DAT Biology: Evolution, Ecology, + Animal Behavior

Sources of Evidence of Evolution

Paleontology, Biogeographic Evidence, Embryology, Comparative Anatomy, Biochemical Methods

What are examples of analogous structures?

Bird Wing and Bat Wing

Cat Leg and Praying Mantis Leg

Shark Fins and Dolphin Fins

What are examples of homologous structures?

Bird forearm and human forearm

What are some of the theories of evolution that existed over time?

Catastrophism, Use and Disuse, Natural Selection

Example of Use and Disuse

Giraffe reaches neck to get tall leaves, over time, the offspring’s neck’s get longer, not as a result of natural selection, but of inheritance of acquired traits/use and disuse

Requirements of Natural Selection

1. Resource demand exceeds supply, resulting in competition for survival

2. Variation of traits exist within a population

3. Variation in traits must be genetically heritable

4. Trait variation must be influential for reproduction and/or survival (fitness)

   1. Genes improving fitness are favored, increase over generations, vv

Types of Natural Selection

Stabilizing Selection, Disruptive Selection, Directional Selection, Sexual Selection, Artificial Selection

Example of Sexual Selection

Birds have profound patterns and displays that make them distinct and good for females to select but bad for predators, showing how while it may be ideal for reproduction, it is unfavorable for survival.

Requirements for Hardy-Weinberg Equilibrium

Large, Random, M&M

1. Large Population to minimize genetic drift

2. Random Mating

3. No Mutation

4. No Natural Selection

5. No Migration/Gene Flow, Population is Isolated

6. Allele Frequency Equation p+q=1

7. Gene Frequency Equation p² + 2pq + q² =1

Factors Causing Microevolution

Genetic Drift, Non-Random Mating, Mutations, Natural Selection, Gene Flow

Sources of Genetic Variation (w/ Elaboration)

Mutations (must NOT be fatal)

Sexual Reproduction (crossing over, independent assortment, and random joining of gametes)

Polyploidy (plants have sets of multiple chromosomes introducing more variety and preserving different alleles) and mask effects of harmful recessive alleles

Balanced Polymorphism: maintains a variety of phenotypes in a population

Examples of Prezygotic Isolation Mechanisms

Habitat Isolation, Temporal Isolation, Behavioral Isolation, Mechanical Isolation, Gamete Isolation (Incompatibility)

Examples of Postzygotic Isolation Mechanisms

Hybrid Mortality (Inviability), Hybrid Sterility, Hybrid F2 Breakdown

Sympatric Speciation Examples

Balanced polymorphism, polyploidy, hybridization

Theories of Macroevolution Types

Phyletic Gradualism and Punctuated Equilibrium

Patterns by Which Evolution Occurs

Divergent Evolution, Convergent Evolution, Parallel Evolution, Coevolution

Parts of a Phylogenetic Tree

Root: represents the common ancestor of all the lineages shown

Node: a branch point representing divergence of a group into 2 groups (typically)

Polytomy: an internal node of a phylogenetic tree that leads to more than two tips

Types of Competition

Intraspecific Competition, Interspecific Competition, Exploitation Competition, Apparent Competition, Interference Competition

Types of Symbiosis

Mutualism (+/+), Parasitism (±), Commensalism (+/0)

Various Species Classifications

Invasive, non-invasive, naturalized, exotic

Trophic Levels in Order from Lowest to Highest

Primary Producers (Highest Biomass) → Primary Consumers → Secondary Consumers → Apex Predators (Lowest Biomass)

What happens when you move from one trophic level to the next?

Only 10% of the energy stored in a given trophic level is converted into organic tissue in the next trophic level

90% of the energy stored in a given trophic level is lost as heat due to inefficient heat transfer

What can species be classified by?

Scavengers, Decomposers, Classified by their Energy and Carbon Sources, Fixing Carbon