Evolution: Origin of an Idea of Origin

Vocabulary flashcards covering the concepts, evidence, and historical theories of evolution, including Lamarckism, Darwinism, and biogeography.

Creation

Beliefs regarding the origin of life that are grounded in traditional and cultural systems and are not scientific because they do not depend on observation and scientific investigation.

Biological Evolution

The change in the gene pool of a population over time as a result of processes such as mutations, natural selection, and genetic drift; also described as descent with modification occurring gradually over millions of years.

Transitional Fossils

The fossil remains of organisms that link one organism to another, demonstrating evolutionary transitions such as the development of the modern horse's front limb over millions of years.

Descent with Modification

The process by which modified heredity material (chromosomes) is passed from parents to offspring through sexual reproduction fertilisation or mutations, resulting in offspring that are modified from their parents.

Biogeography

The study of the distribution of living organisms around the world, illustrating how organisms adapt to similar environments on separate continents or how related species diverge in different environments.

Saddleback Shells

A shell adaptation found in Galapagos tortoises living in drier conditions, allowing them to stretch their necks upward to reach cacti and leaves from bushes.

Genotype

The genetic makeup of an organism.

Phenotype

The physical appearance of an organism.

Pentadactyl Limb

A limb structure featuring five digits that is shared as a basic anatomical plan among land-living vertebrates (such as bats, birds, and humans), even though it has changed shape to perform different functions.

Erasmus Darwin

A country doctor, scientist, and philosopher ($1731-1802$) who proposed in his book Zoonomia that life on Earth descended from a common ancestor and species changed over time, though he provided no mechanism for this transformation.

Zoonomia

The famous book published by Erasmus Darwin ($1794$, $1796$) that put forward the idea of common descent and species change over time.

Lamarckism

An evolutionary theory proposed by French naturalist Jean-Baptiste Lamarck in $1801$ proposing that living organisms change via natural processes according to two laws: the law of use and disuse and the inheritance of acquired characteristics.

The Law of Use and Disuse

Lamarck's hypothesis stating that an organ or structure becomes better developed or enlarged when used regularly, while frequent disuse leads to reduction in size and eventual disappearance.

The Inheritance of Acquired Characteristics

Lamarck's hypothesis that physical characteristics developed during an individual's lifetime can be passed on to their offspring, a claim disproven by subsequent scientific investigations.

Alfred Russel Wallace

A British naturalist ($1823-1913$) who studied the distribution of organisms in the Malay archipelago during the late $1850\text{s}$ and suggested that modern species evolved differently after ancestral populations became isolated by water.

HMS Beagle

The ship on which Charles Darwin traveled between $1831$ and $1836$ to South America and Australia, where he studied living organisms and fossils.

Natural Selection

Darwin's mechanism of evolution stating that in a variable population, individuals possessing favourable characteristics are more likely to survive environmental changes or competition, reproduce, and pass those traits to the next generation.