Jay Sobel, an evolutionary geneticist who joined Binghamton University’s biological sciences department this year, was this week’s speaker for Biology 451: Current Topics in EvoS.
“I am fascinated by why there are so many different types of organisms in nature,” Sobel said in his opening slide.
He discussed the reasoning behind the processes of evolutionary changes due to the environment, and focused his seminar on the adaptive shift in the wildflower species Mimulus aurantiacus.
Sobel and his research team characterized the ecological, genetic and molecular basis for why a particular allele, MaMyb2, causes the flower to possess a yellow or red color.
He said that his team used a basic genetic approach to examine what loci are responsible for color variation.
He concluded that a mutation in a particular transcription factor, r2r4-myb, is responsible for flower color variation. A transcription factor is a protein that binds to specific DNA sequences; a mutation within this flower can generate a different biochemical reaction — in this case, color.
Sobel found that the red allele of MaMyb2 acts to regulate anthocyanin — the pigment that makes fall foliage red — causing the flower to appear a red color.
Originally, he thought other factors might be responsible for the color changes, but after researching, he found MaMyb2 to be the actual causal gene.
In his research, Sobel aimed to answer questions in biology, such as “How predictable is adaptation?” and “Are specific traits, mutations or aspects of genetic architecture most commonly involved in generative diversity?”
He provided another example of adaptive traits, in which a mouse and lizard shared the Mc1r gene that caused them to change to a lighter color.
Sobel’s detailed examples and charts helped to answer why there is such extreme biological diversity across life forms and how it came to be that way. He also discussed evolutionary concepts of natural selection and adaption to prove how an organism’s phenotype, or its physical characteristics, is the result of its genotype, inherited DNA and environment.
Evolution occurs when a shift in environmental factors reinforces selection for certain traits, leaving the best traits to survive and be reproduced. In instances of color shifts, the organism may be adapting to aspects of its surroundings.
Cheng Sun, a teaching assistant for the EvoS course and a graduate student studying anthropology, said Sobel exemplified the “basic model” of genetic adaptation by choosing a particular plant and showing how different colors are signs of different adaptations.
“Unlike other speakers, [Sobel] is from the University,” Sun said, “so he provided the opportunity for undergrads to participate in his own study, and also discussed basic evolutionary ideas. Compared to previous talks, this one was more authentic.”
Other students agreed that Sobel was one of the better speakers of the semester.
“I have a background in genetics and am passionate about evolution, so it was nice to hear that bridged together,” said Natalie Lamb, a senior majoring in biology. “It was interesting to hear him speak, and you can tell that he is very intelligent.”
Jay Sobel offered advice to undergraduates to gain hands-on experience with molecular techniques, but also paid attention to the bigger questions.
“I guess what I’m saying is learn it all,” he said.