Learning about Life from a Molecule

A few months ago, the Canadian Museum of Nature’s DNA research lab was moved into a new and expanded space and renamed the Laboratory of Molecular Biodiversity.

View of the lab.

Lab users work at these benches to determine the DNA codes of plants and animals. The multi-step process starts by isolating DNA from cells of the study organism. Image: Roger Bull © Canadian Museum of Nature

What does molecular biodiversity mean? And why does a museum need a lab dedicated to studying DNA? To shed some light on these questions, we’ll start by considering your very own DNA molecules.

You can think of your DNA as an instruction book on how to make you, organ by organ, from head to toe: hair, eyeballs, nose, kidneys, knee joints, feet and all.

Instead of the instructions being spelled out with letters like in a normal book, DNA instructions are spelled out using four molecules: adenine (A), cytosine (C), guanine (G) and thymine (T).

The letters A, C, G and T and a model of DNA are displayed in the lab.

Your complete DNA instructions are about 3 billion molecules long: a giant string of As, Cs, Gs and Ts that is all packed into each nucleus of the cells that make up your body! Image: Roger Bull © Canadian Museum of Nature

And this applies not just to you but to all living things: from a microscopic single-celled alga to a tall pine tree, from a honey bee to a bowhead whale. The diversity of living things (or biodiversity) on planet Earth is spelled out in the four-molecule code of DNA.

The molecular biodiversity—simply the variety in the DNA codes in living organisms—that we see today is a result of a long history of change since the start of life on Earth about 3.5 billion years ago. DNA codes are passed from one generation to the next and through time they have changed due to several forces such as mutation and selection, the separation and extinction of populations, and a good dose of random chance. This has resulted in the species that are alive today and signals from this evolutionary journey remain in the DNA codes of today’s organisms.

Pipettes and other instruments on a work surface in the lab.

The biochemical reactions used in the lab are on a micro scale. These pipettes are used to precisely measure very small liquid volumes. Image: Roger Bull © Canadian Museum of Nature

Given what it can tell us about the diversity of life and the process of evolution, DNA is an important tool in understanding nature. Because of this, a laboratory dedicated to studying DNA fits right in at the Canadian Museum of Nature, a research institution with the goal of increasing knowledge of the natural world.

In our Laboratory of Molecular Biodiversity, staff, students and volunteers use the tools and techniques of molecular biology to reach into the cells of plants and animals and read the DNA codes within.

A man poses at a lab counter.

Michel Paradis, a volunteer who has worked in the lab for 15 years, stands beside a thermal cycler. Thermal cyclers control the temperature of reactions that replicate DNA. This is an important step in determining the DNA code. Image: Roger Bull © Canadian Museum of Nature

By determining the DNA codes for many different organisms and then comparing them through computer analyses, we can answer questions such as

  • Which groups of organisms should be considered unique species?
  • How are different species related to one another?
  • Which populations are on a path towards evolving into new species?
  • What evolutionary paths have led to Earth’s current species diversity?
Computer screens showing DNA data.

Once the lab work is done, the computer work begins. Analysis of DNA data is complex and requires computers and specialized statistical software to rigorously compare the DNA codes of multiple individuals and species. Image: Roger Bull © Canadian Museum of Nature

With the expansion of our molecular biodiversity lab, we’ve increased our ability to answer questions such as these which are fundamental to understanding the patterns of life on Earth. And all of this simply by figuring out the order of As, Cs, Gs and Ts in the DNA molecules of living things.

Letters to colour: I [heart] My DNA.

Valentine’s Day is coming up: celebrate the day and your DNA by printing out this “I Love My DNA” colouring page. Without your DNA, there would be no you! Image: Roger Bull © Canadian Museum of Nature

This entry was posted in Research, Species Discovery and Change, Tools of the trade and tagged , , , , . Bookmark the permalink.

One Response to Learning about Life from a Molecule

  1. Pingback: My Visit to a New York City Basement | Canadian Museum of Nature – Blog

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