According to Department of environment of Australian Government an invasive species is a species that occurs, resulted by human activities, beyond its distribution threatening valued environmental, agricultural or social. Richardson et. al (2000) defines introduction as meaning that the species has been transported by humans across a major geographical barrier and invasion requires that this species produces reproductive offspring in distant sites from introduction.
 |
| Figure 1 - Cane toad, considered one of the biggest threats to native Species in Australia. |
Cane toads have becoming completely adapted to rainforest and environments where it was introduced. It is considered an invasive species because of the damage caused in native species and it is subject of hate by native population. Why this species that became totally adapted to a new environment should be destroyed as defended by some people? (Just to be clear: The species control is important and the Australian government do it well, despite being a way to fix a mistake committed by themselves).
Following the idea of invasive species as threatening species to environmental area and the production of reproductive offspring in distant sites. Would be humans an invasive species? or the idea of Invasive Species should always be related to humans dispersion? isn't it an egocentric vision?
 |
| Figure 2 - Human migration. |
This map uses the terminology migration for human, even humans have had destroyed the environment wherever they went. The concept of invasive species is controversial related always to a vision where humans are on the outside. There is a big distance or a wall between Homo sapiens and the nature that shouldn't exist.
Last but not least, a video about awareness which bring the idea of Humans as invasive that destroy the nature but could do different:
Works used:
Colautti, R., & MacIsaac, H. (2004, March). A neutral terminology to define ‘invasive’ species. Diversity and Distributions, 10, 135-141.
Environment, D.
(2014, May 17). Invasive Species. Retrieved from Australian Government:
http://www.environment.gov.au/topics/biodiversity/invasive-species/
Richardson, D. M., Pyšek, P., Rejmánek, M., G., B. m., F.D., P., & C.J., W. (2000, March). Naturalization and invasion of alien plants: concepts and definitions. Diversity and Distributions, 6, 93-107.
That is an interesting question – are humans invasives? Also, a poignant video. You raise some interesting questions. I am curious about when invasives are no longer considered invasives. You raised this as a question, so I was just wondering what your thoughts are on the subject?
ReplyDeleteAbout this question about become no longer invasive, Rchardson et al. (2000) suggest that there are three phases (related to plants):
Delete1. INTRODUCTION. As a result of dispersal, propagules … arrive at a site beyond their previous
geographical range and establish populations of adult plants.
2. COLONIZATION. The plants in the founding population reproduce and increase in number to form a colony that is self-perpetuating.
3. NATURALIZATION. The species establishes new self-perpetuating populations, undergoes widespread dispersal and becomes incorporated within the resident flora.
About my thoughts on this subject:
DeleteI think that the biological sciences will never be able to develop in its pure concepts while the political and economical areas are interfering. Now, we have misconceptions because of the influence of this area.
If we think well, the term "invasive species" is related directly to "gain" (in its capitalist essence) as well as many other.
So, while biology does not become detached of these political/ capitalist precepts, our knowledge will never be purely biological.