The skink that breaks the rules
A lizard with a true placenta? That’s what researchers Daniel Blackburn and Alexander Fleming have discovered by dissecting Trachylepis ivensii, a rare species of African skink.
Most people think of reptiles as egg-layers, but about a fifth of them give birth to live young. These live-bearers, however, actually “lay” their eggs inside the mother’s oviducts. There—after deriving various amounts of nourishment from the mother or the yolk—the young are born “live” after the eggshells have thinned or disappeared. Many live-bearing reptiles actually have some sort of placenta to allow the young to receive nourishment through a vascular avenue.
So, if live-bearing lizards typically have some kind of placenta, what is special about this particular skink? Blackburn and Fleming found that the placenta in this case is deeply embedded and intimately associated with the maternal vascular structures. In other words, as placentas go, this one is particularly well-developed.
In the Journal of Morphology they write, “This species has evolved an extraordinary placental pattern long thought to be confined to mammals, in which fetal tissues invade the uterine lining to contact maternal blood vessels. The vestigial shell membrane disappears very early in development, allowing the egg to absorb uterine secretions.”1
Actually, at least two other kinds of skinks possess high levels of placental development. However, T. ivensii’s “pattern of fetal membrane development . . . is unique among vertebrates. T. ivensii represents a new extreme in placental specializations of reptiles, and is the most striking case of convergence on the developmental features of viviparous mammals known.”1
So with the mammalian placenta considered the pinnacle of reproductive evolution, these researchers are describing this skink as the most impressive reptilian example of a great feature that evolved “no fewer than 132 times.” No transitional fossils accompanying this popular evolutionary pathway, however, have been found. Furthermore, the complex design of Trachylepis ivensii’s placenta is not a copy of mammalian placentas but is “unique.” For these reasons, evolutionists invoke convergent evolution, the classic explanation for the existence of common features in organisms for which even the best evolutionary minds cannot invent common ancestry.
Extant live-bearing lizards and other reptiles display an array of placental morphologies. Furthermore, at least two species of skinks contain both egg-laying and live-bearing members.2 While touted as evidence for evolution, these species are actually good illustrations not of evolution but of genetic variation within created kinds. Those dual-mode skink species exist in different climates, each variety being well-adapted to the challenges of its environment. And there is no evidence that those skink populations are changing their reproductive habits at all or evolving into new kinds of creatures.
While we cannot know for certain how many created kinds of lizards God made in the beginning, we could postulate that the genetic ability for egg-laying and live-birth co-existed at least in skinks of the dual-mode types. Whether other variations of Trachylepis ivensii existed in the past, we cannot know. However, the diversity of placental morphology among reptiles is consistent with the biblical concept that the created kinds of creatures diversified to fill the ecological niches of the world. Natural selection (and other mechanisms) would have allowed the best-adapted populations to survive in each habitat.
A skink with a true placenta is no more an example of evolution than is an egg-laying mammal like a platypus. Each has features that appear to “cross” man-made lines of classification, but this should be no surprise since those categories do not represent evolutionary lineages. God’s creatures are not bound by our classification schemes, and the genetic possibilities He built into organisms made diverse adaptations and good ecological “fits” possible.
Kuiper comets capture credit for watering the early Earth.
Evolutionary scientists believe that water was needed for the evolution of life but have long debated how the early earth could have been supplied with that water. Many have suggested that asteroids bombarding the earth about 4 billion years ago brought organic compounds and water, supplying the raw materials for life to evolve.3 Now Paul Hartogh’s team from the Max Planck Institute for Solar System Research, analyzing data from the Herschel Space Observatory, has determined that comets from the Kuiper belt may have been that ancient source.
So why do these scientists suggest an extraterrestrial water source? Believing that the nebular hypothesis explains the origin of the earth, Max Planck Institute’s planetary scientist Paul Hartogh explains, “When the Earth formed it was so hot that most volatiles escaped to space, so when the Earth cooled down it was dry. Water and other volatiles must have been delivered at a later stage.”
