Answering Creationist Claims (Part 5 – The Egg and the Sperm Disprove… What?!)

This time, Bible Life Ministries claim that the “Human Egg and Sperm Prove Evolution is Wrong”. I cannot understand what do the reproductive cells have to do with disproving evolution, but since they put it up, I’ll have to refute their funny claim.

Where in the Universe did you learn about sexual reproduction?

The human female like other mammals has XX sex chromosomes, and the male has XY sex chromosomes. The female egg contains the X-chromosome, and the male sperm contains either an X-chromosome for the reproduction of a female or a Y-chromosome for the reproduction of a male. The female eggs all develop within the ovaries while she is a baby (foetus) within her mother's womb.

So, the female has XX sex chromosomes like other mammals, while the males do not? It seems they think that all mammals have XX chromosomes except human males! Guess I’ll need to give them an elementary crash course on sex chromosomes (if you already understand it, just skip this section).

Sex-determination Systems

XX/XY System

In this system, females have XX chromosomes, and are known as the homogametic sex; males have XY chromosomes, and are called the heterogametic sex. This system is found in most mammals (including humans), some insects of the genus Drosophila, and some plants of the genus Gingko.

Drosophila XY sex-chromosomes.

XX/X0 System

This system is similar to the XX/XY system above. Females have XX chromosomes, while males have X0 chromosomes (the 0 indicates none). This system is observed in a number of insects, including the grasshoppers and crickets of order Orthoptera and in cockroaches (order Blattodea).

ZZ/ZW System

In this system, it is the ovum that determines the sex of the offspring, instead of the sperm as the XX/XY and the XX/X0 system. In this system, males are the homogametic sex with ZZ chromosomes; while females are heterogametic with ZW chromosomes. This is the system used in birds, some fish, and some insects (including butterflies and moths), and some reptiles, including Komodo dragons.

Haplodiploid System

This system is special in the sense that an offspring that is formed from the union of a sperm and an egg (fertilised) becomes a female; an unfertilised offspring becomes a male. Males have have only half the chromosome count of females, and are haploid; females are diploids. This system determines the sex of the offspring of many hymenopterans (bees, ants, and wasps), spider mites, coleopterans (bark beetles) and rotifers.

Haplodiploid diagram.

Temperature-dependent sex determination

The sex of the offspring of this system is determined by the temperature of the eggs. Instead of chromosomal sex determination systems, this is a environmental sex determination system. The eggs are affected by the temperature at which they are incubated during the middle one-third of embryonic development. This critical period of incubation is known as the thermo-sensitive period (TSP).

Temperature-dependent Sex Determination

Polyphenic System

A sex-determining polyphenism allows a species to reproduce normally while permitting different sex ratios. In tropical clown fish, the dominant individual in a group becomes female while the other ones are male, and blue wrasse fish are the reverse. If the dominant individual dies, another individuals will change its sex and replace it. This system ensures that there will always be a mating couple when two individuals of the same species are present.

Other Systems

Some species, such as some snails, practice sex change: adults start out male, then become female. In Bonellia viridis, larvae become males if they make physical contact with the female, and females if they end up on soil. In some arthropods, sex is determined by infection, as when bacteria of the genus Wolbachia alter their sexuality; some species consist entirely of ZZ individuals, with sex determined by the presence of Wolbachia.

So there you go. These are the main sex determination systems found. None of these systems pose any threat to evolution, and instead support it strongly.

Phenotypes Cannot Affect Genotypes

Evolutionists claim environmental factors cause small changes in the offspring in the evolutionary chain. However, the environmental experience of the female cannot change the chromosomes within her eggs and cannot have any effect upon her offspring. Her body cannot go into the eggs contained within her ovaries at her birth to make an intelligent genetic change. Females cannot be a part of the evolutionary theory for these reasons.

They got half of it right. The last sentence is just plain ignorance, though (the same thing is repeated for the male sperm). They foolishly think evolutionists say that evolution can be driven by direct effects of the environment on the genes! Perhaps they meant natural selection + genetic mutation. Here’s a short description of how it works:

Firstly, every time gene duplication/replication occurs, something goes wrong. The gene mutates. Most mutations are neutral as over 90% of our genes are useless. Of the mutations that have an effect on the phenotype, most are harmful. Those individuals with mutations that decrease their survivability will be eliminated from the gene pool. In some cases, though, the mutation is beneficial to the individual, and the individual will be better adapted to the environment, and thus pass on its genes.

It’s just that simple. Can’t Bible Life Ministries even understand this? In contrast to what Bible Life Ministries claim, chromosomal sex determination systems have been studied, and they do support the Theory of Evolution.

Multiple Independent Origins of Sex Chromosomes in Amniotes

The general consensus in the scientific community is that amniotes were sexually determined by environmental factors originally, and chromosomal sex determination systems appeared late on the scene.

Birds evolved the ZZ/ZW sex determination system, and snakes also evolved this system independently. On the other hand, mammals evolved the XX/XY system independently. The split of the mammals from the rest of the amniotes occurred around 315 million years ago, whereas the archosaurs (birds, crocs, dinosaurs, possibly turtles) diverged from the lepidosaurs (snakes, lizards) around 260 million years ago.

There are 2 ways to explain the presence of the ZZ/ZW system in both birds and snakes. The first model is that the ZZ/ZW system appeared before archosaurs and lepidosaurs diverged, and some of the archosaurs/lepidosaurs reversed to temperature-dependent sex determination later. This model has serious problems, as the regaining of a feature is considered extremely unlikely in the Theory of Evolution.

The second model predicts that snakes and birds developed the ZZ:ZW system independently. This system fits the Theory of Evolution nicely, and has been proven genetically. After all, the autosome being converted to sex chromosomes in birds is different from that in snakes.

