One reason for misconceptions and myths about organic evolution is that the human mind is not able to comprehend a timescale that spans millions of years. Very often we hear even educated people say, “If humans came from a monkey, then why do we still have monkeys?” or “Why are the apes not turning into humans now?”. This inaccurate thinking is the result of the presumption that evolution is linear, and its unit is an individual.
As an educator, it is not difficult to understand why is it difficult to comprehend that small variations which accumulate throughout millions of years result in the origin of new species.
Charles Darwin could not explain how variation arose (arrival of the fittest) and even today the public perception of this remains blurred. Variations have been famously called the raw material for evolution. So, what are variations? In simplest terms variation can be defined as “differences between the members of the same species which arise due to shuffling of genes”.
Interestingly, Darwin, who was Gregor Mendel’s contemporary, had not read of his work on Pea plants (it remained unrecognised till 1900!). Not aware of the mechanism of how traits are transferred from parents to offspring Darwin was unable to explain how variations arise.
Today, we know that the shuffling of the genes during crossing over happens during Meiosis. Meiosis is a clever cell division that takes place exclusively to produce sex cells. This contrasts with Mitosis, which produces identical daughter cells with the same number of chromosomes as the mother cell. It is like photocopying a cell. These identical daughter cells grow and repair almost all parts of our body. But it is in meiosis that something very ingenious happens, the chromosomes elegantly exchange segments of the chromatin fibre. This happens very precisely and most elegantly. This recombination of the genes produces immense genetic diversity. Thanks to meiosis, every sperm is genetically different. Imagine a 100 million possibilities!
Darwin’s theory of natural selection is not just well accepted but the ability to evolve is an essential qualification for something to qualify as living. The reason for so many misconceptions around this topic can also be attributed to faulty teaching and logical fallacies in pedagogical methods. Teachers often do not give examples outside the textbook or site examples of variation in their immediate environment. The textbooks used in schools do not update and include new researches and breakthrough in the scientific world. Most often just teaching from an “examination point of view” takes its toll. Students rote learn to answer the most probable questions in the examination and move to the next level. Often the difference between Lamarckism (which has made a comeback as epigenetics) and Darwinism are not brought out clearly.
More often than not evolution is misrepresented in popular culture. It is projected to show as if natural selection functions with certainty and perfection, and has a goal. Evolutionary processes are not perfect. Mutation, migration, and genetic drift — all play an important role in the origin of species. Natural selection acts like the admission officer who decides who goes in. It is the engine that drives evolution.
Understanding organic evolution and its mechanisms lies at the heart of Biology. It is like a unifying mechanism that ties the concepts and observations in ecology, physiology, animal behaviour, taxonomy, genetics etc. Only when viewed from the evolutionary lens, biological processes make sense. For this reason, organic evolution needs to be introduced early in schools and taught incrementally in each grade. Once the evolutionary process is understood well, biology becomes an exploratory discipline – a vehicle to understand the diverse ways of living, thriving and multiplying.
Richa Joshi Pant has been a teacher for 20+ years. She is presently in Welham Girls’ School in Dehradun. She loves the involvement and interaction with young adults that come with her job. She gets to see how cultural changes happen in each generation. She uses theatre as a modality to teach adolescents Biology.
Featured image: Hulki Okan Tabak / Unsplash