{ HOW BIOLOGICAL DIVERSITY EVOLVES Chapter 14

{ THE ORIGIN OF SPECIES Chapter 14.1

 Speciation – process in which one species splits into two or more species  Species – group of members within a population that routinely interbreed SPECIATION

 Morphological  Biological CONCEPT OF SPECIES

 Coevolution – two or more unrelated species evolve together  Predator/prey  Convergent – unrelated species have similar appearance due to environment  Analogous structures  Divergent – related species become more and more dissimilar EVOLUTIONARY PATTERNS

 In isolation, two parts of a formerly interbreeding population stop interbreeding 1. Geographic Isolation 2. Reproductive Isolation MECHANISMS OF SPECIATION

 Results from barriers to successful breeding between population groups in the same area  Prezygotic  (temporal, behavioral, mechanical)  Postzygotic  (infertility, hybrids) REPRODUCTIVE ISOLATION

 Allopatric – Block of gene flow is due to geographic barrier  More common for small, isolated population   Sympatric – Origin of new species without geographic isolation   Large scale genetic changes that occur in a single generation MECHANISMS OF SPECIATION

 Graduated Equilibrium – differences appear little by little in populations  Punctuate Equilibrium – long periods of little change interrupted by brief period of rapid change RATES OF SPECIATION

{ Chapter 14.2 MACROEVOLUTION

 Macroevolution – evolutionary change above the species level  Including:  Origin of evolutionary novelty and new groups of species  Impact of mass extinctions on diversity of life and its subsequent recovery MACROEVOLUTION

 Exaptation – structure can become adapted to alternative function  Light weight bones of birds  Evo-devo – evolutionary developmental biology  Evolution of invertebrates to vertebrates  Features that remain in adults from juvenile HOW DO NOVELTIES FORM?

 Geologic Time & Fossil Record  Use the geologic time scale  Radiometric dating  Plate Tectonics  Mass Extinctions  5 within last 540 my in which 50% or more of Earth’s species died out EARTH HISTORY & MACROEVOLUTION

Did a meteor kill the Dinosaurs?