` That is, until last month. I was totally flabberghasted.
` Here's what happened: A friend of mine said that she had read in a 'science article' that there is an 'unexplainable curve' in human shoulder blades. I thought to myself; "Is that so? If it is, I wonder what that means?" Now, this is what scientists generally think in such a situation because any such oddball fact, if established, could mean any number of things (of course!) until something is found that apparently explains it. Until that happens, the fact is an utter mystery.
` But what she had said next had me totally flabberghasted: Because of the unexplainable curve, scientists apparently know that human ancestors had wings - you know, like an angel? - because it kinda looks that way.
` That was such a huge leap of non-logic that for a second I thought she was talking about a fantasy book (as this was the topic of discussion at the time) and was totally shocked when I realized she was serious! I mean, something unsupported (and remarkably silly) like humans with wings, and she just has faith in it without evidence? Shoulder blades, for one thing, are nothing new and anything that is unexplained about them means - for a scientist - that one should try to figure it out!
` That means you cannot just say something and proclaim that you are correct because you say so! If science worked that way, we would never figure anything out! Meanwhile, everything I knew on the subject was, in my mind, standing up and shouting objections in my ear. Either that, or laughing hysterically. It was like getting hit over the head by one of those huge, plastic whiffleball bats.
` First of all, whomever had written this either had no grasp of the scientific method or was ignoring it: In order for a scientist to write anything like this (without cracking a grin), one would need actual evidence for such a human ancestor. These would include such solid objects as ancient human fossils that support the idea.
` For example, they would need to show characteristics such as plenty of extra parts so that the wings could have a place to grow out of in the first place! Then, these limbs would have have their own muscle attachments - independent from the shoulder blade, as that is fully taken up by other muscles - with a huge, secondary breastbone in front so that they could actually carry the creature's weight (and of course, that weight would also have to be one heck of a lot lighter than any known human ancestor).
` As it turns out, nothing like this has ever been found. (Does that surprise you?) All the evidence points to the fact that our ancestors - all the way back to the common ancestor of humans and chimpanzees, which lived about six million years ago - were medium-sized, ground-dwelling mammals, all of which were considerably heavier and more robust than a flying animal, and all of which had a typical vertebrate body plan with no more than four limbs.
` Even more, no evidence of any vertebrate species with two extra limbs used for anything, living at any point in history, has ever been found! (Does that even surprise you?) Yes, sometimes farm animals are able to survive with cumbersome extra limbs (if they survive such a drastic mutation), but since they are generally useless and sometimes harmful in various ways, this kind of thing is not likely to catch on and dominate a population. Hence, no more than four limbs is still the norm.
` Not only that, but considering that there are many structural and biochemical reasons of why vertebrates can and do grow only four limbs, a primate having wings like this would appear to be impossible - unless perhaps it was able to have an additional, functioning body segment!
` Though this very thing does occur in the miniscule, considerably more simple structure of a fruit fly's body - at least when they are bred in laboratories - a vertebrate animal would appear to be much too large and complex to first pull that kind of stunt and then get away with it! (The 'bithorax' mutation of a fruit fly changes the way the entire back half of its body develops as an embryo. If this kind of thing should happen to a vertebrate, it would probably not survive gestation.)
` So, not only is there no evidence of a vertebrate's body plan being overhauled on such a basic level, it would seem to be insurmountable to begin with! (Especially considering recent ancestors of living species, because they haven't gotten enough chance to change on such a basic level, much less change back without any trace!) This is why any biologist could tell you that this problem could most likely be solved only if one stoops to using Photoshop:
` Alas, evolution must work with what it already has, and in accordance of the laws of physics, so not every mutation is possible. As useful as water-breathing lungs would be for a whale, such a thing cannot evolve because the initial step of inhaling water only too easily removes the individual from the gene pool. Similarly, insects cannot grow as large as humans because their exoskeletons would either break under the pressure or need to grow so thick that there would be no room for their insides, and this would actually cut off their legs!
