Clear cut examples of commensalisms right not

Info icon This preview shows pages 31–34. Sign up to view the full content.

View Full Document Right Arrow Icon
Clear-cut examples of commensalisms, right? Not necessarily. What if the sea anemone provides camouflage for the crab, making it look more like a rock than a crab? What if the load of epiphytes becomes so great—as it frequently does on South and Central American trees—that the trees break? The point is, if we look closely at what appear to be commensalisms, we often find hidden benefits or costs. Some clear-cut examples of commensalisms might be plants such as cockle burrs and stick-tights that passively disperse their seeds on the fur of animals and the cloth- ing of people, and certain mites that hop onto the bills of hummingbirds and hitch a ride from flowers on which the birds are feeding to other flowers. Population Interactions Research types of interactions and find examples of predator- prey, commensalism, parasitism, and mutualism. Mutualism Intimate relationships in which both species benefit, in which partnerships in life are formed, are mutualisms , some of the most fascinating and important relationships known to biology. We have already mentioned several examples of Figure 15-25 Cattle egrets benefit from a commensal relationship by feeding on insects flushed by elephants.
Image of page 31

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

View Full Document Right Arrow Icon
518 C HAPTER 15 Population Ecology: How Do Organisms Interact to Form Populations? Figure 15-26 This red-billed oxpecker feeds on external parasites of water buffalo. Each species benefits the other. mutualisms: Flowers and their pollinators, mycorrhizal fungi and the plants on whose roots they attach, nitrogen-fixing bacteria and their legume hosts, flowering plants and the animals that eat their fruits and disperse their seeds, and lichens. You can probably think of others (Figure 15-26). Notice that there are two broad types of mu- tualisms: Obligatory mutualism , in which both partners are mutually and exclusively dependent on each other (figs and their wasps, for example) and facultative mutualism , in which both benefit when together, but are capable of living independently (for example, corals and the algae that live in their internal spaces). Piecing It Together Species are not independent entities; frequently they interact.Types of interactions in- clude the following: Competition: Both species are negatively affected. Predator–Prey: One species benefits at the expense of the other.There are two kinds of interactions: Plant–herbivore and herbivore–carnivore. Symbiosis: Intimate interrelationships between species that include: Parasitism: One species benefits at the expense of the other. Commensalism: One species benefits while the other is unaffected. Mutualism: Both species benefit. What about humans? Who are our competitors, predators, prey species, parasites, com- mensals, and mutualists? In terms of these categories, what is our relationship with domestic dogs and cats?
Image of page 32
Exploration Where Are We Now? 519 W HERE ARE WE NOW ?
Image of page 33

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

View Full Document Right Arrow Icon
Image of page 34
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern