Changing the way we look at the world
Is evolution really happening?
This is the a blog post about an article on the website of the BBC (British Broadcasting Company) with the title:
How do we know that evolution is really happening?
We are told that:
“The idea that species gradually change over many generations is the cornerstone of biology.”
I don’t think anyone would disagree with the first part of that statement, but as someone who has carried out biological research, I do not agree that it is the cornerstone of biology, insert the word “evolutionary” before “biology” and then the statement is probably true.
Then we are told that:
“Evolution […] sets out to explain life: specifically, how the first simple life gave rise to all the huge diversity we see today […]”.
Here the author overlooks the fact that evolution in its modern formulation sets out to explain life without the need of a creator (e.g. God). With God in the picture evolution could be a mechanism used by the creator to make and maintain life on earth. Evolution sets out to provide a naturalistic explanation, but let’s put that to one side for the moment.
It is asserted that:
“For scientists, evolution is a fact. We know that life evolved with the same certainty that we know the Earth is roughly spherical, that gravity keeps us on it, and that wasps at a picnic are annoying.”
Well this scientist doesn’t accept that statement without some very large caveats.
We can observe the roundness of the earth and we can directly measure the effect of gravity, but evolution of simple life into oak trees and whales is not a fact that can be directly observed. It is an extension of the observation that species change (among other things as stated in the BBC article).
The leading question is then asked:
“Why are biologists so certain about this? What is the evidence? The short answer is that there is so much it's hard to know where to start. But here is a very cursory summary of the evidence that life has, indeed, evolved.”
What follows are some examples of evolution which can and have been observed. Selective breeding to increase egg production in chickens. Wolves as ancestors of dogs. Evolution of finches on the Galapagos islands. A bacteria (E. coli), evolving to survive on a new “food source”. Sickle cell anaemia. The article also provides a story about how giraffes got their long necks, and a discussion of some fossils.
But does this evidence make evolution a fact?
The article goes on to say something that actually seems to give the game away.
“Most of us have the general idea: species change over time, only the fittest survive, and somehow a monkey-like creature gave rise to human beings.”
In passing we note that the term monkey-like is wrong - according to evolutionary theory the ancestor is believed to be ape-like. Darwin observed that species change and he also observed that the fittest survive. Although this is not an absolute rule as often the less fit survive and reproduce. In fact most small changes have very little effect on fitness from an evolutionary point of view. Part of the problem is defining fitness. Fitness in this context is defined as passing on your genes to the next generation.
However, in any given population many individuals who may be less “fit” still manage to reproduce and pass on their genes. This is in fact one of the many problems with evolutionary theory. Unless there is very strong selection pressure (that is unless some change makes it impossible or very unlikely that the individual concerned will reproduce) small beneficial changes are not preferentially preserved. Not to mention the fact that the fittest (however that is defined) do not always survive and do not always pass on the genes, simply because accidents can happen to the fittest.
That somehow is a very big somehow! It appears that to believe evolution is an adequate explanation for all living things we have to have a prior commitment to the belief that evolution can achieve something that is poorly supported by the evidence. Although, to be fair to the author, they consider that the evidence which is presented overcomes this objection.
They go on to write that:
“As organisms compete for food and mates, those with the advantageous traits produce more offspring, while those with unhelpful traits may not produce any. So within a given population, advantageous traits become common and unhelpful ones disappear."
There is a major problem with this; if there is no competition then there will be no evolution. When, there is plenty of food and plenty of mates, evolution will not happen. Even in scenarios where there are massive numbers of eggs laid and survival is limited it is mostly random effects that decide if any particular individual survives. Take the common example of fish that lay millions of eggs which then hatch and the majority of which will be eaten by predators. It is very unlikely that the slightly faster minnow will somehow escape when a shark scoops up hundreds at one time. It is hard to see how a slightly faster minnow could escape when the shark arrives. Unless the change is massive then all minnows have an equal probability of surviving and living to produce the next generation.
