized by a seasonally dry climate.”1
Fricke’s team measured oxygen isotope ratios in enamel scraped from 32 Camarasaurus teeth. These fossils are dated from the late Jurassic period (160 to 145 million years ago) by evolutionary reckoning. The team also measured isotope ratios in the basin’s sedimentary rock. Some enamel had ratios matching local rocks, and some did not.
If isotope ratios don’t match those in the local rocks, scientists assume the animal traveled elsewhere for a time. There is typically less oxygen-18 in water at higher elevations, so animals with tooth enamel low in oxygen-18 are believed to have spent time at higher elevations. Currently, the nearest higher elevations are about 300 kilometers from the Morrison Basin. Therefore, the finding of enamel low in oxygen-18 in some of the enamel is interpreted as evidence the dinosaurs migrated to those highlands.
Fricke’s team also compared isotope ratios from the recently formed enamel on the base of one animal’s tooth with the older enamel at the tip. Because tooth enamel incorporates oxygen from an animal’s drinking water, the enamel provides a record of the animal’s travels while that tooth formed. Internal tooth characteristics suggest these teeth reflect 4-5 months of growth.2 In this case, the older enamel’s isotope ratio was consistent with life in the basin, and the enamel formed later was suggestive of a highland location. The team therefore concludes this animal lived in the basin, migrated to the highlands, and returned to the basin shortly before death, probably in a seasonal migration.
Fricke says, “[These sauropods] are huge — they would probably have eaten themselves out of house and home if they stayed in one place. Now we have evidence that demonstrates that, and a method to move forward and study other dinosaurs.”
It is quite impossible to observe the behavior of an extinct fossilized animal, so clues must be interpreted to draw inferences about ancient behavior. The interpretation of this enamel evidence illustrates the extent to which worldview-based assumptions can influence scientific conclusions.
In this case, the scientists are assuming that the sauropods lived in a basin habitat with geography, seasonal climate, and topography similar to today’s—even though they believe million years have elapsed since those animals became extinct. Therefore, they not only assume these sauropods died and were fossilized in their native habitat but also that the basin habitat was subject to seasonal droughts. Thus, assuming the sauropods had a reason to migrate, they interpret the enamel variations as conclusive evidence that they did. They’re even confident that the place to which they migrated was the same highlands seen on today’s map, again assuming the topography remained unchanged for millions of years.
But stripped of assumptions, what Fricke’s group has demonstrated is that the sauropods fossilized in Morrison Basin probably spent time in different habitats, probably at different elevations. While it is possible that ordinary seasonal migration produced the isotopic variations, it is equally possible that the sauropods, faced with rising floodwaters in the time of Noah, migrated to higher elevations. The Flood did not instantaneously engulf the earth but according to Genesis 7:17–18 rose for quite some time before all the land was covered.
Eventually, sauropods and other dinosaurs that moved to higher ground were engulfed in the Flood, possibly got swept to different locations, and were rapidly buried. The sediment in which the dinosaurs were buried may or may not have been related to their original habitats. The ability of animals like dinosaurs to flee to higher ground during the earlier part of the Flood year explains their higher position in the geologic column. The rock layers represent the order of Flood-related burial, not an evolutionary timeline.
We cannot be certain oxygen isotopes were distributed in the pre-Flood world just as they are today. And biblically there is absolutely no reason to doubt that animals, including dinosaurs, could be migratory in the pre-Flood world. But, if the lower amount of oxygen-18 at higher elevations was the condition early in the Flood year, the tooth enamel may be not a record of seasonal sojourning, but a dinosaurian attempt at flood evacuation. Fricke’s findings are entirely consistent with the biblical model.
Spectral signposts suggest interstellar seeds of life.
Stardust is the latest source suggested as a supply for complex organic molecules supposed to be the precursors for the evolution of life. Sun Kwok and Yong Zhang from the University of Hong Kong analyzed infrared spectral emissions from circumstellar and interstellar locations. They determined the spectral patterns can be explained by the presence of complex organic molecules.
