Do Plants & Animals Hitchhike? Do hitchhikers invade? A short answer for Anekeia

I want to thank Anekeia for taking the time to point out these metaphoric challenges.  I am delighted to answer.  I look forward to more comments and hope you have something to say:

Anekeia has left a new comment on your post "Invasive species are all around us": 



    "An interesting perspective, more thoughtful than many. But the metaphor seems mixed. Do hitchhikers invade?" 


The word invasion comes from two words in Latin: IN meaning into and the verb VADO VADERE INVASI INVASUM meaning to go and in the past with past forms - to go into, Hence invade is simply the action of going in (without invitation I suppose). In English the word comes with a pejorative sense related to military, cultural or economic actions that have a negative consequence for the receiver of the invasion.

 

    " Do plants and animals hitchhike?" 


Yes the metaphor could be tightened; yes hitchhiking strictly speaking based upon current usage has a sense of intent.  Better might be the insertion of "accidental or unintentional hitchhiker".



    " Either action seems to require some kind of intention, and a sense that there is somewhere to be besides here. It must be a more desirable place for a hitchhiker to want to visit or inhabit. It must be a place worth the risk of conquering by an invader. If awareness or intention are lacking, they are abductees or castaways rather than hitchhikers or invaders. And what invader invades by reproducing? " 


Here is where the analogies may have failed for I anthropomorphized the actions of non human species, I gave them human perspectives, intentions and agency in my choice of words. Anekeia correctly notes that invasion is a human activity in its basic sense though metaphoric use should let me use it with inanimate object such as the solar system was invaded by a new comet or the sterile operating room was invaded with dust particles. On the other hand hitchhiking at the root is a human activity and therefore my metaphor at best seems to have been a poor attempt at rhetorical, poetical liberty.


 
Strictly speak, geophysical processes such as water currents and wind, As well as other organisms, may provide a platform or vector that serves as a pathway for the transportation of the non indigenous from one ecological system to the next. In our current use of the term invasive species, we carefully define the method of movement as one due to human agency. Therefore non indigenous species are transported by human activities including the platforms and vectors of trade and commerce as well as simple human movement from one ecosystem to another. For a species to be invasive there is no need for intent as accidental introductions are possible and common.



Anekeia has correctly identified a key problem in the definition(s) of invasive species. The use of the word invasive itself is loaded with centuries of contextual meaning that colors the conversation before it starts. As a note even the word species has problems, but that is another post.