So, how did the zebra get its stripes?
Move over, Rudyard Kipling. Here’s a “Just So Story” extrapolating from Hungarian horseflies and plastic zebras to the evolutionary past of zebras on the African savannah. Yet for all its limitations (most of all, it does not demonstrate any evidence for molecules-to-man evolution), the study just published in the Journal of Experimental Biology is the first experimental evidence actually documenting a potential selective advantage to having stripes.
Hungarian and Swedish researchers observed Hungarian horseflies bothered dark horses worse than white ones and set out to learn why. Horseflies—of which there are 41542 pesky species worldwide—use their mandibles to tear flesh, driving some animals to distraction while extracting blood and often transmitting blood-borne infections to their victims.3 The team noted light bouncing off dark horses was polarized, whereas light reflected from white coats scattered. Light reflected off water is polarized, with the light waves aligned. Knowing horseflies lay eggs in water, the researchers suggested polarized light attracts horseflies for this reason.
Having confirmed experimentally that horseflies were attracted to polarized light, the team set out to discover the zebra’s secret. Zebra embryos start out black and acquire white stripes by prevention of melanin deposition in species-specific patterns. After luring horseflies to a sticky demise on a several surfaces at a horsefly-infested Hungarian horse farm, the team discovered horseflies were actually repelled by stripes even more than by plain white. The narrower the stripes, the more repulsive.
“We created an experimental set-up where we painted the different patterns onto boards,” said Dr. Susanne Akesson. “We put insect glue on the boards and counted the number of flies that each one attracted.” The most realistic zebra pattern attracted the fewest horseflies, “even less than the white boards that were reflecting unpolarised light,” she explained. “That was a surprise because, in a striped pattern, you still have these dark areas that are reflecting horizontally polarised light. But the narrower (and more zebra-like) the stripes, the less attractive they were to the flies.”
Since zebras are notably absent from Hungary, the final field experiments involved life-size plastic horses sporting brown, black, white, and realistic zebra-patterned “flypaper” (actually, a coating of insect-monitoring glue). The plastic ponies confirmed the findings in the sun and in the shade.
The shunned stripe widths are actually those present on the head and legs of the three living zebra species, leaving zebra backs unprotected. The team writes that thin skin doesn’t protect blood vessels well on the head and legs, making them more vulnerable to irritation. They write, “In the head, there are several sensory organs (eyes, ears, tongue, muzzle), the efficient functioning of which is most important for survival. The legs also are indispensable to escape from predators. Consequently, head and legs must be protected in the best possible way from blood-sucking parasites . . . since any injury to these body parts due to aggressive biting insects might result in their insufficient functioning, undermining the escape and survival of the animal.” The team suggests biting horseflies distracted ancestral horses from grazing efficiently, thus hampering reproductive fitness and survival of stripe-less creatures.
While the researchers don’t claim horseflies were the only selective pressure giving zebras an evolutionary advantage in Africa, they point out that none of the other ideas explaining zebra evolution—camouflage, visual confusion of predators, social recognition, mate attraction, and thermoregulation—have any experimental data to support them. Darwin maintained the ancestral horse was striped,4 so from an evolutionary point of view, according to University of Manchester’s Matthew Cobb, the researchers need to “show that tabanid [horsefly] fly bites are a major selection pressure on zebras, but not on horses and donkeys found elsewhere in the world... none of which are stripy.”
Biblically and scientifically, we know zebras, horses, ponies, and donkeys are of the same created kind. God created animals to reproduce “after their kinds.” The fact all these animals are able to mate and produce hybrid offspring that are fun to see and name—zonkeys, zorses, zebrulas, hebras, and mules—confirms they are of the same kind. Answers in Genesis molecular geneticist Dr. Georgia Purdom agrees, “A pair of the equine kind got off Noah’s ark about 4,300 years ago, and genetic information—including genes for various coat colors—in that pair provided the raw material for all the equine varieties we see today. Speciation mediated through natural selection and other means enabled their descendants to adapt to many environments in the post-Flood world.” There is certainly no “hydrocarbon-to-horse”5 evolution evidenced in this study, just one possible means by which annoying insects could have been a factor in the speciation of horses.
Atheist websites scramble to stack the deck.
Budget Travel is taking a poll for “15 places every kid should see before 15.” Several atheist groups are very upset the Creation Museum recently made it to the top.
