Intro To Comparative

Front 1

functional morphology vs. physiology

Back 1

functional morphology:

the function of body parts on a gross scale - muscles, bones, joints, etc.

physiology:

function on a fine scale - measuring oxygen consumption, metabolic rates, molecular interactions, etc

Front 2

evolution:

the four parts of natural selection

Back 2

1 - organisms reproduce @ higher rate than what can be managed by environment/individuals

2 - species are variable, variations are heritable

3 - some variants are more favorable for survival/reproduction

4 - more favorable variants contribute disproportionality to the next generation

Front 3

evolution:

adaptation

Back 3

any feature of an organism that improves its ability to survive and reproduce in a given habitat

Front 4

species:

biological vs. evolutionary

Back 4

biological species:

consists of interbreeding natural populations that cannot reproduce with other groups

evolutionary species:

single lineage of ancestor-descendant populations which maintains its identity from other lineages; has own evol. tendencies & historical fate

Front 5

evolutionary patterns:

micro vs. macro

Back 5

microevolution:

study of evolutionary processes within populations (changes in genetic types & their frequences)

macroevolution:

study of diversity of organisms, and evolutionary development of that diversity

Front 6

systematic studies

Back 6

attempt to recover evolutionary relationships among organisms

a group of organisms realted to one another on some level called a taxon/taxa

Front 7

two ways to investigate morphological evolution of a lineage

Back 7

comparative method:

examine extant taxa and compare their characteristics

paleontological method:

examine fossils of related taxa in a sequence of fossils that lived at different times

Front 8

constraints on evolution

Back 8

- new forms must evolve from older, currently well adapted forms

- structures cannot arise "de novo" but must be derived from a previously existing body part

- all structures must be adaptive throughout their existence including evolutionary intermediates

Front 9

preadaptation

Back 9

structures are preadapted to a particular function if their current design allows a facile transition to a new function

ex: bird feathers - original function to thermoregulation, preadapted for flight

Front 10

adaptive radiation

Back 10

extensive ramification of a lineage

may result from:

evolutionary innovation ; ecological release ; invasion of unoccupied territory with moderate barriers to gene flow

ex: cleidoic egg, radiation of modern mammals, darwin's finches

Front 11

adaptive radiation:

evolutionary innovation

Back 11

stem reptiles (cotylosaurs) became:

ichthyosaurs

plesiosaurs (& other related marine forms)

ruling reptiles (later became birds)

lizards & snakes

tuatara (sphenodon)

primitive mammal-like reptiles (advanced mammal-like reptiles, later mammals)

turtles

Front 12

adaptive radiation:

ecological release

Back 12

mammals coexisted with dinosaurs for 120 million years and had less than 5 lineages;

did not undergo extensive adaptive radiation until extinction of dinosaurs - exploded with different species to fill ecological niches now empty

Front 13

adaptive radiation:

invasion of unoccupied territory with moderate barriers to gene flow

Back 13

darwin's finches - once released onto the islands, they invaded ecological niches and adapted to these niches

fringillid ancestor broke into vegetarian v. insectivorous tree finches ; ground finches ; cactus-feeding finches ; warbler finches

Front 14

homology

Back 14

concept of sameness (horse's hoof vs. human fingernail)

determined by:

- similarity in position

- point for point similarity of structure

- similarity of function

- similiarity of developmental origin

Front 15

three problems of homology/phylogeny

Back 15

- evolutionary convergence

- evolutionary parallelism

- evolutionary reversal

Front 16

evolutionary convergence

Back 16

evolutionary selective pressures make similarly evolved functions in organisms in completely different locations, making the selective pressures separate and different even if they caused the same function.

ex: marsupial moles (australia) vs placental moles (USA)

Front 17

evolutionary parallelism

Back 17

similar structures develop from environmental pressures that have no connection to lineage

ex: skinks across the globe developing limbs or losing limbs

Front 18

evolutionary reversal

Back 18

habitats and environments change - create patterns of change when organisms respond

ex: the peppered moths vs. environmental soot

Front 19

systematics

Back 19

the study of relationships and classification of biotic organisms

Front 20

taxonomy

Back 20

the study of the nomenclature of biotic organisms

Front 21

phylogeny

Back 21

a hypothesis of relationships

Front 22

cladistics

Back 22

also known as phylogenic systematics - the current practice of analysis based ont he primacy of synapomorphy

Front 23

synapomorphy

Back 23

a shared, derived character

novel features that are evolved by one group and passed on to all of its ancestors can be distinguised from shared primitive characters that were evolved from a distant ancestor

Front 24

monophyly vs. paraphyly

Back 24

monophyly:

describes a taxon that is composed of an ancestral species and all of its descendants

paraphyly:

describes a taxon that includes ancestral species, but not all of its descendents/group of descendant species & is not the ancestral form

Front 25

homoplasy

Back 25

similarity among several taxa that is not due to inheritance from a common ancestor

usually a product of convergance/parallelism/reversal