Did “human ancestors” come down from the trees to graze?
Another australopithecine species is in the news for the dietary innovations it supposedly achieved for the human evolutionary story. The only known fossil of Australopithecus bahrelghazali, found in 1993 in Koro Toro, Chad, is a partial lower jaw with seven teeth. Analysis of carbon isotopes in a tooth suggests the owner ate a diet heavy in grasses and sedges. Since australopithecines are considered by most evolutionists to be human ancestors, evolutionists see the discovery as evidence that evolving primates were using their bipedality to exploit new food sources by coming down from the trees to graze.
Chad is in Central Africa, roughly 1,700 miles west of Hadar, Ethiopia, where the famous Australopithecus afarensis “Lucy” was recovered. Current evolutionary reckoning considers Lucy about 3.2 million years old, and sandstone fossil beds of Koro Toro where Au. bahrelghazali was buried are dated at 3.0–3.5 million years, putting them in the same general evolutionary timeframe as Lucy. Lucy’s diet has yet to be assessed, although some scientists suggest Au. bahrelghazali is really another Au. afarensis fossil.
Whatever sort of australopithecine the jaw may have belonged to, its discoverer Michel Brunet and archaeologist Julia Lee-Thorpe are excited by the possibility that this hominin was out of the trees grazing more than a million years earlier than the other hominin grazer, Paranthropus boisei. That extinct ape is also known as “Nutcracker man” though he was neither a man nor, it turns out, a nutcracker.1
Most carbon is carbon-12. A tiny amount is carbon-13, a non-radioactive isotope having one extra neutron per atom. Plants utilize carbon dioxide for photosynthesis, but the first step varies. Most plants, including trees and their products like fruit and nuts, first form a three-carbon compound. Others, such as tropical grasses and sedges, can start with a four-carbon compound. Plants utilizing the three-carbon approach discriminate against carbon dioxide containing carbon-13. Therefore, high levels of carbon-13 in the Au. bahrelghazali specimen suggest it ate more like a cow than a modern ape.
Primates don’t usually eat grass, lacking a ruminant’s gastric modifications to facilitate its digestion. Therefore Lee-Thorp suggests Au. bahrelghazali may have eaten underground tubers and bulbs of these grassland plants as well as stems of sedges like papyrus. (Others note they also could have eaten grazing animals, but no one has yet shown australopithecines to be carnivorous.)
Actually, no one has shown australopithecines to be human ancestors, either. They are extinct apes. The researchers have learned something about the sorts of plants that were in their food chain. And while primates that eat grass may seem unusual, the diet likely reflects the environmental availability of food where the animal lived. It does not, however, push “back the date that our ancestors came down out of the trees and began eating C4 grasses.”3 Our ancestors were created fully human by God on the same day as apes. Conclusions to the contrary are based on numerous unverifiable assumptions about the past and the imaginative determination to explain our existence apart from a Creator.
Untestable age of the earth becomes contestable political litmus test.
Apparently the answers that work for the winner don’t work for people who don’t currently occupy the Oval Office. To blend political cartoon caricatures with the old proverb about geese, turned upside down, we could say, “What’s good for the ‘donkeys’ isn’t good for the ‘elephants.’”4 That’s the message of the media feeding frenzy that has overtaken Florida Republican Senator Marco Rubio, someone mentioned as a possible Republican presidential candidate for 2016.
Asked about the age of the earth during an interview for GQ, Rubio offered an answer that respected the freedom of Americans. Americans have different ideas about this worldview-based issue of historical science. Rubio’s answer indicated his respect for those who accept the historical record of the Bible above the untestable speculations of those who deny God’s eyewitness account. And his answer mirrored the answer given by then-presidential-candidate Barrack Obama in 2008. Yet, ironically, the media has now characterized him (and everyone else who doesn’t step up to avow allegiance to evolutionary interpretations of earth’s history) as an unscientific ignorant rube.