` For the sake of argument, even if it did seem possible that primates could evolve an extra thorax with its own arms, which could then further evolve into wings (therefore getting rid of our necessity to explain how it can contradict everything we know on the subject and still make sense), the reasoning behind this particular claim seems to be; 'make up something and tell everyone it's true without checking!'
` That's a far cry from doing science:
` As I have stressed throughout my entire blog; science (and critical thinking) is done by looking for evidence that backs up your hypothesis. In other words, if your hypothesis predicts that something would be found in an observation, a discovery or as the result of an experiment, and this prediction holds true, then it has some credibility!
` Simple enough, right?
` In this way, the real world can tell you whether or not you could be correct! That's really handy because it's very easy for even the most well-educated person to be wrong. (They usually are in the case of hypotheses.) Not surprisingly, in most cases when a hypothesis is tried out, it dies a horrible death.
` Only a few manage to escape the scrutiny of being compared with things that really happen, and they are quite rare. Of these, the hypotheses that work well enough to be used regularly in the real world are called theories - which, far from meaning the same thing as 'a hypothesis', actually means 'a valid explanation of how this works'.
` Which is why this whole thing is so unscientific, and frankly sounds like the kind of thing that is purposely meant as a joke. In fact, I have no idea why I am taking this so seriously. But I am, probably because it bothers me that I could offend someone so much for not agreeing with something so small.
` Come to think of it, studies of embryological development would have, more than likely, already found evidence of a winged stage in human evolution if such a thing existed. It is such a simple thing that one would think it could have been found way back in Charles Darwin's time!
` I'm sorry - does everyone know what I'm talking about, here? I should probably write some about it then, as any layman may find this subject incredibly interesting:
` As you may or may not know, it has been well-established that the development of any given embryo is constrained to more or less 'repeat' parts of the evolutionary history, not of its fully-grown ancestors but of the embryos of its ancestors! This is because a new complexity in evolution usually comes into existence by merely adding onto or changing existing structures in early development to become something new!
` What do I mean by this? A rather fascinating example concerns the tiny bones of our own inner ears, whose dramatic history has been observed in both the fossil record and in embryonic development: It all starts in the jaw bones of ancient (and modern!) reptiles, which are composed of a mosaic of several bones that are fused together into a solid mass. The actual hinge of a reptile's jaw occurs between the articular bone of the jaw and the quadrate bone of the skull.
` Mammals, in contrast, have a single bone - the dentary - to make up the entire jawbone, which also forms a hinge with a different bone called the squamosal. In addition, while reptiles have one inner ear bone (the stapes), mammals have two more inner ear bones (the malleus and incus), which reptiles seemingly do not have... or do they?
` It turns out that these 'extra' inner ear bones are not extra after all! This is because they are not new structures in any way! When looking at all the transitional fossils between reptiles and mammals (the earliest ones using the articular as a jaw joint, the latest ones using the squamosal, and the ones in between having both articulations at once!), we can see from whence those inner ear bones have come:
` The fossils clearly show the transformation between the reptillian jaw bones becoming the single mammalian jaw bone and one of the inner ear bones! This is because the malleus is actually present in reptiles - it is the articular bone of a reptile's jaw! Similarly, the incus of mammals is actually the quadrate of reptiles!
` And, for your viewing pleasure, an image of some of the fossil jaws which illustrate this transition:
` So, what has happened here is not that mammals have evolved new bones, but that the bones of their reptillian ancestors have switched functions! (This kind of thing is quite common in nature.) As would be expected, this evolutionary stage can be seen in action when the malleus and incus of a developing mammal embryo are visibly ripped from the jaw joint and migrate to the inner ear!
` Interestingly, Dr. Timothy Rowe has discovered that in opossums (which retain some characteristics that many other mammals do not), the inner ear bones-to-be of the embryo simply stop growing after three weeks and instead are torn away and pushed backward over the next nine weeks by the growth of the brain. It would seem that, since these middle ear bones are known only in species with large-ish brains, that brain growth was originally the mechanism by which the bones migrated!
