Macroevolution and Speciation

Macroevolution

Bigger changes that can happen above the level of species as a result of accumulated changes; creation of new species

Speciation

One population of organisms split and evolve independently of one another; can result in distinct, but related species; diversity of life increases

Allopatric Speciation

Population forms a new species while geographically isolated from its parent population

Sympatric Speciation

Subset of a population forms a new species without geographic separation (there is also habitat differentiation)

Habitat Differentiation

When a subpopulation exploits a habitat or resource not used by the parent population (think of apple maggot and Hawthorne flies)

Morphological Species Concept

Classification based on physical traits (shape, size and form); developed by Linnaeus in the 1700s

Biological Species Concept

Group of populations whose members have the potential to interbreed in nature and produce fertile offspring; cannot be applied to asexual species

Prezygotic Barriers (reproductive isolation separates biological species)

Block fertilization from occurrinfactors that impede members of two (usually closely related) species from interbreeding and producing viable gametes

Postzygotic Barriers (reproductive isolation separates biological species)

Development errors or post birth problems that decrease the chance of surviving long enough to reproduce

Phylogenetic Species Concept

Individuals that share ancestry based on multiple characteristics - morphology, DNA, sequences, biochemical pathways

Ecological Species Concept

Live in different niches and are adapted to different communities

Taxonomy

Ordered division and NAMING of organisms; 18th century Carolus Linnaeus; two part names and hierarchical classification

Hierarchical Classification

Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain

Binomial Nomenclature

Latinized two name system to classify organisms; Genus=Capitalized, species=lowercase; made by Linnaeus

Homology

Shared morphological and genetic similarities

Convergent Evolution/Analogy

Similar environmental pressures resulted in similar features (think of flying squirrels and sugar gilders)