Whats the difference between migration, invasion and immigration?
Answer:
Migration occurs when living organisms move from one biome to another. In most cases organisms migrate to avoid local shortages of food, usually caused by winter. Animals may also migrate to a certain location to breed, as is the case with some fish.
The species that periodically migrate are called migratory, those that do not are called resident (or sedentary).
Bird migration is common. The longest known migration of a bird is that of the Arctic Tern, which migrates from the Arctic to the Antarctic and back each year. Flyways are routes that certain bird species take to migrate.
Whales and other animals, such as gnus, butterflies, moths, salmon, eels, and lemmings are also known to migrate. The periodic migration of plagues of locusts is a phenomenon recorded since Biblical times. Occasionally (and usually unexplainedly) an animal may deviate markedly from its customary migration. A widely publicized incident involved Humphrey the whale, a humpback whale who errantly entered San Francisco Bay.
Human migrations also happen on a large scale, in history and in modern times. Seasonal human migration is very common in agricultural cycles.
In population genetics and evolutionary biology, gene flow describes to migration's effect on the genetic makeup of the population migrated into.
In archaeology, migrationism describes an interpretative framework where all major cultural changes are explained by large-scale movements of people.
Modern transport, particularly the volume and speed of air transport has facilitated the rapid migration of bacteria and viruses which cause diseases. One of the earliest examples is the infamous plague epidemics or "Black Death" which arrived in Europe along trade routes via the Middle East from the Orient. More recently, virulent strains of influenza and AIDS.
The term "migration" may also be applied to the movement of non-living things:
* In geophysics, migration is a process which keeps in account the correct positions of samples in sections with dipping reflectors and structural complexity.
* A piercing migration is said to occur when a piece of body jewelry, during or after healing, shifts or is rejected by the body.
* In control systems when a set of instructions or programs, i.e. PLC (programmable logic controller) programs, are moved from an old platform to a new. In this way the needed reengineering can be kept to a minimum.
* In computer clusters, process migration refers to what happens when one instance of a program is being moved from one of the cluster computers to another.
an invasion is a military action consisting of armed forces of one geopolitical entity entering territory controlled by another such entity, generally with the objective of conquering territory, or altering the established government. An invasion can be the cause of a war, it can be used as a part of a larger strategy to end a war, or it can constitute an entire war in itself.
The term usually connotes a strategic endeavor of substantial magnitude; because the goals of an invasion are usually large-scale and long-term, a sizeable force is needed to hold territory, and protect the interests of the invading entity. Smaller-scale, tactical cross-border actions, such as skirmishes, sorties, raids, infiltrations or guerrilla warfare, are not generally considered invasions. Because an invasion is, by definition, an attack from outside forces, rebellions, civil wars, coups d'état, and internal acts of democide or other acts of oppression, are not considered invasions.
Although human migration has existed for hundreds of thousands of years, immigration in the modern sense refers to movement of people from one nation-state to another, where they are not citizens. Immigration implies long-term permanent residence (and often eventual citizenship) by the immigrants: tourists and short-term visitors are not considered immigrants (see expatriates). However, seasonal labour migration (typically for periods of less than a year) is often treated as a form of immigration. The global volume of immigration is high in absolute terms, but low in relative terms. The UN estimated 190 million international migrants in 2005, about 3% of global population. The other 97% still live in the state in which they were born, or its successor state.
The modern idea of immigration is related to the development, especially in the 19th century, of nation-states with clear citizenship criteria, passports, permanent border controls, and nationality law. Citizenship of a nation-state confers an inalienable right of residence in that state, but residence of immigrants is subject to conditions set by immigration law. The nation-state made immigration a political issue: by definition it is the homeland of a nation defined by shared ethnicity and/or culture, and in most cases immigrants have a different ethnicity and culture. This has led to social tensions, xenophobia, and conflicts about national identity, in many developed countries.
Well I immigrated with my family,ducks migrate every year and Bush invaded Iraq with a little bit of help from his friends
THE AMERICAN WAY!!!!!!!!
The immigration information post by website user , MyTend.com not guarantee correctness