One atheist website—which dubs itself “The Friendly Atheist”—begs people to “Keep the children out of here” and to “go vote for anything so that the museum gets kicked off the list,” adding, “Then tell your friends to vote too.” Another atheist website, well known not only for its vehement attacks on Christians but its blasphemous attacks on God, noted “The Creation ‘Museum’ was at #1 earlier, but it has begun to slide downward. How about pushing it farther?” and then recommended a strategy. Others have nominated mock names to the travel website—“Creatard Museum,” “Creeashun Muzm,” and “Crustacean Museum”—though, to the travel web monitors’ credit, these have been removed. More deliberately, variations of the name Creation Museum, slightly misspelled, kept popping up on the travel site, probably placed there by anti-Creation Museum nominators hoping that museum supporters will not vote for the correct listing and spread their votes out over a few wrong names (and thus dilute the total museum vote).
How very unfair these atheists are to deprive the public of a fun and helpful poll in order to advance their own agenda! In any event, the atheists’ campaign has not only produced some rather curious fluctuations in the tallies but also captured the attention of many who wish to express their opinions by more than a simple “click” on the “thumbs up.” While most listings have few if any comments, and only a few—as of our press time—had between 5 and 20 comments, the Creation Museum KY listing contained 959 comments. Opinions vary, as we would expect, but many are positive and thoughtfully written. But love it or hate it, a lot of people are speaking up!
Despite the fact atheists such as Richard Dawkins favor teaching children the evolutionary tale from age five,6 the “Friendly Atheist” asserts, “Of all the places kids ought to visit at a young age, the Creation Museum should be faaaaaaar down on the list. It’s much more entertaining when you’re older and know enough about how the world works to realize the whole thing’s a sham.” In fact, Dawkins asserts creation accounts such as what he calls “the Adam and Eve creation myth”6 leave a “child's questions unanswered, or they raise more questions than they appear to answer.”6
Answers in Genesis and the Creation Museum exist to equip people—including children—with God’s answers to their questions about our origins. In fact, we point people to God’s answers for life’s most important questions—“Where did we come from? Why are we here? Where are we going?”7 The many displays and videos in the Creation Museum help people of all ages see the answers God provides in the Bible are consistent with the evidence we see in the physical world. Hearing what the Bible says from the very first verse, even young children can understand where we came from, why there is suffering in the world, and why Jesus chose to come into this world “to seek and to save that which was lost” (Luke 19:10).
God, after all, was the only eyewitness to our origins. And God does not lie—neither about our origins nor about our sinful natures. And no scientist, no matter how well meaning, can overcome the limitations of time and space to go back and make testable, repeatable observations of the origin of life. Dawkins writes, “Evolution is a truly satisfying and complete explanation of existence, and I suspect that this is something a child can appreciate from an early age.”6 Yet what can be more satisfying for a child than to learn Jesus Christ loves children enough to give them answers and to say “Let the little children come to Me, and do not forbid them; for of such is the kingdom of God” (Luke 18:16).
Peppered moth: “the poster child of Darwinian evolution”8
The peppered moth—widely hailed as “a compelling example of evolution in action”—is back in the news thanks to the posthumous publication of “the last experiment of Michael Majerus.”9 Majerus, an evolutionary biologist, in 1998 wrote Melanism: Evolution in Action, a book in which he suggested “the peppered moth case is fatally flawed as an example of Darwinian evolution.” Majerus was critical of naturalist Bernard Kettlewell’s methodology. Kettlewell’s experiments in the 1950s had given the peppered moth iconic status in evolutionary texts.
A subsequent book review in Nature in which evolutionist Jerry Coyne wrote, “My own reaction resembles the dismay attending my discovery, at the age of six, that it was my father and not Santa who brought the presents on Christmas Eve,”10 really caught media attention. Coyne, summing up his critique, wrote, “Depressingly, Majerus shows that this classic example is in bad shape, and, while not yet ready for the glue factory, needs serious attention.”10
The color of the moth Biston betularia is a fine illustration of Mendelian genetics. The black color of the carbonaria variety is conveyed by a single dominant gene, but the peppered typica form predominated in mid-18th century England. When the Industrial Revolution resulted in soot-covered trees and acid rain destruction of tree lichen, the lighter peppered moth lost its camouflage, contended Kettlewell, and became vulnerable to bird predation. The moth population soon became predominantly black. Once clean air controls were instituted, the population shifted in favor of the peppered variety.
Much of the legitimate criticism of Kettlewell’s classic experiments devolved on the question of whether moths really rest on tree trunks during the day and whether the population shift was related to bird predation. Majerus set out to solve the moth mystery, correcting weaknesses in Kettlewell’s work. Majerus observed 4864 moths during his six-year study. He died before results could be published. Analysis of his data by colleagues published online February 8 in Biology Letters confirms “camouflage and bird predation as the overriding explanation for the rise and fall of melanism in moths.”9
Public distrust of “the prize horse in our stable,”10 as Coyne described the moth tale, unfortunately skyrocketed due to scathing allegations of fraud in Judith Hooper’s book Of Moths and Men: An Evolutionary Tale. (Hooper is not a creationist.) Majerus and others have refuted her allegations. Nevertheless, visually compelling accounts of moths glued to tree-trunks transformed the “textbook example of evolutionary forces in action” into a laughingstock.
