Complex Animals
The word animal comes from the Latin word ‘anima’ meaning spirit. One might find it funny how the Romans 2,000 years ago had a better grasp of the complex nature of animals, compared to how many think they are simple machines today. Consider bugs. I’ve heard so many times that insects are just like tiny emotionless robots. Yet even they are surprisingly complex, here are just a few examples of their complexity.
The common myth of “oh they can’t feel it, they are just insects” is simply not true. Insects have a nervous system where nerve cells send electrical impulses to a neurotransmitter. They also have neurosecretory cells, they are a hybrid of neurons and endocrine glands. When it comes to hormones have not only do they have multiple hormones but they have so many scientists have classified them into different types of hormones like prothoracicotropic, ecdysteroids, juvenile, and other neuropeptides.1
Insects have a sensory organ called chordotonal organs. These are only found in insects and crustaceans. 5 They are complex organs found throughout the body. They can detect mechanical stimuli (position and movement), sounds, temperature, and the circadian clock 2,5. They can harbor just one sensory neuron, such as in the tympanal ear of a notodontid moth, or up to several thousand sensory neurons, such as in the antennal ears of a male mosquito.”5
The Manduca Sexta Moth develops new sensory organs during metamorphosis. When they turn into adults they grow an array of sensilla on their legs. Includes two classes of innervated hairs, innervated spines, and three classes of multiply innervated sensilla. They also have chordotonal organs, subgenual organs, and multipolar joint receptors. 3 All these receptors allow the moth to gather a ton of information from its surrounding environment. They probably detect things that we have no idea are going on.
Still, think insects don’t have much going on?
Then let’s talk about a mosquito. Not the whole mosquito just its antenna. In just the antenna alone it has many sensory organs, we are going to talk about just two types. The sensilla trichoidea and sensilla basiconica;. after a study, it seems likely that sensilla trichoidea senses attractive odors, and sensilla basiconica senses repellent odors. On top of that, they have other setae that have a whole other set of functions that we aren’t going to talk about today. All that just in the tip of an extremity of a tiny little insect. 4
The best part is that we are still learning more. they may be even more complex and we just don’t know it. Every single day scientists discover more about the wonderful world around us and prove how we underestimated it the day before.
2https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/jemt.20051
3https://link.springer.com/article/10.1007/BF00318442
4https://cdnsciencepub.com/doi/abs/10.1139/z63-030
5 https://www.cell.com/current-biology/pdf/S0960-9822(13)00350-3.pdf
