Knowing now that Hardy-Weinberg appears to be the source of the logic was a huge help, and you're answers was within my range of plain-English. Also, assuming mating was completely random, why would emigration affect evolution? Meaning it would appear that other conditional changes would be the source of the evolutionary change, not emigration. The ultimate source of all variation is mutation but note that the thing that evolves is a population, so you can change the allele frequency by having individuals enter or leave a population.
By mechanism[ edit ] Competition occurs by various mechanismswhich can generally be divided into direct and indirect.
These apply equally to intraspecific and interspecific competition. Biologists typically recognize two types of competition: During interference competition, organisms interact directly by fighting for scarce resources.
For example, large aphids defend feeding sites on cottonwood leaves by ejecting smaller aphids from better sites. In contrast, during exploitative competition, organisms interact indirectly by consuming scarce resources.
For example, plants consume nitrogen by absorbing it into their roots, making nitrogen unavailable to nearby plants. Plants that produce many roots typically reduce soil nitrogen to very low levels, eventually killing neighboring plants.
Interference[ edit ] Interference competition occurs directly between individuals via aggression etc. An example of this can be seen between the ant Novomessor cockerelli and red harvester antswhere the former interferes with the ability of the latter to forage by plugging the entrances to their colonies with small rocks.
For example, use of resources depletes the amount available to others, or they compete for space. The increase of species A may cause the decrease of species B, because the increase of As may aid in the survival of predator Cs, which will increase the number of predator Cs, which in turn will hunt more of species B.
The degree of size asymmetry has major effects on the structure and diversity of ecological communities, e. Female intrasexual competition Competition can occur between individuals of the same species, called intraspecific competition, or between different species, called interspecific competition.
Studies show that intraspecific competition can regulate population dynamics changes in population size over time. This occurs because individuals become crowded as a population grows. Since individuals within a population require the same resources, crowding causes resources to become more limited.
Some individuals typically small juveniles eventually do not acquire enough resources and die or do not reproduce. This reduces population size and slows population growth.
Experiments demonstrate that when species compete for a limited resource, one species eventually drives the populations of other species extinct. These experiments suggest that competing species cannot coexist they cannot live together in the same area because the best competitor will exclude all other competing species.
Intraspecific competition Intraspecific competition occurs when members of the same species compete for the same resources in an ecosystem. Interspecific competition Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area.
If the resource cannot support both populations, then lowered fecunditygrowth, or survival may result in at least one species. Interspecific competition has the potential to alter populationscommunities and the evolution of interacting species.
An example among animals could be the case of cheetahs and lions ; since both species feed on similar prey, they are negatively impacted by the presence of the other because they will have less food, however they still persist together, despite the prediction that under competition one will displace the other.
In fact, lions sometimes steal prey items killed by cheetahs. For example, in southern California coyotes often kill and eat gray foxes and bobcats, all three carnivores sharing the same stable prey small mammals.
Russian ecologist, Georgy Gausestudied the competition between the two species of Paramecium that occurred as a result of their coexistence. Through his studies, Gause proposed the Competitive exclusion principleobserving the competition that occurred when their different ecological niches overlapped.
For example, mammals lived beside reptiles for many millions of years of time but were unable to gain a competitive edge until dinosaurs were devastated by the Cretaceous—Paleogene extinction event.
The theory originates from work on island biogeography by the ecologists Robert MacArthur and E.Clearly there are a lot of different factors, large and small, that may influence an animal's population size. This includes: Nutrition: More nutrition can sustain a larger population.
AP Biology sample essays: Scientific Method Chemistry Cell Biology Energetics Photosynthesis Photosynthesis & of mammals called pointy-eared bombats, found on an isolated island in the temperate zone. Describe the cycle of activity for the bombats. Discuss how three of the following factors might affect the physiology and/or behavior of.
The dormant state of a mammal during the winter in which its body temperature falls to near the freezing point hibernation a relationship in which two organisms are competing for the same limited resource (i.e. food, water, shelter). John D Rockefeller Population ecology is a perspective that seeks to explain the factors that affect the life cycles of organizations.
Wildlife Conservation and Biology Essay I should be a wildlife biologist so I can study land mammals. Wildlife biology is a field of biology in which land animals are studied. It deals with all animals.
The key groups and species present a broad diversity of biological traits. Most are medium-sized, and only three terrestrial mammals have adult weights of over kg.
North America has 11 big game mammals, in a project that covered most of the relevant factors for the management of this population. Competition is an interaction between organisms or species in which both the organisms or species are harmed. Limited supply of at least one resource (such as food, water, and territory) used by both can be a factor.
Competition both within and between species is an important topic in ecology, especially community ecology.