Today’s New Reason To Believe

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Neanderthals Ate Dolphins and Seals

When I was growing up I enjoyed watching reruns of the television series Flipper. As a little kid, I was quite fond of this unusually intelligent dolphin.

According to new research, Neanderthals were fond of dolphins as well.* But instead of delighting in watching them perform, these hominids liked to eat them.

Neanderthals appear in the fossil record between 250,000 and 150,000 years ago and go extinct about 30,000 years ago. They lived in western Asia, Europe, and the Middle East. Popular views about human origins position Neanderthals as immediate predecessors to modern humans. Other more sophisticated treatments of human evolution, like multiregionalism, argue that these hominids gave rise only to European people groups.

Because of their potentially prominent role in human evolution, anthropologists are interested in Neanderthal biology and behavior. This interest motivated an international team of paleoanthropologists and archeologists to analyze the fossil and archeological remains from two coastal caves located in Gibraltar. These caves held several kinds of artifacts that included Neanderthal-made products located at specific levels and layers within the cave, and also artifacts attributed to modern humans found at different sites within the cave. Associated with these finds were fossilized animal bones interpreted as the food stuff leftover from hunting and gathering expeditions.

Cataloging the species that comprise the animal remains provided researchers some insight into the behavior of Neanderthals and some of the first modern humans. For both the Neanderthal and the modern human locales, researchers documented mollusk shells and the remains of red deer, ibex, wild boar, bear, birds, tortoises, and fish, as well as dolphins and seals. Additionally, the scientists discovered rhinoceros remains associated with the artifacts left behind by modern humans.

The researchers interpreted these results as evidence that Neanderthals and modern humans had similar hunting and gathering practices, and, therefore, had identical cognitive capabilities. They were particularly impressed with the ability of Neanderthals to make use of dolphins and seals as a food source. They argue that to effectively do so means that Neanderthals had some sense of the seasonal activities of these animals. Dolphins are known to beach themselves at certain times of the year. It appears as if Neanderthals and modern humans took advantage of beached animals. Seals come ashore during mating season. Presumably, Neanderthals and modern humans clubbed these animals to death during mating season. Interestingly, only juvenile seal remains were recovered from the Neanderthal sites, indicating that they likely went after easier targets.

Based on this new insight, some anthropologists conclude that Neanderthals had skills that compared to modern humans alive at that time, since they seemed to have exploited the same range of resources as modern humans, and likely used similar tactics to hunt and gather. If so, does this mean that Neanderthals are no different than modern humans? What does this discovery mean for the RTB model of human origins?

The RTB View of Hominids

RTB’s biblical creation model views the hominids, like Neanderthals, found in the fossil record as animals created by God’s direct intervention. These creatures existed for a time and then went extinct. RTB’s model considers the hominids to be remarkable creatures that walked erect and possessed some level of limited intelligence and emotional capacity. This allowed these animals to employ crude tools and even adopt some level of “culture” much like baboons, gorillas, and chimpanzees. While the RTB model posits that the hominids were created by God’s divine fiat, they were not spiritual beings, made in his image. The RTB model reserves this status exclusively for modern humans.

The RTB model treats the hominids as analogous to, but distinct from, the great apes. Because of this, the RTB model predicts that anatomical, physiological, biochemical, and genetic similarities will exist among the hominids and modern humans to varying degrees. But, since, the hominids were not made in God’s image, they are expected to be clearly distinct from modern humans, particularly in their cognitive capacity, behavior, “technology,” and “culture.”

In summary, the RTB model predicts that the hominids, including Neanderthals, should be biologically and behaviorally distinct from modern humans. Clearly, this is the case from a biological standpoint.

Neanderthal Biology

Most paleoanthropologists now maintain that Neanderthals represent an evolutionary side branch and dead end. This position derives support from anatomical and developmental studies and analyses of ancient DNA isolated from Neanderthal remains. All research indicates that Neanderthals not only are a distinct species from modern humans, but also could not have evolved to produce the first human beings. (For a detailed discussion of this work, see Who Was Adam?)

These results all bode well for the RTB human origins model. But what about Neanderthal behavior? Maybe Neanderthals didn’t evolve into modern humans. But maybe they independently developed intelligent behavior, similar to modern humans.

Neanderthal Behavior

The vast proportion of the archeological record associated with Neanderthals indicates that these creatures behaved in relatively unsophisticated ways compared to modern humans. (This is discussed in more detail in Who Was Adam?)

Neanderthals made comparatively simpler tools with relatively unsophisticated manufacturing practices compared to modern humans. They left behind no real evidence for symbolic thought and advanced cognitive capacity. They did not produce art or music. They showed no evidence for religious expression. Though these creatures did bury their dead, the burials were clearly non-ritualistic in nature.

In spite of all this other evidence, do the newly recognized hunting and gathering practices of Neanderthals indicate that perhaps they had more sophisticated capabilities than previously thought?

