A contagious cancer wiped out large portions of the Tasmanian devil population, leaving a few survivors with genetic resistance—those individuals have begun repopulating the area.

Island Foxes on California’s Channel Islands have several islands that were colonized by small groups that migrated to them and have unique traits on each island

In certain areas of Costa Rica, hummingbirds have developed beak shapes that perfectly match the curvature of local Heliconia flowers. Birds with the best fit get the most nectar—and reproduce more.

On lava flows in the southwestern U.S., dark-colored rock pocket mice became more common than light-colored ones due to camouflage and predator pressure.

In Nevada, isolated desert tortoise populations became genetically distinct simply because of distance and a lack of movement between regions—no environmental pressure, just separation.

Hunters over-harvest a fish population, leaving just a few fish with rare striping patterns. Now, most of that species has stripes.

Five birds accidentally get trapped in a shipping container and are transported to a new continent. Their descendants look and behave differently than the original population.

In a lizard population, those with longer legs can run faster and escape predators. Over time, long-legged lizards become more common.

Elephant seals were hunted nearly to extinction in the 1800s. All current northern elephant seals descend from about 20 individuals, and now they have very little genetic variation.

In a desert, lizards that blend in with the sand survive more often. Over time, fewer bright green lizards are born.

Cheetahs today have incredibly low genetic diversity. Scientists believe this is due to a past event where only a few individuals survived, possibly due to climate change or overhunting.

Some bromeliads (Neotropical plants) colonize isolated tree islands in flooded forests. Each small population shows slightly different flower colors due to limited gene flow and random allele changes over time.

In industrial England, dark-colored moths became more common due to pollution blackening tree bark, giving dark moths better camouflage.