Section 3, Part C Flashcards
What are the possible outcomes when populations of two species compete for similar resources?
tBA
What are the major types of interspecific interactions that occur within a community?
Types of Interspecific Interactions
§ Effect on Effect on
§ Species 1 Species 2
§Neutralism 0 0
§Competition - -
§Commensalism + 0
§Amensalism - 0
§Mutualism + +
§Predation, - +
§Parasitism, Herbivory
What types of interactions are possible when one species serves as a food resource for another species?
Commensalism benefits one organism and the other organism is neither benefited nor harmed. It occurs when one organism takes benefits by interacting with another organism by which the host organism is not affected. A good example is a remora living with a shark. Remoras eat leftover food from the shark. The shark is not affected in the process, as remoras eat only leftover food of the shark, which does not deplete the shark’s resources.
A well-known example of mutualism is the relationship between ungulates (such as Bovines) and bacteria within their intestines. The ungulates benefit from the cellulase produced by the bacteria, which facilitates digestion; the bacteria benefit from having a stable supply of nutrients in the host environment.
Describe some adaptations of predators (or herbivores) and their prey.
Predation influences the fitness of both predators and prey. Individuals must both feed and avoid being eaten to survive and reproduce. Genetically-determined traits that improve an organism’s ability to survive and reproduce will be passed on to its offspring. Traits associated with improved predation for predators and escaping predation for prey tend to be positively selected by natural selection.
Predators exhibit traits such as sharp teeth, claws, and venom that enhance their ability to catch food. They also possess extremely acute sensory organs that help them to find potential prey. Consider the ability of raptors to spot potential prey from over a kilometer away, the acute sense of smell of moles, the ability of owls to locate mice by sound, the ability of pit vipers to sense body heat when tracking prey, and the ability of bats and dolphins to echolocate. Predators catch their prey either by pursuing potential prey or by ambushing them. Organisms that give chase are capable of short bursts of speed. Those that lie in wait tend to be camouflaged to avoid detection (Figure 1).
In a similar manner, prey species exhibit traits that help them avoid detection or capture. Many, such as leaf insects, moths, a variety of frogs and small lizards, and herbivorous mammals, are cryptically colored to make them more difficult to see. Behaviorally, they freeze after detecting the presence of a predator. This lack of movement helps them better blend in with their background and inhibits the ability of the predator to find them. But when predators venture too close, prey will take flight, running or flying to escape. When a chase ensues, prey will typically survive if they stay out of reach until the predator tires. Some species buy extra time by distracting the predator. Examples include moths that flash brightly colored hindwings, lizards that drop their tails, and insect larvae that discharge slime. Such actions surprise the predator and give the prey time a few extra moments to escape.
Describe some examples of different types of symbiotic relationships.
The 3 types of Symbiosis are Commensalism, Parasitism, and Mutualism. Example of Commensalism is a Spanish moss that receives sunlight by the a tree’s help; the tree gets nothing in return; On parasitism, a dog with fleas benefit from the dog’s blood as food and the dog gets harmed. On Mutualism is E. coli bacteria that gets energy from food eaten by a human producing vitamins that the host uses.
Coevolution
Definition:
Two or more species having a close ecological relationship evolve together such that one species adapt to the changes of the other, thereby affecting each other’s evolution.
Supplement
For instance, at microscopic level, the genes of interdependent species are found to evolve together. At macroscopic level, the traits of interdependent species co-vary over time. For example is the coevolution of insects and flowers they pollinate or the coevolution between predators and their prey.
Consumption
Definition:
(Redirected from Consumption (ecology))
Consumers are organisms of an ecological food chain that receive energy by consuming other organisms. These organisms are formally referred to as Heterotrophs, which include animals, bacteria and fungus. Such organisms may consume by various means, including predation, parasitization, and biodegradation.
Consumers dominate most of a food chain. Consumers have important roles to play within an ecosystem such as balancing the food chain by keeping animal populations at a reasonable number. Without proper balance, an ecosystem can collapse and cause the decline of all affected species. This will lead to a severely effected ecosystem, and a nonfunctional consumer web
Mutualism
Definition:
A symbiotic relationship between individuals of different species in which both individuals benefit from the association.
Supplement
In this type of symbiosis, both organisms of different species rely on one another for nutrients, protection and other life functions, hence, they are usually found living in close proximity.
It can be thought of as a form of “biological barter” since the species trade resources (for example carbohydrates or inorganic compounds), or services such as gamete or offspring dispersal, or protection from predators.
There are two types of mutualism: obligate mutualism and facultative mutualism.
Interspecific competition
Definition:
A form of competition between members of different species inhabiting the same ecological area.
Supplement
An example of interspecific competition is between lions and tigers that vie for similar prey. Another example is a farm of rice paddies with weeds growing in the field.
Predation
Definition:
A form of symbiotic relationship between two organisms of unlike species in which one of them acts as predator that captures and feeds on the other organism that serves as the prey.
Supplement
In ecology, predation is a mechanism of population control. Thus, when the number of predators is scarce the number of preys should rise. When this happens the predators would be able to reproduce more and possibly change their hunting habits. As the number of predators rises, the number of preys decline. This results in food scarcity for predators that can eventually lead to the death of many predators.
Commensalism
Definition:
A form of symbiosis between two organisms of different species in which one of them benefits from the association whereas the other is largely unaffected or not significantly harmed or benefiting from the relationship.
Supplement
As a form of symbiosis, the organisms are typically found in close proximity despite of their differences in speciation. Although they thrive in the same area there is no major competition between them; rather, one of them benefits while the other is neither significantly harmed nor benefiting from the symbiosis. A common example is the symbiosis between the epiphyte orchids on branches of trees. These orchids benefit from the trees by the trees rendering support to the orchids. The orchids can gain more light and air in this way. The trees are neither drastically harmed nor benefiting from the orchids attached to their branches.
Niche
Definition:
(ecology) (1) The specific area where an organism inhabits.
(2) The role or function of an organism or species in an ecosystem.
(3) The interrelationship of a species with all the biotic and abiotic factors affecting it.
(general) A cavity, hollow, or recess, especially in a wall.
Herbivory
Definition:
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage, for the main component of its diet.
As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material. Physically humans share more herbivorous than omnivorous traits despite a high omnivore ratio.
Host
Definition:
An organism that is infected with or is fed upon by a parasitic or pathogenic organism (for example, a virus, nematode, fungus).
The term can also be applied, loosely, to a plant supporting an epiphyte. An animal or plant that nourishes and supports a parasite; the host does not benefit and is often harmed by the association.(medicine) recipient of transplanted tissue or organ from a donor.
An organism that a parasite is situated within.
Competitive exclusion principle
Definition:
In ecology, the competitive exclusion principle,[1] sometimes referred to as Gause’s law of competitive exclusion or just Gause’s law,[2] is a proposition that states that two species competing for the same resources cannot coexist if other ecological factors are constant. When one species has even the slightest advantage or edge over another then the one with the advantage will dominate in the long term. One of the two competitors will always overcome the other, leading to either the extinction of this competitor or an evolutionary or behavioral shift toward a different ecological niche. The principle has been paraphrased into the maxim “complete competitors cannot coexist”.[1]