In principle, water from a particular source should match that source in the ratio of elemental isotopes it contains. “Heavy water” is water in which the hydrogen isotope is deuterium, and earth’s water today contains about 1,558 deuterium atoms to every 10 million ordinary hydrogen atoms.
Asteroids have been proposed as possible sources for earth’s original supply of water since deuterium/hydrogen ratios in carbon-rich meteorites thought to be asteroid fragments are in the right neighborhood: 1,400 deuterium atoms per 10 million regular hydrogen atoms compared to 1,558 in terrestrial water. Comets, because they are typically icy, have also been proposed as the primordial water source. However, previous measurements of deuterium ratios in six comets revealed deuterium ratios of about 2,960 per 10 million, twice the amount seen on earth. Researchers have suggested that these six comets originated from the Oort cloud at the outer fringes of our sun’s gravitational influence.
Now, the Herschel Space Observatory has measured the deuterium/hydrogen ratio in comet Hartley 2 and found a near match for earth at 1,610 to 10 million. Hartogh, lead author of a report just published in Nature, says, “With our finding it may be that more than 10 percent and perhaps all water on earth possibly stems from comets. It may be that all bodies in the inner solar system get their water from these comets. Sampling a larger number of comets for their deuterium-hydrogen ratios could shed light on the matter.”
Hartogh, expressing satisfaction with the single measurement obtained during Hartley 2’s fly-by, says, “With our one data point, we showed that comets can have Earth-like D/H ratios and therefore a larger amount of water may have been delivered by comets, perhaps all. . . . At the time of the Solar System formation there may have been a large reservoir of such comets with the correct ratio that bombarded the Earth.”3
The astronomers believe that Hartley 2 originated from the Kuiper belt, a collection of trans-Neptunian objects orbiting in the outer reaches of our solar system. Secular cosmology maintains that the Kuiper belt contains debris from the explosive origin of the solar system.
The “nebular hypothesis” is believed by many secular scientists to explain our solar system’s origin. They maintain that our solar system formed 4.6 billion years ago from a hot cloud of dust and gas. The solar system supposedly formed as dust orbiting the newborn sun stuck together to make primordial planets. Continuing to collide, some debris stuck together while some shattered. One of the problems with the nebular hypothesis is the notion that colliding stardust would stick together rather than bouncing off or exploding on impact. Another problem is that the nebular hypothesis violates the physical laws of conservation of momentum. Nevertheless, in an effort to avoid a biblical explanation for the origin of all things—in other words, God as Creator—many cling to this explanation despite its aberrant physics.
While the isotope ratios in the comets and asteroids are of scientific interest, they tell us nothing about the origin of the solar system. In fact, other recent isotopic data has punched more holes in the nebular hypothesis. (Read more about the isotopes in solar wind at News to Note, July 2, 2011.) Furthermore, while the Kuiper belt is observable,4 there is not proof that it is the source of short-period comets like Hartley 2. (Read more about it at Kuiper Belt Objects: Solution to Short-Period Comets?) The Oort cloud5 is a hypothetical cosmological birthplace for long-period comets that could not otherwise still exist in the time frame demanded by big bang cosmology. The Oort cloud has never been observed. The Bible explains the origin of the water on earth and the origin of the entire universe. And the time of this Creation, about six thousand years ago, does not exceed maximum comet lifespans or demand a hypothetical birthplace to replenish them.
The Bible in the book of Genesis provides God’s eyewitness account of the origin of the universe. God, as the Creator, has told us that He spoke the earth into existence about six thousand years ago. He made the earth with its generous supply of water, not as a hot molten world that would boil away its water. After providing the earth with an atmosphere, dry land, and plant life, He created the solar system and the other stars. He specifies that He made the sun, moon, and stars on the fourth day of Creation week. There is no way to blend the Genesis account of Creation with secular ideas of cosmology such as the big bang and the nebular hypothesis without calling God a liar.
