Chapter 18: Introduction to Darwinian Evolution

Flashcards covering key vocabulary and concepts from Chapter 18 on Darwinian Evolution.

Species

A group of similar organisms capable of interbreeding and producing fertile offspring.

Population

A group of individuals of one species that live in the same geographic area at the same time.

Evolution

The accumulation of heritable genetic changes in a population over time.

Natural Selection

The process where organisms better adapted to their environment tend to survive and produce more offspring.

Macroevolution

Major evolutionary changes that occur over a long period of time, resulting in large phenotypic changes such as the formation of new species.

Microevolution

Minor evolutionary changes that occur over just a few generations.

Modern Synthesis

An explanation of evolution that incorporates aspects of molecular genetics, phylogeny, natural selection, and mutations.

Convergent Evolution

The independent evolution of similar traits in species of different lineages due to similar environmental challenges.

Homologous Structures

Structures that are similar in different species because they share a common ancestor.

Vestigial Structures

Remnants of structures that were functional in ancestral organisms but no longer serve a necessary function.

Darwin's Four Observations

1. Variation in traits within a population; 2. Overproduction of offspring; 3. Limits on population growth due to competition; 4. Differential reproductive success.

Catastrophism

The principle that events such as catastrophes lead to mass extinctions and subsequent new species.

Gradualism

The theory that evolution occurs slowly but steadily through small continuous changes.

Homoplasy

Similar traits that have evolved independently in different species, not due to a shared ancestry.

Developmental Homologies

Similarities in the embryonic development of different species that suggest a common ancestry.