lecture13

lecture13 - Herbivory, Parasitism, Mutualism July 15...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Herbivory, Parasitism, Mutualism July 15 1 Coevolution – when two or more species affect one another’s evolution Species 1 Species 2 Examples Examples Competitor Species Competitor Species – resource partitioning, character displacement Predators and Prey Predators and Prey – predators select for defensive traits in prey, which selects for traits in predators that weaken the defense of prey. Fish Snails Thicker shells Stronger jaws evolutionary arms race Aposematic (warning coloration) – species that are brightly colored to advertise that they are harmful Predator Prey aposematic recognition Mimicry – when two or more species (usually aposematic) resembles one another Batesian Mimicry – when a non-harmful species resembles a harmful species Harmful species – Model Non-harmful species - Mimic The model species has a positive impact on the mimic species, whereas the mimic species has a negative impact on the model species Mullerian mimicry – when two or more harmful species resemble one another Examples: Wasps, poison arrow frogs All species have a positive effect on one another Examples:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Herbivory, Parasitism, Mutualism July 15 2 Herbivores and Plants Herbivores and Plants – herbivores select for defensive traits in plants, which selects for traits in herbivores that weaken the defense of plants. Herbivore Plant Defense Counter-selection Coevolution Between Plants and Animals Coevolution Between Plants and Animals Pollinators and Plants – beneficial for both species - mutualism Pollinator Plant Attraction Specialization Defense Mechanisms Against Herbivores in Plants Defense Mechanisms Against Herbivores in Plants Mechanical Mechanical Thorns Trichomes – protective “hairs” on leaf surface (glandular or non-glandular) Toughness Chemical Chemical – secondary compounds (chemicals) secondary compounds (chemicals) – not part the primary metabolic pathways that plants use to obtain energy. Some plants contain ecdysone – discovered accidentally at Harvard University when laboratory insects ate paper towels made from balsam fir. Ferns contain high concentration of ecdysone
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 8

lecture13 - Herbivory, Parasitism, Mutualism July 15...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online