Final Exam Review

CLADOGRAM ANALYSIS

Definition of Cladogram

• Cladogram: A diagram that depicts evolutionary relationships among groups.
    - Basis: It is based on phylogeny, which is the study of evolutionary relationships.
    - Relationship to Phylogenetic Tree: Sometimes referred to as a phylogenetic tree, but there are minor technical differences between the two.

Historical Perspectives on Classification

• Past Method: Biologists used to group organisms based solely on physical appearances.

• Modern Method: Advances in genetics and biochemistry allow biologists to examine individuals more closely to understand their evolutionary patterns, leading to a method called evolutionary classification.

Cladistics

• Cladistics: A form of analysis that studies features considered innovations.
    - Definition of Innovations: Innovations are newer features that serve a purpose and are not found in earlier organisms.
    - Derived Characters: Characteristics that appear in later organisms but not in their ancestors, marked as significant in cladograms.

Character Matrix

• Fillable table for traits (cells, legs, antennae, wings, double sets of wings) across various organisms (worm, spider, carpenter ant, house fly, dragonfly).

Analyzing Relationships

1. Species Relationships: Determine closeness based on cladogram analysis (e.g., worms and spiders vs. worms and ants).

2. Connections to Dragonflies: Identify species most closely related to dragonflies based on derived traits.

3. Inclusion of Additional Organisms: Adding new specimens (e.g., June Bug) based on characteristics for further analysis.

Trait Analysis Using Cladograms

• Questions on traits that separate various species (lampreys and tuna, salamanders and turtles).

• Identify the organism most closely related to leopards and DNA variance.

Detailed Trait Matching

• Matching letters to characteristics such as wings, legs, segmented bodies, etc.

Evolution of Land Plants

• Examination of a cladogram depicting the evolution of land plants based on fossil records, including challenges to validity (e.g., discoveries of ancient aquatic plants).

Biological Construction of Cladograms

• Factors: Anatomical features, behavior, molecular similarities, and differences.

• Molecular Analysis: Counting mutations in DNA strands and comparing amino acid sequences.
    - Emphasis on Cytochrome c as a protein involved in cellular respiration with provided amino acid and DNA sequences for various organisms.

Relationship Analysis via Amino Acid Sequences

• Organism relationship conclusions based on amino acid order and similarity, determining the most related organisms to lizards and dolphins.

Hardy-Weinberg Equilibrium

• Hardy-Weinberg Equilibrium: A principle used to compare allele frequencies in populations over time, requiring five conditions to be met:
    1. No gene mutations.
    2. No migration (immigration emigration).
    3. Random mating.
    4. No genetic drift.
    5. No natural selection.

• Note: This equilibrium is an ideal state and rarely occurs naturally due to rule violations. It provides a baseline for measuring gene evolution.

Hardy-Weinberg Equations

1. $p + q = 1$
      - Where $p$ is the frequency of the dominant allele and $q$ is the frequency of the recessive allele.

2. $p^2 + 2pq + q^2 = 1$
      - Where:
        - $p^2$ = frequency of homozygous dominant genotype
        - $2pq$ = frequency of heterozygous genotype
        - $q^2$ = frequency of homozygous recessive genotype.

Example Problem

• Population of 1,000 cats:
    - 840 black (dominant) and 160 white (recessive).
    - Determine allele frequency, genotype frequency, and genotype counts (through steps of calculations).
    - For black cats: Find frequencies of each genotype and their respective counts by substituting into Hardy-Weinberg equations.

Population Comparison Across Generations

• To check Hardy-Weinberg Equilibrium: Compare allele frequencies across generation.

• Example population shift with provided numbers and resultant calculations.

Additional Examples

• Multiple examples of finch populations and beak coloration showing steps of calculation for identifying allele frequencies and checking equilibrium states.

Practice Problems

1. Lizards – analyze scale coloration based on dominance relationships.

2. Future generation population checks for equilibrium.

3. Analysis of rabbits' ear genetics using Hardy-Weinberg principles.

4. Pea plants with petal coloration to determine frequency distributions.

Diagram Labeling

• Diagram labeled parts (A to J).

Classification of Plants

• Classifying images as monocots or dicots as an additional exercise.