bio220 lecture 1 notes


Course Goals Overview

  1. Understanding Ecology and Evolution through Genetics:

    • Apply genetic principles to ecology and evolution

    • Analyze behavior in species such as elephants

  2. Natural Selection and Genetic Variation:

    • Examine the effects of natural selection on genetic traits over generations

  3. Real-World Applications:

    • Explore topics like agriculture, fisheries, and conservation through evolutionary genetics

Key Course Concepts: Genetics and Ecology

  • Genetic Principles and Ecology:

    • Use genetic knowledge to understand ecological behaviors

    • Understand how ecological pressures shape genetic variation

  • Comparative Behaviors Across Species:

    • Study species-specific examples like elephants: their social structures and reproductive behaviors

Case Study: Elephants

  • Social Structure:

    • Females stay with maternal groups; males leave at adolescence

    • Examines reproductive behaviors and inbreeding avoidance

  • Inbreeding Hypotheses:

    1. Inbreeding avoidance evolved due to severe inbreeding depression

    2. Lack of inbreeding behaviors due to high reproductive variance among males

  • Research Method:

    • Use of genetic markers from non-invasive samples (e.g., dung) for ancestry analysis

  • Findings: Males avoid mating with close relatives, supporting strong inbreeding depression theory

Case Study: Coyotes

  • Geographical Structure: Impacted by rivers and roads

  • Genetic Sampling: Using DNA from coyote scat to assess genetic similarity

  • Barriers to Gene Flow: Examined for effects of natural and human-created barriers on genetic variation

  • Key Result: Distinct genetic differences observed across regions, indicating restriction of gene flow

  • FST Metric: Ranges showing some genetic differentiation across populations

Cultural Influences on Human Genetics

  • Human Dispersal Patterns: Impact of cultural practices on genetic traits (matrilocalism vs. patrilocalism)

  • Comparative Genetics: Study of mitochondrial and Y chromosome variation across populations

  • Findings from Thailand: Significant correlation between genetic diversity and social practices within a region

Conclusion

  • Key Takeaways: Genetics reveals social and ecological behaviors in long-lived species, tracks barriers affecting genetic structure, and shows cultural practices shape genetic diversity in humans.

  • Emphasis: Understanding of ecological genetics helps in real-world applications, animal behavior studies, and conservation efforts.


In the context of inbreeding among male elephants, they might be more likely to choose female relatives from the paternal side of their family, such as half-sisters or cousins, rather than close female relatives like their mothers or full sisters. This adaptability helps maintain some genetic diversity while still ensuring the continuation of their lineage.