Twin mixes are on the rise in the U.K.
The BBC recently aired a documentary, Twincredibles, following the stories of five families with fraternal twins whose skin doesn’t match. Just half a century ago, “mixed twins” were almost unheard of. The number is on the rise, however, as a consequence of the rising percentage of so-called mixed race people in the British population. And as a bonus to this demographic change, population geneticists predict a medical benefit to the gene pool.
Even to refer to these children as “black” and “white” or “mixed race” is a misnomer. As the Bible clearly teaches (and as the Human Genome Project confirms), “There is only one race—the human race.”6 Racial designations are human inventions, and the slurs and prejudices which often accompany them are the products of ignorance and sin.
University of Edinburgh population geneticist Dr. Jim Wilson explains, “There are about 20 genes [from a total of about 20,000] known to control skin and eye colour. In each gene you have a light-skinned variant and a dark-skinned variant. If you have more of the dark-skinned variant in your DNA, you’ll inherit dark skin. If there’s more light-skin variant, you’ll inherit light skin. Since parents contribute 50 per cent of the genes each to an offspring, the first generation born to a mixed-race couple will definitely be midway in colour between the two. But second-generation children are different. If one of the offspring marries a white person, it is possible for them to have a white child because you no longer have 50/50 white and black variants. Where you have one mixed-race parent and one white parent it’s still unlikely for a white baby to be born.”
Likely or not, the twins featured in the article, Kaydon and Layton Wood, are the children of a white father and a mom with Nigerian and white parents. With fraternal twins, as with any pair of siblings, each child inherits an assortment of genes for skin pigmentation, and the result can be significantly different skin tones. Actually, the skin color of all of us is determined primarily by the amount of brown melanin pigment in the skin. Therefore, no one is fully “white” or “black” but just varying shades of brown. The presence of pigment is the dominant feature, so the likelihood of a mixed race couple producing a “white” child is fairly low. Statistically, a couple like the Woods (with one “white” and one “mixed race”) expecting non-identical twins has about a one in 500 chance that the babies will have different skin colors.7
With an increasingly “racially mixed” population, the number of mixed twins is naturally on the rise. The Office of National Statistics now says, “There may be around two million mixed-race people living in the UK – 3 per cent of the population and therefore a larger group than any of the defined ethnic minorities.”8
Sadly, many orphaned children have been denied adoption due to social policies prohibiting mixed “race” adoptions. Hopefully, those policies will be changing.
On a happier note, Dr. Jim Wilson points out that the increasingly mixed population could decrease the incidence of several inherited diseases that, along with skin color, have accumulated in certain segments of the population. Cystic fibrosis is common only among white people, and it along with a number of other genetically related illnesses should decrease in the population if trends continue.
The Bible teaches that all people are descended from Adam and Eve. Adam and Eve had an assortment of the “skin color genes” which get reshuffled in every person conceived and produce all the skin tones we see. When the descendants of Noah were dispersed from the tower of Babel into smaller groups, the limited genetic variability available in each group eventually resulted in people groups with a preponderance of particular skin tones.
While other features such as hair and eye color are sometimes also found as dominant features in certain people groups, neither the mental capacity nor the spiritual condition of such people groups differ in the sight of God. All so-called races of people are blessed with the wonderful potential God has granted human beings to learn and achieve great things. And all so-called races are sinners in the sight of God and blessed to have the grace of God through Jesus Christ freely available to them. God is no respecter of persons on the basis of skin color or intellect, but He promises to see every person in terms of his relationship with Jesus Christ. Read more about salvation though Christ at Good News.
The story of the three snails
There is a family of smooth-shelled marine snails called Janthinidae that passively float around subtropical oceans suspended from bubble pontoons waiting to not-so-passively grab a bite of passing jellyfish. Their flotation devices are made of mucus secreted from the janthinid foot and folded into air-trapping pockets. “If you're into mucus, it's a fascinating mucus,” says ecologist Celia Churchill. “It's almost like bubble wrap.”
