Untitled Deck Flashcards
(73 cards)
Macroevolution
Large-scale evolutionary changes over long periods, leading to the emergence of new species.
Biological Species Concept
Defines species as groups that can interbreed and produce fertile offspring.
Ecological Species Concept
Defines species based on their niche and role in the environment, not on reproductive compatibility.
Allopatric Speciation
Geographic isolation leads to new species; populations are physically separated.
Parapatric Speciation
Adjacent populations evolve into distinct species due to partial isolation and environmental differences.
Sympatric Speciation
New species evolve within the same habitat, often due to niche differentiation (no physical separation).
Anagenesis
Gradual evolution within a single lineage (transformation of one species into another over time).
Cladogenesis
Branching evolution, where one species splits into multiple species; fundamental to creating biodiversity.
Phylogenetic Reconstruction
Mapping evolutionary relationships using common ancestors and shared traits.
Tips (in phylogeny)
Represent current or extinct species at the ends of branches in a phylogenetic tree.
Branches (in phylogeny)
Show evolutionary paths connecting different species and their ancestors.
Nodes (in phylogeny)
Common ancestors where lineages diverge in a phylogenetic tree.
Most Recent Common Ancestor (MRCA)
Closest shared ancestor of two or more species.
Ancestral Traits
Traits inherited from distant ancestors (plesiomorphies).
Derived Traits
New traits unique to a particular group (apomorphies).
Parsimony
The principle that the simplest explanation requiring fewest evolutionary changes is usually correct.
Homologous Traits
Traits shared due to common ancestry (e.g., primate hands, whale flippers, bat wings).
Analogous Traits
Traits with similar function but different evolutionary origins (e.g., wings in birds and insects).
Scopes Trial
1925 case where John Scopes deliberately violated Tennessee’s Butler Act by teaching evolution to test the law’s constitutionality.
Butler Act
Tennessee law (1925) that made it illegal to teach human evolution in public schools.
Proconsul
Miocene ape with generalized features, possible ancestor to great apes (lived 23-14 MYA).
Sivapithecus
Miocene ape showing clear affinities to orangutans (lived 12.5-8.5 MYA).
Plesiadapiformes
Paleocene primate-like mammals with some primate traits but not considered true primates.
Adapiformes
Eocene primates related to strepsirrhines (lemurs and lorises).