Shark 6th Sense Related to Human Evolution? 308
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.'"
News flash: orthologous structures... (Score:3, Insightful)
How many senses do we have? (Score:3, Insightful)
Re:I don't get it. (Score:2, Insightful)
most fish can sense electricity (Score:3, Insightful)
Terrestial animals, including humans, can feel strong gradients in the air before thunderstorms.
Re:Definition of Science (Score:4, Insightful)
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
Re:How many senses do we have? (Score:5, Insightful)
The five senses that humans have are classified as such because they are five distinct ways that we can sense our environment and surroundings. (Some even argue that smell and taste are the same sense because they're both a chemical composition sense.) The ability to sense electrical signals is in every way, shape and form a distinct sense from the five that humans have.
The universe allows only so many senses, because there are only so many ways that one object can make itself "known" to another object (which is exactly what senses are about). Think about it... there's radiation in the electromagnetic spectrum (sight), compression waves (sound), chemical traces (smell and taste), and actual contact (touch). But nature has a few other communication tricks up its sleeve, and electical signals is one of them. The fact that humans can't sense them doesn't mean that it's supernatural.
Re:News flash: orthologous structures... (Score:3, Insightful)
Oh, piss off. With that attitude there's no point in doing science at all. It's news to discover the genes and the mechanism and also to find out what structure it was that developed into the organ in question.
Re:People have 6th sense, too (Score:4, Insightful)
Re:6th sense (Score:5, Insightful)
Yeah. He was wrong. That's OK. Trouble is, he was wrong about just about every single thing he tried, and then got cited as an unassailable authority by just about everyone in Europe for over a thousand years.
Re:I don't get it. (Score:3, Insightful)
Let us just say that the preponderance of evidence supports the theorey of evolution. Something that can not be said for creationism as explianed in the bible.
You are right, of course, bad science is everywhere you look. There will be scientists who believe in creationism, even blindly so. Afterall, we are all inherently irrational creatures and scientists are no exception.
Science, on the other hand, strives for the most rational explanations. And when the Grandparent said: We don't consider science to be subject to public policy, and as such, laymen don't get a vote. I think I can safely translate him to mean: Science cares not for an individual's desires, only for the truth
Re:I don't get it. (Score:3, Insightful)
Aren't those the same kinds of similarities between cars that have vastly different designers and designs? You're not proposing that cars are not the product of separate creations just because they have a lot of similarities are you?
Re:How many senses do we have? (Score:3, Insightful)
Total bullshit. You're just saying that to give youself some kind of reason to cling to the outdated 'five senses'. Let's go through them:
"Temperature sense - touch; "
Wrong. Our pressure-sensitive nerve are totally seperate from our temperature sensing nerves. Different sense altogether.
"CO2 sense - smell/taste;"
Tell me, what does CO2 smell/taste like?
"humidity sense - smell/taste and possibly touch;"
Nope. Happens in the lungs.
"air pressure sense - sensed by the ear drum using the same mechanism as hearing, and possibly touch."
Hearing and air pressure are totally seperate. Auditory nerves hear. They do not sense air pressure. Air pressure is not enough pressure to trigger pressure nerves in the skin.
So you see, you are just lumping all of these seperate senses into whichever of the five senses seems most similar to you.
" The 'subjective' senses that you mention not senses in the strict sense of the word, because they're internal feedback mechanisms; they don't actually sense anything about the environment. The sense of "orientation" may be an exception. I don't disagree with calling that a sense, because it senses something about the environment - that is, the direction of gravity."
In this sense, I am talking about sensory data that wouldn't exist without the organism that is doing the sensing. Things like hunger and pain. If I wasn't around, I obviously would be unable to sense my own pain. Similary, orientation is not an absolute sense (like, "How much CO2 is in this room?") but is is relative to the body's orientation towards the earth.
"I wouldn't put it at the same level as what we consider the five main senses, though, because its not nearly as developed a sense, and is (arguably) far less important."
Let me ask you this -- where did you get the phrase "the five main senses". Where are you getting these 'levels' from?
It comes from Aristotle, who was the reigning expert on everything up until about 250 years ago. After we started doing experimental science, it turns out he was wrong about almost everything. We do have a lot more senses that Aristotle thought we did; information is relayed on different nerve cells. Just because different types of information sensing happens in the ear, doesn't mean it's all hearing. Hearing is just sensing sound waves. Air pressure is not sound waves, and it is not sensed by the auditory nerve.
Re:Leave it to junk science (Score:3, Insightful)
Do rocks regularly make imperfect, self-sustaining copies of themselves?
If not, then your analogy is completely and totally inane.
Re:I don't get it. (Score:3, Insightful)
Seriously: When it comes to shared ancestry, the evidence is very, very, very strong. There are hundreds of thousands of datapoints. There are an extreme number of predictions that have been done based on this, there are extreme amounts of verification.
You are actually jumping to a conclusion. I'm assuming this isn't malicious - you seem to want to actually get at the real answer - yet when you take the time to actually inspect the evidence around evolution, you'll find that it is confirmed a million ways. As I said in another post: Evolution explains most variation in nature. There may be other sources of variation we do not know of - yet they cannot displace evolution and the data we have around it. Instead, they may be supplementary theories, used *together with* evolution.
This knowledge is sort of like our knowledge of the continents. 500 years ago, we didn't know about more than a couple of continents - the eurasian continent and africa. Now, we know all the continents *and know we know all the continents*. There is sufficient evidence, criss-crossing and linked together, that we can say this as an absolute fact.
There is sufficient evidence of shared ancestry and evolution that we can say this as an absolute fact, too, with similar interlinking.
Eivind.
Re:I don't get it. (Score:3, Insightful)