Puzzling over the evolutionary origin of this flotation adaptation, Churchill’s team has compared four DNA reference points to reconstruct the snail evolutionary tree “which confirms that janthinids are derived from Epitoniidae (wentletraps).”9 Epitoniids are another family of snails that live on the bottom of the ocean and do not float. With shells resembling spiral staircases, epitoniids munch on sea anemones and coral. And their females tether their eggs (and their small mates) with “elastic mucus threads.”9
Convinced that the presence of some genetic similarities confirm a common ancestry for these two kinds of snails, the researchers sought a transitional form and believe they found it in one genus of the Janthinidae family: the Recluzia. Unlike the Janthina genus, only the female in the Recluzia species examined builds bubble boats, and the Recluzia’s mucoid bubbles also provide a platform for both eggs and young snails. The bubble floats of some species of female janthinids carry eggs but not juveniles. And one particular species, Janthina janthina, uses bubble rafts exclusively for flotation with all genders and ages building their own rafts.9
Therefore, with many permutations of bubble raft biology in view, the researchers believe they have discovered all the pieces of this evolutionary puzzle.
Churchill and colleagues propose that the common ancestor of all these snails was a bottom dwelling intertidal species9 that wrapped its eggs in mucus. Then one day a bubble got trapped in the mucus and buoyed some lucky primordial snail up to the surface where it managed to survive environmental challenges long enough to discover abundant edible jellyfish. Eventually enough snails did this long enough to thrive at the surface and figured out how to stay there. Somehow the males, which in epontiids are tethered to the egg mass, “also learned to fabricate their own, egg-free life rafts.” And the rest is snail history.
Commenting on the report published in Current Biology, Berkeley biologist David Lindberg said the janthinids “are an incredibly extravagant group with an extraordinary evolutionary history.” Praising Churchill’s team for elucidating the stepwise evolution of the bubbles, he adds, “You could have all that diversity, but if you can't order it, you really are just telling stories.”
Lindberg’s comment, when considered in the light of what these researchers are actually proposing, really does sum up the matter: they “are just telling stories.” They are basing all of their evolutionary conclusions on the assumption that some genetic similarity confirms common ancestry of two families of dissimilar marine molluscs. A common Designer explains the presence of genetic similarity between different kinds of creatures.
If, however, these two sorts of snails were of the same original created kind, then diversification based on the genetic options already available in the genome has taken place, allowing varieties of snails to fill various habitats. That would not represent evolution but just speciation. Indeed, the diversity of bubble raft biology within the janthinid family likely does represent just such diversification of the bubble-rafting snails within various habitats. But if the bottom-dwelling epontiids and top-dwelling janthinids are not of the same created kind, then they do not share a common ancestry, as living things reproduce and vary within their created kinds.
What we do know from the Bible is that God made each kind of organism fully functional and capable of coping with different environments through genetic variations. No evolution has happened here. The researchers have simply discovered the possible reproductive function associated with the buoyant bubble wrap of janthinid gastropods.
Sugary sialic acid signatures seen as evolutionary segregators of early humans
Cells must be recognized as “self” to avoid immune system attacks. The signatures of self are often sugar-like sialic acid molecules built into cell membranes. Those same signs also enable disease-causing pathogens to target species-specific attacks. Researchers from San Diego School of Medicine have proposed that ancient malaria attacks and immune-mediated infertility combined to separate early humans from ape ancestors.
The sialic signature on chimp cells is a molecule called Neu5Gc (N-glycolylneuranimic acid). The biochemical precursor of Neu5Gc is Neu5Ac, and Neu5Ac is the sialic signature on human cells. Many of the same genes are found in different types of organisms, and dramatic differences between organisms are sometimes attributable to the active or inactive status of various gene combinations. In this case, human cell membranes do not have Neu5Gc because the CMAH gene that codes for the enzyme involved in the final step of sialic synthesis is switched off.
