Predicting the Evolution of a Modern Horse's Descendant
Most equine (horse) breeds have been selectively bred for specific features, such as speed in race
horses. Like all other species on the planet, the horse has undergone changes as a result of natural
selection. A modern example is the breed of horses living on Sable Island. Sable Island is about 150 km
east of Nova Scotia. About 250 years ago, records show that several horses that looked like the horse in
the first photograph were released onto the island. Although some historians have offered
explanations, exactly why the horses were released there remains a mystery. Today the horses on Sable
Island look very different, as shown in the second photograph. The original horse breed released on
Sable Island was a product of selective breeding. In this project, you will use your understanding of
evolution to predict what a descendant of another modern horse breed might look like in the future,
without human interference.
How might one breed of modern horse evolve if the breed were to exist in the wild, without interaction with
humans?
1) Research the evolution of horses from roughly 50 million years ago (Hyracotherium) to the present (Equus).
Look for three changes (e.g. body size, foot structure, teeth colour) describe what changed and why .
2) Choose a modern breed of horse, as well as three of the breed adaptations (e.g. body size, foot structure, teeth
shape and colour). You will use these adaptations to predict the evolutionary changes that your breed of horse
might undergo in an environment isolated from humans.
3) Choose an isolated geographical area for your horse breed. Consider the initial number of horses, food sources,
predators, and other species competing for food. Record the geographical and climate conditions of the area you
choose.
4) Decide on an evolutionary time period (several centuries to several eons). Take into account the possible effects
of natural selection as well as genetic changes over time on the evolution of the horse breed you have chosen.
Carousel presentation in class on Tuesday December 10th