After being excited by photons of light, molecules can emit energy detectable as electromagnetic emissions. Such spectra act like fingerprints to identify many molecules at a distance. Kwok and Zhang’s analysis of infrared spectra found spectra from over 160 molecules. All of these signatures were consistent with those expected from complex “amorphous organic solids with a mixed aromatic-aliphatic structure.”3
The researchers, describing this stardust in Nature, write that the suspected molecular structures are “similar to that of the organic materials found in meteorites, as would be expected if the Solar System had inherited these organic materials from interstellar sources.”3
The infrared emissions exceed the complexity of the emissions seen with ordinary aromatic hydrocarbons. While no amino acids or nucleic acid components were found, these organic molecules appear to be similar to those in coal and petroleum.
“What impressed me most is that complex organics are easily formed by stars, they are everywhere in our own galaxy and in other galaxies,” Kwok said. And since the emissions were coming not just from stars themselves but also from interstellar regions, Kwok and Zhang conclude that stars are ejecting the material into space. Therefore, they conclude, this stardust could be the sort of source from which the solar system “inherited these organic materials.”3 “Nature is much more clever than we had imagined,” Kwok added.
Evolutionary cosmology maintains that meteorites are remnants of the solar system’s4 formation. As such, by assuming organic compounds ejected by stars could have fortified the primordial solar system, asteroids and meteorites, and of course earth with the building blocks of life, evolutionary scientists see such findings as a source to seed the process of molecules-to-man evolution. Kwok explains, “While it may be too soon to determine whether these organic compounds played a role in kick-starting the development of life on Earth, it certainly is a possibility.”
Since organic molecules such as amino acids,5 keto acids,6 and nucleobases7 have all been found in meteorites, these stellar findings are not surprising. The same elements that react to form organic compounds under the control of enzymes in living organisms can also react to form such compounds through non-biologic means. The enzymes with which organisms catalyze chemical reactions do not provide the only ways for chemical reactions to take place, just the most efficient ways.
Furthermore, even if a vat of organic molecules sat in the sun forever, they could not organize themselves into life forms having neither the informational blueprint nor that mysterious “spark” of life that biology has yet to explain. Finally, even if such life could evolve from organic soup, the source of the elements comprising the soup would still require a divine starting point.
The Bible tells us God spoke the earth into existence. On the third, fifth, and sixth days of Creation Week, He created the living components of His creation. He made the sun, moon, and stars on the fourth day. Genesis specifies God made Adam from the dust of the ground. God created the same chemistry to operate in both living and non-living things. The chemicals in living things may have a great deal in common with the dust in outer space, but God did not require a space nebula to supply His raw materials.
Genesis of the zombies’ curse.
“Zombies have a long natural history, stretching back tens of millions of years, and nature is filled with creeping, oozing, blood sucking and otherwise ghastly creatures just as terrifying as anything Hollywood could concoct.” So writes Brian Switek, author of Written in Stone: Evolution, the Fossil Record, and Our Place in Nature. Switek’s pre-Halloween article for Smithsonian Magazine catalogues a number of these ghoulish parasites. He quotes ecologist David Hughes, who has worked with zombie ants: “Now that we know the behavior like this can fossilize, I would not be surprised if we find more. I believe samples tens of millions of years older are likely.”
The “fossilized behavior” Hughes speaks of refers to fossil evidence that fungal infestation of insects produced the same alterations in behavior long ago as those we see today. For instance, today we know the fungus Ophiocordyceps unilaterius parasitizes ants, prompting them to climb to a certain level in the jungle canopy, bite down on the shady underside of leaves where the temperature and humidity are optimal for fungal growth, and remain there until death. Fossilized leaves from Eocene rock (48 million years ago by evolutionary dating) in Germany preserve markings like those left by the ants on modern leaves.
Of course, the claim that these parasites and their zombie-creating effects are millions of years old comes from the radiometric dating of the rock layers in which such fossils are found. Radiometric dating methods are all based on a number of unverifiable assumptions. (See Radiometric Dating: Back to Basics, Radiometric Dating: Problems with the Assumptions, and Radiometric Dating: Making Sense of the Patterns.)
Switek’s article reviews the “evolutionary success” of a number of parasites infecting ants and snails. He concludes, “It’s not yet clear what chemicals signals alter the behavior and appearance of parasitized ants and other victims,” but “Parasites have evolved to be masters of manipulation.”
All of the zombie-makers in Switek’s hall of creepy fame share a key feature: they affect their hosts so as to enhance their own growth and dispersion. For instance, the snail parasite he describes is a flatworm that infects snail eye stalks. The infected eye stalks are brightly colored and readily attract the attention of hungry birds. The parasites are of course eaten along with the unfortunate snails. The flatworms complete their life cycle inside bird digestive systems, leaving eggs to be deposited in bird droppings where they will be consumed by more snails.
