Question

On Long Island, New York, a population of wall lizards that originated from a group in Italy is present. Several had been imported to be sold as pets many decades ago, and some escaped and started a new population in this suburban area. What concept applies to this situation?

Answer 1

Answer:

Two terms might apply for this situation: "jump dispersion" and "human-assisted invasions".

Explanation:

• Dispersion: It refers to the change in an organism's range or distribution area. Different ecological and biogeographical processes might be involved in organisms' dispersion. The term "jump dispersion" refers to a few individuals in a short time that can cross a barrier and occupy a new area. In this situation, the establishment is not always for sure. For this to happen, they must reproduce and start a new population of a certain size that can survive to the new conditions.

• Biologic Invasions: It refers to new species that establish in a new area far or out of their original distribution range. Once established, these species might be considered exotic or invasive, according to their reproductive rate, population growth, and interaction with native species. Biologic invasions are natural processes, that occur in small groups of individuals that can expand to other ecosystems, and the appearing or despairing of barriers promotes their expansion.  But these biologic invasions have accelerated by human beings, referring to this as "human-assisted invasions". These are the cases in which men transport species from one place to the other for different uses or purposes.

It is very common for these species to scape and start new populations in the new area, where they have less environmental pressure -fewer predators, more resources, better nitches- than in their origin area, which favors their establishment.

The exposed situation in the example is a case of "human-assisted invasions". It might also be considered as jump dispersion (because a few individuals of the species crossed a barrier and established in a new area) but assisted by humans.