Biology 2483A Lecture Notes - Lecture 13: Evolutionary Arms Race, Chestnut Blight, Myxoma Virus
Document Summary
Our own bodies can be a home to many other species. Symbionts: organisms that live in or on other organisms. Pathogens are parasites that cause diseases (an abnormal condition affecting the body of an organism). Parasites consume the tissues or body fluids of the organism on which it lives (the host). More than half of earth"s species are symbionts. Parasites typically harm, but don"t immediately kill, the organisms they eat (cid:523)unlike predators(cid:524). Compare: the fungus that causes athlete"s foot, and yersinia pestis, the bacterium that causes the plague. Parasites typically feed on only one or a few host individuals. Includes herbivores such as aphids and nematodes that feed on one or a few host plants. Parasitoids are insects whose larvae feed on a single host and almost always kill it. Macroparasites are large species such as arthropods and worms. Most species are attacked by more than one kind of parasite even parasite have parasites.
