Chapter 13: Evidence of Evolution - Vocabulary Flashcards

Key terms and concepts from Chapter 13: Evidence of Evolution, including fossils, dating methods, biogeography, homologous/vestigial/analogous structures, embryonic development, and molecular evidence.

Fossil

Remains or clues of past life that provided the original evidence for evolution.

Paleontology

The study of fossil remains or other clues to past life.

Compression fossil

A fossil formed when an organism is pressed and preserved as a carbon-rich film in sediment.

Petrification

Fossilization in which organic material is replaced by minerals, turning the organism to stone.

Impression

A fossil produced when an organism leaves an imprint in sediment.

Casting

A fossil formed when an impression fills with sediment or mineral, creating a cast.

Intact preservation

Preservation of an organism in near-life-like condition, typically due to rapid burial and low oxygen.

Relative dating

Dating fossils by the position in rock layers; lower layers are generally older.

Geologic timescale

System for dividing Earth's history into eons and eras based on major biological/geographical events.

Absolute dating

Dating fossils using chemical methods to determine an actual age, often via radiometric dating.

Radiometric dating

A dating method that uses radioactive decay to estimate the age of rocks or fossils.

Isotopes

Variants of elements with different neutron numbers used in dating and diet inferences.

Carbon isotopic signatures

Variations in carbon isotopes used to infer the diets of extinct species.

Biogeography

Study of the geographic distribution of species and how it changes over time.

Plate tectonics

Theory that Earth's plates move, reshaping continents and influencing evolution.

Pangaea

A supercontinent that existed about 200 million years ago when continents were joined.

Wallace's Line

Biogeographic boundary separating distinct faunas between Asia and Australia.

Homology

Similarity due to inheritance from a common ancestor.

Vestigial structures

Structures that have lost their function but were functional in ancestors.

Analogous structures

Similar in function but not derived from a common ancestor.

Convergent evolution

Evolution that produces similar traits in unrelated lineages due to similar pressures.

Developmental (embryonic) homology

Similar embryonic development patterns revealing evolutionary relationships.

Embryonic development patterns

Early-stage similarities in embryos that indicate relatedness among species.

Molecular homology

Similarity in DNA and protein sequences across species reflecting shared ancestry.

DNA sequences

Genetic sequences used to determine evolutionary relationships.

Protein sequences

Amino acid sequences used to infer relatedness among organisms.

Cytochrome c

A mitochondrial protein present in all eukaryotes, used to show common descent.

Molecular clock

Concept that DNA mutations accumulate at a roughly constant rate to estimate divergence times.

Common descent

Idea that all living things are descended from a shared ancestor.

Gene duplication

Creation of extra gene copies; can lead to new functions (e.g., amylase gene) under selection.

Amylase gene duplication

An example where duplication and dietary pressure increased starch digestion.

Fossil record incompleteness

The fossil record is incomplete because soft-bodied organisms fossilize poorly and fossils can be eroded or destroyed.

Fossils reveal behavior

Fossils can provide evidence of behavior or ecology, such as mating displays or locomotion.

Geologic timescale divisions

Organization of Earth's history into eons and eras to contextualize evolution.