24 DEC 2013 by ideonexus
An Early Experiment Hinting at DNA
Anomaly (2) was observed by Fred Griffith, decades before DNA and the genetic code. He found that if you inject a heat-treated, dead, virulent species of bacteria (pneumococcus S) into a rat previously infected with a nonvirulent species (pneumococcus R), then species R became transformed into species S, thereby killing the rat. About fifteen years later, Oswald Avery found that you can even do this in a test tube; dead S would transform live R into live S if the two were simply incubated tog... 1 
notes
notesV. S. Ramachandran on a fascinating experiment involving combining dead bacteria with live to produce new bacteria.
16 JUL 2013 by ideonexus
DNA Divergence is in How You Count
It’s a common misconception that chimp DNA
differs from Homo sapiens sapiens genes by only a
single percent, but this number is apocryphal. In actuality,
the degree of similarity of human and chimp
genetic code depends mostly on how you count.
Since all complex organisms from Earth possess
great swaths of junk DNA inherited from a distant
common ancestor, there tends to be startling similarity
between many organisms. Sure, humans are like
chimps—but they’re also like flatworms and fruit flies...Folksonomies: dna genetic drift
Folksonomies: dna genetic drift
1 There's much more to the differences between Chimps and Humans than counting genes.
06 JUL 2011 by ideonexus
Piaget's View on Child Learning
Piaget concluded that babies aren't just born in possession of adult knowledge, either from a past life or from DNA. Instead, Piaget thought that children must have powerful learning mechanisms that allow them to construct new pictures of the world, pictures that might be very different from the adult picture. When we learn about the world, when we do science. for example, we don't just hit the right answer once and for all. Rather, there is a very gradual unfolding sequence of corrected erro...
1 Learning is natural, innate.
01 JUL 2011 by ideonexus
A 1985 View of Science and Technology in Year 2000
The glib words of years past from our politicians are hollow
nightmares indeed when we are confronted with the staggering
realities of what has to be done. But the key is there--technology,
using it-and we hardly do now. The future may be unpredictable,
but we can make a few well-aimed guesses about what life will
be like in the year 2000. We’ll fly on supersonic transports, or
more likely hypersonic transports, for which the ground work (or
should I call it air work) has already been laid at...Folksonomies: futurism
Folksonomies: futurism
Prescient with the qualifier that these things will only happen if America puts emphasis on science and technology education.
09 JUN 2011 by ideonexus
Chaos, Order and Snowflakes
In one of his most popular essays, "The Colloid and the Crystal," the nature writer Joseph Wood Krutch wrote about these opposing forces in nature. "Order and obedience are the primary characteristics of that which is not alive," he wrote. "Life is rebellious and anarchical." He was wrong to identify obedience and rebellion with nonlife and life. respectively. We now know that the inanimate snowflake crystal, so apparently lawful and static, grows its six-pointed form under the controlling in... 1 notes
notesNonlife produces beautiful order in the snowflake, where the vibrations of the molecules create different six-pointed patterns.
20 MAY 2011 by ideonexus
Caenorhabditis elegans
Caenorhabditis elegans was chosen in the 1960s as an ideal experimental animal by the
formidably brilliant South African biologist Sydney Brenner. He had recently completed his work,
with Francis Crick and others at Cambridge, on cracking the genetic code, and was looking around
for a new big problem to solve. His inspired choice, and his own pioneering research on its genetics
and neuro-anatomy, has led to a worldwide community of Caenorhabditis researchers that has
grown into the thousands....Folksonomies: biology experiments
Folksonomies: biology experiments
1 notes
notesA species in which we know every cell in its body, making it an excellent experimental specimen.