From the point of view of evolutionists, the moth debacle was unfortunate because it eroded public confidence in the oft-taught assertion that this dramatic example of natural selection supported the notion of molecules-to-man evolution. As evolutionists generally contend, “Macroevolution is simply microevolution writ large: add up enough small changes and we get a large change.”11
From the point of view of biblical creationists, the moth debacle was also unfortunate, though for different reasons. By latching onto the scandalous assertions, some people failed to address the fallacious textbook use of this illustration to support Darwinian evolution. A simple reshuffling of existing genetic information within a created kind (so-called microevolution) is not logically connected to the evolution of new kinds of organisms from lower forms (so-called macroevolution, a process that would require the never-observed acquisition of new genetic information).
Furthermore, creationists pointing to the suspect experiment drew criticism for supposedly denying natural selection occurs. Historically, creationist William Blyth published articles describing natural selection in the Magazine of Natural History 22 years before Darwin published his assertions, some of which were lifted almost verbatim from Blyth’s work.12 We at Answers in Genesis, like most biblical creationists, fully affirm the observable reality and the importance of natural selection (though we submit the term “natural selection” is a poor choice of words to describe the phenomenon; nature does not have a mind and can’t be a “selector”). But natural selection acts only on existing information; it cannot create new genetic information to produce new kinds of organisms. Nevertheless, creationists who question the classic moth model are often falsely accused of denying natural selection.
If the moth population truly shifts in response to change in environmental conditions—which Majerus’s work and another of study13 of similar moths in the polluted northeastern United States suggest—then the peppered moth story is “fine example of natural selection in action.” And with Majerus’s observations now confirming moths really do rest on trunks before sunrise and get gobbled up by birds early in the day, we even know the agent of natural selection, at least in England. But the peppered moth is not and never has been proof of “Darwinian evolution” in the molecules-to-man sense.
Ancient sponges take center stage as “our great-great-great-great-great-great-great grandmother.”
The latest candidate for the supposed common evolutionary ancestor of all multicellular animals is Otavia antiqua, a tiny sponge found in Namibian limestone conventionally dated at 760 million years. The international team reporting in the South African Journal of Science considers their microfossil a real milestone. Its age demonstrates, they say, that multicellular life evolved before the extreme “snowball earth” glaciation 700 million years ago,14 thus fulfilling molecular clock demands for the early origin of life and proving that life could survive two extreme ice ages. The previous occupant of the ancestral multicellular throne—another sponge—was recently dated at only 650 million years old.
“If one looks at the family tree and projects this backward to where you have what's called the stem group, the ancestor of all animals, then yes, this would be our great-great-great-great-great-great-great grandmother,” co-author Anthony Prave says. “The aspect of this that's rather satisfying, at least intellectually, is that it is in broad agreement with what geneticists would tell us based on looking at molecular clocks when we should see the first advent of large multi-cellular life forms.” Trying to explain the sudden appearance of diverse multicellular life forms in the Cambrian explosion, evolutionary geneticists have used molecular clock calculations to calculate life sprang into existence much earlier, predicting the existence of undetected Precambrian microfossils, common ancestors of all life on earth.15
“The fossils are small, about the size of a grain of sand,”16 says Prave. They range from “0.3 mm to 5 mm in length and are pierced by numerous tiny holes and some larger openings typical of sponge anatomy. They were found in limestone units “deposited in shallow marine shelf environments.”17 Some of these limestone units are finely laminated and appear to have been deposited under fairly calm conditions, while other limestone units contain abraded fossils that were likely buried during a more violent upheaval.17 All these limestones were found between sediments (called diamictites) thought to be ancient glacial tillite. The fossils were found in several limestone layers, all sandwiched between volcanic ash deposits dated by the uranium-lead method at 548.8 and 760 million years.17
Molecular clock predictions are built upon a statistical house of cards, attempting to predict how long evolution would take if it could happen and if mutation rates were known to be stable. (See News to Note, December 3, 2011 for more details on the illusion of precision produced by statistical games.) And the notion that earth has endured many ice ages is a product of uniformitarian thinking that cannot even satisfactorily explain the origin of one Ice Age without extrapolating to assume the same thing occurred many times. By interpreting various sediments as glacial tillite, evolutionists believe they have confirmation these ancient ice ages occurred. Yet associated with those sediments are limestones—produced in warm water, not glacial conditions—and the diamictites are more consistent with sediments produced by debris flows in submarine landslides.18 Furthermore, the uranium-lead dating method is based on a number of unverifiable assumptions.19 Thus by re-creating earth’s history along uniformitarian principles, evolutionists created a survival saga starring these abundant little sponges.
