BY ZACHARY GOTTHARDT
SC Staff Writer
On Friday, October 4, the first Biocolloquium of the semester was held in Kurtz Lecture Hall in Moore Biology Hall. There, Dr. Amber Rice of Lehigh University presented her findings on speciation in spadefoot toads to an audience of students and faculty.
Dr. Rice’s presentation entitled “How two species can become four: Species interactions as initiators of speciation” outlined some of the concepts of speciation and a practical example of how it is occurring today. She explained how questions about speciation have been asked since the time of Darwin.
According to Rice, speciation is the process through which new species arise. She also mentioned an alternate definition suggesting that speciation is the evolution of reproductive isolation between previously interbreeding groups. This definition is appropriate because the ability to properly breed is one of the characteristics that determines if two individuals are of the same species.
Amber Rice focuses on evolutionary factors in her work, and her research with spadefoot toads is no different. Rice conducted an experiment between two very similar spadefoot toads in Arizona and New Mexico: Spea multiplicata and Spea bombifrons.
In her research, she discovered that these closely related species are showing signs of new speciation. One of the telltale signs of speciation is character displacement.
S. multiplicata and S. bombifrons can be found separately or together. In areas of allopatry (areas where only one species can be found), the two toads exhibit very similar calls.
However, in area of sympatry (areas where both species are found), their calls are drastically different from each other. It is as if the two species are attempting to differentiate themselves from the other species.
Also, in areas of sympatry, S. multiplicata tadpoles are omnivorous, while S. bombifrons tadpoles are carnivorous. The two species must take different roles to avoid competition with each other. This resource partitioning may be subtle, but the result is a divergence of characteristics.
Adaptations like these were only observed in sympatric locations where differentiation is necessary. Evolutionary theory suggests that, with enough time, these species in the sympatric locations will diverge so much that they will become completely separate species from the populations in allopatric areas. In short, two species may become four.
The next Biocolloquium will be held on October 18, 2013, in Kurtz Lecture Hall in Moore Biology Hall at 4 PM. Dr. Dan Klem Jr. of Muhlenberg College will be presenting on a surprisingly pressing issue in the conservation field—birds flying into windows.
According to his page on the Muhlenberg website, one of Dr. Klem’s interests is “wildlife morality resulting from the actions of man.” Klem is also a decorated ornithologist in his field.
Millions of birds die every year in collisions with man-made structures, and Dr. Klem has dedicated research to decreasing that statistic. All majors are welcome to hear his proposal on Friday, October 18.
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