Just a few months back, children’s TV host Bill Nye charismatically captured the hearts of many with his unfounded assertion that humanity’s future progress depends on today’s children embracing evolutionary fairy tales about the past.5 Now many in the media are tarring Rubio with the same brush they use on young earth creationists—even though he’s not made any such claims—simply because he answered the age-of-the-earth question the same way President Obama did.
Let’s have a look at their answers and compare:
GQ: How old do you think the Earth is?
Marco Rubio: I'm not a scientist, man. I can tell you what recorded history says, I can tell you what the Bible says, but I think that's a dispute amongst theologians and I think it has nothing to do with the gross domestic product or economic growth of the United States. I think the age of the universe has zero to do with how our economy is going to grow. I'm not a scientist. I don't think I'm qualified to answer a question like that. At the end of the day, I think there are multiple theories out there on how the universe was created and I think this is a country where people should have the opportunity to teach them all. I think parents should be able to teach their kids what their faith says, what science says. Whether the Earth was created in 7 days, or 7 actual eras, I'm not sure we'll ever be able to answer that. It's one of the great mysteries.6
Rolling the clock back, using the historical record, we can see how now-President Obama responded to the age-of-the-earth question. Speaking to the Compassion Forum at Grantham, Pennsylvania’s Messiah College, in 2008, Obama said:
What I’ve said to [my daughters] is that I believe that God created the universe and that the six days in the Bible may not be six days as we understand it … it may not be 24-hour days, and that’s what I believe. I know there’s always a debate between those who read the Bible literally and those who don’t, and that I think is a legitimate debate within the Christian community of which I’m a part. My belief is that the story that the Bible tells about God creating this magnificent Earth on which we live – that is essentially true, that is fundamentally true. Now, whether it happened exactly as we might understand it reading the text of the Bible: That, I don’t presume to know.
Though both politicians have, as we see, declined to take a firm stand on the question, media pundits—both liberal and even some conservative—have pounced on Rubio. His answer has been called “ludicrous” and his intelligence and judgment assailed. The controversy continued through the end of the week, and it included a harsh anti-Rubio opinion piece in yesterday’s New York Times by a Noble prize-winner—but whose award was in economics, not science.
Writing for Slate, journalist Daniel Engber asserts that “the age of the Earth is not a matter of opinion, but a scientific fact” and says, “If Rubio suggested otherwise, it’s because he’s uninformed or stupid.” If Mr. Engber thinks Rubio is “uninformed or stupid,” shouldn’t he assess the President’s “I don’t presume to know” as evidence of the same flaw?
Mr. Engber and those who, like him, are convinced the 4.54 billion year age of the earth is a matter of “fact” are themselves ill-informed of the difference between experimental and historical science. (See Two Kinds of Science for a quick and clear video clip explaining the difference.) Despite the popularizing of evolutionary long-age notions—often using the visual image of people co-existing with dinosaurs7 to cement contempt and scorn for acceptance of God’s authority in the public mind—the billions-belief is based on unverifiable untestable worldview-based assumptions.
Those beliefs, among other things, assume—without proof—that all processes (geological, biological, astronomical, etc.) have proceeded at the same pace and in the same way since the universe supposedly sprang into being from nothing. Yet nothing in science can prove such claims. Experimental scientific proof demands controlled repeatable observations. The earth is already here. We cannot go back in time and observe its origins. We must rely on a historical record to understand unobservable past events. And that record of history is not readable from the rocks—it is only readable in the Bible.
Radio show host Rush Limbaugh says that the media—in an effort to derail Rubio’s potential 2016 presidential candidacy—has created “the ultimate gotcha question.” The liberal media portrays those who fail to declare faith in the secular worldview’s interpretations as “unscientific.” They’ve done it before. Limbaugh says, “Essentially what’s happening here is that Rubio is being Romneyed.” Limbaugh, pointing out that Rubio and Obama took exactly the same stand on the age of the earth, says Rubio could have safely declared, “‘I agree with President Obama. I agree with what President Obama said.’ It’s that simple, because Obama and Rubio said nothing different.”