` And so, embryos transform 'indirectly' in all sorts of ways; all our body parts are like modified 'leftovers' from former species, and they may have once functioned quite differently! The gill arches that began to develop when you were an embryo became instead such parts as jaws (and ears!), while your lungs started out as part of your gastrointestinal tract!
` Embryonic development is quite the zig-zagging road, though thanks to evolutionary history - with jawless fish that used their gill arches to capture prey, and ancient fish with air sacs that became both our lungs and the swim bladders of modern fish - it is the only road an embryo can take!
` This whole phenomenon is due to the fact that we share our most basic genes with our most distant ancestors! These genes are like 'master controllers' which determine what part grows and where, with the rest of the genes making each species unique. When they are at work during development, the genes to make a structure are activated, though at some point or another, the genetic activity of newer evolutionary innovations causes the structure to stop growing or change form.
` And so, this applies when an ancient structure is instead absent or vestigial; one can see it to begin growth in the embryonic stage and then atrophy due to the action of further genetic mechanisms which halt that structure's development.
` This is where I bring up the fact that this is relevant to the topic: Since all fossil evidence tells us that the first land vertebrates all had four legs - and most living today still do, because they are darn useful! - you would expect to find that snake embryos have precursors to legs.
` Well, they do! Four limb-buds can be seen to appear briefly before the embryo reabsorbs them. The genes are there to start the legs, though something happened afterwards to stop them again.
` Even in adulthood, pythons have 'anal spurs' which are attached to leg bones and a pelvis, and are homologous to the hind leg - or to put it another way, without genes to further 'twist' the developing limb-buds into small stumps, the anal spur could actually continue on growing into a leg like that of a lizard!
` Similarly, whales also develop pelvises and near-legs in the embryonic stage, though these fail to become hind legs. In primitive species of whale, the hind legs were indeed functional, though in today's whales they instead become immobile bony appendages beneath the surface of the body.
` And for yet another example, there is a species of bird called a hoatzin, which is born with three clawed fingers - much like those of their three-fingered ancestors - which later fuse and develop into normal 'modern' bird wings. Un-'twisting' the genes of birds has actually resulted in the growth of other 'lost' reptillian structures, such as teeth. Hypothetically, with enough gene 'untwisting', you could cause a bird embryo to develop into something that more resembles an Archaeopteryx!
` This kind of developmental atrophy is seen across all animal species for all different types of structures - the more recently the structure has been modified, the more apparent this is. Therefore, it would be quite evident in human embryos (and genetics) if extra limbs and attachment parts were present in our ancestry. Especially if the neccesary body segment was required to begin development and then shrink back to exactly the way it was before.
` As it is, human embryos develop into something similar to a chimpanzee embryo and then smoothly on into a human embryo instead of first developing an extra body segment with its own bones and organs, and then getting rid of them all. Such a conspicuous absence this is, I cannot help but be tempted to say that this is positive evidence (rather than negative evidence) that there were no winged humans.
` I mean, there is zip evidence! Nada! There isn't even, for example, any indication our brains were once adapted to feel and move extra limbs. Nothing at all!
` Unfortunately, I've gotten way too far into this and my creativity is kicking in, because I'm beginning to go into 'what ifs'. Like, what if that could happen? What if a primate ancestor of humans evolved an extra thorax, complete with a pair of arms (to say nothing of the probability of re-arranged internal organs)?
` Take hold of your seat - this is going to get goofy...
` If such a lineage were to develop powered flight, it would probably have to go through a gliding stage to get there, and so it would have to have been light enough to be able to do so within the limits of the laws of physics! Because primates don't have hollow bones, this animal would've had to have been extra tiny.... Behold my crappy mouse-drawing skills!
` So, there. By the grace of Microsoft Paint, a gliding primate with an extra body segment. And an unusually small head for some reason. (Which would be the fact that I could only see one small section of the picture at a time.)
` Because its extra limbs would have been tethered by the gliding membrane, they would have been tricky to use as arms. However, they wound up being put to better use as a gliding controller. Eventually, the fingers developed webbing and they began use for enhancing propulsion. Once powered flight was acheived, body size could now increase dramatically.
