objectives 2:1

Vocabulary and concept flashcards covering introductory topics in phylogeny, the history of evolutionary thought, and the mechanisms of natural selection.

Phylogeny

The evolutionary history and genealogical relationships among individuals, groups of organisms, or species.

Phylogenetic tree

A branching diagram that visually depicts hypotheses about the evolutionary relationships among taxa, where branches represent lineages evolving over time and nodes represent common ancestors.

Sister taxa

Groups or organisms that share an immediate common ancestor not shared by any other group, making them each other's closest relatives on a phylogenetic tree.

LUCA

Last Universal Common Ancestor; the ancestral entity or population from which all existing life on Earth descended.

Biological evolution

A change in the genetic composition and heritable traits of a biological population over successive generations.

Change over time vs. Evolution

Change over time can describe non-genetic modifications or shifts occurring within an individual's lifetime (e.g., development or aging), whereas evolution strictly refers to inheritable, genetic changes across generations in a population.

Two main ideas presented in The Origin Of Species

1) Descent with modification: all organisms are related through common ancestry, and 2) Natural selection: the primary mechanism driving evolutionary adaptation.

Aristotle's understanding of life

The view that living forms are fixed, permanent, and unchanging, organized hierarchically on a ladder of increasing complexity known as the scala naturae (scale of nature).

Fossils (as a source for Darwin)

Preserved remains or traces of historical organisms found in geological rock strata that provided direct evidence of extinction, transition, and change in biological forms over time.

Gradualism

The geological and evolutionary principle that profound changes result from the cumulative effect of slow, steady, and continuous natural processes operating over immense spans of time.

Lamarck's theory of evolution

A hypothesis stating that species evolve through two principles: 1) Use and disuse (body parts used extensively strengthen and enlarge, while unused parts deteriorate), and 2) The inheritance of acquired characteristics (modifications developed during an organism's lifetime can be transmitted to offspring).

1858 Darwin and Wallace proposal

The revolutionary joint presentation proposing natural selection as the mechanism of evolution, which overturned typological and creationist views by offering a testable, purely materialistic, and population-based explanation for biodiversity.

Four requirements for natural selection (Darwin's postulates)

1) Variation: individuals within a population vary in traits, 2) Heritability: some phenotypic variations are transmitted to offspring, 3) Overproduction: more offspring are born than can survive to reproduce, and 4) Differential reproductive success: individuals possessing advantageous traits survive and reproduce at higher rates.