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MagazineR858
Q & A
David A. ShubAfter spending two postdoctoralyears each in the laboratories ofJun-ichi Tomizawa in Tokyo andDick Epstein in Geneva, DavidShub joined the faculty of theBiology Department at theUniversity at Albany, SUNY, wherehe has been ever since. For thepast 17 years his lab has exploredthe self-splicing group I introns inbacteria and phages, withemphasis on their origin,distribution, and function asselfish elements.
What turned you on to biologyin the first place? It was a lateconversion. As a child growing upin New York City, the wonderfuldiversity of nature, which attractsmany children to biology, was notreadily apparent (I think I had seenabout four bird species in my firsttwenty years). School, wherebiology was presented as a set ofunrelated facts that needed to bememorized for an examination,didn’t create a spark.
In my twentieth year, while anundergraduate at ColumbiaUniversity, three experiences werecrucial. While introductory zoologywas taught as a large lecture —and presented as an arbitrarycollection of facts, just as in highschool — all professors wererequired to conduct a discussionsection each week with a smallgroup of students. My sectionleader was Leslie Dunn, adistinguished fly geneticist whohad worked with T.H. Morgan. Theclass dozed through theseobligatory sessions, until the uniton genetics. This had been myfavourite topic so far, involvinglittle memorization and requiringus to do fun problems on bloodgroups and paternity suits. In ourreview session, Dunn seemed towake up from his semester-longnap, becoming animated andenthusiastic. Instead of rehashingthe material from the previousweek’s lectures, he told us aboutsickle cell disease. It was awonderful story, combininghemoglobin protein chemistry,
Dark wings ofdesireBirds vary enormously in theiruse of the pigment melanin tocolour their plumage but thevariation between species andbetween sexes has been apuzzle to researchers. Newwork on the plovers, a diversegroup of mostly ground-nestingbirds which show highly diverseuse of melanin, suggests thatsexual selection during aerialdisplays is one cause of thepigmentation.
Veronika Bokony andcolleagues at the Szent IstvanUniversity in Budapest and atthe University of Bath, UK,report in the Proceedings of theRoyal Society B in London(published online) a comparisonof the wide variation in melanin-coloured plumage betweendifferent species of plover andother aspects of their lifestyle.
The authors hypothesisedthat melanin-coloured plumagemay be more common inspecies where males carry outaerial courtship displayscompared with those usingground-based courtships. And
the plovers include species thatuse both courtship behaviours.The authors thought that blackplumage may help enhance thesilhouette of the bird against thesky during an aerial display andthus increase the attention ofground-based females duringthe display.
The results suggest that thisis indeed the case. Birds withground-based displays showmuch less melanin-colouredplumage compared with themales of species carrying outaerial displays. They looked atwhether melanin colorationmight help with camouflage orin displays to defend territoriesbut found no link betweenmelanin coloration and thesetwo lifestyle aspects comparedto the link with aerobaticcourtship displays by the males.
“Taken together, our resultsare most consistent with thesexual selection hypothesis, andsuggest that melaninisedplumage has evolved to enhancethe aerial display of maleplovers,” the authors report.
Cutting an aerial dash, inblack, seems to be the plumagekey to attracting mates in thisgroup of plovers at least.
Black attack: Studies suggest areas of black plumage in plovers enhance the att-ractiveness of male birds in aerial courtship displays. (Photo: Oxford Scientific Films.)