Not necessarily. First of all, the sophistication of Neanderthal hunting and gathering practices compared to those of modern humans remains contentious among anthropologists. A previous study that examined the isotopic composition of skeletal remains seemed to suggest that Neanderthal practices were much less advanced than those of modern humans when it came to exploiting animal resources. According to this research, modern humans tended to go after food resources that were much more difficult to hunt and collect than did their Neanderthal contemporaries.

The fossil evidence recovered from the caves of coastal Gibraltar could be interpreted in a way that more closely agrees with the bone isotope study. It could be that the animal remains represented creatures that were relatively easy to gather and hunt. Both Neanderthals and modern humans would take advantage of easy to access food stuff. But modern humans also seemed to be capable of hunting animals that were exceptionally difficult to kill, like rhinoceros. Only modern human locales in the caves had the remains of these mighty creatures.

Rhinos would be extremely dangerous to hunt and hard to kill. To use these creatures as a food source would require extremely sophisticated hunting techniques that undoubtedly relied on cooperative and complex interactions among the members of the hunting party.

Just because Neanderthals were making use of seals and dolphins as a food source doesn’t mean they had understanding of seasonal variation. Could it be that they made use of these marine mammals seasonally because that was the only time that they were available?

This recent study of the archeological and fossil remains provides important insight into the behavior of Neanderthals. Yet, it doesn’t reveal any new information that necessarily challenges the RTB view of the hominids. Clearly, as assented to by the model, Neanderthals had some intellectual capacity. But when all the data about Neanderthal behavior is considered in its entirety, it doesn’t support the notion that they possessed sophisticated cognitive abilities on par with those of modern humans.

*This study made science news headlines when first published. I discussed the scientific and biblical implications of this research on the September 24, 2008 edition of Science News Flash. This podcast offers a unique Christian perspective on headline-grabbing discoveries. A free subscription is available through iTunes.

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Newly Discovered Example of Convergence Challenges Biological Evolution

A few weeks ago, while on a hike, I had to climb uphill through a boulder field. It was tough treading. Several times I wound up stuck amid the rocks with seemingly no way to maneuver. You might say I was literally, and metaphorically, stuck between a rock and a hard place.

Similarly, a recent study on the origin of a group of flightless birds called ratites puts the evolutionary paradigm in a difficult position.

To complete this study, scientists used 20 different regions of nuclear DNA taken from 18 different bird taxa to build an evolutionary tree for ratites. It turns out that they identified three distinct lineages for this group of birds. The lineages include: one for ostriches; one for rheas; and one for kiwis, emus, and cassowaries. In other words, flight appears to have been lost not once but on three separate occasions in ratites.

Previously, I’ve discussed this example of biological convergence and its troubling implications for biological evolution. This week I would like to raise an additional problem posed by this study.

Traditionally, biologists have used anatomical comparisons (morphology) to characterize evolutionary relationships and build evolutionary trees. Recent advances in DNA sequencing techniques and data analysis have now made genetic comparisons fodder for evolutionary analysis.

One key expectation is that the evolutionary trees built from anatomical comparisons (morphological phylogenies) will agree with trees built from DNA sequence data (molecular phylogenies). This expectation stems from the fundamental notion that molecular evolution should mirror organic evolution. In many instances, however, evolutionary biologists are discovering that molecular phylogenies contradict those built using morphological features. This latest study on the origin of ratites represents one more example of this disparity. Based on morphological features, evolutionary biologists concluded that the ratites must have had a single evolutionary origin. The foundation for this view stems from the fact that all ratites share common anatomical features, like the absence of keels in breast bones, smaller, simpler, and fewer wing bones, bigger leg bones, and non-aerodynamic feathers, as well as similar behavioral traits.

Yet the evolutionary tree for ratites based on molecular data generated from nuclear DNA sequences indicates something quite different. An earlier study of ratite origins using [mitochondrial DNA] sequences proves equally troubling. It suggests a single origin for the ratites, agreeing with the morphological data but contradicting the most recent study using nuclear DNA data.

This is not the first time that the question of bird origins has caused problems for evolutionary biologists. A few weeks ago I wrote about another large-scale study that yielded similar consternation.

A pivotal idea of the evolutionary paradigm, namely that evolutionary trees built from molecules should agree with those constructed from morphology, is not supported by the evidence. As I pointed out earlier, this disagreement is more problematic than it seems on the surface. According to Morris Goodman in an article he wrote for The Cambridge Encyclopedia of Human Evolution,

If the biblical account of creation were true, then independent features of morphology, proteins and DNA sequences would not be expected to be congruent with each other. Chaotic patterns, with different proteins and different DNA sequences failing to indicate any consistent set of species relationships, would contradict the theory of evolution.

These words were published in 1994, before the widespread use of DNA sequences to build evolutionary trees.

Between Goodman’s observations and the latest work on bird evolutionary relationships alone, it looks as if the evolutionary paradigm is running out of room to maneuver.

Previously Posted on January 27th, 2008 by Fazale ‘Fuz’ Rana, Ph.D.