Independent origins of sex chromosomes in birds, snakes, and mammals. In ancestral amniotes, which presumably used temperature-dependent sex determination, there were no sex chromosomes. Sex chromosomes then evolved from autosomes on three independent occasions in birds, snakes, and mammals. A different autosome was converted to sex chromosomes in each of these three lineages. The ZZ:ZW system emerged twice (once in birds and once in snakes), whereas the XX:XY system emerged once in mammals.

Conclusion

We have now established that Bible Life Ministries claim that the reproductive cells disprove evolution is nothing more but ignorance. You would’ve hoped they would at least do more research if they want to challenge the Theory of Evolution.

Their claim shows an even worse understanding of evolution, which I would take great pleasure in refuting. After all, DNA doesn’t have a mind, does it?

References

Eric J. Vallender, Bruce T. Lahn. (2006) Multiple independent origins of sex chromosomes in amniotes. PNAS vol. 103 no. 48 18031-18032.

Previous: Answering Creationist Claims (Part 4 – Irreducible Ignorance)

Next: Answering Creationist Claims (Part 6 – DNA Repair is Natural)

Answering Creationist Claims (Part 4 - Irreducible Ignorance)

Behold, for what you are going to see is an argument popularised by Michael Behe’s “Darwin’s Black Box” – Irreducible Complexity. Yes, for if a truly irreducibly complex organism is to be found, evolution is utterly crushed. The definition for irreducible complexity is as follows: “A single system which is composed of several interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning.” Despite being refuted by scientists repeatedly, creationists still love to use this tactic, and Bible Life Ministries is no different.

Single Cell Complexity Doesn’t Threaten Evolution

Their claim starts with the saying that scientists believe “that lightning struck a pond of water, causing several molecules to combine in a random way, which by chance resulted in a living cell”. That is certainly oversimplifying and misrepresenting abiogenesis, but I will not tackle it. Instead, I shall tackle the claim that a living cell is so complex that it couldn’t have evolved.

Creationists claim that a cell is too complex to have evolved, but actually it can. The first organism did not have to be as complex as the organisms nowadays. It simply needed to be able to self-replicate. In such a case, even a simple combination of RNA and proteins would’ve been sufficient. Over time, it would evolve into being more and more complex, with new functions rising. This fits the model of evolution nicely.

This may have been the first living organism.

Bible Life Ministries also claimed that the cell is too complex to have evolved by chance. Duh. Evolutionists never claimed that evolution is a fully-random process. While the process of genetic mutation may be random, natural selection is not, even the interaction of chemicals are governed by certain laws.

The Bacterial Flagellum is Reducibly Complex

E. coli cells use long, thin structures called flagella to propel themselves. These flagella form bundles that rotate counter-clockwise, creating a torque that causes the bacterium to rotate clockwise.

The flagellum is arguably the most interesting organelle ever, as it is powered by a rotary motor. This design is almost never found in any other organelle/living organism, and is quite an evolutionary puzzle. Because of this, the flagellum is touted by creationists worldwide as evidence for “Intelligent Design”. How wrong they are.

The flagellum of Gram-negative Bacteria moves using a rotary motor. One cannot help but compare it to the motors in our cars.

The Type -III Secretion Apparatus

The Type-III Secretion Apparatus (often written Type III secretion system and abbreviated TTSS or T3SS) is a protein structure and an organelle, found in several Gram-negative bacteria. T3SS is used by pathogenic bacteria as a method infect other microorganisms. Current evidence suggests that the bacterial flagella and T3SS evolved from a simpler secretion system and share at least nine homologous constituents.

Flagella assembly ATPases - the FliI proteins (Protein flightless-1 homolog) is also homologous to T3SS ATPases. Because ATPases energize numerous biological processes, FliI may have evolved independently of flagella function, having later been recruited to energize flagella assembly.

The T3SS secretes proteins directly from the cytoplasm through the membrane of the bacteria into the cytoplasm of the host cell or into an external medium. It does so by using thin, rigid, hypodermic needle-like protein complexes anchored to the envelope by basal structures resembling those of the flagella. In fact, in some cases, both the flagella and T3SS export same or similar proteins through the cell membrane, thus showing both organelles are highly similar in function and structure.

The T3SS has shown that the flagella can be evolved, and is thus further evidence against irreducible complexity.

Conclusion

I have now debunked the claim that irreducible complexity debunks evolution. Bible Life Ministries used 2 of the most famous structures associated with irreducible complexity, and yet both of the structures could’ve evolved through evolution. (See Part 1 – Birds Support Evolution for my answer to the evolution of flight, another commonly touted example of irreducible complexity).

In the next post, Bible Life Ministries funny claim that “Human Egg and Sperm Prove Evolution is Wrong” will be answered in detail.

References

Wong, Tim; Amidi, Arezou; Dodds, Alexandra; Siddiqi, Sara; Wang, Jing; Yep, Tracy; Tamang, Dorjee G.; Saier, Milton H. (2007). "Evolution of the Bacterial Flagellum: Cumulative evidence indicates that flagella developed as modular systems, with many components deriving from other systems". Microbe 2 (7): 335–40.

Previous: Answering Creationist Claims (Part 3 – What’s a Missing Inferior Branch?)

Next: Answering Creationist Claims (Part 5 – The Egg and the Sperm Disprove… What?!)

Answering Creationist Claims (Part 3 – What’s a Missing Inferior Branch?)

