Units 7 & 8: Evolution & Ecology

Flashcards covering key vocabulary from a lecture on evolution and isolating mechanisms.

Evolution

Change in a species over time.

Theory of Evolution

Darwin's concept based on variation and common ancestry, supported by observations on the Galapagos Islands.

Variation

Differences in traits, like tortoise necks, within a population.

Lamarck's Principle

The idea that organisms acquire or lose traits during their lifetime through selective use or disuse, and these acquired traits can be passed on.

Fossil Record

Evidence showing how living things have evolved over millions of years.

Homologous Structures

Structures with the same basic structure but different functions (e.g., human arm, whale fin, bird wing).

Analogous Structures

Structures with the same function but different structure and traits (e.g., dolphin fin and shark fin).

Natural Selection

The process where only the 'strong' or 'fittest' survive.

Gradualism

A constant process of evolution that occurs steadily over time.

Punctuated Equilibrium

Periods of little to no evolutionary change followed by rapid bursts of change.

Ecology

The study of how species interact with each other and their environment.

Carrying Capacity

The maximum population size that an environment can sustain.

Keystone Species

A species that has a disproportionately large impact on its ecosystem (e.g., beaver).

Divergent Evolution

Species become more different over time, often with homologous structures (e.g., finches).

Convergent Evolution

Species become more similar over time, often with analogous structures (e.g., dolphins and sharks).

Genetic Drift

Random changes in the frequency of alleles in a small population.

Founder Effect

A type of genetic drift where a small group establishes a new population.

Vestigial Structures

Structures that are no longer needed by an organism (e.g., appendix, wisdom teeth).

Comparative Embryology

The study of the similarities in the embryonic stage between different organisms.

Biochemical Evidence

Similarities in DNA between organisms that show evolutionary linkage.

Adaptive Radiation

As organisms spread, they acquire new traits that allow them to better survive.

Behavioral Isolation

Differing courtship or hibernation habits prevent mating (e.g., Blue-footed Booby).

Temporal Isolation

Differing mating times for species prevent interbreeding (e.g., Leopard and Wood frogs).

Geographical Isolation

Physical barriers separating populations (e.g., fruit flies on different islands).

Extinction

The state or process of a species, family, or larger group being or becoming extinct.

Co-evolution

Two separate species evolving together.

Succession

The stages of ecological change, primary or secondary.

Primary Succession

Ecological succession that occurs in an environment devoid of soil.

Secondary Succession

Ecological succession that occurs in areas where a community that previously existed has been removed; it starts with soil.

Mutualism

A symbiotic relationship where both organisms benefit (e.g., clownfish and anemone).

Commensalism

A symbiotic relationship where one organism benefits and the other is unaffected.

Parasitism

A symbiotic relationship where one organism benefits and the other is harmed (e.g., wasp larvae and caterpillar, tick and cow).