Dental Anatomy Gives Important Clues on Hominid Growth and Development

For a little kid, losing teeth is a rite of passage. Each tooth that falls out (or gets unceremoniously yanked loose) serves as a sign that the child is growing up, as, one by one, baby teeth make way for permanent teeth.

The same is true for hominids, which are often interpreted as transitional intermediates between an ape-like creature and modern humans. Hominid tooth eruption, deposition of microanatomical structures, and tooth wear occurred at characteristic times during their growth and development and throughout adulthood. Because of the relationship between dental anatomy and life history, paleoanthroplogists study these features to gain important clues about the behavior and lifestyle of these now-extinct creatures.

Two recent research projects examined dental features of Paranthropus robustus and Neanderthals. Both studies indicate that these two hominids developed and behaved in decidedly nonhuman ways, extending the separation between the hominids and modern humans in accord with RTB’s human origins model.

RTB Human Origins Model and the Hominids

Instead of viewing these creatures as evolutionary intermediates, RTB’s biblical creation model regards the hominids found in the fossil record as animals created by God’s direct intervention. These primates existed for a time and then went extinct. RTB’s model considers the hominids to be remarkable creatures that walked erect, and possessed some level of limited intelligence and emotional capacity. This allowed these animals to employ crude tools and even adopt a type of ‘culture’ much like baboons, gorillas, and chimpanzees. While the RTB model posits that the hominids were created by God’s divine fiat, they were not spiritual beings made in His image. The model reserves this status exclusively for modern humans.

The RTB’s conceptual scheme treats the hominids as analogous to, but distinct from the great apes. Because of this, the model predicts that anatomical, physiological, biochemical, and genetic similarities will exist among the hominids and modern humans to varying degrees. But since the hominids were not made in God’s image, they are expected to be clearly distinct from modern humans, particularly in their cognitive capacity, behavior, “technology,” and “culture.”

In summary, the RTB model predicts that the hominids, including Neanderthals, should be biologically and behaviorally distinguishable from modern humans.

One study examined facial features and tooth wear for 19 specimens assigned to Paranthropus robustus. This hominid lived between about 2 and 1.2 million years ago in South Africa. (Evolutionary biologists don’t think that this hominid is part of the lineage that led to modern humans. Instead they place P. robustus, along with its two sister species, P. boisei and P. aethiopicus, as an evolutionary side branch and dead end.)

The research team noted that for male specimens the most extensive dental wear correlated with fully developed adult features. Those males with underdeveloped adult characteristics showed little dental wear. This pattern was not noted for females in the sample. These observations indicate that males took a longer period of time to develop than females and imply that P. robustus displayed sexual dimorphism, with males possessing a significantly larger body size than females.

Sexual dimorphism impacts mating strategy. Primates like gorillas that display sexual dimorphism based on body size have a social organization centered on a large dominant male who mates with a harem of females. This means that Paranthropus, and by extension the other Australopithecines, employed a mating strategy similar to gorillas.

In contrast, modern humans display relatively limited sexual dimorphism. As a consequence, males and females form mating pairs.

This work indicates that the Australopithecines were biologically and behaviorally distinct from modern humans, in accord with predictions made by the RTB model. The study also widens the gap between the Australopithecines and hominids that belonged to the Homo genus. According to paleoanthropologist J. Michael Plavan:

The finding challenges a theory that early hominids had a relatively low level of sexual dimorphism, inherited from a common ancestor shared with chimpanzees…Instead, the primitive condition may have been more gorillalike, and our female ancestors may not have closed the gap until recently, perhaps in Homo erectus in the past 2 million years.

The implication: the transition in mating behavior (and the accompanying growth and development process) must have happened rapidly.

Another study examined microanatomical features of Neanderthal teeth as a way to assess the rate of growth and development for these hominids. Biological rhythms produce incremental features in the enamel and dentine throughout childhood that can be used as a record for the individual’s life history.

Earlier studies using these markers have been inconclusive about the growth and development of Neanderthals. Some studies indicate that these hominids grew into adulthood at a pace similar to that of modern humans. Other work suggests that the rate of growth and development was accelerated when compared to human beings.

The most recent study took the most-detailed and comprehensive look at the microanatomical characteristics of Neanderthal teeth. Based on this work, the researchers concluded that Neanderthals grew at a much more rapid rate than modern humans. To say it another way, a prolonged childhood and relatively slow life history appears to be unique to modern humans. And these differences in the length and pace of childhood have important consequences for social organization.

Based on this work, it appears as if Neanderthals are both biologically and behaviorally distinct from modern humans. Once again this finding comports with RTB’s human origins model. Scientific advance makes it increasingly possible to make a scientific case that human beings are distinct from the hominids in a way that harmonizes with the notion that humans are uniquely made in God’s image.

While it is commonplace for human children to put their baby teeth under a pillow in the hope that the tooth fairy will exchange it for “gold,” it’s unlikely that Neanderthal children ever went through such a ritual. They grew up too fast.