In the controversy over Sen. Marco Rubio’s comments about the age of the earth, you need to read our current issue of Answers magazine. It presents the ten best scientific evidences that confirm the Bible’s teaching that the earth is young.
The age of the earth cannot be determined by science. But the source of ultimate truth—moral, scientific, theological, and historical—in all areas it addresses is God’s Word. Rubio certainly did not jump in with those who—like us at Answers in Genesis—point out that the plain reading of Scripture is incompatible with a billions-of-years belief. But he did acknowledge the freedom of Americans to hold worldview-based beliefs about the age-of-the-earth—something that has nothing to do with observational experimental science—without being disrespected, demonized, or relegated to the ranks of the ignorant.
Bowel bug type tied to common ape-like ancestry.
You know you have a blood type, but you may not realize you have a “bug type.”8 Back in 2011 scientists discovered that human gut flora—the “good” bacteria that live inside you aiding your digestion, bolstering your immune system, and manufacturing biomolecules you need—come in three different enterotypes. An enterotype is a combination of microbes that tend to be found together in the intestines. “Microbes inhabiting the human gastrointestinal tract tend to adopt one of three characteristic community structures, called ‘enterotypes’, each of which is overrepresented by a distinct set of bacterial genera.”9
Researchers from the Yale Microbial Diversity Institute have discovered that chimpanzees harbor the same sorts of enterotypes as humans. They observed that “chimpanzee enterotypes are compositionally analogous to those of humans.”9 But they interpret their observations as evidence for evolution, writing, “These results support the hypothesis that enterotypic variation was present in populations of great apes before the divergence of humans and chimpanzees.”9
These three graphs show the relative abundance of the genera (genuses) of bacteria in each enterotype. The bacteria of each enterotype tend to be fellow-travelers in that their populations vary in proportion to one another’s. For instance, enterotype 1 (indicated by yellow) is dominated by bacterial species of Bacteroides, Faecalibacterium, and Parabacteroides. This combination of bacteria produces an abundance of the enzymes used to manufacture the vitamin biotin.8 This enterotype 1 combination is found more often in people whose diets are high in animal fats and protein. These bacteria are relatively rare, however, in the microbial ecosystems of enterotypes 2 and 3, which are dominated by their own characteristic bacteria. Image credit: A. Moeller et al.9 at johnhawks.net.
The fact that the ecosystems (aka microbiomes) in human intestines come in three different varieties was discovered through genetic studies. Samples were collected from a wide variety of people from all over the world. DNA fragments were extracted and the human fragments discarded. The remaining microbial DNA fragments were categorized to discover the identity and proportions of bacteria living in each person.
Three, and only three, distinctive ecosystems were found in human digestive systems. Each of these microbiomes consisted of a prominent group of bacteria. Each microbiome was also most suited to manufacturing a “unique balance” of valuable enzymes and other substances.8 Each person’s “bug type” was independent of geography, ethnicity, health, and age. Even the existence of chronic bowel disease did not correlate with the microbial ecosystem. Long-term diet did correlate, however, with one enterotype being more likely to occur in people who eat high carbohydrate diets, for instance, and another in those who regularly consume lots of animal fats and protein. Thus, a microbiome can be thought of as “a multispecies community, in which each kind of bacteria has its own distinctive metabolic role,” possibly supplementing the diet.
The Yale group’s eight-year study of chimpanzees in Tanzania’s Gombe Stream National Park has discovered that, though specific bacterial species vary, the genera (genuses) of bacteria that tend to be fellow-travelers are the same in chimps as in humans. “Chimpanzees possess enterotypes that are compositionally similar to those observed within human populations,” says lead author Andrew Moeller.10 Enterotypes of individual chimps typically changed over the course of the eight years but without any pattern. And the chimp enterotypes showed no patterns within families, by age, or according to seasonal variations in the available diet.
