UNIFYING-THEMES 4

MODULE 7: THE PROCESS OF EVOLUTION, INTERACTION, AND INTERDEPENDENCE

INTRODUCTION

• Study terms in this module using flashcards on separate pieces of paper.

EVIDENCES OF EVOLUTION

• Evolution:

  • Change in heritable traits of biological populations over generations.

  • Responsible for life's diversity on Earth.

  • Patterns of similarity indicate common ancestry.

  • Anatomical structures similarities show common lineage and adaptations.

• Environmental Factors:

  • Drivers of evolution.

  • Organisms adapt via physical, physiological, and behavioral strategies.

• Homology:

  • Structural similarities indicating shared ancestry and evolution.

• DNA/Protein Sequences:

  • Comparing DNA from current organisms and fossils help establish evolutionary relationships.

  • Changes in DNA sequence represent gradual evolutionary processes.

• Plate Tectonics/Geographical Distribution:

  • Similar plants/animals found in different continents suggest common descent and independent evolution.

• Fossil Records:

  • Provide direct evidence of evolution and adaptive strategies.

  • Show extinct organisms differ significantly from current species.

• Embryology:

  • Study of early development stages shows similarities among embryos of different species, indicating a common ancestor.

THE ORIGIN AND EXTINCTION OF SPECIES

• Theory of Evolution by Natural Selection:

  • Charles Darwin’s concept explained in "On the Origin of Species" (1859).

  • All species evolved from simple organisms, including humans.

  • Natural selection favors traits that enhance survival and reproduction.

• Speciation:

  • Process of creating new species through separation and unique adaptations.

  • Types of Speciation:

    1. Allopatric Speciation: Physical barriers separate species.

    2. Peripatric Speciation: Small groups separate from larger populations.

    3. Parapatric Speciation: Species mate within their geographic region.

    4. Sympatric Speciation: Reproductive isolation leads to new species within the same area.

    5. Artificial Speciation: Human intervention creates new species for specific uses.

• Extinction:

  • Process where species cease to exist.

  • Causes include inability to adapt or compete for resources.

  • Examples: trilobites, dinosaurs.

CAUSES OF EXTINCTION

• Natural Extinction:

  • Caused by demographic failure, genetic swamping, or evolutionary changes.

• Anagenesis:

  • Evolution within a lineage leading to different characteristics.

• Mass Extinction:

  • Rapid event leading to extinction of at least 50% of species, usually due to catastrophic events.

  • The largest occurred 250 million years ago, killing 95% of species.

ECOLOGICAL CONCEPTS

• Biotic Potential:

  • Maximum capacity of a population to grow in ideal conditions.

• Environmental Resistance:

  • Factors that limit population growth, such as biotic (predators, competition) and abiotic (disease, climate) factors.

• Ecologist:

  • Studies ecology and its applications, particularly regarding human-environment interactions.

• Anthropogenic Activities:

  • Human actions (deforestation, pollution) that lead to habitat destruction and species extinction.

ADDITIONAL INFORMATION

• General Evolution:

  • Change in heritable traits responsible for diverse life forms, indicating common ancestry.

• Fossils:

  • Preserved remains showing succession and differences between past and current organisms.

• Species:

  • Interbreeding groups reproductively isolated from others, with speciation being crucial to their evolution.

• Types of Ecosystems:

  • Natural Ecosystems: Evolve without human influence. Examples: forests, lakes, wetlands.

  • Man-made Ecosystems: Created for human benefit. Examples: gardens, parks, zoos.

  • Terrestrial Ecosystems: Found on land, covering 28% of Earth's surface (forests, deserts).

  • Aquatic Ecosystems: Cover 71% of Earth's surface, including freshwater, transitional, and marine ecosystems.m