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Shark 6th Sense Related to Human Evolution?
An anonymous reader writes "Scientists at the University of Florida are claiming that certain genes found in sharks that give them their 'sixth sense' and allow them to detect electrical signals could also be responsible for the development of the head and facial features in humans. From the article: 'The researchers examined embryos of the lesser spotted catshark. Using molecular tests, they found two independent genetic markers of neural crest cells in the sharks' electroreceptors. Neural crest cells are embryonic cells that pinch off early in development to form a variety of structures. In humans, these cells contribute to the formation of facial bones and teeth, among other things.'"
Is it implying that we desended from a common ancestor or that we descended from sharks with this ability?
...do different things in different organisms. This is not news. It is a study of cellular fate in two different biological contexts of distantly related organisms.
Which of these cells pinch off to form friggen laser beams?
You're nothing; like me.
It seems we get a new "sixth sense" every few months. Perhaps it's time to review the whole "five senses" thing so that people stop using "sixth sense" as if it's something special or supernatural?
So this is why I was born with a dorsal fin
maybe our teeth can pick up radio stations someday :)
As they evolved, mammals, reptiles, birds and most fish lost the ability. Today, only sharks and a few other marine species, such as sturgeons and lampreys, can sense electricity.
The platypus begs to differ...
A shark's 6th sense.
"I see soon-to-be dead people"
You misspelled laser.
Mix The Sixth Sense with Jaws... "I see dead sharks"
Have you ever, while having your eyes closed, felt the position of a pointy object several contimeters distant from you face, especially from your forearm? I did and many people know that feeling. I have no idea whether this is an electrostatic field or what, or if it has anything common with... sharks, but it is probably quite a common phenomenon. I do not really know why I have not seen it described anywhere in the literature.
In a directly related story, scientists have found THE missing link between sharks and humans in a sub-species. They are calling it entrepreneurius-maximus.
Offer not valid in NY, Conn., CA, MA, etc.
Cogito Ergo Sum
Evolution of AI Minds proceeds by the same sort of recapitulation of evolution.
Robotic Sensorium Modules allow for the robotic evolution of special senses as in this case of sharks, or the Japanese idea of umami as a "fifth taste" on the human tongue.
The Mentifex Theory of Mind for artificial intelligence (AI) explains how even sharks, if left alone as the heretofore pinnacle of evolution on an Earthlike-planet, could evolve into intelligent beings and beyond.
Mentifex AI Mind Design explains the Central Nervous System (CNS) as it evolves in sharks, humans and superintelligent robots.
X the Eliminator; I must have the Neural Crest of Sharkman
sorry, i have mistaken these two words
It's called balance. The mechanisms and nerves are all seperate from the hearing part of the ear. Why is this not considered the sixth sense?
Most fish have some electrical sense, though some may do it better than others. I'd guess this sense was re-invented many times.
Terrestial animals, including humans, can feel strong gradients in the air before thunderstorms.
So...... Lawyers really are landsharks...
6th sense: Your "stuffy room" sensor for excess CO2. 7th sense: Infrared sensors around your lips: Close your eyes. Put your hand three inches from your face. Feel the heat around your lips? 8th sense: Your ears can correlate pressure changes to detect that you're between walls.
The scientific method is pretty much the definition of how you aquire science (systematic knowledge). To agree or disagree with a definition does not make much sense.
;-)
However even if a model or theory cannot be scientificly proven or disproven it might be of use anyway, for example: mathematics is in fact not a science since it is derived from axioms (fundamental concepts *belived* to be true). Even so, no scientist would deny the usefulness of mathematics
The scientific method has the fatal flaw of being limited to collecting information based on the questions you ask and methodology you use. I found this to be a very true statement made by one of my science teachers in explaining the scientific method. Immoral testing is a good example of something that limits or clouds our understanding. I remember some tests done in the 90's that did nothing more than confirm findings from the 40's. The difference was that in the 40's, the Nazis tested on humans in immoral ways and people were afraid to use that information based on the source.
So there's conclusive evidence that there's an evolutionary link between the development of sharks and lawyers? Or does Intelligent Design explain why some sharks have two legs? Inquiring minds want to know!
