Catch My Drift

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.

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

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.

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.

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.

On Pingelap, a small Pacific island, a typhoon reduced the population to about 20 people. One survivor carried a rare gene for color blindness, which is now unusually common in the population.

In Central America, forest fragmentation drastically reduced glass frog populations in some regions. These small, isolated populations now show less genetic diversity than others.

In a Neotropical rainforest, a rare pollinator species declined due to climate change. Orchids that could attract alternative pollinators began to reproduce more, shifting flower shapes over generations.

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.

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

During El Niño events, food becomes scarce and smaller-bodied marine iguanas tend to survive better than larger ones, leading to a noticeable shift in body size in following generations.

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.

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

Modern Icelanders are genetically very similar, with many traits traceable to original Viking settlers.

Several genetic disorders (e.g., Tay-Sachs) are more common in Ashkenazi Jewish populations due to a small ancestral population and historical isolation.

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

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 one Galápagos island, droughts reduced soft-seed plants. Only finches with longer, stronger beaks could crack the tougher seeds, so that trait became more common in the next generation.

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 regions with high malaria, individuals with one sickle cell allele are more likely to survive malaria. Over time, this trait became more common in those populations.

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