BIOLOGY Chapter 18 EVOLUTION AND THE ORIGIN OF SPECIES

Flashcards related to key vocabulary terms discussed in the lecture notes.

Evolution

The unifying theory of biology by which scientists ask questions about the living world.

Evolution

A gradual change in which new species arise from older species.

Natural selection

Individuals with favorable traits survive and reproduce.

Adaptation

A heritable trait that helps the survival and reproduction of an organism.

Divergent evolution

Organisms share a common ancestor and evolve in diverse directions.

Convergent evolution

Organisms develop similar traits and do not share common ancestry.

Fossils

Preserved remains of prehistoric organisms.

Homologous structures

Structures that have similar forms but different functions.

Vestigial structures

Residual structures that are no longer have a function.

Biogeography

The study of the geographic distribution of organisms on the planet and how they adapted due to this distribution.

Species

A group of individuals that can interbreed and produce viable offspring.

Hybrids

When different species do interbreed, the offspring are called _ and are likely infertile.

Speciation

The formation of two species from one original species.

Allopatric speciation

Involves geographic separation of species.

Sympatric speciation

Occurs in the same location.

Adaptive radiation

From one original species of bird, multiple others evolved, each with its own distinctive characteristics.

Temporal isolation

Reproduce at different time periods.

Habitat isolation

Move to new habitat.

Behavioral isolation

Use different mating behaviors.

Gametic barrier

Different reproductive structures.

Hybrid inviability

The hybrids are not able to fully develop.

Hybrid sterility

The hybrids are infertile.

Hybrid Zones

Areas where different species interbreed, creating hybrids.

Gradual Speciation

Species diverge gradually over time.

Punctuated Equilibrium

A new species is formed quickly and then remains unchanged for long periods of time.