Some scientists and fiction writers tend to personify evolution’s ability to manipulate the behavior of parasite victims. Evolutionist Richard Dawkins coined the term extended phenotype to refer to the fact that, while a gene can only encode for the production of a particular protein, a gene’s “extended phenotype” includes all the effects that gene has on all the organisms it affects.
In trying to discover a mechanism by which a gene can extend its phenotype, researchers working with another zombie-like insect8 discovered, in the words of David Hughes, “the first empirical evidence that a gene in the body of one organism can have a direct effect on another organism.”9 A virus affecting gypsy moth caterpillars indirectly prompts the insects to die in treetops by coding for an enzyme that deactivates the hormone that triggers molting. Caterpillar molting behavior is linked to lingering at lower altitudes, so, with no hormonal prompting to molt, the hapless hosts blissfully ascend to die at a location optimal for viral dispersion. This chain of causation illustrates the complexities of natural selection at work in the 6,000 years since the Fall of man and the resultant Curse on creation.
As with the gypsy moth, so with these ant parasites and snail parasites, no new kinds of organisms are evolving. Natural selection is “rewarding” the most effective dispersal strategies. Those parasites that happen to infect their unfortunate hosts in ways that impair neural or hormonal control of behavior or make the hosts particularly vulnerable to predators are naturally selected through successful dispersal.
Genesis says that God called His Creation “very good,” so we are confident that fungi, viruses, bacteria, and even flatworms fulfilled helpful, not harmful, roles in that original world. Since the Fall, a combination of mutations, horizontally transferred genes, environmental changes, and host changes have left us with a number of harmful microorganisms in addition to those that still fulfill vital ecological roles. The zombie-making parasites Switek describes, despite the title of his book, are just reminders of the way natural selection has functioned in this fallen world, not personifications of evolution explaining fossilized behavior. No doubt additional research will elucidate more complicated mechanisms by which natural selection—not evolution—produced extended phenotypes.
Longevity in roundworms lasts until the 3rd generation.
Acquired traits cannot be inherited, but geneticists are increasingly finding epigenetically regulated traits that can. Heritable non-genetic traits include the color of flowers, fruit fly eyes, and mouse fur.10
Stanford geneticist Anne Brunet and Eric Greer have added longevity to that list. Despite the temptation to ponder human applications, this research involved roundworms.
Epigenetic changes provide ways for organisms to respond to environmental changes by reversibly switching genes on and off. The actual genes do not change. Usually this process involves modification of chemical tags on DNA or on the histone proteins that keep DNA packed properly. A typical epigenetic change involves attaching carbon-containing methyl groups.
In the roundworm Caenorhabditis elegans, methylation locks chromatin in an open configuration that alters the expression of nearby genes. Last year Brunet published work showing methylation of a particular complex (H3K4) of roundworm genes increases its life span by 30%.
Greer undertook additional research to see if the improved life span would last through subsequent generations. After inducing the mutation that caused methylation and increased roundworm life span, Greer crossbred the roundworms and selected non-mutant offspring for further study. These non-mutants were genetically identical to ordinary worms that die young, but they nevertheless enjoyed the lingering benefit of ancestral methylation with an extended life span.
The increased life span abruptly ended with the 4th generation. “We would have expected maybe that the effect would gradually wane, but in fact it seems to be disappearing in a more abrupt manner,” Brunet explained. “We don’t know why.”10 The authors hypothesize that the methylated regulatory proteins that are normally “reset from one generation to the next in the germ line” are not being “completely erased and replenished.”11 Thus, until those regulatory proteins are replaced, the fruit of the ancestral epigenetic change continues.
The authors write, “Our study provides the first example of epigenetic inheritance of longevity.”11
And because the same genetic regulators are “conserved from yeast to humans, manipulations of this complex in parents might have a heritable effect on longevity in mammals.”11
This epigenetic methylation mutation is analogous to a confused person breaking all the locks in his house so that they remain in the open position. When the person moves out—analogous to the mutation being selectively eliminated—the locks are still broken. Those locks remain broken until someone has them repaired. The abrupt end of the epigenetic effect may similarly be due to an intrinsic repair process by which the lingering effects of the mutation on DNA-associated regulatory proteins are eventually “cured.” (Ironically, of course, this results in a shorter life for the roundworm, but we’re confident the roundworm doesn’t really care.)
