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Tag Archives: age

We’ve known for years that we can raise our IQ by eating gifted children

Or, we could if experiments done in flatworms translated directly to humans. If you haven’t read about James McConnell’s experiments with Planarians and memory transfer, I urge you to do so, if only just for the opportunity to read science writing that sounds as if it was ripped directly from the pages of Mary Shelley’s Frankenstein. It also turns out that their blood is carrying some youthful factor that we want as well. The trouble is getting it out of them and into us. One might immediately think of vampires – which is not a bad place to start, but it might require a bit of refinement.

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Get ’em while they’re smart!

Science magazine from 9 May 2014 informs us that there is something soluble in the blood of young mice that, when transferred to older mice – well, to put it simply, it rejuvenates them.  “The therapeutic implications are profound if this mechanism holds true in people,” says Matt Kaeberlein in the News and Analysis summary accompanying the article.

This article captured my interest and made me want to write about it for several reasons. First, this is effectively a ‘Fountain of Youth’ experiment – and it seems to work! Researchers have long wondered: what keeps the young, young and makes the old, old? What changes as we age? Can we stop it? Reverse it?

In terms of ethics, should we even be looking at age as a disease? Or is it just something that happens and needs to be accepted?

ImageMost notably, work has been done to show that telomere length and the enzymes that maintain it, may be intimately involved in the aging process. Telomeres are sections of non-coding DNA at the very ends of chromosomes that consist of a number of sequence repeats. The thinking is that these DNA elements are maintained (by telomerase) in order to prevent the chromosomes from getting attacked and destroyed by nuclease enzymes. I think the Ponds Institute has been working on this for years 🙂

The other interesting thing about this work is the technique that gave us the data in support of this hypothesis. It’s a fantastic experiment called parabiosis. From the Greek you can see that this ‘living with one another’ experiment involves making artificial siamese twins of two mice, an old one and a young one.

I hope to be able to discuss this procedure in some detail in upcoming posts. But, until then, let us be satisfied that the technique was done. This now permits the intermingling of soluble blood products between one (clonal) mouse and another. When it’s done, something, crosses from one animal to the other. This provides cellular cues to the fact that something from this young mouse has been lost in older mice, but if it could be restored, it would result in (at least some) regeneration of youth.

– I’ll come back and revisit this more in the future to explain what has actually been observed and also to discuss some other interesting experiments carried out using this parabiosis technique. Right now I’m falling asleep and violating a new family rule on computer time to boot!

 
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Posted by on May 25, 2014 in Uncategorized

 

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Radiometric dating

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An old Rock

My General Biology class is discussing means by which we can date objects. This comes from a question by Ernst Mayr, “What kind of world do we live in?” The basis of this question is, how old is the planet? and how constant is it?

In biology these questions have notable importance because how we explain life’s processes requires that we know how much time these processes are operating over. One would be limited in their explanation of life if we know the world to be young – say, only 1 million years old. Whereas, the current estimate of 4.5 billion years, including ~3.5 billion years with life of some kind, allows for much slower processes to operate.

I discussed one of these measurements, radiometric dating, in an earlier post.  Take a look at how this is done and be sure that you understand the practice problem presented and can work out a similar problem on your own for the quiz.

 
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Posted by on April 9, 2013 in Uncategorized

 

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How Old (Con’t)

From 1912 until about 1953, biologists interested in human evolution were being duped.

One hundred years ago, Charles Dawson presented his new find, a transitional fossil of an organism that plainly appeared part human and part ape, bearing a number of hallmarks of being a ‘missing link’ between modern man and early ancestors.. The fossil, found in Piltdown, England and was dubbed Eoanthropus dawsoni and was accepted as a welcome addition to the record of humanity’s existence.

It was just what was expected.

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The Piltdown Gang

Expectations make fertile soil for a hoax.  Darwin’s work predicted such a find would be made. The question was merely, who would find it? What would it look like? And how famous would this make the man who discovered it?

“Sir Arthur Keith, famous British paleontologist, spent more than five years piecing together the fragments of what he called a ‘remarkable’ discovery. He said the brain case was ‘primitive in some respects but in all its characteristics distinctly human.'”1

Over time, When the skull fragments of E. dawsoni, commonly called Piltdown man, were examined, doubts were raised as to whether it represented a single organism or several, which just happened to become mixed together in the unearthing. But these doubts took decades to culminate into action.

The best way to address the question was to determine whether the several pieces of skull were at least contemporaries of one another. They could still be a jumble, but it was a start. To assess the age of the fragments, fluorine dating was done. This method is used to determine the amount of time that a sample has been buried underground. The principle is that groundwater contains fluorine and the longer a sample remains buried, the more fluorine will become absorbed into the sample. This testing confirmed that the samples could still have come from the same source, but that they were both considerably more recent that initially suggested.2

708px-Pildown_manFollowing this analysis, Carbon dating gave a more accurate age of the samples themselves indicating that they were both quite recent, but not from the same organism. Once this data came in, the house of cards fell and a number of other observations came to light confirming the hoax.

What does this teach us?

1. Science is difficult business. When everyone is working honestly, it is difficult. When people are willfully trying to subvert the process, it can take years to remedy. (I immediately think of the damage done by Andrew Wakefield’s fraudulent 1998 Lancet paper and subsequent work that undermined the public’s trust in vaccines)

2. Science is self-correcting. Again, this can take time, but eventually, mistakes are worked out and our understanding of the world gradually improves.

3. People are people. With an obvious prize, people sometimes make their own luck.

4. No single experiment will always give accurate data. Extra-ordinary claims require extra-ordinary evidence.

References

1. “The Piltdown Man Discovery: Unveiling of a Monolith Memorial”Nature 142, 196-197 (30 July 1938) | doi:10.1038/142196a0

2. “Relative Dating of the Piltdown Skull” Kenneth P. Oakley, Advancement of Science 1950

 
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Posted by on December 20, 2012 in Uncategorized

 

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