Zoology Exam 3

phylogenetic trees are factual evidence of evolutionary past

true/false

false; phylogenetic trees are consdiered hypothesis of evolutionary past. They are not 100% certain and many phylogenetic trees can be formed from one source of concrete data.

homologous characters

different versions of the same structure when comparing one species to another

• can be used to make a phylogenetic tree

• apart of the understanding of the morphological species concept

ex: forlimbs of bats, birds, and humuns are homologous bc they have the same basic bone structure (ulna, radius, humerus, digits)

same origin, different function

analogous characters

independently evolved characteristics

• different morphology across species

• different genetic basis

• ex: bird wing vs bat wing are analogous as flight structures, performing the same function

• not used to make a phylogenetic tree

different origin, same function

what are some possible traits that phylogenetic trees can be made out

definition of ecology:

study of interactions between different organisms, as well as organisms within their enviornment

life history (definition & qualities):

an individual’s pattern of development, growth, maturation, reproduction, and life span

• life history patterns have evolved to suit varied enviornments & ecological roles

• aspects: birth size, growth, age at sexual maturity, reproductive rate & effort, survival at different ages & sizes, overall lifespan

life history trade-offs:

• energy and resources can go toward survivorship or reproductive mechanisms

• survival and reproduction have an inverse relationship

  • the more energy spent invested in reproduction, the less energy spent on survival

• the more offspring produced, the lower the quality of offspring

fecundity definition

an animal’s reproductive rate

• the more fecund the animal, the higher their mortality

• more sexually reproductive organisms die faster

• ex: bunnies have high fecundity; they are very fecund

Definition of Semelparity

one big reproductive yeild for the entire lifetime

• salmon, spiders, insects

Iteroparity

multiple reproductive events during life

• majority of animals

Definition of Population

individuals within a speies that live in a given area, potentially able to breed

• heterogenous enviornments

3 Types of Survivorship Curves

Type I, Type II, and Type III

important figure: Exponential growth (R), Carrying Capacity (K), & Logistic Growth

important figure: Carrying Capacity Firgues of R & K selected species

Fundemental Niche vs Realized Niche

Fundemental niche refers to the [abiotic] conditions that a species can survive in without competition

• potiential habitat & resources

Relaized Niche refers to the [abiotic +biotic] conditions that a given species actually lives in including competition factors

• actual habitat & resources

3D niche of a fish

salinity, pH, and temperature

niche partitioning

species occupying unique niches to minimize competition

• different breeding areas, different nesting, different insect resources

competitive exclusion principle

competition is short-term.

if 2 species don’t parition & compete instead, one species will outdo the other to the point of extinction

specialist vs generalist species

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