My mom and I were watching TV today and she told me to turn off the Crocodile Hunter because she doesn’t like it. Ok, big deal. Then she asked “where do crocs fit on the food chain? What is their purpose?”
So what IS the purpose of crocodiles - and aligators, too. Is it just to keep the mamal/fish population down? Do they do anything special to the ecology of the place in which they live?
I guess we could ask this question about a lot of animals (mosquitoes, starlings, earwigs, etc) but I guess since my mom asked about this specific animal, I might as well ask y’all
What d’ya mean “So what IS the purpose of crocodiles.” If you’re a fundie they’re here for us to use or do whatever we like. Otherwise, you seemed to come close with the part that we could just as easily ask what any animal (including humans) are for. If you like an answer like they keep populations x, y and z down, then what is the purpose of x, y, andz except maybe to give crocs something to eat?
Any purpose you give is just a construct of values you impose. They just are. You could just as easily ask what purpose the moon serves.
Let’s take the mosquito. God created the “creepy crawlies,” including mosquitos. He created them so that they lived on blood. So he had to create blood and He needed something to keep the blood fresh for the mosquitos. So He created humans (and of course other creatures with blood) to keep the mosquitos’ food from spoiling until they were ready to use it.
Ecosystems tend to be divided up into “predator” and “prey”. Crocodiles are predators.
So they perform the same function as lions out on the Serengeti Plains–they weed out the diseased, the elderly, the generally unfit, only they do it in a swamp instead of on the Serengeti.
Their “weeding-out” duties would include turtles, fish, waterbirds, animals that come down to drink, the occasional annoying Australian TV host…
Crocodilians fill a critical, functional niche in the aquatic systems they occupy. They are top predators in these systems, thereby influencing several trophic levels below them as they go through a 3-5 order of magnitude increase in body size. Crocodilians are implicated in positive effects on their environments as keystone species that maintain ecosystem structure and function by their activities. These activities include selective predation on fish and aquatic invertebrates, the recycling of nutrients and the maintenance of wet refugia during periods of drought (Thorbjarnarson, 1992)
I know this is a standard reply, but it bothers me some. For example, the “unfit” are unfit in an environment that includes predators. If there were no predators there would still be “unfit” creatures but it would be different kind of unfitness.
There isn’t any real purpose in weeding out the diseased, the elderly and the generally unfit. Disease will take care of the diseased, old age will eliminate the elderly and bacteria will dispose of the remains. The unfit will probably not get much of a chance to pass on their genes because of breeding competition.
The idea of “keeping the herd fitter” seems to me to be a human value about which nature doesn’t really give a damn. If an individual deer survives long enough to reproduce and is able to do that, it makes no difference whether or not it is as “fit” as it could have been had it been chased around by a predator now and then.
The crocodile is here, just like everything else, because there was an unfilled environmental niche at some point in time and the antecedents of crocodiles filled it. If not the croc then something else would have done it.
Agreed. Crocodiles, in their ecological role as predators, simply act as but one part of the overall “environment” which other animals in the area have to contend (just as all other organisms are, regardless of their ecological role). If anything, like any other animal, they are but ecological placeholders: if not crocodiles, some other animal would likely occupy that niche. That that niche exists at all is simply because it is a viable means of allowing whatever animal that occupies it to further its own species; it is not there to maintain or regulate the fitness of other species.
Crocodiles are here because at some point in the past, a different animal slowly turned into what we now know as the crocodile. Both these animals - the crocodile’s ancestors and the crocodile itself - were able to survive in the wild, thus they did survive.
The ‘purpose’ of them today is to continue to survive and, as pointed out by MEBuckner, to continue propagate the species.
This sounds like quite a pompous answer so far. However, Lady Evolution doesn’t create animals with a specific purpose in mind: if the animal can survive, it does so.
Thanks all, you have answered my question (in a few different ways). I suppose you will continue to argue amongst yourself until you find out the “right” answer
A duty in which crocodiles are seriously failing. Is there any way to impose some sort of sanction on them until they pick up their act in this respect? No plump juicy 'Merkin tourists for dinner (only eel) until they’ve weeded out at least one host, maybe?