Yet we are confidently assured that:
“Step by step, worms became fish, fish came onto land and developed four legs, those four-legged animals grew hair and – eventually – some of them started walking around on two legs”
The problem with this story is that there is no explanation for the appearance of features which did not exist. How exactly does a worm become a fish with fins, complex eyes, jaws, gills? No-one has ever shown how small gradual changes over many generations will produce these highly complex features and link them all together to produce a fish. All the major changes which are needed to get from a worm to a wombat (or any other creature) have never been explained.
What other evidence is there?
We will now start to look at the evidence which, we are assured, will show that evolution is a fact. We are told to do what Darwin did and look around at the familiar things in the farmyard and garden. Apparently, we can easily see that:
“organisms pass on characteristics to their offspring, changing the nature of that organism over time.”
I am not sure that I understand this: if you pass on your characteristics to your offspring then nothing changes!!
However, Darwin was referring to the process of cultivation and breeding which farmers and gardeners have used to bred domestic animals and plants which are more productive. For example, chickens laying more eggs, cows producing more milk and plants yielding more crops.
“Breeders work just like Darwin imagined evolution worked. Suppose you want to breed chickens that lay more eggs. First you must find those hens that lay more eggs than the others. Then you must hatch their eggs, and ensure that the resulting chicks reproduce. These chicks should also lay more eggs.”
Darwin imagined and it seems that we are asked to imagine the same thing! Well that is hardly science, which is based on evidence! It is worth noting that without the interference of humans the number of eggs laid by chickens would not have changed.
Next we are told by an evolutionary scientist:
"That's what evolution is," says Steve Jones of University College London in the UK. "It's a series of mistakes that build up."
How can a build up of mistakes produce anything useful? The more mistakes there are the more things are going to be messed up.
Nevertheless we are told:
“Breeding, Darwin argued, is essentially evolution under human supervision. It shows us that the tiny changes from generation to generation can add up “It's inevitable," says Jones. “It's bound to happen.”
Well yes when someone is controlling the process it will happen, because the someone is selecting the individuals with the required characteristics. Remove the breeder from the process and you will end up with random drift and no selection. The hypothetical evolutionary process which we are told produced chickens from ancestors which were not chickens cannot be observed. All that we observe are “tiny changes”, chickens are still chickens, all that has changed is that they lay more eggs.
Therefore, as the article admits:
“[…] it's quite a step from carefully breeding chickens that lay more eggs to the natural evolution of new species. According to evolutionary theory, those chickens are ultimately descended from dinosaurs, and if you go further back, from fish."
In fact it is a lot more than “quite a step”. What is needed is a number of extremely large steps. To get from fish to chickens via dinosaurs involves the production of entirely different kinds of animals, with new complex features. This is much more than a small step to a new species of an already existing kind of animal.
But evolutionists believe that this is not really a problem:
“The answer is simply that evolution takes a long time to make big changes. To see evidence of that, you have to look at older records. You have to look at fossils.”
Now we come to the section on fossils.
We are shown a picture of a fossilised turtle which, we are told is tens of millions of years old. The interesting thing about this fossil is that it does not show evolution, it shows a turtle that is was buried and fossilised. It is a turtle. What we need is a whole series of fossils starting with something that is not a turtle, gradually changing into a turtle buried in younger and younger rock layers. What we find is rocks with no fossil turtles then rocks with fossil turtles.
Yet we are told that:
“Running through the fossil record makes it clear that life has changed over time.”
In fact Prof Jones is quoted as saying:
"I always think that the most convincing case for evolution is in the fossil record. "It's noticeable that one page in every six in the Origin of Species is to do with the fossil record. [Darwin] knew that that was an irrefutable case that evolution had taken place."
The second sentence is simply not true. Darwin actually admitted that the lack of fossils was a real problem for his theory. However, he was confident that given time enough fossils supporting his theory would be found. More than a 160 years later we do indeed have many fossils, but do they prove evolution?
