What is the genetic basis of evolution? Looking at the shape of the opercle bone in Alaskan stickleback fish

Presenter: Christina Wickman, Marine Biology

What is the genetic basis of evolution? For this study, we used the three spine stickleback fish, which is a model for evolution as both the ancestral and derived populations can be gathered, and crossed to form viable offspring. Our study concentrated on the facial bone known as the opercle and we hypothesized that the shape of the opercle was controlled by Mendelian genetics in a co-dominance relationship. To test this hypothesis a model was created and both the parent and F1 populations were land marked choosing 12 points along the bones edge and the variation between the points were graphed using Principle Component Analysis. From the land marking of the F1 progeny it appeared that the alleles were expressing a dominance relationship and based on our findings we revised our hypothesis proposing this. To test this hypothesis the F2 progeny were landmarked, but did not show a dominance relationship, so we again revised our hypothesis proposing that quantitative genetics are at work: where multiple genes are acting to form different regions of the opercle bone. From this we concluded that the opercle shape is specified by multiple genes acting on different areas of the bone and we can infer that the changing of these genes provides the basis for evolution of the opercle, which provides for more skeletal variation, which can be advantageous evolutionarily