GEOL 1404 Chapter 7 Review Guide

Chapter 7 Review Guide - GEOL 1404

Linnaean Classification System

  • Levels of Classification: The Linnaean classification system organizes living organisms into a hierarchy with the following levels:

    • Domain

    • Kingdom

    • Phylum

    • Class

    • Order

    • Family

    • Genus

    • Species

Biological Species Concept

  • The biological species concept defines a species based on the ability of individuals to interbreed and produce viable, fertile offspring.

  • Key Features:

    • Focuses on reproductive isolation as the primary criterion for defining species.

  • Differentiation from Fossil Record:

    • In the fossil record, reproductive isolation cannot be observed directly, thus paleontologists may rely on morphological similarities and differences rather than reproductive capabilities to classify extinct organisms.

Three Domains of Life

  • The three domains of life are:

    • Bacteria: Unicellular prokaryotic organisms.

    • Archaea: Unicellular prokaryotic organisms that often inhabit extreme environments.

    • Eukarya: Multicellular or unicellular organisms with eukaryotic cells, including plants, animals, fungi, and protists.

Prokaryotic vs. Eukaryotic Cells

  • Prokaryotic Cells: Characterized by the absence of a nucleus and membrane-bound organelles. Typically smaller and simpler in structure. Examples include bacteria and archaea.

  • Eukaryotic Cells: Contain a nucleus and membrane-bound organelles. Larger and more complex in structure. Examples include plant and animal cells.

  • Self-Identification: Students are encouraged to identify which type of cell they are composed of—eukaryotic.

Evolutionary Thinking

  • Simple Definition of Evolution: Evolution is the process of change in the heritable traits of biological populations over successive generations.

  • Evolution of Evolutionary Thinking: Over time, evolutionary theory has shifted from simplistic views to more complex understandings, incorporating genetic mechanisms, natural selection, and environmental interactions.

Cuvier and Extinction

  • Cuvier’s Contribution: Cuvier proposed the idea of extinction through his studies of paleontology, particularly by examining sedimentary rock layers and fossils.

  • Challenges of the Idea: The concept of extinction contradicted the prevailing belief of his time that all species were created and immutable, leading to resistance and difficulty in accepting extinction as a natural phenomenon.

Lamarckian Evolution

  • Inheritance of Acquired Characteristics: Lamarck proposed that individuals can pass on traits acquired during their lifetime to their offspring. For example, the elongation of giraffe necks as a response to reaching for higher foliage.

  • Classroom Examples: Specific examples discussed in class related to Lamarckian evolution may include changes observed in specific traits of organisms due to environmental pressures.

Natural Theology

  • Arguments For and Against: Natural theology posits that the complexity of life is evidence of a creator. Arguments for it include the intricacy of anatomical structures while against it include the scientific explanations for species’ adaptations and evolution.

Influence of Malthus and Lyell on Darwin

  • Malthus’ Essay on Population: Malthus argued that populations grow exponentially while resources grow arithmetically, leading to competition and struggle for survival.

    • This idea influenced Darwin's theory of natural selection, as it highlighted the struggle for existence among individuals within a population.

  • Lyell’s Geology Textbook: Charles Lyell’s principles of geology provided evidence and a time framework for the gradual processes of change observed in the earth, reinforcing Darwin's ideas about slow, gradual evolutionary change over time.

Artificial Selection

  • Definition: Artificial selection is the process by which humans breed animals and plants for specific traits, influencing the genetic makeup of future generations.

  • Darwin’s Introduction: Darwin began "Origin of the Species" with artificial selection to illustrate how selective breeding by humans is analogous to the natural selection process in nature, providing a framework for understanding evolution.

Darwin’s Evidence for Natural Selection

  • Three Facts:

    1. Reproductive Capacity: Organisms tend to produce more offspring than can survive.

    2. Variation: Individuals within a species exhibit variations in traits.

    3. Struggle for Existence: Due to limited resources, individuals must compete for survival.

  • Inference: These observations led Darwin to infer that individuals with favorable traits are more likely to survive and reproduce, passing on those traits to the next generation, thereby driving evolutionary change.