We are given the example of an “animal” called Dormaalocyon. Which we are told MAY be a common ancestor of all today’s lions, tigers and bears. When we read claims like this, we really should check, which you can do because a link is provided here.
When you follow the link, you begin to wonder. And a search for more information suggests that the claims that Dormaalocyon is proof of evolution are somewhat questionable.
The first thing to notice is that the fossils of Dormaalocyon are teeth and ankle bones (which they compared with other teeth and ankle bones). From these they inferred the existence of a group of creatures with similar teeth and ankle bones and suggest that these species are all members of the same genus which they called Dormaalocyon. D. latouri was a species of carnivorous creature that probably lived in trees and had simple teeth. When you read the BBC article you might have thought of the canine teeth of lions, tigers and bears. So you will be rather surprised if you click on this link and check for yourself.
To claim that this was an ancestor of today’s lions, tigers and bears is a bit of an extrapolation.
Indeed the BBC article admits that the fossil record is only so much help, because it is incomplete. The next quote from Prof Jones is interesting:
"If you look at most fossil records, what you actually see is one form that lasts quite a long time and then the next bunch of fossils that you've got is quite different from what you had before."
This rather suggests that the fossil record is not all that convincing after all.
Nevertheless, we are assured that there are many “transitional fossils" which are “halfway houses” between familiar species.
In order to support the claim that birds are descended from dinosaurs we are presented with a small dinosaur called Microraptor, which had feathers similar to modern birds and may have been able to fly. The curious thing about this example is that according to evolutionists, Microraptor lived 30 million years after Archaeopteryx, which had feathers and was able to fly. This example does not explain how birds got their feathers, beaks, aerodynamic wings, shoulder joints designed for powered flight and unique respiratory systems. The other curious thing about Microraptor is that it was a creature with four wings and a large tail aerofoil. Rather than a creature which was a halfway house between dinosaurs and birds it appears to have been designed to be an extremely efficient glider, which was neither dinosaur nor bird.
For more discussion on the question of dinosaurs and birds here is an article from the Edinburgh Creation Group
The next part of the BBC artilce tells us that it is also possible to observe the evolution of a new species as it happens.
We are asked to consider the finches that are commonly called Darwin’s finches, which have been studied for many years by Peter and Rosemary Grant of Princeton University in New Jersey, USA. They reported a new species of finch which developed on one of the Galápagos Islands.
A review of the literature on Darwin’s finches shows that things are not quite as clear cut as the BBC article suggests. What they neglect to point out was that the finch in question was probably a Geospiza fortis × G. scandens hybrid (this can be checked by following this link)
which bred with a G. fortis female. Their offspring (all male) bred with other G. fortis females. The resulting offspring only bred with each other for five generations. However, the fact that one group, occupying a limited area, did not interbreed with other species does not mean that they could not breed with other species of finch. It is known that the various species of Geospiza can and do interbreed. This inter breeding adds to the varieties of finch and the types of finch which survive changes in response to the climatic conditions on the islands. However according to this article these changes are reversable. Indeed, it is questionable as to whether or not there are many species of Galápagos finch or only sub-species and they have remained that way since observations begun.
These small reversable changes are hardly convincing evidence that worms evolved into humans, via fish!
The BBC article recognises this, so we are next told about some more “dramatic” changes. These, we are told, come from the world's longest-running evolution experiment.
Since 1988, Richard Lenski has been tracking 12 populations of Escherichia coli bacteria in his lab. The bacteria are left to their own devices in storage containers, with nutrients to feed on, and Lenski's team regularly freezes small samples for later study. When looking at some of these, he discovered that some had changed, they were now able to use a chemical called citrate as a food source, something which the original E. coli could not do. However, this is not the whole story; E. coli have always been able to feed on citrate see here for publication which makes this clear. In the abstract we read:
Under anoxic conditions in the presence of an oxidizable cosubstrate such as glucose or glycerol, Escherichia coli converts citrate to acetate and succinate.
