Birds: An Evolutionary Conundrum

on Monday, January 31, 2011

Thanks to the mass media, paleontology has been almost completely focused on trying to find the common ancestor between our modern birds and the reptiles of the past. Science is still a great many fossil finds away from solving that mystery completely, but thanks to a new fossil finding in the Chinese Liaoning Province, paleontology has started filing in the blanks.

A newly uncovered Darwinopterus fossil has given some insight into the egg formation and reproduction of these winged beasts. It appears that this female broke her wing just before her death, and as a result became entombed along the edge of a prehistoric lake. While this female underwent the early stages of decay and fossilization, a great deal of pressure built up within the body causing an egg to be expelled and preserved along with the mother. Needless to say this in itself was a superb find because it allowed the scientists to determine the relationship in size between mother and offspring when previously this had been unknown. However, the real gem of this finding was the nature of the egg itself.

Chemical analysis of the egg determined that this species of pterosaur laid soft shelled eggs, similar to that of our modern turtles. This radically changed the previously conceived parental behaviors for this species. It seems that instead of a mother laying hard-shelled eggs and then monitoring them, as our modern birds are prone to do; these females let the environment provide most of the nurturing. This style of parenting would allow the least amount of energy expenditure from the mother, while still ensuring the relative safety of the offspring. All in all, it seems that it takes more than simply looking like the ancestor of our modern birds to explain the evolution of hands on parenting.

My Review: I initially tried to " hook" my readers with my title. I felt that by beginning with discussion of the mystery behind our modern birds, my readers might be more inclined to find out what exactly this new finding had uncovered. I tried to remain mindful of my " word- sentence-paragraph- story" formation in order to keep my readers interested throughout the entire course of the posting. I tried to keep most scientific jargon out in order to appeal to the largest audience.


Mason Posner said...

I like your transitions between paragraphs and your use of language. I agree that your lack of jargon makes this appropriate for non-scientists, but still a valuable read for scientists too.

As far as the science goes, it would be hard to say from this one specimen if this represents the ancestral state for birds, or an egg type that evolved in this one group. And why would softness to the egg mean less parental care? Crocodiles and alligators lay soft, leathery eggs, but provide parental care? Interesting work.

Karie said...

I think this is a great blog entry. It was easy to read and to the point. Dinosaur research is always facinating to me because scientists can make discoveries based on such limited evidence.

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