“Is learning science relevant to my life?”

Dear student,

Today in the chemistry lab, you asked me a question that every teacher dreads facing the most: “How is this relevant to my life?” I thought it was an excellent question but did not have an appropriate answer that could convince you. After all, why is knowing the use of phenolphthalein indicator in an acid-base titration any important to your life? As a student myself, I completely understand how you feel and have also wondered about the ‘big purpose of it all’ many times.

First, I told you how this particular concept could help you in the higher-level chemistry courses you may take in the future. You said that you were merely fulfilling a credit requirement and had no intention of taking any other chemistry course ever. This is why I am motivated to write to you today. Not to make you sign up for all the science classes, but to make you understand how any of this may add to your growth as a student, and most importantly, as a learner.

The way I see it, nothing we learn in our lives ever goes waste. The key is to stop looking for specific answers for every question and to start enjoying the learning process! To be blunt and brutally honest, no, not everything we learn is applicable to the modern world that we live in today. As you mentioned in our conversation, we can look up almost everything on the internet within seconds. What’s the point of memorising the elements in a periodic table or remembering their atomic masses? With the increasing use of technology and its easy accessibility, our brain cells are on their way to a vacation forever. This does not mean we should become robots for the rest of the years at school. What I am saying is that we need to be able to connect the dots and ask the right questions in order to make sense of everything. The point of science is to have practical approach towards things and cultivate critical thinking in everyday life.

Let me give you an example. Today you said, “What I learnt was simply to turn some solution pink and that’s it.” Well, I wanted you to ask, “Why did the acid turn pink in the presence of base and indicator? What happened to the molecules in the solution? Why didn’t this reaction work with other indicators?” You see, the point is not to know the answer to all these questions, but to simply ask these questions in the first place.

Learning science gives us a new perspective into the world we live in. Learning science may not directly affect our day-to-day activities, but it influences the way we approach and handle different situations. Science clears the emotional sensitive cloud that surrounds the vulnerable human mind and makes room for rational thinking. It is said that as humans grow older, we lose the will to learn new things and maintain a curious mind. Learning science ensures that a part of us never ceases to be a child ever again.

I hope this made sense to you and encouraged you to open up to learning science, even if that includes learning how to balance chemical equations.

Priya.

How Genetics can help rescue endangered species – Case of the whale sharks

Whale sharks are the largest fish in the ocean and are about eighteen to twenty meters long. They weigh around twenty tons and can live up to a hundred years. Though normally pelagic animals, whale sharks are seen in large feeding aggregations in certain parts of the tropical and warm temperate zones around the world, like the Gulf of Mexico and the Indian Ocean. They are known to consume twenty kilograms of food per day that mainly includes plankton, small fish, crustaceans, and coral spawn1.

Source: Wikiemedia Commons
Credit: Courtesy of Wikimedia Commons

The decreasing number and size of whale sharks at some aggregations suggests the species may be declining2. While they are protected in many parts of their range, whale sharks are fished legally and illegally for food (especially for their fins in the Asian markets) and medicinal purposes. Their slow growth and late maturation (when they are 25-30 years old) prevents them from being recovered from over-fishing or habitat disruption.

Whale Shark Habitat Around the Globe. Source: Wikimedia Commons
Whale Shark Habitat Around the Globe. Credit: Courtesy of Wikimedia Commons

Genetic analysis can tell us about whale shark migratory behaviour, social structure and breeding habits. The genetic drift between their populations can help us study the gene flow and interbreeding.  A key question for whale shark conservation is whether the fish aggregations represent isolated populations, or whether whale sharks are migratory and comprise a single global population.

The highly polymorphic microsatellite DNA sequences undergo frequent mutations over time and aid in understanding the population genetics of the species. These mutations are passed on to the offspring and thus provide great resolution for studying the variation and differentiation between populations. The degree of relatedness between different whale shark groups tells us about their migration and breeding patterns (closely related species have similar genetic sequences). For their research, Dr. Schmidt and her colleagues at UIC tagged the satellite sequences to pool the whale shark samples geographically into Pacific Ocean animals, Atlantic Ocean animals and Indian Ocean animals for analysis3. Polymerase Chain Reaction (PCR) was used to amplify and analyse DNA sequences and Principle Components Analysis (PCA) was done to examine the population differentiation. Through DNA analysis of 68 whale sharks from 11 locations, it was shown that the species found in different locations were in fact, quite similar. The little genetic variation among populations confirmed the migratory behaviour and interbreeding among populations. These results further calls for more stringent conservation plans to protect the big fish of the ocean.

As to this day, whale sharks mating has never been observed. The location of their mating is not known either. None of them have been observed giving birth and very young whale sharks are rarely seen. These facts pose a lot of questions regarding the whale shark reproduction. In 1995, a litter of more than 300 whale shark embryos were found inside of a captured female animal at Taiwan5 (the only pregnant female whale shark ever studied scientifically) which suggested that whale sharks are ovoviviparous animals i.e., they give birth to live young that hatch from eggs within the uterus. Paternity analysis through DNA fingerprinting suggested that a single male fathered all the embryos4. Since multiple paternities is common in many shark species, genetics could be used to determine whether the embryos were sired by a single male or multiple males.

The ability to use genetic analysis to study the whale shark behaviour, population and breeding patterns can help us design appropriate tools for their conservation across the oceans. Conservation genetics is an important tool and should lead the way for rescuing many other endangered species around the globe.

Sources:

  1. World Wildlife Org –  http://worldwildlife.org/species/whale-shark
  2. Whale Shark (Rhincodon typus) Issues Paper by The Department of the Environment and Heritage, May 2005, Australian Government – http://www.environment.gov.au/node/15909
  3. Schmidt J.V., Schmidt C.L., Ozer F., Ernst R.E., Feldheim K.A., Ashley M.V., Levine M. (2009) Low genetic differentiation across three major ocean populations of the whale shark, Rhincodon typus. PLoS One, 4:e4988.
  4. Schmidt J.V., Chien C.C., Sheikh S.I., Meekan M.G., Norman B.M. and Joung S.J. (2010) Paternity analysis in a litter of whale shark embryos. Endangered Species Research, Vol 12: 117-124.
  5. Over 300 embryos found in pregnant whale shark – http://www.theepochtimes.com/n2/science/over-300-embryos-found-in-pregnant-whale-shark-41759.html