This means that E. coli can use citrate as a food source but usually only does so when there is no oxygen. There is a biochemical “switch” that is turned off when there is no oxygen which allows the E coli to feed on citrate. What happened was the mechanism controlling the switch broke and the system which allows the E.coli to feed on citrate got turned on. Others have found that this happens quite easily under the right laboratory conditions. See here and here for more about this story.
It would appear that far from being a dramatic example of evolution of a radical change, it is only an example of something breaking (the switch, keeping the system for using citrate as food, turned off).
The ability to use citrate was not something new. All that happened was that the switch which keeps the system off when there is oxygen had broken.
Next we will look at genes and giraffes.
We are told that all organisms share many genes and that:
“Thousands of genes found in human DNA may also be found in the DNA of other creatures, including plants and even bacteria.”
Which is true, but the conclusion:
“That all modern life has descended from a single common ancestor, the "last universal ancestor", which lived billions of years ago”
This not the only valid conclusion.
An alternative explanation is that as we are all designed to live on the same planet and use the same resources. Many of these shared genes are involved in metabolism and as we all live on the same planet and consume the same basic materials then it is not surprising that we share the genes for metabolism based on oxygen. Similarly, we are all made up of the same basic building blocks (amino acids) so need to digest and manufacture the same proteins.
Then we are informed that:
“By comparing how many genes organisms share, we can figure out how they are related. For instance, humans share more genes with apes like chimps and gorillas than other animals, as much as 96%. That suggests they are our closest relatives.”
But this assumes that the theory of universal common descend is correct and once again common design could be an equally good explanation. But even more importantly this ignores the fact that genes only make about 2% of our DNA. It also ignores the fact that there are major differences in the rest of the DNA. For example, the chimpanzee genome (about 3.0 billion base pairs) is about 300 million base pairs smaller than the human (about 3.3 billion base pairs). If we use that measure, then the difference is 10%. Also, when you look at the genes which we share we find many differences. This is especially so for the Y chromosome carried by all males. The difference is at least 30% for this chromosome.
Then there are the genes that humans have which chimpanzees do not have. These are called orphan genes (taxonomically restricted) genes. The evolutionist cannot explain how all these new genes (there are about 1000 of them) evolved in the 5 to 6 million years (about 250 thousand generations) since the supposed split from the last common ancestor. This is not possible with the usually quoted mutation rates, there is simply not enough time. Furthermore, orphan genes are everywhere, as more genomes are sequenced, more orphan genes are found. This is a direct challenge to the theory of universal common descent.
Now we come the question:
“How did giraffes […] get their long necks?”
We are told that natural selection did it. (This is natural selection of the gaps!)
“Darwin had an alternative theory: natural selection. It offers a completely different explanation for giraffes' long necks. Imagine an ancestor of modern giraffes, something a bit like a deer or antelope. If there were lots of tall trees where this animal lived, the animals with the longest necks would get more food, and do better than those with shorter necks. After a few generations, all the animals would have slightly longer necks than their ancestors did. Again, those with the longest would do best, so over many years, giraffes' necks would gradually get longer, because those with short necks tended not to have offspring.”
This is a classic Darwinian “just so story”!
There are some major problems with this theory.
Firstly, if you were a hungry proto-giraffe, would it not be easier to move to where the grass was greener or the trees where shorter?
How come it was only the giraffes which got longer necks and none of the other animals?
And how did young giraffes survive? Did their parents feed them leaves?
And how come female giraffes are on average 20% shorter than the males!
The writer of the article then tries to correct our perception that living things look designed. We are told hat we are confused because living things look designed.
But the question we should be asking is, “Why do we think living things are designed?”
What makes us think they are designed?
Maybe they look designed because they are designed. We recognise design when we look at something which we know was designed, so our perception that it appears to be designed is correct. So why when we see the evidence of design in living things, is our inference suddenly wrong? Living things look designed because they were designed.
This is true at the macro level and the microscopic level. It is true of the living cell, organs, body parts and whole bodies, and it is true of the planet we live on which is designed for life.
The BCC article finishes with a defence of the belief in human evolution.
