General Zoology Study Guide: Characteristics, Organization, and Scientific Process

Introduction to General Zoology

Zoology is one of the broadest fields in the study of biology, dedicated to the investigation of all aspects of animal life, including structure, function, and evolutionary history.
The primary goals of studying zoology include:
- Understanding the origins of animal life.
- Gaining knowledge of particular structures, functions, or processes in relation to animal biology.
- Identifying various adaptations that facilitate the success of animals within their specific habitats.
Zoology is often approached through two primary lenses:
- Evolutionary Perspective: Focuses on the genetic changes and historical lineages of animal life.
- Ecological Perspective: Focuses on the interactions between animals and their environments.

Specializations within Zoology

General Specializations:
- Anatomy: The study of the structure of entire organisms and their specific functions.
- Cytology: The study of the structure and function of cells.
- Ecology: The study of the interactions of organisms with their environment.
- Embryology: The study of the stages of animal development.
- Genetics: The study of the mechanisms regarding the transmission of traits from parent to offspring.
- Histology: The study of animal tissues.
- Molecular Biology (Mol. Biology): The study of subcellular components and their interactions.
- Parasitology: The study of parasitic animals and their interactions with hosts.
- Physiology: The study of the function of organisms and their constituent parts.
- Systematics: The study of classification and evolutionary relationships.
Taxonomic Specializations:
- Entomology: The study of insects.
- Herpetology: The study of amphibians and reptiles.
- Ichthyology: The study of fishes.
- Mammalogy: The study of mammals.
- Ornithology: The study of birds (avifauna).
- Protozoology: The study of protozoa.
Notable Faculty and Experts:
- Dr. Angel Alcala.
- Dr. Nina Ingle.
- Dr. Jade Aster Badon.

Zoology: An Evolutionary Perspective

Biological (Organic) Evolution: Defined as a change in the genetic makeup of populations of organisms over a period of time.
Evolutionary processes are essential for explaining:
- How the vast diversity of animal structures and functions arose.
- The complex family relationships within the animal kingdom.
Classification groups reflect a hierarchy of relatedness; individuals are considered more closely related if they share more DNA.
Taxonomy and Nomenclature:
- Taxonomy is the branch of biology tasked with naming and classifying species into increasingly broad groups.
- Binomial Nomenclature: A system established by Carl von Linne ( $1707-1778$ ) where each species receives a two-part name.
- Part one is the Genus name; part two is the species epithet.
- Examples: Draco spilopterus (italics or underlined).

Hierarchy of Taxonomic Relatedness

The classification system utilizes a specific hierarchy from broadest to most specific: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Example Classifications:
- Housefly:
  - Domain: Eukarya
  - Kingdom: Animalia
  - Phylum: Arthropoda
  - Class: Hexapoda
  - Order: Diptera
  - Family: Muscidae
  - Genus: Musca
  - Species: Musca domestica
- Horsefly:
  - Domain: Eukarya
  - Kingdom: Animalia
  - Phylum: Arthropoda
  - Class: Hexapoda
  - Order: Diptera
  - Family: Tabanidae
  - Genus: Tabanus
  - Species: Tabanus opacus
- Cichlid (Fish):
  - Domain: Eukarya
  - Kingdom: Animalia
  - Phylum: Chordata
  - Class: Osteichthyes
  - Order: Perciformes
  - Family: Cichlidae
  - Genus: Perissodus
  - Species: Perissodus microlepis
- Human:
  - Domain: Eukarya
  - Kingdom: Animalia
  - Phylum: Chordata
  - Class: Mammalia
  - Order: Primates
  - Family: Hominidae
  - Genus: Homo
  - Species: Homo sapiens
- American Black Bear:
  - Domain: Eukarya
  - Kingdom: Animalia
  - Phylum: Chordata
  - Class: Mammalia
  - Order: Carnivora
  - Family: Ursidae
  - Genus: Ursus
  - Species: Ursus americanus

Zoology: An Ecological Perspective

Ecology: The study of relationships between organisms and their environment.
Failure to understand these relationships has led to significant detrimental consequences for planetary health.
Specific Environmental Challenges:
- Species examples: Rhinella marina (formally Bufo marinus) and Swietenia macrophylla (Mahogany).
- Human Global Overpopulation: Considered the root of all other environmental problems.
- Human population is estimated to reach $9.6 \times 10^9$ (9.6 billion) by the year $2050$ .
- Overpopulation stresses world resources, leading to climate change, deforestation, water shortages, and species extinction.
Case Study: Negros Island Forest Cover Evolution:
- $1875$ : High forest cover density.
- $1949$ : Significant reduction in cover.
- $1970$ : Further fragmentation.
- $1987$ : Thinning forest lines.
- $1992$ : Minimal forest remnants.
Case Study: Habitat Destruction:
- Reference to Boracay: Recognized as the 7th World's Best Beach in $2015$ , but subjected to $15$ years of significant environmental destruction (images show "Before" vs "After" decline).

