July 30, 2013 | David F. Coppedge

Birds and Their Evolution (or Design)

Several recent science papers try to find evolution in bird brains, genes, and behaviors.  Do they succeed?

Sexual selection conundrums:  Sexual selection seems to work except when it doesn’t.  That’s the apparent observation from two articles, one on Science Daily that claims shorebirds choose looks over brains, and one on Live Science that shocks readers with the news that peahens don’t pay much attention to the elaborate tail feathers of peacocks.  This seems to contradict a classic case of sexual selection.  Sure enough, tiny video cameras on peahens followed their gaze and found that they tended to focus below the neck, a Purdue biologist found: “The males put on this huge display, and females seem to look at only a small portion of it.”  What’s a male to do?  Neither article mentioned whether sexual selection matters in species like crows that show virtually no sexual dimorphism.

Chicks vs mice:  A study in PNAS tried to find how much divergence and convergence there is in the expression of brain genes between chickens and mice.  The authors claim that their study “potentially resolves the complex relationship between developmental homology and functional characteristics on the molecular level and settles long-standing evolutionary debates,” but the actual results were mixed.  The authors found some surprising examples of convergent evolution (homoplasy) – surprising given “very different developmental trajectories” of birds and mammals.  They admitted their limited data set could have led to different results.  As a result, their conclusions were tentative, requiring further study:

Our results suggest that the pallium has undergone major transcriptomic reorganization, with traces of both molecular homoplasy and homology …. These results do not imply that there is no homology among other pallial sectors, only that homology is not a dominant factor in their adult gene expression patterns. Homology might have a greater impact on pallial gene expression if we had studied a greater number of smaller regions or even individual cells….  Considering these results, subsequent investigations into the evolution of the neocortex should complement studies of homology based on cell lineage with multiple levels of information in various taxa toward a holistic understanding of how its molecular programs were repurposed, resulting in such cognitive convergence.

Cockatoo puzzle solving:  Speaking of bird brains, cockatoos can perform intelligence tests on spatial and navigational skills as well as toddlers, and sometimes better than great apes, according to new experiments reported on Science Daily.

Darwin’s finches again:  A new book is out about Darwin’s finches – not so much about the birds, but about David Lack, the “father of evolutionary ecology,” who spent a lot of time trying to defend Darwin’s views about them.  Ben C. Sheldon liked Ted Anderson’s book in his review for Nature.  Some readers might be surprised to find out that Lack did more work than Darwin:

Charles Darwin had remarkably little to say about how the birds that bear his name — Darwin’s finches — came to have such a variety of beaks, despite their iconic status in evolutionary biology. It was left to an English schoolmaster on sabbatical in the late 1930s to carry out the first serious work on this question.

Sheldon did not mention the subsequent work by Peter and Rosemary Grant who found that changes to the birds’ beaks oscillated according to the weather.  Lack only spent 4 months on a field trip studying the birds, compared to the Grants’ three decades.  It’s doubtful Lack’s work contributed much to scientific understanding of the Galapagos finches as much as the starting of a new movement: “The central message of Anderson’s book is that Lack should be understood as someone who bridged the gap between traditional natural history and the development of its modern academic descendant, evolutionary ecology.”  In short: the book is short on science, and big on name-dropping of the evolution giants Lack interacted with.  Whether “evolutionary ecology” is a productive use of biologists’ time is another subject.

Homing pigeon navigation:  A bird article with no need for evolutionary theory, but implications for design, concerned homing pigeons’ uncanny ability to find home.  Science Daily reported that new experiments show the birds are not simple “flying robots,” but use cognitive ability when deciding what cues to follow.  They build a spatial map of their surroundings and can choose to head toward a feeder or home, depending on how hungry they are:

“As we expected, the satiated pigeons flew directly to the home loft,” explains Prof. Hans-Peter Lipp, neuroanatomist at UZH [University of Zurich] and [Nicole] Blaser’s supervisor for her doctoral thesis. “They already started on course for their loft and only deviated from that course for a short time to make topography-induced detours.” The hungry pigeons behaved quite differently, setting off on course for the food loft from the very beginning and flying directly to that target. They also flew around topographical obstacles and then immediately adjusted again to their original course. Based on this procedure, Blaser concludes that pigeons can determine their location and their direction of flight relative to the target and can choose between several targets. They thus have a type of cognitive navigational map in their heads and have cognitive capabilities. “Pigeons use their heads to fly,” jokes the young biologist.

There was no mention of evolution in the article.

Was there ever a more useless, time-wasting, distracting theory than Darwinian evolution?  It made some people famous who were able to look like they were doing science.  It created camaraderie between fellow Darwine drinkers.  But did it ever produce understanding of the natural world?  After reading these articles, you be the judge.  We think an intelligent design perspective would have brought the coveted “insight” and “understanding” far earlier, without all the obstacles forcing observations to fit the hunches of a Bearded Buddha.  If you really need convincing, watch the new Illustra film Flight: The Genius of Birds.

 

 

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