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Symbioses - Mutualism. Symbioses. Symbioses - species living in close association Parasitism +,- parasite benefits, host harmed Commensalism +,0 or 0,0 can have positive effect for one species or for neither Mutualism +,+ both species benefit . Mutualism.
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Symbioses • Symbioses - species living in close association • Parasitism +,- parasite benefits, host harmed • Commensalism +,0 or 0,0 can have positive effect for one species or for neither • Mutualism +,+ both species benefit
Mutualism • Definition - the individuals in a population of each mutualist species grow and/or survive and/or reproduce at a higher rate when in the presence of individuals of the other. Each benefits (+,+)
General Features of Mutualisms 1. The life cycle of most mutualistic species is very simple (in contrast to parasites) 2. There is no conspicuous dispersal phase for most endosymbionts (endomutualists) 3. Populations of most mutualists are stable in size - no epidemics as seen in parasites 4. The ecological range (niche breadth) of organisms in mutualisms usually appears to be greater than that of either species alone 5. Host specificity is usually flexible 6. Within populations of mutualists, the number of endosymbionts per host is relatively constant
Two types of Mutualism • Facultative - each partner gains a benefit but is not dependent on the other - the vast majority of mutualisms are facultative. • Obligate - one or both partners is dependent on the other and cannot survive without the other.
Pollination syndromes among the phloxes
Honeybee covered with pollen
Honeybee pollinating beebalm – Monarda sp.
With visible light with UV light Nectar guides for honeybees
Cyrtid fly pollinating a composite
Human Agriculture Sustainable Dairy Industrial Wheat
Coral polyp with zooxanthellae - a dinoflagellate, Symbiodinium
Coral polyp – coral animal is green, Zooxanthellae is red
Endosymbiotic Origin of Eukaryotes Lynne Margulis