University Biology 1104: Summer Session Orientation, Pedagogy, and Evolution Fundamentals

BIOL 1104: Course Logistics and Summer Session Expectations

  • The Nature of Summer Sessions:

    • Summer courses operate at twice the speed of a regular semester. Each class meeting is equivalent to a full week of material in a standard term.
    • The schedule is described as a "marathon" requiring a steady pace to avoid being overwhelmed.
    • Exam frequency is high: The first exam typically covers approximately five chapters within the first week and two days of the course.
    • The workload is intensive; students working full-time or taking multiple other classes are advised to reconsider their schedule due to the rigor of the material.

  • Classroom Policies and Interaction:

    • Punctuality: Polling and questions begin exactly at 10:55, not 11:00.
    • Seating: Students are required to move forward and sit in front of the pillars to facilitate interaction.
    • Active Learning: The instructor uses a random number generator to select students to answer questions after they have discussed the topic with their peers.
    • Group Study: Data collected from past students at Georgia State University (GSU) indicates that students who participate in study groups tend to achieve higher grades.

Grading, Deadlines, and Buffer System

  • Homework Deadlines:

    • Deadlines are generally set for Mondays, Wednesdays, and Fridays.
    • While there is some flexibility for the very first assignment (hard deadline on Friday), students are encouraged to complete it by Thursday night to avoid a backlog of four chapters due on Monday.

  • The Buffer System:

    • The buffer is an automatic system that accounts for absences or missed work without the need for individual excusal requests.
    • Attendance Buffer: In the summer, students are allowed only one "no questions asked" excused day. Surpassing this buffer triggers the excessive absence policy.
    • Homework Buffer: Equivalent to three assignments. This buffer is often exhausted quickly due to the rapid pace of the summer term.
    • Scope: The buffer covers all reasons for missing class or work, including technical issues (computer failure) or personal emergencies (family deaths).

  • Laboratory Particulars:

    • There is only one lab exam in Biology 1104, occurring at the end of the semester.
    • This single exam accounts for $40\%$ of the total grade.
    • Attendance Rule: Missing three lab sections (even if for valid or excused reasons) results in immediate removal from the course because the student is considered to have not effectively taken the class.

Required Tools and Academic Resources

  • Top Hat Platform:

    • Used for the digital textbook, homework assignments, and in-class polling.
    • Registration: Students must use their GSU email for registration. A 14-day free trial is available.
    • Trial Warning: The trial expires at the exact minute it was started (e.g., if started at 2:00 PM, it expires at 2:00 PM 14 days later). Expired trials during class may prevent participation in polling.
    • Access Path: Students must click the Top Hat link through iCollege at least once to sync their account. Accessing Top Hat directly can lead to being kicked out of the course roster nightly.

  • iCollege (Brightspace):

    • The Brightspace Pulse app is recommended for receiving push notifications regarding announcements and grade postings.
    • All lecture slides for Exam 1 (covering chapters 11, 12, 15, 16, and 17) are available on iCollege.

  • Textbook and Material Responsibilities:

    • The textbook focuses on societal issues (e.g., cancer, binge drinking) to make biology more relatable.
    • Students are responsible for all material in the chapters, even if not discussed in lecture, as well as supplemental topics not found in the book (e.g., the evolution of sex, human partner preferences, and bed bug biology).

Instructor Background: Dr. Frank Castelli

  • Academic Credentials: PhD in Behavioral Evolutionary Neuroscience from a psychology department.
  • Research Focus:
    • Dwarf Hamsters (Phonopus): Studied two closely related species (Phonopus sagoras and Phonopus campelli) separated by roughly 300,000300,000 years. Researched how oxytocin and vasopressin receptors in the brain influence paternal behavior (nesting, cleaning offspring vs. lack of involvement).
    • Voles: Investigated genetic influences on monogamy versus promiscuity, specifically looking at microsatellite length polymorphism in the promoter region of the avpr1aavpr1a (vasopressin 1a) receptor gene.
    • Naked Mole Rats: Studied their eusocial structure (queen-led reproduction similar to ants/bees). Dr. Castelli is a volunteer at the Atlanta Zoo.

