Historical Geology Chap 7-13 Study Guide

Who is Charles Darwin?

An unpaid naturalist who went on a 5 year voyage (1831-1836) visiting the Galápagos islands.

What area was Charles Darwin sailing around and what animal did he observe when he formulated the Theory of Evolution?

Galápagos islands (pacific ocean), west of Ecuador, South America. Darwin was observing 13 species of Finches living on the islands.

Artificial Selection

The practice of selectively breeding plants and animals with desirable traits.

Natural Selection

A mechanism accounting for differential survival and reproduction

1. Organisms in all populations posses inheritable variations (size, speed, color, etc.)

2. Some variations are more favorable than others; some variant types have a competitive edge in acquiring resources and or avoiding predators.

3. Those with favorable variations are more likely to survive and have offspring, thereby passing on their favorable variations.

Genes

A specific segment of a chromosome consisting the basic unit of heredity. Genes control the same trait occurring in alternate forms (alleles).

Alleles

A variant form of a single gene.

Species

A population of similar individuals that have the capacity to interbreed and produce fertile offspring in nature.

Speciation

The phenomenon of new species arising from an ancestral species, well documented, but the rare and ways it takes place vary.

Speciation involves change in the genetic makeup of a population, which also may bring about a change in form and structure.

Microevolution

Evolutionary changes within a species. A small scale evolutionary process that involves gene pool changes and can result in alternations in characters over time.

Macroevolution

Evolutionary changes such as the origin of new species, genra, families, ordeas, and classes; long term changes.

Allopatric Speciation

A new species arising when a small population becomes isolated from its parent population so that once isolated, the two populations share little of any genetic material.

Phyletic Gradualism

Gradual accumulation of minor changes eventually bringing about the origin of a new species; a new species arises gradually and continuously.

Punctuated Equilibrium

Species changing little during most of their existence and then evolving rapidly, thus giving rise to a new species in as little as a thousand years.

Divergent Evolution

Ancestral species giving rise to diverse descendants adapted to various aspects of the environment.

The diversification of a species into two or more descendant species.

Convergent Evolution

The development of similar characterizes in distantly related organisms.

The origin of similar features in distantly related organisms as they adapt in comparable ways.

Parallel Evolution

The development of similar characteristics in closely related organisms.

Evolution of similar features in two separate but closely related lines of decent as a result of comparable adaptations.

What percentage of species that ever existed have gone extinct?

99%

Biogeography

Geographic distribution of organisms both past and present, providing compelling evidence for evolution.

The study of geographic distribution of organisms and communities of organisms.