Dr. Hird

Birds & Bacteria: Evolution of the Avian Microbiome

How Did I Get Here?

  • Definition of Biodiversity: The variety and variability of life on Earth, encompassing all organisms and their interactions in ecosystems.

Understanding the Microbiome

Definition of Key Terms

  • Microbiome (n): A characteristic microbial community found in a particular environment.

  • Trait (n): A distinguishing quality or characteristic, typically belonging to an individual, body site, or condition.

How Do We Describe the Microbiome?

  • Function: The function of microbiomes can play a significant role in the host's health.

  • Bacterial Genome: The identification of microbiomes is often done through studying the 16S rRNA gene, which provides insights into the bacterial community.

The Power of the Ribosome

  • Discussion on the highly conserved sequence and hypervariable regions, which are essential for distinguishing between different bacterial genera.

  • Reference to the work from Del Chierico et al. (2015).

Microbiota Specificity

  • Microbiota specificity (n): Refers to how consistently a microbe is found in a particular host.

  • Example provided: Light organ of the Bobtail Squid & Vibrio fischeri demonstrates high specificity.

  • Historical Context: A quick history explains that mammal poop microbiota clusters by diet and taxonomy as per research from 2008.

Biology Basics: Differences Between Mammals and Birds

  • Comparison

    • Birth:

    • Mammals: Live birth (usually).

    • Birds: Eggs hatch in nests (usually).

    • Early Diet:

    • Mammals: Milk (always?).

    • Birds: Bugs &/or fish (usually).

    • Flight:

    • Birds: Powered flight (usually).

    • This highlights the biological adaptations which lead to differing microbiomes between mammals and birds.

Goals of Evolutionary Biology

  1. Discover and describe biodiversity, including phylogeny

  2. Understand natural history, lifestyle, and traits of organisms

  3. Elucidate the forces and processes affecting natural history and phylogeny

  • Implication: Microbiomes are implicit within these aims, underscoring their relevance in evolutionary studies.

Research Highlights: Bird Microbiomes

  • Presentation cites specific research observances reflecting upon microbiome diversity related to body size:

    • Body size poorly predicts microbiota diversity in wild birds - A study by Elizabeth Herder et al.

    • Statistical metrics and findings include 1,740 samples from 214 species and different body sites (e.g., Blood: N=723, Buccal: N=358, Gizzard: N=45, etc.).

Methods Used in Study

  • Sampling and Data Matrix:

    • Shows a data matrix involving different samples taken from various body sites and sequences analyzed.

    • Example of sequences across body types shows both diversity and some unique populations.

  • Results section provides graphical representations of observed bacterial ASVs versus mass (g) across studies with significance thresholds discussed (e.g. padj<0.001).

Understanding Phylosymbiosis

  • Definition: Phylosymbiosis (n) is described as an eco-evolutionary pattern in which microbiota similarity recapitulates host phylogeny.

  • The role of phylosymbiosis is explored in both mammals and birds, showcasing results from various studies including Hird et al. (2015).

  • Graphical representation shows Dendrograms of hosts and microbiota similarity evaluations.

Summary of Findings

  1. Avian Ig-Seq: Illustrates how host-immune system interactions with microbiota can be documented, alongside biodiversity implications.

  2. Phylosymbiosis Testing: Discussion on results indicating varying levels of phylosymbiosis and how methods used can provide different insights into microbiome data.

Ethical and Environmental Implications

  • A strong argument is made for the relevancy of studying bird microbiomes, not just for species knowledge but also for understanding broader ecological dynamics and conservation efforts.

Encouragement for Questions and Further Learning

  • Sarah invites questions and encourages deeper engagement with the material and environmental activities beyond the seminar.

Acknowledgments

  • Recognition of lab members and funding sources.

  • Special thanks extended to peers and organizers of the talk.