We are told that:
“Homo sapiens is believed to have evolved in Africa before spreading all over the world.”
Science is not about belief; it is about theories supported evidence; where is the evidence for this claim?
We are also told that:
“People of European and Asian descent carry Neanderthal genes in their DNA.”
This doesn’t say anything about evolution, it only tells us that humans and Neanderthals belonged to the same species. Individuals which are capable of producing viable offspring are by definition from the same species.
Nevertheless we are assured that:
“The fossil record shows a gradual change from ape-like animals walking on all fours to bipedal creatures that gradually developed bigger brains.”
The only problem with this is that it is not true! There is no published sequence of fossils showing a gradual change from ape-like creatures on all fours to bipedal creatures. There are fossil apes and there are creatures like Ardipithecus, which appears to have been a creature that could stand upright. But there are no fossils demonstrating a gradual change from apes to Ardipithecus. Furthermore, there is no fossil sequence from Ardipithecus or any of the other ape-like creature to humans. Statements that humans evolved from apes are beliefs that are held because of a prior commitment to common descent.
We are also told that, we are still evolving and sickle cell anaemia is cited as evidence for this.
” […] For instance, in the 1950s a British doctor called Anthony Allison was studying a genetic disorder called sickle-cell anaemia, which is common in some African populations. People with the disorder have misshapen red blood cells, which don't carry oxygen around the body as well as they might. For those people, it was worth carrying the sickle-cell mutation […]. It turned out that people carrying the sickle-cell trait got an unexpected benefit. It protected them from malaria. For those people, it was worth carrying the sickle-cell mutation, even if their children might be anaemic."
If that is evolution, then I am an evolutionist!
Malaria is a serious, often fatal disease. Sickle cell anaemia is also a serious disease which significantly reduces life expectancy. Sickle cell anaemia does indeed protect people from malaria and that is why a defect like this persists. Without malaria, sickle cell anaemia would disappear. Natural selection eliminates defective genes, it does not produce anything new. The only reason natural selection has not completely eliminated sickle cell anaemia is because it protects people from dying from malaria.
Furthermore, sickle cell anaemia is caused by a single point mutation which is a copying mistake, that has serious consequences. This is no way to produce new features that are required to get from worms to apes and humans. As more and more errors accumulate in any species, extinction is the only likely outcome.
As the article states:
“there are all sorts of questions about evolution that we still haven't answered.”
The example given is a very good one:
“what was the genetic change that allowed humans to walk upright, and why was that mutation so successful?”
The answer of course is that there is no evolutionary explanation, indeed there is no need for an evolutionary explanation. However, if we had indeed evolved from ape-like ancestors, then the number of things which would have had to change to get from a quadruped to a biped, is so great that it is amazing that people believe that natural selection did it. Especially when you realise that according to evolutionists, all of these changes took place in parallel.
So in the end the article asks us to take a leap of faith and simply believe in evolution, even though it cannot answer some very simple questions.
Here are some more things that evolution cannot explain:
- the origin of the genetic code,
- the first cell,
- the first multicellular organism,
- the first organs, legs, arms, wings eyes and brains…
So I would suggest that next time you're out and about, whether it's in your garden or on a farm or just walking down a road, take a look at the animals and plants around you and remember how they all got there.
They are the descendants of the living things created by the God who made the universe. The existence of all this life in its various forms are evidence of the wisdom and power of the creator.
The origin of life
In this blog post I want to review an article recently posted by Science Daily about the origin of life.
The sub-title is:
“An experiment in recreating primordial proteins solves
a long-standing riddle”. Click here for the paper.
The riddle is the origin of positively charged
amino acids, like arginine and lysine, which are
part of almost all proteins found in living things.
But before looking at the solution to this problem,
consider the whole notion of primordial proteins
arising spontaneously in a primordial soup.
This whole scenario is completely hypothetical!
After a summary which gives the background to the problem of how the first proteins appeared spontaneously, without the necessary cellular equipment or an external intelligent agent, the article states that:
“Scientists believe that the very first true proteins materialized from shorter protein segments called peptides.”