Case Study: Bed Bug Biology (Cimex lectularius)

  • Anatomy and Sensory Capabilities:

    • Five stages of growth from egg to adult.
    • Superhuman antennae allow for the detection of body heat and carbon dioxide (CO2CO_2) exhaled by hosts.
    • The sense of smell is used to pinpoint exact feeding locations on a host.

  • Feeding Behavior:

    • Feed for 55 to 1010 minutes. They appear flat and brown when hungry but become red and engorged after a meal.
    • Can survive 33 to 66 months without feeding by entering a resting state.
    • They do not transmit diseases, which is considered an evolutionary advantage as it prevents humans from prioritizing their total eradication.

  • Reproduction and Movement:

    • Traumatic Insemination: Males pierce the abdomen of the female to mate, which damages her and shortens her lifespan.
    • Females can lay up to 55 eggs per day.
    • Bed bugs are attracted to vertical objects (like bedposts) because humans sleep at the highest elevation in a room.

  • Extermination and Resistance:

    • Ineffective Methods: Ultrasonic repellents, dryer sheets, mothballs, baking soda, and essential oils do not kill bed bugs.
    • Chemical Resistance: Many strains are immune to standard pesticides. Most sprays/fogs have a mortality rate of only 12%12\% (equivalent to water) unless sprayed directly on the bug.
    • Effective Methods:
      1. Heat: Bed bugs die instantly at 122∘ F122^{\circ}\,F (50∘ C50^{\circ}\,C). Clothes dryers and steamers are highly effective.
      2. Diatomaceous Earth: Crushed fossilized shells of diatoms. The silica-based shells physically damage the bugs and dehydrate them, resulting in a 90%90\% mortality rate after 1010 days.
      3. Freezing: Placing items in a bag in the freezer for 33 days.

Taxonomy and Biological Classification

  • The Hierarchical System: Students must memorize the order: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. (Mnemonic: "Dear King Philip Came Over For Good Sushi").
  • Bed Bug vs. Human Taxonomy:
    • Human: Domain Eukarya, Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Primates, Family Hominidae, Genus Homo, Species sapiens.
    • Bed Bug: Domain Eukarya, Kingdom Animalia, Phylum Arthropoda, Class Insecta.
  • Characteristics of Arthropods:
    • Possess an exoskeleton that must be molted to grow.
    • Bilateral body symmetry.
    • Jointed legs.
  • Characteristics of Insects:
    • Three body parts: head, thorax, and abdomen.
    • Six legs (Arachnids have eight and only two body parts).
    • Order Hemiptera (True Bugs): Defined by sucking mouthparts (proboscis) rather than chewing parts.

Evolutionary Principles and Evidence

  • Natural Selection:

    • Evolution is the change in the allele frequency of a population over time.
    • Mutations are random errors in DNA copying. Most are neutral or harmful; rarely, one provides a benefit.
    • Resistance in bed bugs is an example of natural selection: exposed populations see an increase in the frequency of mutant alleles that provide immunity to pesticides because the non-resistant individuals die off.

  • Common Myths Regarding Evolution:

    • Organisms do not "wish" or "need" mutations into existence. Mutations are random.
    • Example: Whales did not evolve gills because they moved to water; they evolved modified lungs and nostrils (blowholes).

  • Lines of Evidence (The Cetacean Case Study):

    1. Comparative Anatomy: Whales have placentas, nurse young, are warm-blooded, and have lungs. Flippers contain the same bone structure (one bone, two bones, wrist/fingers) as human arms.
    2. Embryology: Dolphin embryos have leg buds that fade during development.
    3. Fossil Record: Intermediate species like Basilosaurus (nasal opening in the middle of the head) and Myasetus (a "walking whale") show the transition from land to sea.
    4. DNA Evidence: The closest living genetic relative to the whale is the hippopotamus. They share a common ancestor from approximately 5454 million years ago.

  • Shared Traits between Whales and Hippos:

    • Internal testicles (rare among mammals).
    • Multi-chambered stomachs.
    • Lack of a fur coat.
    • Ability to nurse young underwater.