Now we know where lawyers come from!!!
They'll be happy to know that they haven't evolved from monkeys after all!
"Human evolution" is just a theory.
If you don't believe me, ask the next A&M dropout you meet.
Sheesh, evil *and* a jerk. -- Jade
so don't mess with the ninja
> I disagree that science is restricted to that which can be demonstrated using the scientific method. Humans have been engaging in scientific inquiries for millenia, yet the scientific method is a recent invention.
Arguably we have been using the scientific method for millenia as well. It's just a formulation of "guess the cause and then check to see if you were right" - exactly what you do when your computer starts making noise or your car won't crank.
Sheesh, evil *and* a jerk. -- Jade
Have they even linked human evolution to anything besides common genetics? Isn't there a huge gap somewhere?
Back when there was magic on the Earth, and magicians thru lightning bolts around with abandon... especially this Zeus fellow... it was beneficial to be able to sense electricity.
Now, only a few people such as electricians would benefit, so no reason for mammals to sense electricity.
Besides, I like a good shock every now and then. Keeps ya on your toes.
I only look human.
My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
The ability to sense electrical signals is useful in aquatic environments because water is so conductive. On land, however, the sense is useless.
Well, some people have the ability to sense electronic signals in their teeth fillings, which gives a whole new meaning to Bluetooth enabled.
He who knows best knows how little he knows. - Thomas Jefferson
found in sharks that give them their 'sixth sense'
The shark turns out in the end to be dead all along.
There's a saying in developmental biology circles that neural crest cells are the only really interestng part of vertebrate embryology. They form (IIRC) the autonomic nervous system, endocrine glands and pigment-producing cells too, as well as the ganglion of the auditory nerve - which is why some animals show a link between colouration and deafness.
By this argument, no science was practiced until the invention of the scientific method (during the Renaissance). This definition is overly narrow. Perhaps it would be better to refer to the scientific method as the experimentally falsifiable method (of acquiring scientific knowledge) to help disentangle science from the methodology.
Terrestial animals, including humans, can feel strong gradients in the air before thunderstorms.
My personal experience with this is that a very strong field actually causes your fine hairs to react to the field pattern, and you actually feel it as mechanical stimulation of the follicles. No doubt a truly mammoth field gradient would tangibly impact your nervous system to the point of being directly aware of it in some way, but that "hair standing on end" effect is something you can actually see. I was once doing an emergency dish repair on the roof of a commercial structure as a front came through (brilliant!), and seconds before lightning hit a radio mast about 20 yards away, the guys working with me were all pointing at each other's hair... which was actually standing up. The heavy hair, on their heads. We all hit the dirt (well, the gravel, on the roof), and kablooie, right next to us. I will never forget that one. Um, or get on a roof in a thunderstorm again, no matter how much a customer tells me they'll lose important accounting data transfer opportunities if they can't get their dish re-aligned.
Don't disappoint your bird dog. Go to the range.
> I disagree that science is restricted to that which can be demonstrated using the scientific method. Humans have been engaging in scientific inquiries for millenia, yet the scientific method is a recent invention. The scientific method facilitates the acquisition of scientific knowledge, but it is not the only possibility. There are times when performing a scientific experiment is impossible or immoral. In these cases, we can still make observations and construct models, even though we cannot directly test those models.
It sounds like you're saying that "the scientific method" = "laboratory experimentation". If so, that's not correct. Astronomy, for example, uses the scientific method.
Also, "directly test" is a pretty slippery concept. Arguably nothing is direct, e.g. when we weigh a compound we are getting its weight indirectly (through whatever mechanism the scale uses), and we only see the output via the photons that our retina catches.
Sheesh, evil *and* a jerk. -- Jade
do you mean to tell me that these scientists found cells that are similar to cells found in other organisms, like humans? wow!! next they'll be telling us that you can group organisms together based on similar physical, structural or functional traits!
ConsultingFair.com
Um... I think I speak for all of the Department of Obvious Assholes when i say: Monkey -> Human makes sense. We look alot alike, and I bet many /.ers still drag their knuckles .
Shark -> Human = rediculous. If we do share similar genes, they probably come from a mutual protozoa, making them our great great great .......... cousins.