They should have qualified “scientists” by writing “some scientists” or “evolutionist scientists”, or “scientists who believe in evolution” because not all scientists share this belief in the miraculous “materialisation” of proteins from peptides which it is claimed,
“would have been sticky assemblies of the amino acids that were spontaneously created in the primeval chemical soup”.
The origin of this “primeval chemical soup” has never been explained because it cannot be explained. It is simply assumed to have existed even though no-one can provide a rational explanation. Or even a definitive list of ingredients for this “soup”.
Instead there is a rather disingenuous attempt to provide a credible argument by referring to “the famous experiment by Miller and Urey” who by using carefully arranged laboratory apparatus and carefully selecting the starting ingredients and carefully excluding oxygen, were able to manufacture a mixture of amino acids. The idea that this replicated conditions on earth prior to life is completely incorrect, unless there were retort stands, glass flasks and other laboratory equipment used by Miller and Urey on the "early" earth!
Neither do they mention that the amino acids formed in this experiment were a racemic mixture of L and D amino acids (two different optical isomers of each amino acid). Proteins are made up of only L amino acids. A protein or peptide made up of an equal mixture of L and D amino acids is non-functional.
Another problem it that if you put amino acids in water, they will not spontaneously form chains of amino acids known as peptides. So the peptides have to form in some non-aqueous solution. The origin and nature of this non-aqueous solution is a mystery. Not to the mention that peptide synthesis is a very complicated process and requires carefully controlled conditions and precisely timed introduction of highly purified reagents or a living cell. To anyone with a basic understanding of the chemistry of peptide synthesis, this hypothetical primeval chemical soup appears to be somewhat magical!
All of these problems makes the problem of the missing positively charged amino acids like arginine and lysine which this article claims has been solved, rather less of a triumph than the authors suggest.
In the next post I will look at why, even though on the face of it the scientists’ solution to this problem is ingenious, this does not really make origin of life theories any more credible.
In this 2nd blog post on this subject I want to look at the solution to the riddle which the Science Daily article mentions.
As I wrote earlier the solution to this problem is ingenious, but this does not really make origin of life theories any more credible?
They started with the fact that one positively-charged amino acid did form in the Miller-Urey type experiments, an amino acid called ornithine. This amino acid is an intermediate step in arginine production in living cells.
They then designed an experiment based on proteins which contains arginine and lysine and binds to DNA (e.g. histones). This required the manufacture of similar, but smaller proteins, of about 60 amino acids of which about one sixth were ornithine instead of arginine and lysine. This protein also bound to DNA, but not very well. By converting more and more of the ornithine to arginine they were able to show that the protein bound more strongly to DNA.
They stated that ornithine can be converted to arginine under “those conditions assumed to have prevailed on Earth at the time the first proteins would have appeared”. What they mean is the absence of oxygen. However, that is not enough because other chemicals which they introduced in carefully control conditions were required to convert ornithine to arginine. Furthermore, they did not provide a plausible mechanism which works without the intervention of a chemist.
Just because a reaction can occur under certain conditions if the right chemicals are brought together at the right time, does not make that a plausible route for abiogenesis, in a hypothetical primeval chemical soup. There also has to be a mechanism to assemble the amino acids into a peptide chain. This is not straight forward, because a random mixture of amino acids will not produce a linear sequence of a peptide since there are reactive side groups. So even if somehow the right amino acids were produced in the right proportions and somehow brought together, they are very unlikely to have formed the peptide constructed by the scientists who carried out the experiment.
Have look here to see what is involved in real peptide synthesis!
Then the researchers went on to show that, in the presence of RNA, phase separation took place which is analogous to the formation of isolated droplets. From there they make another leap to proto-cells from which true living cells might have evolved.
Let’s look at what they are suggesting:
- First: amino acids have to appear, and in the right proportions.
- Second: these all have to be the same optical isomer.
