Evolution of Lizards Post Hurricanes

Summary Notes on Turks and Caicos Anoles Evolution Study

Key Findings:

1. Species Studied: Turks and Caicos anole (Anolis scriptus).
2. Geographical Focus: Pine Cay and Water Cay, islands in the Turks and Caicos.
3. Natural Events:
   • Hurricane Irma (September 8, 2017) with winds of 265 km/hr.
   • Hurricane Maria (September 22, 2017) with winds of 200 km/hr.
   • Both hurricanes significantly damaged vegetation and impacted lizard populations.

Evolutionary Changes Observed:

• Morphological Adaptations Post-Storm:
  • Longer forelimbs.
  • Shorter hind legs.
  • Shorter toes on hind legs.
  • Larger toepads (front and back).
  • Evolutionary trait of a shorter fourth hind toe (previously longest toe) examined.

Genetic Insights:

• Study Publication: Research findings published in Current Biology.
• Gene Frequencies:
  • Five genes showed increased frequency post-hurricanes, linked to muscle and skeletal development.
  • Notably, hs6st1 gene associated with shorter fourth toe development.

Experimental Methodology:

1. CRISPR Technology:
   • Applied to brown anole (Anolis sagrei) embryos to investigate the role of hs6st1.
   • Resulting phenotype exhibited shorter fourth toes and altered toe cartilage.
2. Wind Tunnel Experiment:
   • Brown anoles subjected to winds of 118 km/hr.
   • Observed behavior indicated that shorter first toe bones improved grip, allowing lizards to cling longer.

Implications for Evolutionary Biology:

• The rapid genetic changes underscore potential adaptive evolution in response to extreme environmental challenges.
• Highlights the significance of studying the impacts of climate change and extreme weather on wildlife populations, potentially observable within a single generation.

Environmental and Scientific Context:

• Extreme Weather Trends: The research emphasizes awareness of increasing frequency and severity of extreme weather events due to climate change and their effects on biodiversity.
• Future Research Directions: Calls for further investigation into evolutionary adaptations in wildlife as environmental conditions evolve.

Conclusion:

The study demonstrates rapid evolutionary changes in lizards due to extreme weather events and signals broader implications for understanding adaptation mechanisms in species amidst climate change.