If a nation expects to be ignorant and free, in a state of civilization, it expects what never was and never will be.-TJ
Look, this whole 5 senses thing goes back to Aristotle. He was just trying to find some order in a chaotic world.
So the dude was wrong. Give him a break, he's dead, ok?
Why would this be better? It would not be science and the only thing you would gain would be to make it easier for religious constructs like creationism/intelligent-design to pretend beeing science.
;-) After all, look at the explosion in science and technology that took place from then and until now. Surely you dont think the old way was better?
When you say this argument means no science was practiced until the renaissance, perhaps this is true?
You talk about indirect measurement and come out with a statement like "we only see the output via the photons that our retina catches"!
"The White House is not an intelligence-gathering agency," -- Scott McClellan, Whitehouse spokesman.
Now they's saying we evolved from sharks? What will those heathens say next?! Pfff, probably that we evolved from bacteria!
Don't lead me into temptation... I can find it myself.
If I were asked to guess what embryonic tissue shark's electroreceptors came from, my first guess would be neural crest. After all, this is the tissue that gives rise to electrically active tissues like nerve and muscle, which have receptors that do indeed "sense" electrical fields. This is not to allow the animal to sense electrical fields in its environment, but simply the way nerve conduction and muscle contraction work--a change in electrical field (typically produced by a chemically activated ion gate in a membrane) is "sensed" by a voltage-gated ion channel that responds by opening up additional channels, further altering the electric field, which stimulates other voltage-gated ion channels, and so forth. It is easy to see how such a process could be evolutionarily adapted for sensory purposes, just as fish that generate strong electric fields, such as Torpedo (the electric ray) do so with tissues that are evolutionarily derived from muscle.
So basically, all this is saying is that we and sharks have a common ancestor and as a result share similarities in the development of nervous tissue (which we knew already), and that sharks' electro receptors develop from the tissue that any biologist would identify as the "usual suspect."
Anyway, one of the hard-to-pin-down aspects of shark encounters is a "sense" people report having just before they become fully aware of a big shark's presence. This may just be memory colored by the adrenaline rush that came with the encounter -- but it's very commonly reported that, moments before the water starts boiling or whatever, the surfer gets a cold, "something isn't right here" feeling.
(Which would also be a touch of an evolutionary advantage for the person able to sense it, yeah?)
"Fundamentalism" isn't about divine morality. It's about human authority.
I for one welcome our psychic laser-wielding shark overlords.
The 'Net is a waste of time, and that's exactly what's right about it. - William Gibson
Is that how (human) drivers know I'm looking at them when I'm passing them in traffic, but before they're facing me, without using their mirrors?
--
make install -not war
Sharks can sense electric signals? Are they sure they didn't observe wrong shark species?
I certainly do not think that the old way was better. I enjoy the benefits gained by rigorous testing, and I enjoy engaging in science.
However, according to the scientific method we must 1) form a hypothesis, 2) collect data and 3) use that data to refute the hypothesis. In many cases, though, we need to accumulate data so that we can identify patterns (formulate hypotheses). These retrospective studies still (IMHO) qualify as scientific even though the scientific method was violated.
This approach is not ideal, and the results generated by such a study cannot as easily be generalized. But, retrospective and longitudinal studies are (or rather, can be) scientific.
As an aside, I don't think we should pay any heed to ID when thinking about what is (or is not!) science. We can simply reject as unscientific, any conjencture based on unobservable phenomena. Science is based on data, regardless of where we insert hypothesis-generation.
Leave it to junk scientist to make connections where none exists.
Common elements of humans found in rocks. Have we evolved from a common ancestor?
Scientists have discovered that the fundimental building blocks in humans is common to all rock formations. The atoms of some structures of rock formations have been discovered in human DNA. This list includes atoms souch as oxygen and sodium.
Athiesm is a religion like not collecting stamps is a hobby.
Well this makes more sense than you previous post.
But I do not see what is the problem. Collecting data before you formulate your hypotheses does not violate the scientific method as long as it would be possible to collect more data afterwards that could possibly falsify the hypotheses.
