B. dendrobatidis
Where did B. dendrobatidis (Bd) likely originate, and how did it spread globally?
It likely originated in Korea and quickly spread via amphibian trading
Who was found to live longer among the guppies?
Hybrids and pure immigrants
Figure B: What do the different colors in the tree mean?
The colors show different Bd lineages
Figure 1: In general which river had the greater census size?
Caigual
Why is the BdGPL lineage considered so dangerous to amphibians?
higher infection rate compared to other lineages, ability to survive and thrive in different environments and easily spreads through trades, has undergone genetic recombination and hybridization
Why did certain genes remain common?
Natural selection is preserving traits that help the population adapt to its local environment.
Figure A: Why do North America and Australia have fewer types of Bd?
because these regions were primarily invaded by the highly virulent BdGPL lineage, which spread rapidly and outcompeted or excluded other lineages
Figure 2: How does longevity (lifespan) differ between males and females?
Generally, females lived longer than males
What are some limitations of the study ?
Possibly uneven sampling of isolates, impact of environmental factors, no longitudinal sampling
What is one limitation to the study?
Guppies breed year round!
Figure B: Why is the BdASIA-1 lineage so distinct from the others?
BdASIA-1 is highly divergent, indicating it separated from other lineages a long time ago. This supports the idea that Bd originated in Asia and evolved separately over time.
Figure 2: What do the dashed lines/diamonds represent in each graph? (Hint: at what point in the curve are they seen?)
The maxima and the shaded region is the 95% confidence interval
What steps could be taken to improve international biosecurity and prevent the spread of amphibian pathogens?
stricter regulations on amphibian trade, mandatory pathogen screening before export/import, enhanced border inspections
Gene flow from a related source into what kinds of populations can produce benefits? (Hint: what size?)
Small populations Bonus: with low genetic diversity
Figure A: Why is BdGPL (Global Panzootic Lineage) so widely distributed across continents?
BdGPL has spread globally due to its association with the amphibian trade and human-mediated translocation of amphibians -- could suggest it's highly adaptable
Figure 1: What do the black arrows represent in section A?
Gene flow