For some reason, after denying that the phylogenetic tree of life exists, Bible Life Ministries goes on to claim that so-called “Missing Evolutionary Inferior Branches” prove evolution wrong (Why do they try do disprove branches of a tree which they claim doesn’t exist is beyond my understanding). This isn’t even an argument, but another ignorance of the Theory of Evolution.

Do You Even Know How Evolution Works?

Their claim is that some individuals will branch off and create new evolutionary pathways. Those which are superior would create succeed in surviving and the branch would progress until this day. The less adaptable individuals would create new branches as well, but would eventually die out.

Well, here’s one thing I need to admit: They got this right. Those that survived and reproduced successfully would have their genes passed down, but not those who didn’t. But they get it wrong straight after this.

They claim that scientists have been searching so much for superior evolutionary branches that they missed all those branches that didn’t survive until this day. Well here’s the truth: Every fossil found almost certainly did not had its lineage until this day. No scientist would ever claim that a fossil represents our direct ancestor. Instead, every fossil is a great-great-great-great…… grand uncle/aunt. Archaeopteryx did not evolve into modern day birds; we did not evolve from Tiktaalik, but from a similar tetrapod. There is no way to confirm whether a fossil is our direct ancestor, and the odds are much higher that it is on a similar, but separate branch.

As you can see, there's quite a big number dead branches on the Tree of Evolution. So yes, the fossil record is consistent with the Theory of Evolution after all.

No scientist ever claimed that we directly descended from this fishes/tetrapods, nor do they say that this set of fossils represent a perfect, linear evolution. Instead, they are more like cousins.

Conclusion

Thus, as I have shown, the "missing inferior branches" are in great abundance. So maybe (almost certainly) the fact is that Bible Life Ministries is completely ignorant of evolution.

Bible Life Ministries next claim involves a old creationist tactic: Irreducible Complexity. Let me shred this claim in the next post.

Previous: Answering Creationist Claims (Part 2b - No Intermediates? Wake Up, Please.)

Next: Answering Creationist Claims (Part 4 - Irreducible Ignorance)

Answering Creationist Claims - (Part 2b - No Intermediates? Wake Up, Please.)

Ignorant of the theory of evolution, Bible Life Ministries goes on to claim that all fossils doesn’t represent intermediates; those that do are frauds. Funny how creationists would refuse to consider all those verified fossils and instead claim that the Paluxy River footprints are proof of creation. Without wasting time, let’s take a look at their claims.

Ardipithecus ramidus

Probable life appearance in anterior view of Ardipithecus ramidus.

The find for “Ardi” began in 1994, in the Middle Awash region of Ethiopia. Dated at 4.4 million years ago. Ardi further completes our understanding of human evolution. Such a fossil would certainly be picked apart by creationists with the “greatest” claim ever: “It’s just an ape.” Not an average ape, mind you.

By bringing us closer to the 6,000,000 BC point in which humans-to-be and chimpanzees-to-be diverged, Ardipithecus revolutionised the way we think of our ancestry. It weakened the theory that protohumans were savannah apes that diverged from a quadrupedal ape. Instead, Ardi was a fully bipedal, woodland ape.

What Makes "Ardi" a Great Fossil?

Feet Unlike Chimp's and Human’s

Ardi’s feet is quite intermediate between those of humans and those of chimps. Just like chimps, the toes are opposable, but they’re shorter. Plus, the feet aren’t flexible enough to from climbing trees and grasping veins, and they’re more human-like from that point of view.

Human-like Hands

The fingers of Ardipithecus ramidus are long and dexterous, much like human’s. Its wrists are also more flexible than those of contemporary apes.

Small Canines

Canines are used by apes as a sign of male superiority. In a monogamous society, male apes have large canines, and they’re used in conflict with other males when fighting over females. However, Ardipithecus ramidus fossils showed that males did not have large canines, and certainly not larger than those of females. This feature shows that our ancestors did not have much conflict between males and males, and is great evidence that our ape ancestors had more pair-bonding and parental investment than previously thought.

Pelvis Suited for Walking

Ardi’s pelvis, although crushed and needed to be reconstructed by advanced digital technology plus anatomy experts, it nevertheless points to the fact that Ardi’s pelvis are wider than quadrupedal chimps and narrower than bipedal Australopithecines aka intermediate. This is greater evidence that our ancestors became bipeds before geniuses (Ardi’s brain volume is estimated to be 300 and 350 cm³, which is about the size of a modern bonobo’s/female chimp’s brain, but smaller than Lucy's 400 to 550 cm³ brain).

Archaeopteryx

Archaeopteryx Fossil (Berlin)

Archaeopteryx – arguably the most famous fossil ever. Found in a limestone quarry in Southern Germany in 1861, the bird is now widely recognised as the best example of the reptile-bird transition. And guess what, Bible Life Ministries call it a fraud. They claim that it is a dinosaur fossil with fake feathers, and thus shows how dishonest evolutionists are.

OK, so the source came from In the Beginning: Compelling Evidence for Creation and the Flood, written by Dr. Walt Brown, who isn’t a scientist. Here’s the quote: “Allegedly, thin layers of cement were spread on two fossils of a chicken-size dinosaur, called Compsognathus. Bird feathers were then imprinted into the wet cement”. It’s on page 148.

Unfortunately, the case doesn’t hold strong for Bible Life Ministries. Palaeontologists that examined the London Archaeopteryx arrived at a quite different conclusion - “Proof of authenticity is provided by exactly matching hairline cracks and dendrites on the feathered areas of the opposing slabs, which show the absence of the artificial cement layer into which modern feathers could have been pressed by a forger.”. This is featured here: Archaeopteryx is not a forgery..

