What This Document Is
This is a completed lab write-up for Biology 253L, specifically Lab Three focusing on an introduction to evolutionary biology. It details a student’s responses to questions posed during a virtual lab exercise centered on the three-spine stickleback fish.
Why This Document Matters
This document is intended for students enrolled in Prin Of Biology Lab (BI 253L) at Portland State University. It serves as a model response to the lab’s questions, demonstrating how to apply concepts learned about evolution, adaptation, and model organisms. It’s used to fulfill the requirements of the lab assignment.
Common Limitations or Challenges
This document provides a completed example, but does not offer instruction on *how* to complete the lab or understand the underlying evolutionary principles. It’s a finished product, not a learning tool in itself. Students still need to engage with the virtual lab and formulate their own answers.
What This Document Provides
The write-up includes answers to 18 questions covering topics such as the definition of a model organism, the evolutionary advantages of stickleback spines, the relationship between pelvic spine loss and limb loss in other vertebrates, and the differences between marine, sea-run, and freshwater stickleback populations. It also includes descriptions of pelvic structures (complete, reduced, and absent) and an explanation of the experiment's objective. This preview does *not* include the full dataset analyzed during the virtual lab, nor does it contain any post-lab questions.