Mathematics and science gives me a good analogy. You can think of science (eg: theory of evolution) as a mathematician trying to determine what a functional equation is, not by looking at the equation itself, but by systematically providing inputs and analyzing the outputs. Doing this enough starts to give us a dataset where we can start "guessing" what the underlying equation actually is. We have no "proof" that the equation that we have guessed is the correct one, but if our "guessed" equation ALWAYS works, what difference does it make? (Philisophically speaking?)
Evolution is a guess of God's equation for the creation of complex organisms. It has never been shown to be false. It may not be right, but why does that matter if it has always been working so far? Intelligent Design simply throws its arms up and says "Don't even try to figure out the equation, because you may be wrong!" Sure, but this is of no practical use to a person who wants to understand the world around him.
Land shark...
Yeah. Mod me off topic, but don't mod people who say "not news, move along". Not necessarily here, but I've seen it in dozens of other articles. They add sooooooo much to the discussion.
Feels like the Bush Administration.
*waits to be modded flamebait or troll*
I shoulda posted the first one anonymously, too.
Is it just me, or can other people detect whenever a TV has been turned on (even with no signal)? It's like a faint high-pitched buzz, so I search for the source, and ta-da, the TV was turned on. It's the same with fluorescent lamps.
Something that strikes me is that the article (or the summary, whatever) says the same cells gave origin to the ears in humans.
Or maybe i'm just jumping into conclusions.
Why is it the absolute conviction of Creationists that God could only create a finished product? Doesn't that seem like they are applying a rather large limitation on their "all powerful" God's abilities?
As an "ultimate being" wouldn't it a bit more creative and a bit more challenging to create something that keeps creating?
Also an all-powerful God might appreciate the ability of his creation to surprise him from time to time!
(religious suggestion: quit regurgitating what you hear and process the ideas for yourself and see if they are consistent!)
"We also have some sense of where all the different parts of us are, though that one may be a derived sense."
It's seems that it's not, it's a distinct sense, as demonstrated in people with specific types of aphasia.
And it's called "proprioception".
http://en.wikipedia.org/wiki/Proprioception
How pathetic are you that you follow me from topic to topic and waste all your mod points at once modding me down?
This is flamebait but he makes a valid point. "Mainstream science" aka the ones that get all the credence around here have a huge double standard in that a testable hypothesis derived from the idea of interventionism is automatically discredited where as a non-testable idea from the naturalism school of thought is given a fair look. Science just works inside whatever paradigm is currently going...Anythign else is discredited... The evolutionist fundies are just as bad as the right wing religious fundies in that they cannot admit that maybe, just maybe, some of the other side makes valid points. / I am not a scientist , I am not experienced, therefore feel free to attack me and discredit me because I don't know what I'm talkign about.. go ahead.. I won't blame you.. I see it done all the time on here, it's what i've come to expect when slashdot has a discussion mentioning any part of origins.
replacing it with NEW Folger's Crystals! (lets see if they notice the difference)
I was tought in school five, but I had a science teacher that argued seven.
The standard: Smell, touch, taste, sight, sound.
But then 2 more: Heat, because you dont have to touch anything to feel its hot. A more obscure definition of touch I guess.
And Time, he said people have an inherient ability to know about what time it is. He claimed NASA had proven this with rooms that have no windows or clocks or anything that would give away what time it is, and by having people live in it, on completely different schedules as everyone else. Apparently (and im paraphrasing/quoting here) they could guess with stunning accuracy what time it was and eventually realligned their schedules.
Food for thought.
I beg to differ, as evidenced by the effectiveness of an electrified fence.
Hypothetically speaking... suppose we do find a previously undiscovered 'sense'... like this electro-thing-a-ma-jiggie... Just imagine the impact on say the legal system! Quite a bit of personal law is based on a sense... good touch versus bad touch, ogling, assault, battery, and so forth... I wonder how the legal system would take such a system shock to update all the laws or revamp them...
Yeah, yeah, yeah.. I know it will probably never happen, but this is a great time to point out the almost non-perceived bed rocks of the system.. the five senses and how we use them to interact with each other (for good or ill)..
