Chapter 24 (Evolution by Natural Selection) Flashcards
(23 cards)
acclimation
Gradual physiological adjustment of an organism to new environmental conditions that occur naturally or as part of a laboratory experiment.
adaptation
Any heritable trait that increases the fitness of an individual with that trait, compared with individuals without that trait, in a particular environment.
descent with modification
The phrase used by Darwin to describe his hypothesis of evolution by natural selection.
developmental homology
A similarity in embryonic form, or in the fate of embryonic tissues, that is due to inheritance from a common ancestor.
extant species
A species that is living today.
extinct
Said of a species that has died out.
fossil
Any trace of an organism that existed in the past. Includes tracks, burrows, fossilized bones, casts, etc.
fossil record
All of the fossils that have been found anywhere on Earth and that have been formally described in the scientific literature.
genetic correlation
A type of evolutionary constraint in which selection on one trait causes a change in another trait as well; may occur when the same gene(s) affect both traits.
genetic homology
Similarities in DNA sequences or amino acid sequences that are due to inheritance from a common ancestor.
geologic time scale
The sequence of eons, epochs, and periods used to describe the geologic history of Earth.
homology
Similarity among organisms of different species due to their inheritance from a common ancestor. Features that exhibit such similarity (e.g., DNA sequences, proteins, body parts) are said to be homologous.
morphology
The shape and appearance of an organism’s body and its component parts.
natural experiment
A situation in which groups to be compared are created by an unplanned, natural change in conditions rather than by manipulation of conditions by researchers.
natural selection
The process by which individuals with certain heritable traits tend to produce more surviving offspring than do individuals without those traits, often leading to a change in the genetic makeup of the population. A major mechanism of evolution.
phylogeny
The evolutionary history of a group of organisms.
population
A group of individuals of the same species living in the same geographic area at the same time.
primate
The lineage of mammals that includes prosimians (lemurs, lorises, etc.), monkeys, and great apes (including humans).
sedimentary rock
A type of rock formed by gradual accumulation of sediment, as in riverbeds and on the ocean floor. Most fossils are found in sedimentary rocks.
structural homology
Similarities in organismal structures (e.g., limbs, shells, flowers) that are due to inheritance from a common ancestor.
transitional feature
A trait that is intermediate between a condition observed in ancestral species and the condition observed in more derived species.
tuberculosis
A disease of the lungs caused by infection with the bacterium Mycobacterium tuberculosis.
vestigial trait
Any rudimentary structure of unknown or minimal function that is homologous to functioning structures in other species. Vestigial traits are thought to reflect evolutionary history.
