Macroevolution Lecture Notes Flashcards

This set of vocabulary flashcards covers key terms, evolutionary hypotheses, biological lineages, and major geophysical events discussed across Lectures 1 through 19.

Trait space

The range of possible phenotypic characteristics in a population.

Microevolution

Individual changes in development controlled by regulatory genes, which ecology regulates through selective pressures.

Macroevolution

The regulation of the biodiversity produced by ecology-diversified development over geologic time.

Emergent properties

Characteristics of a complex system not possessed by individuals by themselves; essentially, the "whole is not just the sum of its parts."

Synapomorphies

Shared and unique characters used to define groupings and affinities in phylogenies.

Long-branch attraction

An artifact of molecular sequencing that can misrepresent the phylogenetic position of lineages which have experienced a high amount of evolutionary change.

Key innovations

Novel features that allow a lineage to exploit a previously unavailable adaptive zone.

Adaptive radiations

A time interval where speciation happens much more than extinction, occurring when a new group develops to fill an unlocked adaptive zone.

Modern Synthesis

The standard evolutionary theory including inheritance, natural selection, gene mutation, and speciation.

Adaptive zones

A "way of life" that many species can occupy, determined by physical, ecological, and evolutionary access.

Red Queen’s Hypothesis

The concept that lineages must continuously adapt to overcome competitive pressures or they will lose the "arms race" and go extinct.

Index fossils

Small, abundant groups which rapidly evolve and are used to differentiate between rock ages in relative geologic dating.

Signor-Lipps effect

The principle that the first and last individuals of a species are very unlikely to be found in the fossil record, leading to an underestimation of its duration.

Great Oxidation Event (GOE)

The production of free oxygen by early photosynthetic prokaryotes around $2.4\,bya$, causing a reduction of iron in seawater and killing anaerobic prokaryotes.

Bioturbation

The turnover and oxygenation of the seafloor surface evidenced by burrowing tubes, tracks, and marks made by animals with fluid-filled body cavities.

Lagerstätten

Sedimentary deposits with exceptional fossil preservation, often capturing soft-bodied organisms from various angles.

Contingency

The idea that evolutionary outcomes are dependent on prior events; if the "tape of life" were replayed, results would be unpredictable and unique.

Court Jester Hypothesis

The approach focusing on unpredictable abiotic events (like climate change or asteroids) that drive evolution independently of diversity.

Cope’s Rule

The tendency for evolutionary radiations to be founded by small species whose descendants progress toward larger body sizes.

Lazarus taxa

Groups of species once believed to be extinct but later discovered to still be living, such as coelacanths.

Exaptation

A trait that exhibits a function different from the function it originally evolved to serve.

Adaptive Grid Model (AGM)

A formalization of Simpson’s concepts that models radiations in adaptive space by partitioning environment into niches.

Collinearity

The conserved ordering of regulatory genes along chromosomes within the genome.

Gene Regulatory Networks (GRNs)

Inherited groups of genes, such as homeobox clusters, that encode transcription factors to control the expression of structural genes.

Biomineralization

The ability of organisms to acquire and process calcium or silica into shells or skeletons.

Metamerism

The partitioning of the body into serially similar segments, enabling specialization such as tagmosis.

Siberian Traps

The volcanic eruption site near the northern tip of Pangea believed to have triggered the Permian mass extinction $251.9\,mya$.

Archosaurs

A lineage including crocodiles, dinosaurs, and birds, characterized by extra snout openings and 4-chambered hearts.

Lepidosaurs

A lineage including tuatara, lizards, and snakes, characterized by horizontal cloacal openings and vomeronasal organs.

Heterodont

Dentition consisting of a diversity of sizes, shapes, and functions of teeth, which is a mammalian key innovation.

Younger Dryas

A period of global cooling during an otherwise warming period that led to the extinction of megafauna and Native American Clovis cultures.

Tagmosis

The regulatory control of the number, morphology, and presence of body structures across different arthropod lineages.

Eusociality

A complex social system involving reproductive division of labor and sterile castes, found in several hymenopterans and termites.

Toxicofera

A proposed but controversial clade based on gene sequences and venom orthologs that unites Iguanians, Anguimorphans, and snakes.

Zoonotic diseases

Pathogens transmitted directly from wildlife or livestock to humans, often spreading from hotspots like Africa and East Asia.