Isn't that just detecting the effects of electricity on the body,
not the electricity itself. Like detecting a hammer by the bruise
on your thumb when you tried to hit that nail held in your fingers.
It could have been elbow and ass. Then you could apply for a career in marketing. (shamelessly plagiarized from Dilbert)
You better watch out, there may be dogs about . .
This article fails to adequately explain the Lava Girl phenomenon
All senses are just detecting the effects on the body. We do therefore detect electricity -- and it IS a unique sensation that can be distiguished from being burned, hit, cut.
Please respond with links, quotes etc etc.
TIA
there may be "true believer" syndrome among some evolutionary scientists. However, if they falsified data, or twisted interpretations, they would quickly be shunned, just as creation "scientists" are. The fact of the matter is, no creation scientist has ever published evidence in a peer-reviewed journal (and they've resorted to trickery to try, as well). So they wage a PR campaign instead. PR is not science. By the way, what are all these "good points" I've heard so much about?
I don't think of it as a problem at all, but in many cases, all you can do is keep accumulating data. You cannot introduce a test that tries to disprove the hypothesis. Thus, Darwin and Mendel were engaging in science even though they were not trying to create conditions that would falsify their hypotheses.
In short, I guess it boils down to the extent to which one believes the scientific method demands actively trying to discredit one's hypothesis. The definition I'm familiar with requires experimentation, which I view as more than passive observation.
produces over a million hits on Google.
You won't find any webpages proclaiming a "creationist has discovered" anything.
Of course, by the same standard that smell and taste are the same, we could claim that sound and touch are the same, since they involve physical contact with a medium.
Likewise, I could argue that some aspects of touch should be considered separate senses, since they require different mechanisms for detection (ie feeling whether something is against your skin, versus detecting heat or cold.)
To me, it's all a question of semantics. I would say it makes more sense to consider how an observer perceives a sensation rather than the mechanism by which that sensation was produced.
Procrastination Man strikes again!
Had that happen once at a zoo here in Minnesota, too. The morning there'd been an ice storm, and the place was basically deserted, but I took my twins around in their dual umbrella stroller. They were between one and two, probably. In the big cat building my son toddled out ahead of me, and I knew it was a bad idea suddenly, even though the room was empty of other people. Came around the corner and one of the female lions had fixed her attention on my son; she was hunkered down at the glass wall, with her eyes wide, looking every bit the predator.
(Personally I think this is an effect of memory, not a true "sixth sense" thing, and that the AC who responded talking about selective memory probably has it right. With the sharks, though -- well, if they're sensing electricity there's at least the precedent of something happening this way with them.)
"Fundamentalism" isn't about divine morality. It's about human authority.
From the (since updated) US Army Field Manual 21-150 Chapter 7 Sentry Removal:
"However, it is important not to stare at the enemy because he may sense the stalker's presence through a
sixth sense."
OK - I'll give you one. The entire universe as we know it was created 100 hours ago by a Supreme Being. Any memories you have prior to 100 hours were created then too. Anything that seems old, like a fossil, was created to look that way. Likewise for carbon dated objects. I see no way to test this one way or another.
Fortunately we can implant small magnets under our skin to regain something similar! See bmezine for details: http://www.bmezine.com/news/pubring/20040226.html
Humans sure do have all those feelings, but not every "feeling" is a sense. A sense is an interface that allows an organism to get information about the world around it, not its own self. There's some discussion around whether to classify pressure, pain and temperature separately or to group them all as "touch", but the classical 5-sense classification prevails.
Other than that, the ever-so-suggested "equilibrium" doesn't count because it is just another information we have about our own selves. So is thirst and hunger, and headaches, and the feeling your body gives you when it's time to take a dump.
My other account has mod points.
Actually, you could argue that psychological self-awareness is much more important than other senses, because it tells us when we're laughing out of fear, or pleasure, or for a myriad of other reasons. And, of course, it makes us capable of questioning ourselves, and our humanity, and how many senses we have ;)
Will all you religious zealots please piss off somewhere else.
I wanted to read about sharks, stem cells and human facial features, not this incessant whining about creationism that's polluting damn near every biology thread on Slashdot.
"I've got more toys than Teruhisa Kitahara."