` Flyyyy, my pretties! Ah hah hah!
` There you go, a really crummy drawing of a primate with the extra limbs it uses to fly with. Observe the extensive and oddly-shaped flight muscles which cover much of its second chest! Unlike with fictional images of winged primates, it couldn't fly without them.
` Indeed, a bird's breastbone - which anchors its flight muscles - is so large that extends down to its knees! Flight muscles must be enormous in order to give a flying animal the power to take off, to keep it in the air, and to allow it to land.
` Ironically, just before this whole incident even started, I had watched the movie X-Men 3, which features the mutant called Angel. He is a prime example of a creature who has no visible means of keeping its wings from flopping to the ground! If you will notice, he has a normal human body, with normal human muscles and no room for wing muscles, and so they just move as if by magic (or as if they are actually attached to an invisible bird)!
` Well, it's based on a comic book. The whole mutant superpower thing doesn't make any sense to begin with. Anyway, even if a human ancestor evolved a body segment to support wings and then completely got rid of it within the timespan of six million years - the timeframe in which our ancestors needed to evolve less dramatic things such as standing upright and developing language - there is absolutely no actual evidence to support it, and plenty of reasons to think that this wouldn't work anyway.
` A feature of our shoulder blades by itself is not really evidence: Any 'curve' that looks odd to us may be a quirk of the shoulder blade related to something, or a combination of things, that we do not expect. Hence, it is difficult to explain why zebras have stripes, or why we have extensive sinus cavities. Or, perhaps there is an explanation that the author failed to recognize, and in the realm of pseudoscience, where contrary evidence is flat-out ignored, this is also very likely.
` In sum, all the evidence we do have says 'no', and there was not even any supporting evidence to begin with. Therefore, all the evidence lies within the author's head - it is clearly a fantasy idea! It's the type of thing that belongs in comic books or fairy tales or other works of fiction! In fact, this assertion is so ridiculous that it is exactly the kind of thing that a scientist would write as a joke!
` ...And maybe it was and my friend mistook it for a legitimate article. It is true that spoof science articles are written all the time, and a lot of people are not able to recognize them apart from real ones. In fact, the 1997 April Fool's article in Discover magazine (along with the corresponding segment on the TV show, Discover Magazine) got a lot of people - including myself - believing that musical instruments made by Neanderthals had been discovered! (Though, I admit, a caveman that made instruments out of wooly mammoth tusks is actually plausible - unlike a caveman with wings!) Yes, this joke article fooled me until I decided to do some research on Neanderthals about six years later!
` I kept coming across statements such as; 'There is no evidence that neanderthals made musical instruments.' And I thought; 'Well, this isn't up-to-date. Wait. Yes it is!' This happened a couple of times before I even thought to check my source! Guess what I found?
` It was a joke and so I stopped believing it! However, my exchange with my friend suggests that perhaps, even if her article was meant as a joke and she found out about this, she would probably keep believing it anyway!
` Needless to say, I tried to tell her all of the stuff I just wrote about, but I didn't get a chance because her face grew very red and she did her best to shut me up. I began to get very angry, so I insulted her by saying that this was a subject I had spent a lot of my life learning about, but she didn't know anything about it - which is true! - so how would she know whether or not I was wrong?
` She continued to be uncomfortable with my rational arguments, so I said; "Look! I speak on behalf of all biologists when I say that this is one of the silliest, stupidest ideas I have ever heard, and I can't believe you think it's true, even though there is no evidence whatsoever."
` Her face got even redder and she said; "Stupid, huh?"
` And I said (or at least tried to say); "I don't even know why anyone would even think of that in the first place. Scientific ideas come from looking at evidence. You look at the evidence, and then you come up with ideas about the evidence - you do not come up with ideas for the sake of coming up with ideas! Science is about discovering the world, not about discovering people's fantasies, because you can't! Fantasies don't make things real when you think them up!"