While the researchers do not claim that the microbial ecosystems have remained stable for millions of years, the fact that three analogous types occur in humans and chimps is being interpreted as evidence that ancient gut flora shaped the course of human evolution. “This shared [human and chimpanzee] organization of the gut microbial community is millions of years old and the findings attest to their functional importance,” explained Howard Ochman, director of the Microbial Diversity Institute. “Now that we know enterotypes have been maintained over evolutionary timescales, our goal is to determine their functions and how they might be important to the health of their hosts.”
Further research to discover the causes, consequences, and advantages of the various microbiomes is certainly needed. As that information is discovered, the Yale team’s findings could well lead to helpful medical applications. But the discovery has nothing to do with evolution and does not support the notion that humans and chimps share a common ancestor. Chimps and humans, created to live in the same world, benefit from similar combinations of helpful bacteria. Each enterotype is an ecosystem that promotes production of certain vitamins. It is not surprising therefore to find that each enterotype is best suited for symbiotic relationships with humans that eat certain types of diets. Potential medical applications depend upon testable observations and experimental science in the present, not evolutionary insights.
The Yale Microbial Diversity Institute was established to discover more about microbial diversity because “Microbes govern processes ranging from biogeochemical cycles to the health of individual humans, animals, and plants.”11 This fact is a reminder that the majority of microbes are actually helpful, not harmful. And furthermore, God created a perfect world in which microbes without a doubt fulfilled their proper roles in their proper niches, helping the environment and all the living things God created. Only after sin’s curse entered our world did the ordinary processes by which microbes vary lead some to become harmful. Hopefully these discoveries will eventually be useful to medical professionals dealing with the challenges that occur in the present world.
Common ancestor of Neanderthals and Homo sapiens said to have made spears.
“Hafted” spear tips—stone spear tips attached to shafts—were important tools for Neanderthals and for early modern humans. Fossils of animals with injuries suggesting they had been brought down by projectile weapons abound. Dinner-on-the-hoof could be more reliably obtained with a real spear than with a sharp stick or a club.
“There is a reason that modern bow-hunters tip their arrows with razor-sharp edges. These cutting tips are extremely lethal when compared to the effects from a sharpened stick. Early humans learned this fact earlier than previously thought,” explains Benjamin Schoville, co-author of a study just published in Science. He and his colleagues have meticulously analyzed a group of stone tips from a 1979 excavation at the Kathu Pan 1 archaeological site in South Africa. The tips were found in a Middle Pleistocene excavation that was later dated to around 500,000 years using optically stimulated luminescence12 and U-series/electron spin resonance dating.
The apparent antiquity of these tips combined with good evidence that they were hafted onto spear shafts suggests, the researchers say, that the earliest humans had developed the skill of making hafted spears before the common ancestors of Neanderthals and early modern humans diverged. Previous evidence for hafted spear tips is conventionally dated at about 300,000 years.
“Rather than being invented twice, or by one group learning from the other, stone-tipped spear technology was in place much earlier,” Schoville says. “Although both Neandertals and humans used stone-tipped spears, this is the first evidence that this technology originated prior to or near the divergence of these two species.” Based on the dates obtained from the site, the researchers attribute the stone tips to Homo heidelbergensis, believed by evolutionists to have been the last common ancestor of Neanderthals and early modern man.
Given that the wooden handles of spears would have long since rotted, how can researchers determine that the stone tips found at Kathu Pan 1 were mounted on spears? There are a number of clues.
“When points are used as spear tips, there is a lot of damage that forms at the tip of the point, and large distinctive fractures form,” explains coauthor Kyle Brown. “The damage on these ancient stone spear points is remarkably similar to those produced with our calibrated crossbow experiment, and we demonstrate they are not easily created from other processes.” Brown made replicas of the stone tips from similar materials (mainly banded ironstone), hafted them onto dowels, and fired them at animal carcasses. Though these were spears, a calibrated crossbow was used to achieve uniformity. They performed adequately and upon subsequent examination showed the kind of wear found on the original tips.