To add to the point, Compsognathus’s skeleton is much more different from those of Archaeopteryx – there are too much differences between the 2 species. In fact, there could not have been a better reptile-bird intermediate. I shall not reinvent the wheel, as there is already a good source here: Archaeopteryx's Relationship With Modern Birds

Titaalik roseae

One the most beautiful discoveries in the early 21st century would be Titaalik. Found in 2004 by Neil Shubin and his team in the Arctic Circle, it is now in the Hall of Fame as one of the most important fossils, well alongside Archaeopteryx and Australopithecus. Tiktaalik is the perfect example of the fish-tetrapod transition. Once again, Bible Life Ministries claim it is a fraud.

Tiktaalik Model with Fossil Cast

Here’s their funny argument: “Since Archaeopteryx is a fraud (of course it’s not), therefore Tiktaalik is a fraud!” Don’t understand their logic? Me too. Unlike Piltdown Man, Archaeoraptor, and other frauds, Tiktaalik was certainly not found by “amateurs”, and the process of finding and excavating it is quite well documented. Bible Life Ministries, perhaps you would be kind enough to read “Your Inner Fish” by Neil Shubin?

Yet in a twist, Bible Life Ministries suddenly change their mind and acknowledge that Tiktaalik is true, just not an intermediate - it is nothing more than another species of fish. Notwithstanding the confusion, let us show the poor (wilfully ignorant) creationists why is Tiktaalik so exciting, and how it contributes to a better understanding of evolution.

What Features of Tiktaalik Make It a Fish-Tetrapod Intermediate?

Loss of the Operculum

The operculum is a plate of bone that forms a flap that covers the gills in most bony fishes. The operculum’s primary function is to assist the fish in moving water across the gills. Losing the operculum allows the neck to move freely. All tetrapods don’t have the operculum, while primitives ones still retain the gill but have lost their operculum nevertheless. Tiktaalik lost its operculum but retained the gill, which is only expected from a fish-tetrapod intermediate. By losing the operculum, Tiktaalik was able to move its head independent of its body, and had a true neck. Also, without the operculum, Tiktaalik should’ve breath mainly using its mouth.

Dwarfing of the Hyomandibula

The stapes is a piece of bone in our middle ear. It was originally a gill arch bone known as the hyomandibula. In Eusthenopteron, the hyomandibula large and boomerang like, in Acanthostega it's a small piece of bone, and in Tiktaalik it's exactly between.

Comparison between the operculum and hyomandibula of fish and tetrapods.

The Skull

The main difference between fishes and tetrapods is the shape of their skull. Fishes have round, conical skulls with their eyes on the sides; tetrapods have flat skulls with their eyes on top. Tiktaalik has a flat skull, yet with some leftover characteristics from fish skulls.

Dorsal view of Tiktaalik skull. Scale bar equals 5 cm.

Primitive Wrist Bones and Fingers

Fishes have fins, tetrapods have limbs. This is one of the main differences between them. To crawl on land, the fins are expected to evolve into limbs. And that’s what seen in Tiktaalik.

The difference between fins and limbs lie mainly in their skeletal layout, The base of a typical fin contains 4 or more pieces of bones; limbs have a single bone known as the humerus that connects to the shoulder, which are connected to 2 forearm bones, then to pieces of bones, and finally to digits.

So let’s take a look at Tiktaalik’s fin/limb. One can only awe at what a great finding it is indeed – to have found such a perfect intermediate between swimming fins and walking limbs. Read the description, and see for yourself.

a, Dorsal view; b, ventral view. Elements with stipple shading were preserved in articulation in NUFV 109 and prepared in the round. Elements with a dashed outline are reconstructed based on their presence in the articulated distal fin of NUFV 110. It is not known how many radials lie distal to the first, second and fourth in the proximal series. Note the dorsal expansion of the distal articular facets on the ulnae and third distal radial/mesomere. The dorsal expansion of these facets would have facilitated extension of the distal fin.

Other Claims

Here’s a list of species which are obviously unrelated to transitional fossils, yet somehow included by Bible Life Ministries in their unfounded claims.

The Coelacanth

A living fossil.

Once thought extinct since 70 million years ago, the coelacanth was found in December, 1938 off the eastern coast of South Africa. Quite a startling discovery indeed, as it is such a great “living fossil”. That is, not counting the opportunity that the coelacanth provided for creationists to annoy us.

So it basically boils down to the same old question: “Since the coelacanth has remained unchanged for 350 million years, evolution is false.” This assumption is so wrong on many levels.

Firstly, this thought wrongly assumes that evolution is linear, continuously progressing towards humans as an end product. Instead, evolution is continuously branching, a process known as speciation. A fish can keep on evolving into a better fish while another fish may evolve to survive on the land. The coelacanth is one that stayed in water.

It is also wrong to think that evolution is working towards a goal with an end product in mind. It is driven by the force of natural selection, that is the continuous interaction between individuals in a struggle to survive and reproduce. Our ancestors did not have a great plan to live on land, it was just natural instinct for survival that led them to venture out of water, perhaps to escape larger, predatory fishes. The coelacanth is a fish that managed to survive in its current form, and thus did not need to change.

Lastly, the living coelacanths represents the genus Latimeria, not a species, and has changed from its ancestors. It is just that the changes were minor.

The Platypus

Evolution: Results may vary.

I’m not very sure what exactly is Bible Life Ministries is trying to prove by using the platypus, but I’ll address it nevertheless.The platypus and the echidna are monotremes, the only mammals that lay eggs, and the platypus sure seems to have quite mix of mammalian and reptilian features (At least Bible Life Ministries is right on this one). What I find funny comes next.

Bible Life Ministries then goes on to claim that the platypus has the characteristics of many creatures but is not a link to any of them. Duh!!! No one ever said that the platypus was a link to any species! Mammals diverged into 2 different branches about 140 million years ago, one of them which would later diverge into placentals and marsupials; the other branch consists of the monotremes. Get your facts straight.