..."the lawyer".
What else would you call the common ancestor of sharks and men?
Digressing for a paragraph: I want to know what the common ancestor between octpuses and man is, since we share an uncommon eye structure, and why the others in our line (cats, for example) abandoned said structure.
Bill Gates is widely regarded as an evolutionary throwback to this time before emotions other than greed had developed. A certain amount of inbreeding allowed his McDuck gene to be expressed.
Got time? Spend some of it coding or testing
...halfway between man and fly must have been a wonder to behold.
Got time? Spend some of it coding or testing
Ummm, I believe that your "fact of the matter" is WRONG. For one example, take the world of Robert V. Gentry on polonium microspheres found in granite. An overview of this peer-reviewed work is availabe at http://www.halos.com/
Here's a quote from the site:
Did you know that scientific evidence abounds to support the biblical accounts of creation and the flood? Were you aware that reports outlining this evidence passed peer review, and were published in the open scientific literature? Have you heard that, decades later, this evidence still stands unrefuted by the scientific community?
I suspect that your answer to all of these questions is "no." I advise you to put serious study into Dr. Gentry's work and find any published evidence in a peer-reviewed journal that refutes his findings and the resulting conclusions that the earth's granite was formed in a very short period of time and could NOT possibly have taken "billions of years" to cool from an early, molten state.
I did LSD a couple times in high school. Whoa.. it seemed to have awoken something in me because I feel like I think about things and am aware of them more than before..
The one thing I kept thinking about during my 'trips' was how we are so unaware of our own selves. For instance, just a little while ago, my friend showed me how to crack the joint between my thumb and the base of my hand.. I was never aware of that before - and most people aren't aware of it. Some people can move their eyeballs in and out, some can wiggle their ears, some can control their own blood pressure to an extent.
Anyway, as for LSD, it typically enhances contrast to a great degree. In my case, I was able to see where things have been spilled on my floors before, where the paint rollers went on my walls, and I could easily read some of what I had written on paper on my desk by looking at the grooves the pen left behind.
It really made me think that we, as humans, should attempt to be much more aware of ourselves and our environment. Just as blind people develop 'super-hearing' sense, it seems to me we can develop this kind of talent for all our senses - and perhaps even realize new senses.
BTW, kids, don't do LSD. It's bad. Government says so.
--- We need more Ron Paul!
Indeed. Even if a particular sensation does not pass the threshold into conscious observation, the subconscious gathers a tremendous amount of data from minute clues, such as faint sounds or odors. People can often tell when they are being stalked, even without being able to consciously single out the source of their increased aprehension.
:)
I remember one time I was standing in a dark alleyway a few hours after sunset, when I suddenly had the distinct impression of a large, hulking, furry monster, about my height, poised right behind my neck. Since it was behind me, I hadn't seen anything up to that point, nor do I recall any smell or sound, and I certainly didn't taste it. I must have scared that poor raccoon senseless when I turned and yelled... it lost its footing and nearly fell off the fence as it scampered away.
Procrastination Man strikes again!
As a trained microbiologist and a student doctor, you obviously haven't read many papers. What do you think antibiotic resistance is? Why is it if you stop antibiotic therapy and your illness returns, you can't start taking the same antibiotic again? Is it an "intelligent designer" waving his hand and declaring some bacteria should survive and kill you because of your sins? Or natural selection at its most blunt? By taking the antibiotic you yourself have created the selection conditions necessary for the propogation of the bacteria. By the way, most bacterial mutations related to antibiotic resistance aren't related to "latent genes" or "highly regulated mutagenesis". They're variant amino acid sequences for antibiotic targets that produce slightly different proteins. Or transmembrane pumps that serve another purpose until an antibiotic wanders in. Or community plasmids or viral sequences that don't have any advantage normally, but the bacterial community keeps around because those that don't are periodically wiped out.
Natural selection explains almost nothing. All natural selection means is that dead things don't reproduce, and sick things don't reproduce well. This is a conservative, not a creative process. And random mutation has too big of a search space to do anything productive. Perhaps you should take a 21st century view of evolution rather than the 1950's version of it you are looking at now.
