Week 11 Flashcards
What are the 2 transitions steps for multicellularity?
Independantly replicating units come together to form a new, more complex individual that can then only replicate as a whole (mutual dependance)
How many times did multicellularity evolve?
Evolved independantly more than 25 times
What can cause multicellularity in single celled organisms?
Cells form groups when predators are around
How is the anti-predator response seen in algae?
Exposure to predator poo and preadators cause algae to always group together, across different alage and different predators
How can vertical transmission led to dependance?
Strict vertical transmission = allignment of fitness interests = dependance
How can symbiosis led to dependance for hosts?
Symbionts provide essential nutrients = hosts evolve dependance
How can you meausure ‘dependance’?
The % reduction of host fitness.
Hosts can’t survive without symbionts vs hosts survive well without symbionts
What experiment did scientists do to learning between symbionts and hosts?
They removed 106 symbionts which use bacterial symbionts, using hosts from diverse groups using MCMCglmm comparative analysis. This was done across different metrics, transmission mode, symbiont function and symbiont genome size
What is MCMCglmm?
A package for fitting Generalised Linear Mixed Models using Markov chain Monte Carlo techniques
What does vertical transmission of symbionts mean for host dependance?
Vertical transmission = higher host dependance
Are hosts more dependant on defensive or nutritional symbionts?
They are more dependant on nutritional symbionts
In vertical transmission are larger or smaller genomes of symbionts?
Hosts are more dependant on symbionts with small genomes
In horizontal transmission are larger or smaller genomes of symbionts?
Slight increase in genome size causes increase in dependance
How is vertical transmission shown to have impacted genomes?
Vertically transmitted symbionts have smaller genomes
What is twisted symbionts?
Co-operation, tinged with conflict and manipulation
What are examples of twisted symbionts?
Ants and acacia trees
Cleaner wrasse health spa
What is an example in aphids with a mutualistic microbe indirectly harm hosts?
Aphid primary endosymbiont, though essential, release airborne molecules that attact hoverflies (predator)
How does our gut microbiome accidently harm us?
They make the polio virus more effective
How does mice gut microbiome accidently harm them?
MMTV (Mouse Mammary Tumour Virus) causes breat cancer in mice, using host bacteria like fake ID, displayig them to the host system to gain safe passage into cut
What is dysbiosis?
The break-down of symbionts
How is human activity causing dysbiosis in corals?
More CO2 = warmer oceans
Warmer oceans cause corals to expel algae then get sick causing diseases like white pox (coral become bleached as a result of dysbiosis)
What is the anthropocene?
Humanities influence is causing climate change and drastic changes in species richness
How has Prof Daniel Janzen referred to humans with co-evolutions?
The most co-evolutionary animal of them all
How can coevolution effect environmental change?
It may increase or decrease the effect of environmental change depending on the type of interaction between the different species
Antagonistic = reduced effects
Mutualistic = increased effects + higher extinction