The global Flood described in Genesis buried billions of organisms and created conditions that caused the subsequent single Ice Age, which is clearly evidenced in earth’s geology.20 Most Precambrian rock layers were formed before the Flood and contain only microfossils. Some of these microfossils could have been deposited in comparatively quiescent waters of the pre-Flood world. The abraded fossils appear to have experienced the violent conditions caused by the collapse of the pre-Flood continental shelves at the beginning of the Flood which generated earthquakes and submarine landslides. Thus these micro sponges may well have been among the first creatures buried at the onset of the Flood, about 4,300 years ago. The geologic column is a timeline of earth history—but not of millions of years, only of about 6,000—and much of it is a record of the order in which organisms were buried during the Flood.
Nothing about these fossils demonstrates they are the ancestor of anything or anybody. In fact, even Prave notes the sponges apparently didn’t evolve during their alleged 200 million year existence, as “the oldest and youngest Otavia fossils all have the same quasi-ovoid form, with large openings leading from the exterior.”16 They are just very small sponges that lived in the wrong place at the wrong time and so got buried under the right conditions to be preserved. Neither their age—which is “known” on the basis of unverifiable assumptions—nor their anatomy suggest they are anything but tiny marine invertebrates, one of the kinds of organisms God created about 6,000 years ago.
Epigenetic inheritance allows rapid adaptation without loss—or gain—of information.21
Inheritance of acquired characteristics? It sounds impossibly Lamarckian, but it’s not because no actual genetic change is involved. Sydney researchers led by Catherine Suter report inheritance of an acquired characteristic without a genetic change in Agouti mice.
Epigenetic changes are modifications of regulators of gene expression. They result in a phenotypic change without alteration in genetic sequences. If epigenetic changes affect the DNA in germ cells or if organisms prone to develop these changes possess a selective advantage, the phenotype may be passed on to offspring. Heritable epigenetic changes have been reported in plants,21 fruit flies,22 mice, roundworms,23 and humans.24
If the new phenotype is advantageous, natural selection may lead to an increase of that phenotype in a population. Yet whenever the factor triggering the epigenetic change goes away—because the actual genome has not changed—the epigenetic change can be reversed and population demographics return to normal.
Since there is no genetic change involved, there is no loss of information. But despite the hopes of evolutionists that this epigenetic form of inheritable change could be an agent of evolution, epigenetic change also does not result in the acquisition of new information. Existing genes are simply switched on and off. Therefore, epigenetic change is instead a reversible method of adaption leading to temporary variation within a kind of organism.
Research involved genetically identical highly inbred Agouti mice. These mice all possessed a mutation of one dominant gene causing them to be fat and yellow.25 Gene regulation determines whether a gene is expressed or not. This particular mutation is known to be subject to epigenetic changes—changes in its regulators—induced by foods supplying a particular substance (methyl donors). When fed that food, the gene for being fat and yellow gets switched off and the mice become lean and brown.
The researchers therefore fed male mice the special diet to turn off their fat-and-yellow allele and then bred them with normal females. They repeated this over the course of four generations, in each generation only breeding lean brown mice—those with the deactivated gene. Finally, they stopped the diet. The next generation was still lean and brown. But after that, the lean brown mice reverted to having fat yellow offspring. The epigenetic change had worn off.
Although the research team has not yet been able to determine the molecular mechanism of this particular epigenetic change, whatever change is being induced by the special diet is only inherited temporarily. This experiment demonstrates a way environmental changes can trigger inheritable changes without loss of genetic information with reversion to the original phenotype when the environmental challenge goes away. Although the researchers were the agents of selection, in the wild the same sort of result would probably occur, as fat yellow mice aren’t as hardy as lean brown ones.
“This kind of reversibility could be very advantageous if a change in environment was only temporary. Populations could revert to the way they were before fairly rapidly, if need be, because a genetic change hasn't occurred,” says Suter.
Evolutionists have suggested epigenetic changes could have a role in evolution, “but there has never been any evidence of it up until now,” says lead author Jennifer Cropley. There still isn’t. This study demonstrates no sort of evolution that could be extrapolated to produce a new kind of organism. Instead it reveals a mechanism God put in place to allow plants and animals and possibly even people to adapt to changes without losing genetic information.
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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