Around 4,000 years ago, on the wind-swept island of St. Kilda, Scotland, people started creating a food storage of sorts. They moved a population of sheep to the island, likely as a back-up food resource for when times were tough. Little did they know that their actions would affect 21st century science. Today, rather than ending up as a meal, sheep from this isolated population are the subjects of research on immune function. Ecologist Andrea Graham takes Dr. Biology on a trip of exploration through the dangerous cliffs, windy conditions, and wormy world that the Soay sheep deal with on St. Kilda.

If you could travel back in time what would you find 50 million years ago? What was the climate like? Would you find the same plants? What animals were crawling, walking, and flying around? Paleoentomologist Bruce Archibald takes Dr. Biology back in time to explore the planet during the Eocene Epoch where things were a bit different than today – there was even a giant flying ant that would make anyone look twice.

Remember your last paper cut, or the bad cold that had you coughing and blowing your nose? It was your immune system that was busy trying to make you better by battling the bacteria or virus that was attacking your body. How your immune system works is the discussion Dr. Biology has with pediatrician Paul Turke. They also talk about how our immune systems have to reboot to keep up with evolving bacteria and viruses.

According to an old German proverb the animal that is the subject of this show was made by the devil. Dr. Biology gets a lesson about this devilish study subject from biologist Raghavendra Gadagkar. They talk about what he has learned from years of observing these misunderstood animals. There is even a surprise ending that we call the 'Queen Switcharoo'.