Chapter 17: Speciation and Macroevolution

These flashcards cover key terms and concepts related to speciation and macroevolution as presented in the lecture notes.

Macroevolution

Evolution on a large scale, best observed within the fossil record.

Speciation

The origin of new species through the splitting of one species into two or more.

Microevolution

Small-scale genetic changes within a population.

Morphological Species Concept

Defines a species based on physical characteristics and traits.

Evolutionary Species Concept

Identifies species based on common ancestry and evolutionary lineage.

Phylogenetic Species Concept

Defines species based on shared ancestry and relationships.

Biological Species Concept

Defines species based on reproductive isolation and potential to interbreed.

Prezygotic Isolating Mechanisms

Processes that prevent mating attempts or fertilization.

Postzygotic Isolating Mechanisms

Processes that prevent hybrid offspring from developing or being fertile.

Habitat Isolation

Occurs when two species live in different habitats and do not meet.

Temporal Isolation

Occurs when species reproduce at different times or seasons.

Behavioral Isolation

Occurs when different species have distinct mating behaviors.

Mechanical Isolation

Occurs when reproductive organs are incompatible.

Gamete Isolation

Occurs when sperm and egg of different species are unable to fuse.

Hybrid Inviability

Occasion when hybrid zygotes fail to develop properly.

Hybrid Sterility

Condition where hybrids are sterile and cannot reproduce.

Allopatric Speciation

Speciation that occurs due to geographical separation.

Sympatric Speciation

Speciation that occurs without geographical barriers.

Adaptive Radiation

Rapid evolution of diversely adapted species from a common ancestor.

Convergent Evolution

Evolution of similar traits in unrelated lineages due to similar environments.

Gradualistic Model

Model of evolution proposing gradual changes over time leading to speciation.

Punctuated Equilibrium Model

Model of evolution suggesting long periods of stasis interrupted by rapid changes.

Development Genes

Genes that control the development and morphologies of organisms.

Pax6 Gene

Gene crucial for eye development across a variety of species.

Hox Genes

Genes that determine the body plan and structure in animals.

Tbx5 Gene

Gene involved in limb development, influencing structure and morphology.

Pitx1 Gene

Gene that plays a role in the development of pelvic fins in fish.

Polyploidy

Condition where an organism has more than two complete sets of chromosomes.

Autoploidy

A type of polyploidy occurring from doubling of a single species' chromosome set.

Alloploidy

A type of polyploidy arising from hybridization between two different species.

Reproductive Isolation

Mechanisms preventing different species from interbreeding.

Diagnostic Traits

Physical characteristics used to identify and define species.

Monophyletic Groups

Groups consisting of an ancestor and all its descendants.

Cryptic Species

Species that are morphologically similar but genetically distinct.

Speciation Modes

Different processes through which new species arise.

Fossil Record

Historical remnants that provide evidence of past life and evolutionary changes.

Gene Flow

The transfer of genetic information between populations.

Natural Selection

Process where organisms better adapted to their environment tend to survive.

Genetic Drift

Random changes in allele frequencies in a population.