Coevolution

Between plants and animals A relationship develops between two organisms such that, as they interact with each other over time, each exerts a selection pressure on the other. Evolution of each becomes interdependent on that interaction

Coevolution a reciprocally induced evolutionary change over time between two organisms

Types of relationships...

Symbiotic relationship Ants and Acacia tress Beltian bodies thorns nectaries Ants, caterpillars and acacia

How is it a mutual relationship? Ants provide tree services too! Attack herbivores, chew up nearby trees so Acacias arent in shadows. Tree provides ants- nectar for food, thorns for nest, protein rich Beltian bodies (on leaf tips)

Example #2- Figs and Wasps synconium

Why is it mutually beneficial? Reproductive system of both are tied together. Fig benefits from pollination Wasps benefit by having a food source for larva

Some primate examples Mutualism –Seed dispersal –Pollination Predation –Seed predation Parasitism –Strangling fig –Polyspecific associations

Plants and Seed Dispersal Processing techniques Dispersal location Seeds Mechanical properties Shape- Oval seeds Size- large seeds Color?

Processing technique Damage seed Molars used Undamaged seed Incisor used brown lemur Sifaka

Dispersal location Not under the tree- tree shadow (why?) Lemurs have short gut passage rate (less than 30 minutes) So there must be some travel away from parent tree.

Seeds fate? Not get eaten by secondary predator (rats) Buried or in enough feces to germinate Seedling survival (limited- 1 out of 4000 seeds)

Seed properties Should be resistent to chewing Oval shape facilitates swallowing whole Color attractive to primate (bright?) Large to prevent damage

Pollination Morphological adaptations Flower size, color, smell Number of plants visited Flower handling

Morphology Muzzle length Tongue (lemur picture) Ruffed lemur Mouse lemur

Flower morphology Large flowers Tough petals Produce copious nectar Brightly colored Smell strongly Travelers palm

Visits and handling Must visit more than one tree with flowers to transfer pollen Need to handle flowers carefully so dont destroy reproductive parts.

Seed Predation Fruit and seeds Eats seeds protects seeds Fruits simultaneously Still eats seeds but not all seeds Thwarts protection

Parasitism Strangling fig Polyspecific associations- not true Coevolved relationships

Summary table

Are these really examples of Coevolution? ??

Seed Dispersal: Not a tight relationship Seeds fate once on the ground? Seedling survival? Not dependent on one organism for dispersal- secondary dispersers Dung beetle Agouti

Pollination: not a tight relationship Flowers can rely on many different pollinators (insects, bats, birds, mammals) BUT- Madagascar- limited pollinators (few bats, birds)

Once upon a time... In general, a hard relationship to document- a bit of story telling Evolutionary Story Telling- the Angiosperm hypothesis (Handout in coursepack)