But what about the supposed “mix” of the characteristics in the platypus? Well the platypus is halfway between mammals and reptiles, so no surprise that it moves quite awkwardly. It lays eggs because it works, so no reason to change it. The males have poison as a result of sexual selection, and it doesn’t kill, just create great pain. Its famous bill is simply convergent evolution, and works quite differently from a duckbill. No problem for evolution whatsoever.

An Atavistic Dolphin

An atavistic dolphin was caught in November 2006.

It seems here that Bible Life Ministries thought that we actually labelled the dolphin with rear flippers as evidence that dolphins evolved from dogs. Please, creationists, the article itself stated that it was a dog-like ancestor, not dogs. Sheesh. Moreover, Bible Life Ministries last sentence stated that the dolphin was just another odd species that “god” created. That shows their complete misunderstanding of what the fuss was all about.

What we find fascinating here is not that we found a vestigial flipper. It is long known that cetaceans’ hind limbs are hidden within their body (See my previous post for more details). Instead, what we are dealing with here is an atavism, which is the appearance of a structure that was present it the individual’s ancestor, but not anymore in the present. In other words, it means that hind limbs of mammals were once present, but have since been reduced to pieces of bone in the dolphins body; this bottleneck dolphin however has hind limbs, and thus is a case of atavism. Another example is the growth of toes in atavistic horses. Atavisms are caused by a abnormal reading of genes, in which pseudogenes are accidently transcribed.

Conclusion

It certainly looks as if Bible Life Ministries did not do any research on the transitional fossils listed. They're just repeating the mantra: "There're no transitional fossils... Just show me one, just one...". It it shown in this post that there are quite a large number of transitional fossils, despite the fact that this is just a tip of the iceberg. No more excuses, creationists. Face the fossil record.

Bible Life Ministries 3rd claim focuses on missing evolutionary branches. However, this claim isn’t even an argument, but simply a gross misunderstanding of the Theory of Evolution. I’ll explain it in the next post.

References

Shubin, N.H. (2009) Your Inner Fish. Penguin Books. ISBN 978-0-141-02758-6

Daeschler, E.B. et al. 2006. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan. Nature 440: 757-763.

Charig et al, Archaeopteryx is not a forgery., Science, 1986, v.232, p.622-626.

Previous: Answering Creationist Claims (Part 2a - We Don't Jumble Fossils Together)

Next: Answering Creationist Claims (Part 3 – What’s a Missing Inferior Branch?)

Answering Creationist Claims (Part 2a - We Don't Jumble Fossils Together)

In this post, I shall refute “Bible Life Ministries” claim that “Species Without a Link Proves Evolution is Wrong.” Let’s start with their claim:

The evolutionist will claim that the presence of many individual species proves evolution. This shallow statement is devoid of reason, logic and scientific proof. Evolutionists line up pictures of similar-looking species and claim they evolved one from another. The human "family tree" is an example of this flawed theory. Petrified skulls and bones exist from hundreds of species of extinct monkeys and apes. Evolutionists line up the most promising choices to present a gradual progression from monkey to modern man. They simply fill in the big gaps with make-believe creatures to fit the picture. This procedure can be done with humans only because there are many extinct monkey and ape species. They never do this with giraffes, elephants or the Platypus. The pictures are placed in all of the textbooks that evolutionists use to teach kids this nonsense. The pictures are simply a grouping of individual species that does not prove evolution.

They’re trying to claim that scientists simply jumble similar looking fossils together and call it evolution. As usual, this claim is full of false statements and ignorance. You would’ve thought that if they really wanted to refute evolution, they should at least do a little research. Let us see how easy it is to refute them.

How To Determine a Fossil’s Place on the Tree

Scientists most certainly do not simply pick out similar-looking fossils and say: “Well this fills the missing link.” There are a few things to consider when analysing fossils:

Geology

The Geologic Time Scale

The Earth’s crust is divided into many layers known as strata(singular: stratum). Every stratum can be distinguished from each other through its own unique characteristics. A few examples are the Devonian, Carboniferous, Permian, Triassic strata. The Law of Superposition states that sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top. However, sometimes the sequence is changed as a result of thrust faults. There are multiple methods to determine the age of strata, namely: radiometric dating  thermoluminescence dating  and incremental dating. Through the combination of these theories, we can create the geologic time scale for the Earth.

The theory of evolution predicts that we evolved from earlier, simpler life forms into later, complex life forms, and this is exactly the case. The current fossil evidence shows an increase in complexity from the first microorganisms which were found to be 3.5 billion years old straight up to today. Older strata usually contains less diverse and smaller number of fossils, while older strata houses complex and more abundant fossils, save for the multiple mass extinctions that occurred.  This is known as the Principle of Faunal Succession and strongly supports the theory of evolution. In other words, a species below the stratum of another species couldn’t have evolved from it.

Human history is too short to be visible on this timescale.

Continental Drift

Why do we find whales in the deserts? Why was Tiktaalik found in the Arctic Circle? And why are similar species distributed unevenly all over the world? The answer is continental drift. This theory states that the Earth’s continents were once joined together in a super-continent called Pangaea in the Permian period. Pangaea later broke off in the Jurassic period to form Laurasia to the north and Gondwana at the south. Both of these continents would later separate off again and finally arrive at the places they are today.

The movement of continents are explained in plate tectonics. The surface of the Earth consists of lithospheric plates that moved through geological time, resulting in the modern-day position of the continents. The continents as we know it are only elevated areas of the the lithospheric plates. The lithospheric plates consist of the continental and oceanic crust plus the upper mantle. The plates lie upon a fluid layer of lava known as the asthenosphere, which is responsible for the movement of the plates.