This research of course involved neither evolution of any sort of new creature nor any permanent changes in roundworms. The statement that these regulatory genes are “conserved from yeast to humans” implies these important genes have been transmitted through many kinds of organisms along the evolutionary tree. Beyond that implication, the authors make no evolutionary claims. Epigenetic changes can never offer a way to acquire new genetic information but can only alter the expression of information already present in the genome. It is as yet unknown whether heritable epigenetic changes produce phenotypic variations in humans, but there is good evidence that epigenetic modification does occur in humans, as demonstrated by a recent twin study.12 Epigenetic changes are evidently one of the ways God designed for living things to vary enough to cope with changing conditions.13
Net of Denisovan cousins widens.
Denisovan people—considered “archaic humans” by most anthropologists—are known only on the basis of a finger bone and a couple of teeth from a Siberian cave. The discovery of Denisovan genes in natives of Oceania14 has now been joined by research published in the Proceedings of the National Academy of Sciences to compel further adjustments in the popular model for human evolution.
Although Denisovan people apparently left little in the way of an archaeological or anthropological footprint, their legacy is a fairly wide ancestral contribution. Mattias Jakobsson and Pontus Skoglund of Uppsala University, analyzing genotype data from around the world, have found that Denisovan genes are not only found in Melanesian people but also in Southeast Asians.
“We found that individuals from mainly Southeast Asia have a higher proportion of Denisova-related genetic variants than people from other parts of the world, such as Europe, America, West and Central Asia, and Africa. The findings show that gene flow from archaic human groups also occurred on the Asian mainland,” says Jakobsson.
“Our study covers a larger part of the world than earlier studies, and it is clear that it is not as simple as we previously thought. Hybridization took place at several points in evolution, and the genetic traces of this can be found in several places in the world. We'll probably be uncovering more events like these.”
Because complete genomes of modern humans “are only available from some dozen individuals today,” Skoglund and Jakobsson cast a wider net by searching genotype databases. Genotype information is less complete than full sequences, but a vast amount of genotype data exists. Analysis using genotypes can overlook “unusual variants” and thus prejudice results, but genotype data provided a way to screen a large worldwide sample for Denisovan genes.
“While we can see that genetic material of archaic humans lives on to a greater extent than what was previously thought, we still know very little about the history of these groups and when their contacts with modern humans occurred,” says Skoglund. The absence of Denisovan genes in other parts of the world coupled with the wide presence in Asia and Oceania is prompting anthropologists to consider other permutations of the “Out of Africa” model. That model has already had to morph to conform to the admission of Neanderthals to ranks of people co-existing with modern humans.
Evolutionary anthropologists suggest modern humans diverged from the Neanderthal-Denisovan branch 300,000 to 500,000 years ago. And they suggest the “hybridization” of Denisovans with those moderns occurred 20,000 to 40,000 years ago. However, the latter estimate, like the initial divergence, “is based on models of the rates that genes typically mutate and could be off the mark.”15
As the “Out of Africa” model for humans evolving in Africa gets adjusted to allow multiple migrations of co-existing interbreeding people groups, we need to realize that the model is based on the notion that humans share a common ancestor with apes. Museums abound with assertions that the fossil record proves this connection. In reality, the only ape-men are ape fossils mislabeled as human-related and human fossils misidentified as apes.
Jakobsson says, “It is not as simple as we previously thought. Hybridization took place at several points in evolution, and the genetic traces of this can be found in several places in the world.” In fact, the story is actually quite simple. The Bible tells it.
Emerging genetic data on Neanderthals and now Denisovans is increasingly demonstrating that humans are all of one race. “Hybridization” is a terrible term for this genetic mixing since all people groups—whether classified “archaic” and modern—descended from Adam. All those descended from Noah’s family—the only people to survive the Flood—supplied the gene pool we see today, unmixed with ape or any sort of transitional subhuman. Noah’s descendants dispersed from the tower of Babel. As people groups became isolated, limitations in genetic variability combined with other genetic phenomena such as founder effects produced the people groups in anthropological catalogues, including Neanderthals and Denisovans. The fact that their genetic presence can now be tracked across the world’s geography testifies to the fact they and all other people are related, some more closely than others, with dispersal patterns now being found not representing evolutionary emergence from Africa but dispersal from the plains of Shinar.
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