- Third: the conditions have to change to cause the amino acids to form peptides with the right proportions of each to make the proto-histone.
- Fourth: the ornithine has to be converted to arginine.
- Fifth: Then RNA has to appear (where did that come from!)
- Then the droplets of RNA and histone like protein form and these somehow develop into proto-cells.
- Last but not least the proto-cells evolve into cells with all the machinery needed to maintain metabolism, manufacture proteins, RNA and DNA. A cell capable of life.
Each of these steps alone is so improbable as to be impossible in the supposed life-time of the universe, even if you accept that the universe is more than 15 billion years old!
All that we know about chemistry makes this impossible.
There is no abiotic pathway to pure optical isomers of amino acids.
There is no known route to form a peptide of more than a few amino acids from a random solution of amino acids. Even though one experimenter showed that heating a mixture of carefully selected amino acids produce short peptides of a few amino acids. The problem was that these were cross-linked and therefore not the linear peptide chains that are required (see here for more information )
What we are talking about here is the abiotic generation of a peptide more than 60 amino acids long.
And what about the RNA that suddenly becomes available in this primeval chemical soup.
There is no known abiotic route to RNA, not even the production of all four nucleotide bases, in some primeval chemical soup. Not to mention that these too would all have to be the same optical isomer.
All of these things have to occur without anyone controlling the process. The hypothetical conditions would have to produce amino acids, peptides and RNA at the right time and in the same place in high enough concentrations to interact.
The best that can be said for this scenario is that some of components can be manufactured under what is believed to have been the atmosphere of the early earth.
But there is another problem for abiogenesis. This all has to start in an atmosphere without oxygen. Evolutionists say that there was plenty of time for these improbable events to take place, but the best evidence we have suggests that oxygen was present in the atmosphere very soon after the formation of the Earth as shown here. So even if you believe that the Earth is billions of years old, you still only have a few 100 million years to overcome the improbability of life appearing.
In conclusion the claim that this experiment solves a riddle and somehow makes the theory of abiogenesis more of a possibility is hardly a valid statement.
The whole process from chemical soup to chemical engineer is so improbable that we really should examine the alternative of an intelligent designer.
Morganucodon and the mammalian jaw joint
This blog post is about the theory that mammals evolved from creatures called therapsids (which were a subgroup of non-mammalian synapsids) which according to evolutionists lived about 200 million years ago.
This includes the supposed evolutionary transition from creatures with one ear ossicle and a quadrate-articular (reptilian) jaw joint to mammals with three ear ossicles and a dentary-squamosal (mammalian) jaw joint.
The diagram below shows the names and relative positions of different bones in the jaw and the middle ear bones (ossicles) of reptiles and mammals.
According to this Wikipedia article,
“The evolution of mammalian auditory ossicles was an evolutionary event that resulted in the formation of the bones of the mammalian middle ear. These bones, or ossicles, are a defining characteristic of all mammals. The event is well-documented and important as a demonstration of transitional forms and exaptation, the re-purposing of existing structures during evolution” (downloaded 8th May 2020).
However, according to the abstract of a paper, published in 2016 in the Journal of Anatomy, on the subject of the evolution of the mammalian middle ear, there are some major problems with the evolutionary account. The authors Maier and Ruf wrote:
“(…) a number of morphological details remained to be solved, such as the origin of the tympanic membrane. (…). The present review emphasizes the problem of how the mammalian middle ear structures that developed at the angle of the lower jaw were transferred to the basicranium (…)”
To find out more go here.
Creation biologists have shown that actually there is no gradual evolutionary progression. Rather there are major discontinuities and reversals which seriously undermine the theory that mammals evolved from non-mammals. See here to read about it.
Evolutionists get around these problems by invoking homoplasy (parallel evolution),
One fossil which is supposed to show a key stage of the evolutionary transition is Morganucodon.