By collaborating the our knowledge of continental drift with molecular biology, we can determine where fossils belong in the phylogenetic tree, but let’s postpone this matter.

Tectonic Plates with Their Movement Vectors

Comparative Anatomy

Homologous Structures

We can find a lot of anatomical similarities between groups of living things. For example, all vertebrates share a backbone, all flowers have petals, stigma, anthers etc. The difference is that they vary in form and look, but the overall pattern remains the same.

The adaptation of groups of animals that share homologous structures (same form, different function) to fit their environment is known as adaptive radiation. The gradual spreading of organisms with adaptive radiation is known as divergent evolution.

As individuals or groups which share more features in common are supposed to have diverged earlier from a common ancestor, comparative anatomists look for homologous structures in animals to determine how closely related are they. The comparison of homologous structures allowed scientists to show that bats evolved from shrew-like creatures, instead of birds (Leviticus 11:13-19).

The concept of homologous structures is presented here. All mammals share the same pentadactyl pattern for their limbs, yet have adapted it for different uses.

Vestigial Structures

Vestigial structures are one of the strongest evidence for evolution. A vestigial structure is a homologous structure that is underdeveloped and useless or adapted for different uses. There are plenty of vestigial structures found in organisms, be it extinct or alive. A vestigial structure suggests that the environment the species lived in no longer had selection pressures on that structure, and could focus on other parts.

A lot of skeletons show traits of vestigiality, such as wings on flightless birds, the coccyx of apes etc.  The best example is the hind limbs of whales and other cetaceans. The appearance of vestigial pentadactyl limbs in cetaceans is strong evidence that whales were not simply created, but evolved from a earlier tetrapod that lost functionality for its legs. As Douglas Futuyma said, vestigial structures do not make sense without evolution. Why would a creator create such structures cannot be explained by creationists.

One of the ways to determine whale evolution is the vestigiality of its hind limbs.

Molecular Biology

Molecular Clock

Differences between homologous molecules can be quantified and expressed as, for example, the number of nucleotides and amino acids that have changed. We can use the differences between homologous molecules to determine the rate of evolutionary change much more precisely than we can simply through the phenotypes of the genes.

In the 1960s, it was discovered that the the number of differences between amino acid sequences of the proteins of different species was proportional to the time they were predicted to diverge from a common ancestor. The more differences in the amino acid sequences, the longer the divergence. Since the rate of change was identical for every species, we can use not only update the sequence of branching events in a phylogenetic tree, but the time when it occurred.

But how reliable is this method, you ask? Of course, the molecular clock is not expected to work like our watches do, which measures time accurately based on standard units. Instead, a similar analogy can be found in radiometric dating. Radiometric dating is founded on the observation that the half-life of same types of elements are same, while the molecular clock is based upon the observation that the difference between homologous molecules increase proportionally to the time since divergence.

Although scientists have found out that the molecular clock is more erratic than other clocks, such as radiometric dating, it is not too large. To increase accuracy, a large number of proteins are compared to determine the average rate of evolutionary change. The more differences, the more accurate the clock. This clock is later collaborated with outside sources (the fossil record, continental drift) and to determine its accuracy. Yet even with such efforts to minimize error, the clock is still found to be estimate dates older when compared with other methods. Nevertheless, the molecular clock still provides very compelling evidence for evolution, and so far it has been very consistent with other methods.

So how does this contribute to classification of fossils, anyway? Well, we can determine whether a fossil is truly a member of a specific genus(or class, species, etc.) So if we find a humanoid that is 25 million years old in Australia, we can safely conclude that it must be unrelated to the Homo genus, since the molecular clock puts the divergence of the Homo genus from chimps at around 6 million years ago, and continental drift also says otherwise.

Conclusion

In this post, it has been made very clear that we do have a lot of methods to determine where a fossil belongs, and whether it really represents a transition between earlier and older species. It is certainly not just, “Well I think this is the best guess”. I may have missed other methods of determining a fossil’s place in the phylogenetic tree, and if that is so, any comments would be greatly appreciated.

By the way, you have shown your ignorance again, creationists. And yes, in my next post, your alleged claims that all those beautiful fossils such as Australopithecus, Tiktaalik, Archaeopteryx etc. cannot support evolution will be utterly destroyed. At the meantime, take your time and do a little research, please.

References

Futuyma, D. J. (1995). Science on Trial: The Case for Evolution. Sunderland, MA: Sinauer Associates Inc.. pp. 49. ISBN 0878931848.

Anne Waddingham. (2009). The Britannica Guide to Genetics. Encyclopaedia Britannica Inc. pp 209-211. ISBN 970-0-7624-3620-0

(2005). Oxford Dictionary of Science Fifth Edition. Oxford University Press Inc. ISBN 978-0-19-280641-3

Previous: Answering Creationist Claims (Part 1 - Birds Support Evolution)

Next: Answering Creationist Claims: (Part 2b - No Intermediates? Wake Up, Please)

Answering Creationist Claims (Part 1 - Birds Support Evolution)

“One of the best examples of evolution nonsense is the thought that a wingless bird began to evolve a wing. Why this would occur is not answered by evolutionists. The wing stub did not make the bird more adaptable to his environment. The first wing stubs would be much too small for the bird to fly. Why would a bird evolve wing stubs that are useless?…A bird with a useless wing is at a severe disadvantage…

…We are then led to believe that some birds got tired of carrying around a worthless half-size wing, so they grew fingers on the end to help climb trees. The wings became arms and a new species was developed.”

