Symbiosis, Emergent Property, and Self-Interest Flashcards
What is the antiquity of genomic traits related to mycorrhizal evolution based on?
Molecular clock estimates
What happened during the middle Ordovician period?
Spores attributed to terrestrial plants
Spores and hyphae attributed to Glomeromycotina
What occurred during the Sil. period?
Possible origin of the common symbiotic signaling pathway
Terrestrial plant remains and charophytes (multicellular algae) found
Stratified lichens found
What occurred during the early Devonian period?
AM and CMm para-mycorrhizas
Occurrence of Ascomycota
What happened during the middle Devonian period?
Trees and forests
What happened during the Mississippian Carboniferous period?
Occurrence of Basidiomycota based on clamp connections
What occurred during the Pennsylvanian Carboniferous period?
AM involving roots = true mycorrhizas
Early saprophytic or parasitic Agaricomycotina; limited ligninolytic peroxidases and CAZymes
Loss of plant cell wall-degrading enzymes in Glomeromycotina
What happened in the Permian period?
Origin of white rot
Diversification of saprophytic cellulolytic apparatus: expansion of CAZymes
What occurred during the Triassic period?
Podocarpaceae
What happened between the Triassic and Jurassic periods?
Multiple origins of brown rots
What appeared during the Jurrasic period?
Pinaceae
What appeared in the early Cretaceous period?
Angiosperms
What happened during the Jurassic period?
Multiple origins of ectomycorrhizas: losses of PCWDEs; diversification of MiSSPs
What happened during the Cretaceous period?
Origins of soil and litter decomposers: loss of lignin oxidoreductase; CAZymes expanded
Multiple origins of ectomycorrhizas and orchid mycorrhizal: maintenance of PCWDEs
What appeared during the late Cretaceous?
Ericaceae
What appeared during the Palaeogene period?
Ectomycorrhizas
What did Mereschkowski argue?
That evolution is only possible via symbiosis
Used lichens as an example of the evolutionary innovation arising from symbiosis
What did Elenkin argue?
Insisted on describing lichen symbiosis as a tug-of-war rather than a friendly mutualism
What is Margulis known for?
Recognized as the discoverer of bacterial origin of mitochondria
How do we know which type of symbiosis is occurring>
Effect on host
Goods or services exchanged
Types of transmission
Interdependence
Effect on genomes
What is a host?
When the partner is larger and easy to see, or when it is clearly parasitized
What is the difference between open and closed symbiosis?
Open = the host can encounter other partners
Closed = the partner range is limited
What is auxotrophy?
An organism that does not have the machinery to make something essential
What are goods and services exchanged or syntrophy restricted to?
Open systems
What does extracellular secretion lend itself to?
Symbiosis
Biological market: AM fungi
Fungus receives: C for growth
Partner receives: P, N
Other partners? Yes, open market
Biological market: EM fungi
Fungus receives: C for growth
Partner receives: P, N
Other partners? Yes, open market
Biological market: Lichen fungi
Fungus receives: sugars for cell preservation
Partner receives: Protection against herbivory, UV light
Other partners? Yes, open market
Biological market: Insect fungi
Fungus receives: ?
Partner receives: essential amino acids
Other partners: depends, some open and some closed
Are species fixed to a lifestyle?
No
Shift in emphasis from status to function
What is a cooperative partner?
May take a fair amount of P for a given amount of C
What is a non-cooperative partner?
May take more C for the same amount
What is a cheater partner?
May take C and give nothing in return
What is vertical transmission?
Like Soredia - co-transmission
What is horizontal transmission?
Couples disassemble and regenerate every cycle
What is leaky vertical transmission?
It is like vertical transmission but lots of mistakes are made
Other organisms might get into the packages
What is the effect of genomes on symbiosis?
Genome sizes tend to be smaller with vertical transmission than with horizontal transmission
What is the effect of fitness on symbiosis?
Host fitness drop is higher with vertical transmission
Host fitness drop is higher when the symbiont function is nutritional
What do most plastids have?
Symbiotic origins
What is a holobiont?
An assemblage of a host and many other species living in or around it, which form a discrete ecological unit through symbiosis