` However, she completely shut me up by saying; "Listen; I'm one of those people who doesn't need evidence. All I need is to know how I feel, and I just have a good feeling about this."
` I was just staring, wide-eyed and mute. I wanted to reprimand her, saying that if she believed a cliff wasn't there, then she should step over the edge just to prove her way of reasoning, which she essentially just admitted did not even count as reasoning. At the same time, I suddenly realized that I could no longer talk to her about something that is a part of my personality.
` I felt very isolated. It was as if I was being personally dismissed, as if I could never talk to her again because I couldn't be myself around her.
` And then she said; "Scientists think they know everything. But they don't."
` That being a big lie - and common misperception - it felt rather like a slap in the face. (It's also striking how noncritical thinkers renounce science while sticking by what they take to be a particular scientist's claim. Hello?) I tried to tell her that indeed this is far from the truth: I don't reject this idea of humans having wings because I pretend to know the answer; I don't! You just can't do that. You need evidence first. That's why we have science! That's what science is for!
` I tried to tell her that when people do science, they actually go around saying; "I don't know this! Therefore, I have to find the answer!" so then they work on finding it. And on the way, evidence that would explain it needs to be found. Because there isn't any evidence for humans having wings, skipping to a fanciful conclusion is exactly what you would do if you claimed to already know the answer.
` Such is the case with my friend, who then accused me of the one doing this!
` I'm sorry; in science, you can't say something is true and ask questions later - you have to find it out first. Since that hasn't been done, there is no way she could know what she believes is true, though this doesn't trouble her in the slightest. So what kind of article was it? Not a science article, because science is not about holding dogmas, it's about making discoveries - hopefully ones which expand our view and overturn assumptions about things we didn't know about very well.
` Why is that so difficult for most people to understand? Indeed, this is why I implored members of the Skeptic Forum about whether or not they had even heard about this. Here were the responses:
Silly Green Monkey: I'm actually more curious about what unexplained feature of the human scapula indicates flight. I've not heard anything like that in my osteology classes.
Paul Anthony: There is truth to the age-old adage: "Ignorance is bliss". From ignorance comes "good feelings", and with good feelings the ignorant blissfully follow charlatans.
Tsukasa Buddha: This reminds me of my favorite creationist line made by a classmate:
|If humans evolved from birds, why don't we have wings?|
Philosophical Skeptic: That response shows both hilarity & tragedy in the same sentence. It's tragic, yet funny!!!
Me: ` Is that called 'Tragi-Comic'?
` That's also hiy-larious that someone said 'then why don't humans have wings?' much less assumed that we evolved from birds!
` I myself have heard; 'Whales could not have evolved because they have so much in common with mammals! And yet they are fish!'
Xipe Totec: Hm, this is an interesting take on the "we don't need no evidence" mentality. I'd lump it all under the heading of partial brain use.
St. Jimmy: Why would humans dis-evolve wings? Surely if we once did possess the ability to fly then the first wingless mutant would be less able to get around and hence would produce fewer offspring... no?
` Though nobody could figure out from whence the article had come, Kitiara offers an explanation on who the 'scientist' author might be....
` Of course!!! Now it all makes sense!
` Seriously, though, this whole argument had me upset for a while because I felt like I had been cut off from yet another friend. Then I talked to Lou about it, and he reminded me that he had long suspected that this particular friend has a very small intellectual comfort zone, since she hasn't had a lot of exposure to the world. Thus being uncomfortable with people threatening her beliefs, she is very adamant about defending them no matter what.
` Finally, I began to feel better. Besides, I'm used to having friends who believe other types of strange things: Just before I began working on this post (for the first time), I was out in a graveyard with a friend who claims to have studied with Jesus himself and he was telling me about the social interactions of the dead people standing around us.
` It was soooo cute! I don't know why....
` Oh, that's right - I also passed up an invitation to see this woman he says channels the real Mother Mary (and he even offered to pay the $30!) because I had to go be myself in a cornfield. And she's only a couple of blocks from my house! Indeed, my neighborhood is full of all kinds of insanity.
` So much weirdness, so little time....