So here’s the first claim. Birds could not have evolved their wings, since a wing stub would've been useless. The creationist tries to tell us that a wing could not have evolved through evolution, for what is the use of half a wing? Yet this attempt is simply laughable.

Bird Wings came from Dinosaur Arms

The creationist makes 2 serious mistakes in the claim above. Wings did not evolve from wing stubs, and they did not evolve in to arms. They evolved from arms. According to current evidence, birds evolved from small theropods. This can be shown through the many similarities between the physiology and behaviours of birds & dinosaurs. In fact, the current fossil evidence shows quite a smooth transition from theropods to archaic birds to modern birds. Molecular evidence also puts crocodiles to be more closely related to birds than they are to lizards, turtles, snakes and other reptiles, which strongly supports the theory that birds evolved from dinosaurs, since dinosaurs and crocodiles share a common ancestor known as archosaurs. The wings of birds are evolved theropod arms.

From left to right: Compsognathus, Archaeopteryx, Gallus gallus(chicken).


From left to right: Deinonychus Hand, Archaeopteryx Hand


Birds are classified in the phylogenetic tree as dinosaurs.

OK, so we have now established that birds did evolve from dinosaurs. However, the creationist puts may ask: “But still, what is the use of a something halfway between a wing and an arm?” Don’t worry. Science has its answers.

Flight involves 4 physical forces (thrust and drag, lift and weight). For a bird to fly, many characteristics are required: feathers (improve aerodynamics), wings (create lift), hollow bones (increase structural strength), beaks replacing jaws (reduce weight) and so on. At first glance, this may give the look that since non-fully developed characteristics would've been useless, the Theory of Evolution has been determined false. It's not. Let's see how birds could've gained flight.

Flight evolutionary models

Archaeopteryx, the earliest and most primitive bird known.

The Cursorial Model

This model states that flight evolved in running bipeds through a series of short jumps. As the length of the jumps extended, the wings were not only used for thrust but also for stability, and eventually eliminated the gliding intermediate. The model was then modified to describe the use of wings as an insect foraging mechanism which then evolved into a wing stroke. By running then jumping, less energy would've been used compared to only running. Combined with Archaeopteryx’s long and erect legs, supporters say that birds gained flight through jumping from the ground.

However, although this model sounds plausible, current evidence refutes it. Due to its weight, Archaeopteryx would need to run faster than birds by a factor of 3 to fly! Also, the heavier the bird, the longer it needs to run. For Archaeopteryx to fly, just guess how much energy it has to waste! Archaeopteryx’s ineffective aerodynamics also means that it could only fly for extremely limited times before falling! Thus, physics strongly disagree with this theory.

The Arboreal Model

The model states that Archaeopteryx was a reptilian bird that glided from tree to tree. After the leap, Archaeopteryx would then use its wings as a balancing mechanism. Archaeopteryx developed gliding to save energy according to the model. Although climbing trees may sound energy-wasting, the benefits are great. By gliding from tree to tree, Archaeopteryx would've conserved a lot more energy than staying on ground.

This model is supported by the fact that Archaeopteryx’s foot claws and hallux are very similar to those of modern perching(standing on branches) birds. This characteristics strongly support the view that Archaeopteryx was arboreal. Current tests have also shown that despite not having a supracoracoideus pulley system (SC), Archaeopteryx can still glide jumping from trees. It would've not been able to fly by running though.

However, a study suggested that the arboreal and cursorial model are not mutually exclusive, as many extant birds exhibit different degrees of ground- and tree-based behaviours. Instead, the study proposed that birds should be placed on a spectrum according to the extent of ground and/or tree foraging they exhibit.

The Pouncing Proavis Model

This hypothesis was first proposed by Garner, Taylor, and Thomas in 1999. This hypothesis is distinct from the hypotheses above in that it “proposes that locomotor control, rather than some direct attribute of flight such as speed or efficiency, was the selective pressure that initiated the evolution of fight in birds”. This hypothesis makes the claim that birds evolved from small predators that ambushed their prey from elevated positions. Over time, natural selection would favour those predators that had greater lift-based control, slowing turning the action from pouncing into swooping. Further selections for greater swooping ranges will then lead to flight.

The authors believed that this model is superior the previous models for these reasons:

The Mosaical evolution of Archaeopteryx

Both of the models are unable to explain why Archaeopteryx has a theropod-like skeleton and yet has a fully feathered wing, as they predict the co-evolution of the whole suite of skeletal and non-skeletal flight characteristics in birds. On the other hand, the Pouncing Proavis Model predicts the evolution of an Archaeopteryx-like grade of organization through continued selection for enhanced control of body position during a jump or controlled fall.

The Coexistence of Primitive Pouncers and More Advanced Fliers

Fossils of feathered dinosaurs were found in Late Jurassic and Early Cretaceous deposits, such as Sinosauropteryx, Caudipteryx, and Protoarchaeopteryx. Rahonavis, a dromaeosaur with bird-like characteristics were even found in the late Cretaceous! On the other hand, archaic birds such as Iberomesornis were found at the same period. This means that bird-like-dinosaurs and birds coexisted.

The arboreal and cursorial model predicts that as theropods became more adapted to flight, natural selection will eliminate theropods that did not show such abilities. But this is not the case. In contrast, the Pouncing Proavis Model predicts animals that started evolving Archaeopteryx-like features would have been selected for flight control instead of speed and agility. Gradually, however, natural selection pressures would begin selecting for improved flight efficiency, allowing those theropods to develop into a more bird-like niche. As pouncing bird-like dinosaurs and fully developed birds would not compete directly, they can coexist, and this matches the fossil record.

