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Blog for May 14, 2008


By harrisjensen - Posted on 14 May 2008

A little rain goes a long ways these past several days...Even more than one week ago, leaves are popping out all over, on sage brush, in the grass and hundreds of herbs that inhabit the native prairie on the open spaces around Fort Collins, here in Colorado...The Western Kingbird, as in the photo at bottom is singing like it's manic.  What a show!

It's easy to take all this for granted, but there are so many miracles around us in nature...Eric Kandel in "In Search Of Memory" talks about how information is the driving force in nature...the DNA in our brains is what helps us adapt to life's stresses, and the information in DNA is what is directing all the wonderful things around us this spring...

Kandel won the Nobel prize, for, among other things, showing the humble little Aplysia salt water snail is able to learn things, code it on its DNA, and pass it on to the next generation!  He broke down DNA from Aplysia that learned to approach a light source, fed the "bits" of snail to other snails, who then repeated that behavior!  Isn't our DNA amazing.  Some of the things we "know" may have come to us from things our ancestors learned, and they passed it on to us in their DNA!

I am so thankful for the wonders in our DNA.

The meadowlarks are singing full force now...we got a bird identification book that has bird songs in it.  You can push a button on this book and it will play the bird song corresponding to the number you selected on a small screen!  We showed the picture of a western meadowlark to our three year old daughter Jillian, and she learned to correctly identify it, and to identify it by its spring song as well.  But probably her love of learning didn't just come from her experiences and books and her parents...it came from her DNA, which has captured important lessons and passed them down for hundreds or thousands of generations.

Amazing!

Thank you Barnes and Noble for having great nature books, as well as Dr. Kandel's book.  It's a real eye opener.

Type in Google Scholar "Brain structures and bird song" and you'll find fascinating articles that show you how birds sing.

Some of that song you hear from a meadowlark, singing from the top of a fence post, comes from notes it learned from its parents.  Some of the song, however, will be produced even if the bird was raised apart from its parents.  Some of a birds song is coded right in the DNA!  The trigger for a bird to sing certain songs, such as the melodic spring territorial song of the meadowlark, comes when nerves grow from the center of the bird's brain up into the "song center" area of the brain.

In the late summer, in response to declining hours of sunlight, these nerves receive a chemical signal to regress back into the middle of the brain, and voilah! the bird's mating or territorial song stops, but the other songs continue.

Next spring, however, increasing hours of daylight will trigger chemical signals to cause those same nerves to once again grow into the "song center."

Isn't nature amazing?  Bird brains are truly one of the great wonders of the world.

I'm grateful for these feathered companions of ours in the natural world.

Harris Jensen, MD

5/14/08

GDJ