2024_10_09 - Posted Slides - Lecture 9 - Domains

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1854 Cholera Outbreak

  • Key Figure: John Snow

    • Created one of history's most influential visualizations regarding epidemiology.

Notable Figures in the 1850s

  • Florence Nightingale:

    • Statistically influential in nursing and healthcare.

    • Managed 38 volunteer nurses during the Crimean War.

    • Reduced death rates among wounded soldiers from 42% to 2%.

Importance of Data Visualization

  • Purpose:

    • Useful and honest visual displays are crucial for data interpretation and understanding.

    • Continued practice with graphs and visualizations will occur throughout the course.

Key Learning Outcomes

How to Think Like a Biologist

  • LO 7.5:

    • Analyze scatter plots, bar charts, or histograms relevant to course topics.

History of Life

  • LO 12.1:

    • Define adaptive radiation; give examples regarding ecological opportunities and key innovations.

Unresolved Questions in Evolutionary Theory

  1. Conditions of life origin on Earth.

  2. Timeline of living species.

  3. Impact of mass extinctions.

  4. Evolution of major lineages and traits.

Changes in Biodiversity

  • Mass Extinction Events

  • Adaptive Radiation

    • Exploration of fossil records reveals patterns indicative of these phenomena.

Examples of Adaptive Radiation

  • Galápagos Finches:

    • Originated from a single species, diversified into ~15 species.

    • Adapted various beak shapes and sizes for different food sources.

Influences on Adaptive Radiation in Finches

  • Key Factors:

    • Low competition, disease outbreaks, diverse food sources across islands.

    • Variations in environmental conditions enhancing adaptations.

Roles of Bacteria and Archaea in Human and Ecosystem Health

LO 13: Bacteria and Archaea

  1. Discuss beneficial and harmful roles.

  2. Classify an unidentified organism from characteristics.

  3. Explain antibiotics' effects on bacteria vs. hosts.

Characteristics of Living Organisms

  1. Energy acquisition and utilization.

  2. Regulation of internal environment.

  3. Waste elimination.

  4. Growth and response to surroundings.

Historical Perspectives on Microbial Life

  • 'Microbiocene' Era:

    • Microbes have dominated Earth for 2.5 billion years, evolving prokaryotic forms.

Prokaryotic Characteristics

  • General Features:

    • Cell membrane and wall structures, DNA storage in circular chromosomes, diversity in shapes.

Unique Properties of Bacteria

  • Metabolic Diversity:

    • Methods of obtaining energy: photosynthesis, respiration, fermentation.

Antibiotics and Their Impact

  • Mechanisms of Action:

    • Target structures essential to bacterial survival.

    • Side effects stem from harm to beneficial microbiota.

Comparison: Bacteria and Archaea

  • Similarities:

    • Unicellular, DNA in circular form, lack of nucleus, presence of plasmids.

  • Differences:

    • DNA packaging and cellular membranes.

Eukaryotic Radiation and Its Key Attributes

Key Characteristics

  1. Meiosis, enabling sexual reproduction.

  2. Presence of a nucleus containing linear chromosomes.

  3. Mitochondria for energy production.

Endosymbiotic Theory

  • Co-evolution of Organelle and Host:

    • Mitochondria from engulfed prokaryotes; mutual benefits observed.

Supporting Evidence for Endosymbiotic Theory

  • Mitochondria: Similar size to bacteria, circular DNA, and ribosomes resembling those of bacteria.

  • Implications: Endosymbiosis illustrated through mutualistic relationships observed today.

Conclusion

  • Eukaryotes: Eukaryotic cells exemplify a rich tapestry of evolutionary history blending diverse characteristics.

  • The study of adaptive radiations, evolutionary lineage, and endosymbiotic relationships provides vital insights into life’s biological processes.