The primitive perfection of feathers

Both the arboreal and cursorial models proposes that feathers evolved under natural selection for increased life. However, it is hard to see how any feathers more primitive than modern feathers can generate enough lift. Instead, the Pouncing Proavis Model proposes that feathers were initially selected for increased drag, not lift, as this model proposes that the initial selection was for improved control during pouncing/swooping. Through continuous selection for increased drag and improved structural stability, feathers suitable for flight would evolve. This process of getting entirely new functions from existing systems is known as pre-adaptation.

Diagram showing the stages of feather evolution as outlined by Xu & Gou 2009.

Successful Prediction of the Theropod-Bird Transition

The Pouncing Proavis model is consistent with the current evidence, whereas the arboreal and cursorial model are not. This model matches the currently observed sequences of character acquisition by theropods. For example, the Pouncing Proavis Model and the cursorial Model successfully predicts that Archaeopteryx is ground-dwelling; while the arboreal Model fails to do so. On the other hand, the arboreal and cursorial models proposes wrongly that weight reduction evolved parallel to an improvement in wing aerodynamics; however, the fact is that birds reduced weight after that, and the Pouncing Proavis model predicted is consistent with this finding.

Wing-assisted Running(WAIR) Model

Wing-assisted running is a recently discovered locomotor behaviour that allows birds to ‘run’ up obstacles(Dial, 2003). While such a task seems formidable for a biped, WAIR is used by ground-dwelling birds to escape from danger. Instead of supplying thrust in the direction of travel and lift to support body weight, the WAIR hypothesis suggests that the wings of ground birds serve to increase hind limb function and push the bird towards the substrate(the place they are running on), increasing traction. This is achieved through the simultaneous flapping of wings and running. The WAIR model have been documented in up to 4 species of ground birds.

So how does this explain the evolution of flight? When escaping from predators(perhaps when chasing prey?), protobirds that are able to use WAIR will have much higher odds of survival compared to ‘normal’ theropods, as they can reach elevated positions(cliffs, hills, trees, etc.) For protobirds to achieve this feat, the wing doesn’t need to be very big, but feathers are required. 3-day old hatchlings were documented to use their partial wings the run up steep inclines, while those with feathers removed could not.

There has been however research that disagrees with WAIR. It was found that the shoulder joint orientation in protobirds prevented the lifting of of the wing higher than the backbone, thus preventing flapping flight, and WAIR as well. (Senter, P. 2006)

Despite the importance of such a hypothesis in explaining the evolution of flight in birds, much remains unknown about the mechanics of WAIR, and work still needs to be done.

Could this be how birds conquered the sky?

Conclusion

We have now refuted the creationist claim that birds cannot be evolved from earlier, transitional forms:

“The idea that birds or anything else has million-generation evolutionary plans is childish. The evolutionary concept of growing a wing over millions of generations violates the very foundation of evolution, natural selection.”

You’ll need to try harder, evolution-deniers.

But that's not all! In the same topic, further claims are made that no species are able to evolve into another species, aka fish-to-amphibian, amphibian-to-reptile, archosaurs-to-dinosaurs….. (with added insults). This is a common creationist claim, and I shall address it in the next post: Missing links? Wake up, creationists.

PS: There is this claim about how Cetiosaurus’s long neck disprove evolution. I would like to address this, but it’s not important in this series. Perhaps I will give a answer after this series.

References:

Glen, C.L., and Bennett, M.B. (November 2007) (abstract page). Foraging modes of Mesozoic birds and non-avian theropods. 17.

Garner, J., G. Taylor, and A. Thomas. 1999. “On the origins of birds: the sequence of character acquisition in the evolution of avian flight.” The Royal Society. 266, 1259-1266.

Xu, X. and Guo, Y. (2009). The origin and early evolution of feathers: insights from recent paleontological and neontological data. Vertebrata PalAsiatica 47 (4): 311-329.

Matthew W. Bundle and Kenneth P. Dial. 2003. "Mechanics of wing-assisted incline running (WAIR).” The Journal of Experimental Biology. 206, 4553-4564"

Senter, P. 2006. Scapular orientation in theropods and basal birds, and the origin of flapping flight. Acta Palaeontologica Polonica 51 (2): 305–313.

Previous: Answering Creationist Claims (Introduction)

Next: Answering Creationist Claims (Part 2a: We Don’t Jumble Fossils Together)

Answering Creationist Claims (Introduction)

The Christian site "Bible Life Ministries” has given their so-called "Top 10 Scientific Facts Proving Darwin’s Theory of Evolution is Wrong, False, and Impossible" (They actually listed 13. Learn to count, creationists). Their 13 “scientific facts” are these:

1. Evolution of Birds.
2. Species Without a Link.
3. Missing Inferior Evolutionary Branches.
4. Single Cell Complexity.
5. Human Eggs and Sperms.
6. DNA Error Checking.
7. Chaos From Organization.
8. Chromosome Count of Humans.
9. Origin of Matter and Stars.
10. Lack of Life on Mars.
11. Radio Silence from Space.
12. Timeline and Archaeology
13. Statistical Mathematics.

If you think that proves evolution wrong, think again. The points that they raise are in fact very fallacious, and shows that they do not know anything about evolution.
In the following posts, I shall give a point-by-point refutation of their claims, and prove that yes, evolution is true.
There are a few claims however, that I will not answer, as they are unrelated to evolution:

• Point 6: Origin of Matter and Stars – This belongs to the subject of physics, and the current explanation for this would be the Big Bang Theory.
• Point 10: Lack of Life on Mars – This is the topic of abiogenesis, not evolution. Evolution addresses the diversity of life, not its origin.
• Point 13: Statistical Mathematics – Same as above.

Let’s get started.