EVOLUTIONARY ADAPTATIONS IN FUNGI
o Biogeographic Patterns in Fungi:
o Historically fungi were both treated like plants and like bacteria. They were expected to be
highly endemic (restricted to a certain place) and host specific while at the same time globally
distributed and always present. The divergent expectations are supported by modern analyses
of genetics, supporting the idea that different fungi do it differently.
- Globally distributed fungi
- Locally unique fungi
- Host specific or generalist fungi
- Human driven dispersal of fungi
o Globally distributed fungi can still show patterns of differentiation, but perhaps on continental
scales or based on microgeographic variation (‘the environment selects’):
- Aeroflora – the global fungi of the air
- Global plant pathogens
- Global human pathogens
- Global saprophytes
o Examples:
- soybean rust often causes 50% yield loss. It is now pandemic having spread by
urediospores from SE Asia
- Puccina striiformis f.sp. Tritici (wheat yellow rust) – spreads by spores and people
- Schizophylllum commune is a globally distributed wood rotting fungus. It has genotypes
that are nearly identical found on opposite sides of the world, but there is a broad scale of
more closely related individuals being found within continents – this may be the scale of a
fungal population.
o Why might fungi not be found all over the world?
- Dispersal restricted (e.g. depends on animals to eat them)
- Climate restricted (e.g. humidity, temp., water availability)
- Host restricted (e.g. rust fungus requires a host in order to survive to cannot be found
where the host isn’t present)
o Adaptations for Dispersal
o Ballistospores (many fungi have them, but basidiospores are unique) – spore is forcibly
discharged:
- As water droplet gets larger and touches water droplet on spore, surface tension brings the
water droplets together, bringing water rushing to the top of the spore – spore shoots off.
o Cooperative dispersal:
- Fungal spores generate their own air currents by dispersing together
- They increase their overall travel distance and can improve their
navigation around obstacles
- Cooperation can be between and within fruiting bodies
o Spore morphology:
- Spores have shapes that promote dispersal through air and water
o Sporocarp morphology:
- Many sporocarps show adaptations to disperse via specific means (e.g.
splash, rodent eating)
o Biogeographic Patterns in Fungi:
o Historically fungi were both treated like plants and like bacteria. They were expected to be
highly endemic (restricted to a certain place) and host specific while at the same time globally
distributed and always present. The divergent expectations are supported by modern analyses
of genetics, supporting the idea that different fungi do it differently.
- Globally distributed fungi
- Locally unique fungi
- Host specific or generalist fungi
- Human driven dispersal of fungi
o Globally distributed fungi can still show patterns of differentiation, but perhaps on continental
scales or based on microgeographic variation (‘the environment selects’):
- Aeroflora – the global fungi of the air
- Global plant pathogens
- Global human pathogens
- Global saprophytes
o Examples:
- soybean rust often causes 50% yield loss. It is now pandemic having spread by
urediospores from SE Asia
- Puccina striiformis f.sp. Tritici (wheat yellow rust) – spreads by spores and people
- Schizophylllum commune is a globally distributed wood rotting fungus. It has genotypes
that are nearly identical found on opposite sides of the world, but there is a broad scale of
more closely related individuals being found within continents – this may be the scale of a
fungal population.
o Why might fungi not be found all over the world?
- Dispersal restricted (e.g. depends on animals to eat them)
- Climate restricted (e.g. humidity, temp., water availability)
- Host restricted (e.g. rust fungus requires a host in order to survive to cannot be found
where the host isn’t present)
o Adaptations for Dispersal
o Ballistospores (many fungi have them, but basidiospores are unique) – spore is forcibly
discharged:
- As water droplet gets larger and touches water droplet on spore, surface tension brings the
water droplets together, bringing water rushing to the top of the spore – spore shoots off.
o Cooperative dispersal:
- Fungal spores generate their own air currents by dispersing together
- They increase their overall travel distance and can improve their
navigation around obstacles
- Cooperation can be between and within fruiting bodies
o Spore morphology:
- Spores have shapes that promote dispersal through air and water
o Sporocarp morphology:
- Many sporocarps show adaptations to disperse via specific means (e.g.
splash, rodent eating)
