In the 'neck' of time: Scientists unravel another key evolutionary trait

Jul 27, 2010

By deciphering the genetics in humans and fish, scientists now believe that the neck - that little body part between your head and shoulders - gave humans so much freedom of movement that it played a surprising and major role in the evolution of the human brain, according to New York University and Cornell University neuroscientists in the online journal Nature Communications (July 27, 2010.)

Scientists had assumed the pectoral fins in fish and the forelimbs (arms and hands) in humans are innervated - or receive nerves - from the exact same . After all, the fins on fish and the arms on humans seem to be in the same place on the body. Not so.

During our early ancestors' transition from fish to land-dwellers that gave rise to upright , the source for neurons that directly control the forelimbs moved from the brain into the , as the torso moved away from the head and was given a neck. In other words human arms, like the wings of bats and birds, became separate from the head and placed on the torso below the neck.

"A neck allowed for improved movement and dexterity in terrestrial and aerial environments," says Andrew Bass, Cornell professor of and behavior, and an author on the paper. "This innovation in biomechanics evolved hand-in-hand with changes in how the nervous system controls our limbs."

Bass explained that this unexpected level of evolutionary plasticity likely accounts for the incredible range of forelimb abilities - from their use in flight by birds to swimming by whales and dolphins, and playing piano for humans.

Explore further: A clear, molecular view of how human color vision evolved

More information: The research, "Ancestry of motor innervation to pectoral fin and forelimb," was authored by Leung-Hang Ma (first author) and Robert Baker (corresponding author).

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GSwift7
2.2 / 5 (6) Jul 27, 2010
I'm surprised it didn't say this: "A neck allowed for improved movement and dexterity in terrestrial and aerial environments, eventually leading to GLOBAL WARMING."

lol, I couldn't resist. However, the article was very interesting and I always like out-of-the-box thinking. Congratulations to the researchers for innovative ideas. This one really does make a lot of sense though. I would be interested in reading more about the mechanics of neural development they spoke about, and how the area of control changed.

I wonder if the "hand-in-hand" comment was a deliberate pun?
kevinrtrs
1.4 / 5 (9) Jul 28, 2010
During our early ancestors' transition from fish to land-dwellers that gave rise to upright mammals, the source for neurons that directly control the forelimbs moved from the brain into the spinal cord, as the torso moved away from the head and was given a neck. In other words human arms, like the wings of bats and birds, became separate from the head and placed on the torso below the neck

Now where exactly are the fossils of the transitional forms that should have resulted from this little episode?
Whilst this was happening would the organism have been functional and able to go about feeding itself or would it simply have been impossible and the organism become extinct before reaching the final target form?
This is an enormous problem for evolutionary theory: these transitions from one organism into the other requires that the target specimen be reached in one single flurry of simultaneous mutations or else the target can not be reached in any manner or form.
kevinrtrs
1 / 5 (8) Jul 28, 2010
Basically, going from the one form into the other requires a miracle upon miracle for the transiting animal to survive.
Now, because there are so many different organisms alive today, there should be an incredibly rich domain of transitional fossils in the world - but there isn't.
For such an enormous amount of evolution to have occurred, we should now be witnessing billions of mutations going on in EVERY species. But we don't see that. Why billions? Because for the theory of evolution to work, billions of attempts at improvement are to be made to achieve any kind of transitioning from one form to the next. Remember that it's not just the physical shape and mechanical form that is required, it's also the information in the form of necessary control systems to operate those new developments. PLUS the feeding and maintenance that is required.
Evolution just doesn't cut it. Not in the real world.
It's time to face the truth: It doesn't work, it's just someone's fairytale for adults.
Skeptic_Heretic
4.5 / 5 (8) Jul 28, 2010
Basically, going from the one form into the other requires a miracle upon miracle for the transiting animal to survive.
How tall was your great-great-great-great-great grandfather.

How tall are you?