The stone tips had markings near the bases consistent with additional flakes having been chiseled away to create a groove to secure the tip to a spear handle. The tips are the right size and contour for spear tips but are too large for arrowheads or darts. Additionally, these sharp stones were symmetrically sharpened, as would be expected from a sharp tool used as a projectile. A cutting tool is ordinarily sharpened asymmetrically, sharpening only the side used for cutting.13
“It now looks like some of the traits that we associate with modern humans and our nearest relatives can be traced further back in our lineage,” says lead author Jayne Wilkins. “This changes the way we think about early human adaptations and capacities before the origin of our own species.”
Evolutionists consider Homo heidelbergensis to be more evolved than Homo erectus and to be the last common ancestor of Neanderthals and early modern man. Homo heidelbergensis skulls have less prominent features than heavier boned, brow-ridged Neanderthals. Most of the known Homo heidelbergensis fossils have been found at La Sima de los Huesos in Spain. (See News to Note, June 16, 2012 for a discussion of the controversial re-classification of these fossils and diagrams of the evolutionary tree.)
The people descended from Noah’s family were technologically capable, intelligent people. (See The Genius of Ancient Man) They initially used their technological prowess to construct the Tower at Babel and to stubbornly root their civilization in the region of Shinar in defiance of God’s command to disperse and spread humanity around the globe. God therefore confused their languages to scatter them. Different groups carried with them differing degrees of skill, knowledge, and ability to exploit the resources in the environment. But all of these people would have been intelligent, certainly capable of constructing some tools as needed. Thus it is no surprise that evidence of human intelligence in ancient varieties of humans keeps turning up.
Fossils of people descended from those dispersed from the Tower of Babel are found in various layers of Pleistocene rocks, which were laid down during the Ice Age. (The Ice Age occurred after the global Flood of about 2350 BC and was triggered by it.) Variations exist between these skeletons, with Homo erectus being found in the deepest layers, but they are as human as we are. Homo heidelbergensis fossils are found in layers dated by evolutionists back to around 600,000 years. Neanderthals appear above that level, and only early modern humans are preserved in layers above these. Biblically we understand that a variety of intelligent people dispersed from Babel, and these human fossils track the dispersal of them and their descendants. The evidence of early and sophisticated spear construction is consistent with the biblical record.
Larval adversity affects genetically mediated behavior in adult fruit flies.
Are personalities and behavioral patterns a product of genetics or environment early in life? This “nature versus nurture” question is likely oversimplified. Recent advances suggest the two are interrelated. Epigenetic effects, by which organisms reversibly switch genes on and off, provide a way that environment can affect genetic expression, and in some cases those effects, though temporary, may be adaptive and even passed on to offspring.14
“Biologists used to think that our differences are pre-programmed in our genes, while psychologists argued that babies are born with a blank slate and their experience writes on it to shape them into the adults they become,” says behavioral geneticist Marla Sokolowski. “Instead, the important question to be asking is, ‘How is our experience in early life getting embedded in our biology?’” She suggests that a fruit fly model may offer food for thought on this question.
The classic “rover” and “sitter” behavior of fruit flies, variants with respect to the “foraging” gene, is easily quantitated in the larva. After several minutes of crawling on a tasty paste, these larvae have produced very different paths, traced in blue. Watch the full video of these rovers and sitters in action in behavioral geneticist Marla Sokolowski’s laboratory at www.wwnorton.com.
Sokolowski’s studies with fruit flies show that environmental adversity—chronic nutritional deprivation—in early life produces a biological footprint that affects adult behavior. The effect varies depending on the genetic make-up of the fruit fly. Sokolowski and colleagues have identified the gene whose expression mediates this effect.