Perhaps you should wonder why human populations in equatorial areas that receive a lot of sunlight tend to have darker skin pigmentation and populations with endemic malaria have a high incidence of sickle cell disease. For doesn't it make sense that the only peoples who could survive conditions perfect for a high incidence of lethal skin carcinomas are those with an built-in resistance to mutation by UV radiation?
And what about sickle cell disease? If "sick things don't reproduce well", why is still around? What kind of fucked-up "intelligent designer" keeps around a genetic disease that is inevitably and messily lethal in its untreated, homozygous state? But if you think about it as a random genetic mutation in the structure of a blood protein that, in its heterozygous state, confers great resistance to a lethal disease, uncaring natural selection sounds like a pretty good explanation for it still existing.
How about cystic fibrosis? If "sick things don't reproduce well", cystic fibrosis should have been history long before modern medicine got around to diagnosing it. And again, what "intelligent designer" would ever design cystic fibrosis? Until you realize that in pre-modern medicine caucasian populations (in which 1 out of 25 people are cystic fibrosis heterozygotes), infectious diseases were 9 out of the top 10 biggest killers. And some of the nastiest killers in those 9 were cholera, typhoid fever, and tuberculosis. And that the microorganisms behind cholera and typhoid fever require a working cystic fibrosis transmembrane conductance regulator protein (CFTR), the exact protein that is defective in cystic fibrosis. And that the increased, thickened mucus production in cystic fibrosis heterozygotes appears to be protective against Mycobacterial infections.
"Please tell me what the evidence is that (a) everything shares a common ancestor, and that (b) random mutation + natural selection is sufficient for creating the diversity that exists today from that common ancestor. If you want to be really adventurous, you can also show how (c) life could have proceeded from non-life."
Try looking up "ribosomal RNA sequencing" sometime, since you say you're big on scientific papers. Or hell, try picking up an introductory microbiology book published in the last 10 years. How could life arise from non-life? The Wiki entry on "origin of life" has a good summary of the theories on how that could happen. As well as the experimental proof behind them.
Light a fire for a man and he'll be warm for a day. Light a man on fire and he'll be warm for the rest of his life.
I have no problem with creationism being taught in a philosophy class. I also believe that it is possible some god created everything 100, or 6,000 or so years ago, so that it looked like evolution happened. However, that's not the issue here. The issue is not that creationism is right or wrong, it's that intelligent design isn't science. Intelligent design is unfalsifable, and as such, has no predictive power. Natural selection as put forward by Darwin can be falsified, thus, it is a "theory", which intelligent design is not. Natural selection puts forward that an occasional random mutation enables an organism to outproduce other organisms for that niche, preserving it's DNA and not others. Intelligent design doesn't predict anything (that we could test), but it looks like an explanation. Criticism of the lead theory is not in itself a prediction or explanation. Creation science/intelligent design has never been proposed as an explanation of any phenomenon in a credible, peer-reviewed scientific journal, at least in modern times. I have a real beef, for that matter, with blasphemers who, for instance, take medication, because I can assure you, all of it was tested on foreign animal flesh (god forbid, monkeys), which is of course not the same stuff as our human stuff, other than it does most of the same things and works in most of the same ways. The creationists were very clever to start talking about evolution being "just a theory". It is a theory, but so is Newtonian physics. Newtonian physics explains almost all (but not quite) of what we can experience, but it doesn't constitute absolute truth. However, other than relativity and quantum mechanics, we don't have a contravening theory, of any kind. We haven't reverted to Ptolemic astronomy, even though it seems more common sensical (the sun does look like it turns on the earth, it squares with our intuition for the world to be flat). Common sense isn't an expanation, though Occam's Razor is. Occam's Razor would say that creation science multiplies entities needlessly, as we have a credible explanation that doesn't require an outside agent. Show me evidence, or better yet, a peer reviewed journal article showing these so-called "holes in evolutionary theory". Otherwise, stop your jibber-jabbering arguments from ignorance.
No wonder I keep hearing the theme to Jaws in my head. Bum Bum...Bum Bum...Bum Bum...
Table-ized A.I.
...back in the day.