If that number is different, according to you it's a miracle!
It's time to face the truth: It doesn't work, it's just someone's fairytale for adults.
And the guy in the clouds who lives forever and sends you to a huge amusement park after you die isn't....
jdmimic
5 / 5 (5) Jul 28, 2010
Too bad the article wasn't clearer about what they were actually talking about. The nerves that innervate our arms are found in our neck, in about the same relative place that the fish nerves out to the limbs are.

There are a whole bunch of fossils that demonstrate the transition, kevinrtrs. There is acanthostega and tiktaalik, just to name two, but there are many more. Read up a bit on it. Evolution does not require miraculous numerous change all at once. You clearly have no understanding of evolutionary theory, so maybe you should educate yourself on the subject before making statements about what it does or does not require. Oh, and as for the billions of mutations in every species? They do happen. There are 3 billion basepairs in every cell of the human body. This has to be copied billions of times for every person on the planet. That creates more than enough to create all the genetic variation you need and doesn't begin to touch all the variation from recombination.
jdmimic
5 / 5 (8) Jul 28, 2010
Kevinrtrs: I don't think you appreciate just how much our DNA is copied. Here are some numbers to think about: there are 3 billion basepairs in the human genome, which have to be copied into every sperm. There are about 250 million sperm in every single ejaculation. The average mutation rate in humans is 2.5x10^-8. running the numbers, you will find that every man creates over 40 TRILLION mutations in his lifetime. Multiply that by the number of men on the planet and you find that males alone create over 1x10^22 mutations every generation. Add to this that mutation is only a small part of genetic variation. Are we getting enough variation for you?
Skeptic_Heretic
4 / 5 (4) Jul 28, 2010
Are we getting enough variation for you?

@jd,

Kev is about as bad as it can get for young earth creationists. He probably still believes that a man's testicles contain smaller immature men that grow to babyhood in their mothers' wombs and that the birth of a daughter implies that the mother did something wrong to the child.
trekgeek1
4.3 / 5 (3) Jul 28, 2010
It's time to face the truth: It doesn't work, it's just someone's fairytale for adults


Really? Glass houses Kev. Your bible is the definition of a fairytale for adults. You have a book that talks about COMPLETELY unsubstantiated occurrences, an author who couldn't make it in higher circles and was forced to pray on the simple minded, and magic. Here's a good question, when you read the bible to children, do they ever forget and think it's one of their fairy tales? Do you ever read them one of their books and have them believe that the fairy god mother actually performed magic because jesus did it once?
FrancineOfGarda
not rated yet Jul 28, 2010
A remarkable insight by the two Cornell University researchers! I have a keen interest in the processes that drive such creative insights. I recently read an interesting blog post on creativity and innovation — Google “The Role of Psychological Distance in Creativity and Innovation” and have a read. (Link is http://thelaughin...vation/)
DamienS
Jul 28, 2010
This comment has been removed by a moderator.
GSwift7
1 / 5 (1) Jul 29, 2010
Yes Francine, that's what I was thinking. This seems kinda like one of those big Eureka moments for the researchers. I'll bet they were excited when they realized what they were seeing.

Another joke: If this migration of our arms continues down our torso, and our neck continues to grow, then I guess we'll end up looking like a giraffe? Lol, we'll end up being quadrapeds again!
sherriffwoody
Jul 31, 2010
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satyricon
not rated yet Aug 01, 2010
We might not have a tail but we do have the coccyx - remnants of a vestigial tail where important muscles are attached.

If you study comparative embryology and organogenesis, the 'transitional forms' starts to make more sense. Of course, evolution is not linear.
Ethelred
3 / 5 (2) Aug 01, 2010
wheres our tail????


You have posted this same remark in two threads now.

Do you have a point to make? Other wise go learn anatomy. ANY book with a modicum of information will give you the answer. It is so hard to avoid knowing the answer that I am assuming that you DO have a point.

So drop the other shoe and get on with it.

And don't worry about Kevin. He is the sites resident non-thinker. Thinking about how things evolve scares him so he retreats into ancient fantasies and posts things that make it clear that he hasn't ever thought about how things could evolve.

Oh and that article was profoundly uninformative.

Even Kevin can be excused for not understanding this time. There wasn't anything to understand.

Ethelred

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