Defining Characteristics of Life

Life is difficult to define in a single sentence but is recognized by the activities living things perform:
- Order: Composed of cells.
- Genetics: Contains genetic material (DNA).
- Metabolism: Regulates metabolic processes.
- Reproduction: Growth, development, and reproduction.
- Homeostasis: Response to stimuli and maintenance of internal balance.
- Evolution: Ability to evolve and adapt to the environment.
Example Species: Pristimantis mutabilis (found in Ecuadorian rainforests; discovered $2009$ , published March $24$ , $2015$ ).

Homeostasis and Internal Regulation

Homeostasis: The process of maintaining internal balance through feedback mechanisms. The normal body temperature range for humans is approximately $35.6\,^\circ\text{C}$ to $37.8\,^\circ\text{C}$ .
Heat Feedback Loop:
- Stimulus (Increased Temp): Body temperature rises (e.g., during exercise). Hypothalamus activates heat-loss center. Skin blood vessels dilate to radiate heat; sweat glands secrete perspiration to cool the body.
- Stimulus (Decreased Temp): Body temperature falls. Hypothalamus activates heat-promoting center. Skin blood vessels constrict to minimize heat loss; skeletal muscles activate (shivering) to generate heat.

Hierarchy of Biological Organization

Life is organized in a hierarchy of increasing complexity:
- Cellular Level:
  1. Atoms: Smallest unit of a pure substance (e.g., Carbon atom).
  2. Molecules: Groups of joined atoms (e.g., DNA).
  3. Organelles: Membrane-bounded structures with specific functions (e.g., Chloroplast).
  4. Cells: Fundamental unit of life.
- Organismal Level:
  1. Tissues: Collections of specialized cells (e.g., Epidermis).
  2. Organs: Tissues organized to carry out specific functions (e.g., Leaf).
  3. Organ Systems: Connected organs functioning together (e.g., aboveground plant parts).
  4. Organism: A single living individual.
- Ecosystem Level:
  1. Population: Group of the same species in the same place/time.
  2. Community: All populations occupying the same region.
  3. Ecosystem: Living and nonliving components of an area.
  4. Biosphere: The global ecosystem including the atmosphere.
Emergent Properties: New properties that emerge at each level of the hierarchy; form and structure are correlated at all biological levels.

The Scientific Process

Scientific Method: A body of techniques for investigating phenomena based on empirical or measurable parameters.
Process Steps:
1. Observations: Knowledge amassed before the experiment.
2. Ask a Question: Identifying the specific phenomenon to investigate (e.g., Is a rotavirus vaccine effective?).
3. Background Research: Consulting prior knowledge.
4. Hypothesis: Potential, falsifiable explanation for the observation (e.g., The vaccine will stimulate the immune system and reduce disease).
5. Predictions: Specific, testable outcomes expected if the hypothesis is true (e.g., Vaccinated children should have a lower incidence of illness than those receiving a placebo).
6. Experimentation: Testing the prediction through a designed study.
7. Data Interpretation: Using statistical analysis to test for statistical significance (the probability results arose by chance).
8. Conclusions: Determining if data supports or refutes the hypothesis.
9. Peer Review & Publication: Results are evaluated by other experts.

Experimental Design Components

Sample Size: The number of subjects in a group.
Independent Variable: The variable manipulated by the investigator (e.g., Dose of vaccine).
Dependent Variable: The variable measured to determine effect (e.g., Number of children with illness).
Standardized Variable: Variables held constant for all subjects (e.g., Age and health of children).
Control Group: The untreated group used for comparison; may receive a placebo (substance lacking the active ingredient).

Limitations of Science

Science is mechanistic in nature.
It is subject to multiple interpretations or potential misinterpretations.
Observations and results must be repeatable to be valid.
Science cannot provide answers to:
- Subjective questions.
- Moral, aesthetic, or philosophical standards.
- Supernatural explanations (it cannot support or falsify them).

Questions & Discussion

Interviewer/Presenter Prompts:

1. What unique feature does the animal have?
2. If you were this animal, what would your daily routine be?
3. Describe this animal using $2$ to $3$ words.
Scientific Discovery Reference: Cartoon strip "The Far Side" by Gary Larson ( $1984$ ) depicts scientists Ellington and his colleague claiming to have mathematically expressed the purpose of the universe: "Gad, how I love the thrill of scientific discovery!"