Connections I. – “Dinosaurs Aren’t Gone….They Just Grew Feathers.”

Have you ever given much thought to “connections,” thoughtful reader?  There are all kinds of vital, essential connections in Life, planet Earth, and the Universe.  “Ecosytems” are all about connections between life forms, habitat, climate and weather.  “Food chains” are all about connections between predators and prey, animals and the plants they eat….and sometimes – to the fascination of young and old alike – plants and the animals they eat.  “Communities and societies” are all about the connections of human beings with each other in corporate structures.  It’s a long list….connections.

To my way of thinking, some of the most fascination connections are in the form of all that molecular biologists and other scientists have been discovering about life forms’ DNA (deoxyribonucleic acid).  DNA is a nucleic acid that contains the genetic instructions used in the development and functioning of all living organisms – with the exception of RNA viruses.  The segments bearing the specific “instructions” – likened to a blueprint or road map – are called “genes.”  Consequently, for example, if your DNA possesses a recessive gene for “red” hair, you may indeed be a “redhead.”

The primary role or purpose of DNA is the long-term storage of information.  It’s how long-term it really is that is one of the most fascinating facts about this essential key for all living things.  So long-term, that it connects all life over billions of years of evolutionary development – including dinosaurs extinct for hundreds of millions of years….to the myriad (nearly 10,000) varieties of modern birds, the most diverse group of vertebrates found on dry land.

When I was a young school child, just like children of today, I was fascinated with fossils and paleontologists’ descriptions of dinosaurs.  Early on, we learned that “dinosaur” was a combination of two ancient Greek words:  “dino,” meaning “terrible,” and “saur,” meaning “lizard.”  Yet today, “saurian” refers to lizards, and is sometimes extended to crocodilian reptiles as well.  In any case, we all thought of dinosaurs as extinct, terrible, giant reptiles (although many dinosaurs were pipsqueaks, all sizes)….and certainly not as close relatives of birds.

The fact that they are is not really a new realization.  English biologist Thomas Huxley wrote an 1870 work entitled Further Evidence of the Affinity between the Dinosaurian Reptiles and Birds. Huxley was a great student of anatomy and was struck by virtually no difference between the bones of Compsognathus – one of those smallish dinosaurs, about the size of a turkey – and, well, a turkey.  His case was certainly helped by the discovery shortly before of an Archaeopteryx fossil in Germany in 1861, clearly a 150 million-year-old dinosaur with feathers.

In fact, textbooks have long identified Archaeopteryx as “the first bird;” but the dinosaur-bird connection is probably longer-term and more subtle and gradual, extending at least to an ancestor common to both dinosaurs and the famous, flying pterodactyls, and living about 95 million years before Archaeopteryx – some 240 million years before today.  The key to this DNA-borne connection is in the anatomical link of first, “filaments” or fibers jutting from dinosaur skin….to “barbs” starting to appear on the filaments and interlocking with neighboring filaments….and eventually to actual feathers as we find on modern birds.

All of the above, developmental changes to the dinosaurs’ DNA long-term storage of genetic code or blueprint have been found in the fossil record of theropods – a suborder of dinosaurs that includes birds, “raptors,” and even no less than Tyrannosaurus rex, an interesting combination of ancient Greek and Latin, literally meaning “the king-tyrant lizard.”  They are all what the paleontologists call “Maniraptoran” dinosaurs, seizing prey with “hands” or feet with talons.

So, it turns out that dinosaurs aren’t really gone from Earth – they just grew feathers, perfected the ability to fly, and now perch on our bird feeders.  Modern birds are the direct descendants of those Maniraptoran dinosaurs.  The critters that went extinct millions of years ago and are truly gone – presumably forever – are now referred to by those paleontologists and biologists as “non-avian” dinosaurs.

But how fascinating!  To think that cute little, seemingly delicate chickadee carries DNA connecting it really long-term to Tyrannosaurus Rex. How marvelous!  It could go a long way toward explaining in my mind the fact that that chickadee is not really so delicate.  On the contrary, those tough little birds brave brutally cold winter days, 25-30 below zero, cheerily singing their chick dee, dee, dee call as though they actually enjoy the snowstorm and freezing cold.

Chickadees were considered to be very “wise” birds by Native American tribes of the north; and I find it amazing that as small as they are (though certainly not as delicate as one would suppose), they can be quite fearless, often coming close to humans, even learning to take food from one’s hand.  They seem to know when there’s no reason to fear.  Despite their apparent mild manner, a nesting chickadee will indignantly “spit” at the person who comes too close and becomes annoying.  And truth be known, some two-thirds of the chickadee’s diet is made up of animal matter, primarily insects.  I guess that when Tyrnnosaurus rex and Velociraptor are in your DNA, you continue to be fearless and predatory.

(The Rev. Dr.’s Musings on Nature, Life, God….may not be reprinted, whether in whole or in part, without prior permission of the author.  The use of some posts involves compensation agreements with publications, or persons, who wish to use them for publishing purposes.)