Taxonomy &

Macroevolution

Macroevolution refers to the major evolutionary trends

• Major phenotypic changes such as wings with feather, legs, the opposable thumb

• changes are usually based on a preceding structure or form (lungs from swim bladders)

• read about regulatory genes, rates of growth and timing on page 340

Adaptive radiation

• Diversification allows an organism to fill a variety of ecological roles (niches)

• Diversification may result in speciation

• Adaptive zone = ecological niche

Extinction

• Background extinction

• Mass extinction

• Extirpation

• Extinction vortex

• Minimum viable population

Evolutionary change

• Punctuated equilibrium

• gradualism

Taxonomy

• Scientific classification of living things

• everything is classified, even things that died a long time ago…(missing link)

Taxons

• Kingdom (Animalia)

• Phylum (Chordata)

• Class (Mammalia)

• Order (Carnivora)

• Family (Felidae)

• Genus (Felis)

• Specific epithet (Catus)

AnimaliaChordata

Mammalia

• Carnivore• Felidae• Felis• Catus

• Primates• Hominidae• Homo• Sapiens

AnimaliaChordata

Mammalia

• Order Primate Primate Primate

• Family HominidaePongidae Lasiopygidae

• Genus Homo Pan Macaca

• Spc Epi sapiens troglodytes mulatta

• Taxon Human Chimpanzee Rhesus Mnk

5 Kingdoms

• Prokaryote (sometimes called monerans)

• Protista (protozo, algae, slime molds)

• Fungi

• Plantae

• Animalia

Systematics

• Classification of organisms into groups determined by evolutionary relationship

• evolutionary history of a species (phylogeny)

• Monophyletic - common ancestor (clade)

• Polyphyletic - not a common ancestor

Systematics

• Ancestral characters - traits shared with ancestors

• Derived characters - traits not shared with ancestors

• see discussion of importance of traits on p 368

3 approaches to taxonomy

• Phenetics - based on phenotypic traits (why are dolphins more closely related to humans than to fish?)

• Cladistics - stresses phylogeny (evolutionary history, common ancestry)

• Classic taxonomy - phylogenetic tree