Leaps and bounds as Life evolved
It was the natural next step after exploring the world of atoms, molecules and elements to proceed into the evolution of life in the four billion year long history of the planet. The essential chemical reactions were skipped for the next session due to more immediate semester requirements of biology.
But not before the class was taken through a mind-boggling journey down the billion and million concepts. Kshama explained how it takes 12 days to add up 1 million seconds and 33 years to make 1 billion seconds. She also gave another example using the number of letters in a book to drive home the stupendous scale of million and billion.
Taking over the class Geetha Arvind then traced the billion years of evolution of life from nucleic acids to the 1.9 million species on the planet today. She took the class of 40 teachers through the various eras and periods and the life forms that put in an appearance, sometimes disappeared and at times flourished.
Beginning with single-celled prokaryotic cells like bacteria 3.8 bn years ago and the start of photosynthesis to multicellular life a billion years later, to fish, amphibians, reptiles, birds, dinosaurs and then the mammals 200 million years ago, to finally primates, apes, great apes and finally humans, gorillas and chimps, the class heard about Proterozoic era, Paleozoic era, Mesozoic era to the present Cenozoic era and the various periods they were further classified into.
At the end of the session, a participant quipped, “What will we evolve into next?” while another curious one wanted to check if what he heard on TV was correct – that humans evolved from pigs and this has been a well kept secret!
From humans, the class then went on to learn about cells, tissues, organs and various systems. Here they saw how every system in the body is interconnected and works in tandem. The vital processes of diffusion, osmosis and active transport were demonstrated using illustrations and experiments.
Bhama Sridharan was ready with potatoes, some cooked and some raw, a few spoons of salt and sugar and water. Osmosis was demonstrated in the uncooked ones with salt or sugar, showing how water moves up to equalize the concentration of the solvent above and below.
The class ended in another session on Mathematics with Kshama developing an algebraic expression for number of sticks used in pictures of increasing number of squares. The participants then learnt to frame algebraic expressions for rectangles drawn on a sheet marked with evenly/unevenly spaced dots.
Both a pre-test and post-test was conducted before and after the class, as also the 10 minute breathing-based meditation. Assignments given after the first session were collected for evaluation and the teachers quizzed on how many had implemented the learnings at school for Class 5. Barring a couple of them who could not use it as they were handling class 6 or 7, most others expressed satisfaction with their lessons. “I was able to teach without the text book” “I was able to explain the concept first and then give names of definition” “I felt more confident now” “The masala dosa game for factors and multiples was a big hit with children”…. went the feedback.