Chapter 22: Descent with Modification Flashcards

Vocabulary flashcards grounded strictly in the Chapter 22 lecture transcript, covering evolutionary concepts, historical figures, mechanisms, and scientific evidence.

Descent with modification

The process by which species accumulate differences from their ancestors as they adapt to different environments over generations, originating from a shared ancestry.

Plato

Greek philosopher (427-347 BC) who viewed species of plants and animals as perfect and unchanging.

Aristotle

Greek philosopher (384-322 BC) who viewed species as fixed (non-changing), recognized affinities among organisms, and organized them by complexity.

Scala Naturae

Meaning 'scale of nature,' an early biological classification system created by Aristotle that organized organisms on a ladder of increasing complexity, where each group was considered perfect and unchanging.

Carolus Linnaeus

Swedish botanist, physician, and naturalist (1707-1778) who developed a latinized, two-part binomial classification system to identify unique species and grouped similar species into taxonomic groups.

Georges Cuvier

French naturalist (1769-1832) who helped develop paleontology, determined the history of life by examining rock strata, accepted extinction, but vehemently opposed evolution.

Paleontology

The study of fossils.

Fossils

Impressions left by an organism from the past.

Jean-Baptiste de Lamarck

French biologist (1744-1829) who recognized that evolutionary change could explain fossil evidence and environmental adaptation, though his proposed mechanism was flawed.

Inheritance of Acquired Characteristics

Lamarckian hypothesis proposing that physical traits modified during an animal's life through use or disuse could be directly passed down to its offspring.

Biogeography

The study of the past and present geographical distribution of organisms.

Alfred Russel Wallace

Naturalist who independently proposed that natural selection was a key mechanism explaining evolutionary change in 1858 while studying species in the Malay Archipelago.

Population

Individuals of the same species that are living in the same area at the same time.

Artificial selection

Species modification over generations by selective breeding (domestication) engineered by humans for desired traits.

Adaptation

A heritable trait that increases an individual's biological fitness in a particular environment relative to individuals lacking that trait.

Biological fitness

The ability of an individual to survive and produce offspring.

Acclimation

Short-term physiological changes (phenotypic change) an organism relies on to counter environmental stress, unlike adaptation which is long-term genetic change across generations.

Phenotype

Observable morphological and physiological traits of an organism.

Genotype

The genetic makeup (alleles) of an organism inherited from its parents.

Homology

Similarity that exists in species descended from a common ancestor.

Genetic homology

Similarity in the DNA sequences of different species.

Developmental homology

Similarity in embryonic traits shared by different species, such as tails and pharyngeal gill arches in chordate embryos.

Structural homology

Similarity in adult morphology, such as the common structural plan in vertebrate limb bones.

Vestigial trait

A reduced or incompletely developed structure in an organism that offers little to no function, but is homologous to functioning structures in closely related species.

Convergent evolution

The independent evolution of similar traits in unrelated species driven by similar selective pressures.

Analogous features

Traits that result from convergent evolution, where unrelated species possess similar features due to similar selective pressures rather than shared ancestry.