The San Diego researchers maintain that the common ancestor of chimps and humans had Neu5Gc signatures. They point to previous studies suggesting that a CMAH mutation about two to three million years ago—about the time commonly assigned for the emergence of Homo erectus—produced a divergent population with a Neu5Ac signature.
Different forms of malaria attack chimps and humans. The chimp-type typically attacks red blood cells with the Neu5Gc signature, and the human-type attacks red blood cells with the Neu5Ac signature.10 Therefore, the researchers suggest that natural selection favoring the Neu5Ac hominid population in the face of an ancient chimp-type of malaria produced a population of early humans. Dr. Pascal Gagneux calls this phenomenon “speciation by infection.”
Ganneux’s group hypothesizes that this early human population became distinct because it was infertile whenever it mixed with the ancestral chimp-type ancestor. In essence, Gagneux’s group is proposing that early humans became “reproductively allergic” to the ancestral sialic cell marker. This immune system response would then cause some degree of infertility due to antibody attacks on sperm bearing ancestral sialic markers.
To explain how humans developed antibodies that attack the ancestral/chimp kind of sialic acid, Gagneux says, “This occurred at about the same time as early humans were apparently becoming major predators in their environment. It's hard to be sure exactly what happened because evolution works on so many things simultaneously, but the change in sialic acid meant that early humans developed an immune response to Neu5Gc. It became viewed by their immune systems as foreign, something to be destroyed. At about the same time, they started eating red meat, a major source of Neu5Gc, which may have further stimulated the immune response.”
Gagneux believes human immunity to Neu5Gc conveyed an evolutionary advantage to those diverging humans with the mutated marker, Neu5Ac. The reason? His team’s experiments show that human anti-Neu5Gc antibodies will attack and destroy chimp sperm in the laboratory. Also, their experiments with mice showed that mice immune to the sialic markers on mouse sperm were somewhat infertile. Thus, they believe that any ongoing in-breeding between early humans and other chimp-like hominids was unfruitful and that chimp-malaria weeded out any remaining hominids lacking the CMAH mutation.
“Over time, this incompatibility would reduce and then eliminate individuals with Neu5Gc,” Gagneux says. Co-author Dr. Ajit Varki concludes, “We suggest that the immune mechanism described here was involved in the origin of the genus Homo.”
So what are we to make of this? This study asserts that the earliest humans were animals interbreeding with ancestral apes until a lucky mutation conferring immunity to chimp-malaria culled the population, leaving the newly divergent group of early humans. It further asserts that these early humans experienced evolutionary success in their divergence because they developed immune-mediated infertility affecting mismatched matches.
The supposed chimp-human genomic similarity is overstated. Even if the genomes were as similar as some assert—and those figures are based on gross oversimplifications11 and technological limitations—the “small” percentage of differences amounts to millions of differences. Furthermore, many additional differences arise due to regulatory “junk” DNA our common Designer12 built into genomes to utilize the same sets of designs and achieve radically different outcomes.
Beyond that, the three million year divergence time is based on the assumption that chimps and humans share a common ancestor—a direct contradiction of God’s statement (Genesis 1:26) that He made man distinct from the animals and in His own image. The three million years is calculated from molecular clock assumptions13 about how long it would take mutations to accumulate to produce a brand new creature. Yet mutations are a loss of information and cannot add up to make something new any more than a business can make up consistent losses by volume.
Finally, there are distinct differences between chimps and humans that extend far beyond what has been quantified in the genome. The dramatic physical and mental differences may derive in part from difference in the functions of so-called “junk DNA.”11 And the Bible makes it clear that God made man in His image, giving humans a spiritual dimension14 and enabling us by grace to have fellowship with our Creator.
The concept of “speciation by infection” is a reasonable mechanism by which a kind of organism could diversify. Furthermore, immune-mediated infertility is a real phenomenon affecting some human couples. However, neither of these concepts applies to the ape-human divergence since they in fact never had a common ancestor.
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– Ken Ham, president and founder of AiG–U.S.