Candidate talks of cannibalism

Bronwyn H. Bleakley, a candidate seeking a professorial position at Eastern Michigan University in evolutionary biology and genetics, gave a lecture titled, “Evolutionary Genetics of Cooperation and Cannibalism.”

Bleakley began by reviewing the theory of evolution by natural selection. She explained that natural selection is the process by which evolutionarily advantageous traits evolve among members of a species. Those who’ve developed those traits are better prepared to survive in their environment, while those that did not eventually die off.

Next, she explained how genetic variation plays into the evolution of species. Genetic variation involves mutations that cause a population to be different from another.
Bleakley said there are three types of selection.

“There is natural selection like with Darwin’s finches, sexual selection like with peacock tails, and social selection,” Bleakley said. “Social selection is the interactions between animals.”

She discussed how an individual’s traits are the product of the interaction of parental genetics, expressed in phenotypes. Parents become attracted to one another and rule out other potential mates through the process of social selection.

“It makes us able to define social status and it does not have to be a positive interaction like cannibalism,” Bleakley said. “There can be an interaction between the three types of selection.”

“A social interaction can make an animal subordinate which will make it less likely to mate and more likely to be eaten by the dominant animal.”

Bleakley said social selection is important because interactions among potential breeding pairs sculpt the magnitude and rate of evolution.

“The genetic model measures the indirect genetic effect or the interaction of individual’s phenotypes by the genes of its social partner,” Bleakley said. “It is scaled by the strength that directly impacts evolution.”

“Zero means that there is no interacting trait. A positive or negative number is twenty seven the magnitude affects of how traits evolve and how similar the social partners are.”  

Bleakley said indirect genetic effects are hard to measure.

“The environment and the direct effects have to be held constant,” Bleakely said. “If the inbreeding coefficient is greater than point one then it is significant and genetically distinct.

She further explained that by influencing the social group, the social context can be changed.

“If there is an adaptive response, then all of the individuals in the social group respond the same,” Bleakley said. “If there is a non-adaptive response, then all of the individuals in the social group respond differently.”

Liz Scott, a computer science major, enjoyed the speech, but thought Bleakley covered too much information in an hour’s time.

“If you have little knowledge in biology and genetics like myself, then you would find it hard to follow,” Scott said.

Amanda DuBey, biology major, had a different opinion.

“I thought that the speech was interesting and informative,” Dubey said. “My only criticism is that I thought she spent a little too much time going over the basic terminology.”  


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