(deem roll of eyes included)
Got time? Spend some of it coding or testing
...and you can have directionality even without pits. Walk past a working slow-combustion stove with your eyes closed and you should be able to point to it reasonably reliably.
There is, however, a stupendous amount of ground to cover between a photosensitive patch and anything remotely resembling the eye (of an octopus, cat or person) and the very weakest of unintelligent forces working, hah, blindly along that path. Given a generational time of (reaches down, pulls out figure) one week, you only have about twenty (american) trillion generations to get the transition done in.
This is, of course, likely to be a massive overestimate in anyone's terms since the typical generational times will go up as the beastie becomes complex enough to support an eye, and things like trilobites are found interred in Cambrian rock with incredibly complex vision systems already in place. Call it five trillion, give or take.
Now consider an eye. There's lots of info there, a rather excellent site, so have fun clicking on the links to the right to learn a bit more about all of the components. Bear in mind that each component here is composed of many different and usually highly specialised cells, each of which in turn makes a modern oil refinery look hopelessly simplistic.
Are five trillion generations enough to convert a photosensitive patch into one of these, step by step, with each intervening generation no worse off than the one before (else you'd expect natural selection to cull them), along with the corresponding physically supporting and neurological updates required in parallel to make the better vision useful rather than a confusing, clumsy, expensive burden? How many generations does it take for said selection to cleanse the population of less developed eyeball carriers, so that the race as a whole might proceed? How many pioneering organisms were killed inadvertantly, despite being the bearers of better eyes?
Five trillion sounds like a lot of generations, but it gets used up in a mathematical trice despite the possibilities for massive parallelism (overlapping developments, independent population groups etc).
What of features like an inverted retinal layer? How do you have a halfway inversion process? Eye development would have had to be repeated many times, and in many ways; for example, humans focus by changing the shape of the lens (without distortion!), but octopi (which share our backwards retina) focus by moving the lens in and out; others by changing the sape of the eyeball.
I don't really have time, space or inclination to spend on the maths, but many others have done so. GIYF.
Got time? Spend some of it coding or testing
I see shark people
...since I already covered parallelism, and parallelism doesn't cure all -- there are many definitely sequential dependencies -- and parallelism doesn't necessarily help as much as one might hope, considering that natural selection operates against the development of useless features (towards homeostasis unless there's a clear and present benefit in the difference).
New features are not cost-free, and large morphological changes aren't the same as useful morphological changes. Those ~2000 changes have to happen in the first place (and it's not like each generation gets to roll the i ching and decide which part they want to change today), and in roughly the right order, and without branching off into a dead end, and be conserved, and be selected for. That's what makes such a development impossibly hard.
The example you chose also left out a serious number of necessary supporting changes. A fish eye would be an encumbrance (ie selected against) if not well attached, and not appropriately connected to a suitably-adapted brain. It has to be useful to be selected for, so every single one of the steps has to be more useful than its predecessor if the change is to be driven by mutation-plus-selection. Why, for example, would a more-vulnerable and muck-accumulating dent in the skin be selected for until it conferred a distinct compensating advantage? This makes progress an essentially random factorial progress rather than a linear one, and is why Mr Gould spoke of "survival of the luckiest".
There's also that word "can"; even useless large morphological changes are very much in the minority, which of course leaves to facing the prospect of choosing way-more-than-2000 correct mutations this way from a field of squillions of wrong (useless or damaging) ones.
Got time? Spend some of it coding or testing
can be found in the study of Gouldian Finches, which were selected for bigger beaks (more access to food) during times of hardship, but that selection relaxed again when the hardship eased. This is not theory, competent people watched it happen.
Got time? Spend some of it coding or testing
can be found in the study of Gouldian Finches, which were selected for bigger beaks (more access to food) during times of hardship, but that selection relaxed again when the hardship eased. This is not theory, competent people watched it happen.
You are making the unlikely assumption that there is no selective advantage to smaller beakes that offsets the large beak advantage depending upon diet. It is easy to imagine how some food sources can be more accessible with a small beak and some can be more accessible with a large beak.
There is no mechanism in Darwinian theory to select against features that are merely useless, although in small populations they are at greater risk of being lost by genetic drift.