Biology-Chapter 6 Section 2 Vocab (Quizs)

Directional Isolation

When nature favors individuals with one extreme version of a trait over the others.

• Butterflies with bright green wings are better at hiding from predators than butterflies with other colors.

• Butterflies with dull colors are more attractive to mates than brightly colored ones.

• Butterflies with varied wing colors are more likely to survive in the jungle.

• Butterflies with blue wings are the most common in the jungle.

Postzygotic Isolation

Involves barriers that prevent hybrid offspring from surviving or reproducing.

• A lion and a tiger can mate and have a baby, but the baby, called a liger, can’t have babies of its own. This stops the liger from passing its genes on to the next generation.

• Hybrid offspring can survive but are unable to find mates in the wild.

• Postzygotic isolation occurs when two species do not mate at all.

• Hybrid offspring are always fertile and can reproduce.

Convergent Evolution

When different species develop similar traits because they live in the same kind of environment.

• A penguin and a seal both have flippers to help them swim in the ocean.

• A lion and a tiger both have stripes to help them camouflage in the jungle.

• A bat and a bird both have wings to help them fly in the sky.

• A fish and a whale both have gills to help them breathe underwater.

Founder Effect

Occurs when a small group starts a new population, leading to less variety in the new group.

• A small group of birds flies to a new island. Because only birds with blue feathers made the journey, soon all the birds on the island have blue feathers.

• A large group of animals migrates to a new habitat, increasing genetic diversity.

• A few individuals from a population are isolated, leading to increased variation in traits.

• A population of fish is introduced to a new lake, resulting in a mix of colors and patterns.

Sympatric Isolation

When a species splits into two new species without being separated by a physical barrier.

• Two groups of beetles live in the same field, but one group likes to eat grass, and the other likes to eat flowers. Because they eat different foods, they no longer mate and become two different species.

• Two groups of birds migrate to different areas, leading to a physical separation and the formation of new species.

• A population of fish is divided by a dam, resulting in two distinct species over time.

• Two groups of frogs in the same pond develop different mating calls, leading to reproductive isolation.

Allopatric Speciation

Occurs when a species splits into two new species because they are separated by a physical barrier.

• A mountain range separates a group of rabbits into two groups, leading to the formation of two new species.

• Two groups of birds evolve differently due to varying food sources in the same area.

• A river divides a population of fish, causing them to adapt to different water conditions.

• A group of insects changes color to blend in with their environment, resulting in new species.

Macroevolution

Involves big changes over a very long time that create new species or groups of species.

• Involves small changes that occur quickly within a species.

• Involves big changes over a very long time that create new species or groups of species.

• Involves changes that happen only in plants.

• Involves changes that are reversible and do not lead to new species.

Coevolution

When two species change over time because they depend on each other.

• A flower and a hummingbird rely on each other, with the flower needing the hummingbird to spread its pollen and the hummingbird needing the nectar from the flower.

• Two species that do not interact will evolve in the same way over time.

• Coevolution occurs when species evolve independently without any interaction.

• Coevolution is the process where one species evolves to become more dominant over another.

Prezygotic Isolation

Involves barriers that prevent mating or fertilization between different species before the formation of a zygote.

• A type of frog and a type of salamander live in the same pond, but the frogs lay their eggs in the water while the salamanders lay their eggs in wet soil. This keeps them from mating.

• Two species of birds that have different mating calls but live in the same area.

• Two species of plants that bloom at different times of the year, preventing cross-pollination.

• Two species of fish that can mate but produce sterile offspring.

Species

a group of organisms that can reproduce with one another

• Different breeds like Labrador Retrievers or German Shepherds are examples of the same species (Canis lupus familiaris) because they can breed and produce puppies together.

• All animals that can fly belong to the same species.

• Species are defined solely by their habitat and environment.

• Different species can always interbreed and produce viable offspring.