Since behavior patterns affect survival and reproductive success, such epigenetic effects are a key factor in assessing how natural selection can affect creatures. The “foraging” gene that mediates the adult behavioral consequences of larval malnutrition has homologues in a variety of invertebrates as well as in mammalian animals and in humans. It is often associated with food-related behavior.
Chronic malnutrition is a serious problem for human populations. The authors of “Biological Embedding of Early Social Adversity: From Fruit Flies to Kindergarteners” believe their fruit fly findings highlight the urgency of prioritizing resources to address global problems of childhood malnutrition, recognizing both their immediate and long-term consequences.
Sokolowski’s laboratory subjects are two groups of fruit flies with variants of the “foraging” gene (for). Appropriately named “rovers” and “sitters,” the fruit flies—both larval and adult—differ in their behavioral response to food. Rovers are aggressive explorers, darting about in a staccato of motion, as if they are searching for food but are too busy to eat much. Sitters display a more laid-back approach to finding food but tend to eat more.15 When the larvae are raised with plenty of food, this behavior continues into adulthood.
When larvae are raised with chronic dietary deprivation, however, both rover and sitter adult flies display the desperate-appearing darting about as they focus on finding food and eating it. And while the rovers’ darting behavior appears unchanged, they do eat more. Fat storage and memory are affected.15 Furthermore, while nutritionally deprived young rovers grow up to be fertile adults, nutritionally deprived sitters have diminished fertility.
“The foraging gene makes an enzyme called PKG, which is found in the fly as well as in most other organisms, including humans,” Sokolowski explains. Homologues of the foraging gene influence “energy balance, food intake, and food-related movement and learning in flies, ants, nematode worms, bees, and even humans,” she reported at an Association for Psychological Science conference in 2009.15 It also is associated with honey bee transformation from nurse to forager.16
“When faced with a nutritionally adverse environment while growing up, the levels of the enzyme dropped in flies. This told us that the foraging gene listens to its environment,” says Sokolowski. “This is the first volume of collected research to provide a substantial and comprehensive picture of the interaction between experience and biology in the early years. Developmental neuroscience is extraordinarily intricate and complex.”
Sokolowski and colleagues, like most evolutionists, believe the foraging gene and its homologues demonstrate the common ancestry of living things. They therefore write that “reasoning from evolutionary biology” may help explain “individual variations in how humans react to their environment.”17 As we regularly point out, however, common design—including similarity of some genes in a wide variety of organisms—does not prove common ancestry but is consistent with the existence of a common Designer. God created all kinds of living things to live in this world and to be able to vary within their kinds. No evolution of new kinds of organisms is supported by this research.
The discoveries of epigenetics will doubtless continue to shed light on the genetic and environmental influences on animals and humans. And learning of possible long-term effects of childhood malnutrition on survivors only increases the urgency of such human tragedy, yet these issues have nothing to do with evolution.
Sokolowski and colleagues acknowledge the enormous complexity and the vast number of variables that can influence fruit fly behavior. And humans are still more complex. We must be cautious and avoid extrapolating to unwarranted conclusions about humans. An evolutionary bias could increase the likelihood of this error.
Much work remains to be done in exploring the interplay of genetic expression and environment as well as the potential for long-term impact on behavior and personality in both animals and humans. There is non-material spiritual aspect to human personality and behavior, and we are not just the sum of our parts and our past. Every person is a sinner who is accountable to our Creator, and each of us—privileged or deprived—needs the grace offered through Jesus Christ.
Remember, if you see a news story that might merit some attention, let us know about it! (Note: if the story originates from the Associated Press, Fox News, MSNBC, the New York Times, or another major national media outlet, we will most likely have already heard about it.) And thanks to all of our readers who have submitted great news tips to us. If you didn’t catch last week’s News to Note, why not take a look at it now? See you next week!
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