I have been looking into various aspects of this story and decided to get hold of a copy of one of key papers on Morganucodon (the abstract can be found here) which claimed to show that it had a double jaw joint, which was a key step in the evolution of the jaw and middle ear bones. I wanted to read this paper because it is often cited and Morganucodon is a very important part of the evolutionary story. When I started reading the paper, I could not believe how poor the evidence was and the amount of guess work which was involved. Nevertheless, the paper is cited and modified diagrams of Morganucodon are presented to support the case for evolution. Most people just assume that the evidence is good, without checking the source data, which shows that the modifications are based on very flimsy evidence and a lot of guess-work guided by evolutionary assumptions.
The current evolutionary theory is that animals with a reptilian jaw joint gradually evolved a mammalian jaw joint. The dentary bone increased in size and formed a secondary jaw joint with the squamosal bone of the skull side by side with the articular-quadrate reptilian jaw joint. According to this theory the articular and quadrate were also part of the system for hearing (the so-called mandibular ear). The theory is that the new jaw joint took over and the articular and quadrate were separated from the jaw and became the malleus and the incus, respectively. At the same time an eardrum evolved as a new sound receiver. At the end of the process the dentary bone became the only bone of the lower jaw and mammals had a more efficient ear.
Which brings us to the publication I mentioned above, on the skull of Morganucodon which Kermack and colleagues published in 1981 with a detailed description of the fossil skull of Morganucodon.
Here is my drawing of the skull which is based on figure 2 from that paper.
Notice that rear part of the dentary was broken off. The skull was damaged and none of the jaw joint and ear bones were attached.
Nevertheless, Morganucodon is claimed to have had a double jaw joint, that is, both a dentary-squamosal (mammalian) joint and a quadrate-articular (reptilian) joint which were side by side. As shown in the diagram below (which I drew, based on Figure 91 of the paper by Kermack et al).
This reconstruction was made even though key parts were missing or found separately. Only a partial dentary bones was found. Furthermore, the squamosal, quadrate and articular were not attached. A complete squamosal bone has never been found and all were damaged. It is no surprise to read that, “the correct orientation of the squamosal was difficult”. Lastly, only the foot-plate of the stapes bone was found.
Therefore, key parts of the double jaw joint were inferred, as shown by dashed lines in the diagram above.
Another missing bone was the quadratojugal bone which has never been found. Yet the authors stated that “(…) its existence is certain from the presence of the facets on the quadrate and the squamosal with which it articulated” (emphasis added). They go on to write that, “The quadratojugal formed the main articulation between the quadrate complex and the squamosal”. Furthermore, Kermack et al wrote that the articular had two facets, one for the quadrate and another for the quadratojugal.
The fact that the reconstruction was based on the belief in the existence of the missing quadratojugal and that it linked the quadrate and squamosal, and was an important part of the jaw joint, makes their interpretation of the double jaw joint rather doubtful.
Nevertheless, a modified version of this diagram is repeatedly re-drawn as evidence of a transitional stage in the evolution of the mammal jaw and ear bones. The modifications which are made are significant. They all leave out the quadratojugal and close up the gap, while at the same time maintaining that Morganucodon had a double jaw joint. In addition, no attempt is made to explain the role of the two facets on the articular bone.
Another problem with the revised reconstruction is that if only the quadrate is involved in the reptilian joint, this requires a more robust articulation between the quadrate and the articular which would have limited its movement and consequently reduced its effectiveness in sound transmission as part of the so-called mandibular middle ear.
All of these problems with the joint between the quadrate, quadratojugal and articular are good reasons to conclude that Morganucodon only had a mammalian jaw joint between the dentary and squamosal. Both interpretations are equally valid unless and until more evidence is found.
Reading the original paper on Morganucodon has shown that there are many uncertainties and a lack of clear evidence for the double jaw joint of Morganucodon.
The available evidence is consistent with suggestion that Morganucodon had only a dentary-squamosal jaw joint and that it was a mammal.
There is clear gap between Morganucodon and the proposed therapsid ancestors.
The argument for Morganucodon as a transitional fossil with a double jaw joint is clearly a matter of interpretation.