Workshop on Classification of Animal Kingdom

The desire to learn something arises out of curiosity or the necessity to know something. How to kindle the desire in students to organise the incredible variety of organisms? By making them aware of the vast variety of living beings around them which are similar to each other in some ways and yet unique. This vastness of living beings brings out a sense of wonder in students which in turn generates curiosity and awe towards the wonderful natural world.

A workshop on the Animal Kingdom was conducted on 25 Aug 2018 at Villianur ERC. The session began with the observation of specimens collected from – Veerampattinam, Thengaithittu, Serenity beaches. Such specimens can be preserved for use in the biology labs at school.

Teachers raised a concern that although the basis of all classification is grouping similar organisms together, the greatest challenge is helping students remember the naming convention.

Remembering the scientific names with ease

It was shared that the scientific nomenclature of most organisms begins or ends with Latin/Greek root words. If the meaning of the root words of the nomenclature are known, associating it with the context becomes very easy.

History of Classification

Today we have lot of genetic information to help us classify organisms but previously, there were only morphological and reproductive traits based on which they were categorised. Here is an interesting video that describes the basics of history of classification - https://www.shapeoflife.org/video/taxonomy. Aristotle began classifying based on the internal and external traits of organisms, followed by Carolus Linnaeus who introduced the standard convention of naming organisms using genus and species. This was done under the assumption that living beings are perfect and unchangeable organisms. Charles Darwin with his theory of evolution completely changed the view by showing that species can actually change over time. This also implied that a single common ancestor might have branched into billions of varieties of living organisms that we see today.

Living beings – A wonder!

It is a wonder to even explore the simplest unicellular organism amoeba which is classified under the Kingdom Protista.  Does digestion occur in an amoeba? If not, how does an amoeba derive energy without digestion? Can digestion happen even without the digestive system? Questions like these can kindle a sense of wonder in students.

What is an animal?

It is a general conception that animals are creatures that can move, feed themselves, reproduce and care for their young. But what could have been the first animal on earth? Would it have been complex? Did it have a nervous system, limbs and brain? If it didn’t have any of these, what makes these animals?

The Sponges: Origins (https://www.shapeoflife.org/video/sponges-origins)

A common question among students is that if sponge is an animal without a mouth, how does it feed itself? Here is a great video resource that shows how the apparently lifeless looking sponge dynamically pumps water to feed itself. The sponge cell’s regenerating capacity and the communication between the cells that enables them to work together creates an awe and wonder towards these simple looking creatures.

Cnidarians: Life on the move

(https://www.shapeoflife.org/video/cnidarians-life-move)

This video shows that cnidarians could have been the first animals with a mouth like structure and an incomplete digestive system. Due to evolution cnidarians developed muscles and nerves for the first time. With muscles that enable them to bend and the nerve cells that help in controlling the contraction of these muscles, making them probably the first predators on the planet. The cnidarian with its tentacles, hunting a far more evolved creature like a fish is a sight to watch!

A natural question aroused in the discussion. If the cnidarians were indeed the first animals that existed before the swimming animals appeared, what could have the cnidarians predated upon back then? Were they just digesting microorganisms? Maybe, the cnidarians developed tentacles with toxins much later because of adaption for the sake of survival. The stationary cnidarians could have evolved into the well-known swimming jelly fish for the sake of food. We can only speculate on how the evolution might have occurred. All that we see today are creatures that have adapted based on the needs of the current environment.

Flatworms: The first hunter (https://www.shapeoflife.org/video/flatworms-first-hunter)

The need to capture food with ease led to the next level of evolution. Flatworms might have been the first animals with stereo senses to accurately locate the direction and position of its prey. Be it the development of a central nervous system or internal fertilisation, this creature has so many similarities to the way human body is designed. There is an interesting section in the video where the sexually dimorphic (having male and female reproductive organs in the same organism) flatworms get into a fight. Here sex is more like a war! The losing worm carries the burden of motherhood.

Evolution is dependent on the Animal’s need for – Food, shelter and mate

Here are the video resources of the other phyla –

Evolution of Reproductive systems

Not just the morphological features, even the reproductive systems have been evolving to ensure survival of the species. This progress has been driven by the need to safely store the eggs – from out in the open waters >> inside the shell >> dug into shores >> placed on top of the tree >> located within the body.

Taking these to the classroom

In the classroom, introducing animal classification by describing its structure might not kindle the interest of students. The presence of each structure and adaptation in an animal has a special reason. If students are guided to explore the living organisms on this perspective, animal classification can be far more exciting for them.