BIOL208 Lecture Notes - Lecture 20: Nectar, Metapopulation, Mycorrhiza
1 May 2018
School
Department
Course
Professor
Mimicry
• Batesian mimicry: Evolution of a nontoxic species to resemble a poisonous or inedible
species
• Mullerian mimicry: When several poisonous or inedible species look similar, mimic one
another
Refugia
• Spatial
o A populatio that ca’t perfor a actio like siig eoles to do so
• Metapopulation Rescue
o Rescue Effect: Idiiduals fro larger populatios a iigrate ad rescue
smaller populations
• Protection in Numbers
o Have populations so large that the risk of any one individual being eaten is low
• Size
The Mutualist-Parasite Continuum
• Exploitative relationship between organisms can range from mutualistic (both incur
fitness benefits) to parasitic (donors gain while the hosts do not)
• Different kinds
o Symbiotic
o Mutualism
▪ Facultative: Species does not require mutualistic partner for survival
▪ Obligate: Species is dependent on mutualistic relationship
• These relationships are VERY DIVERSE
• Parasites: Wil sometime manipulate the behaviour of the host to increase their own
fitness
• Infestation
o Eg. Moose and ticks
• Protection
o Foliar nectaries: Drip sugary sap on their own (leaflet tips) = food source for the
ants
• Construction
• Added complexity: interactions that switch between mutualistic to parasitic
o Interactions between organisms can switch from parasitic to mutualistic,
depending on environmental conditions
o How and why?
1. Most mutualistic interactions are facultative, not obligatory
2. Most mutualisms involve more than two species
o Most utualiss are’t friedl, its actuall a pair of eploitatie iteractios
that happen to be reciprocal
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