Phylogenics Biology

Binomial Nomenclature

provides a unique identifier for each species

Genus species

most basic level of biological categorism

phylogeny

is the evolutionary history of a species or group of related species

taxonomy

is the ordered division and naming of organisms

cladistics

organize and groups organisms by common descent

A clade

a group of species that includes an ancesteral species and all its descendants

plesiomorphies

shared ancesteral characteristics originate in an ancestor of the taxon

apomorphies

shared derived characteristics in an evolutionary novelty unique to a particular group of related organisms. (These traits can arise through evolutionary processes and help distinguish clades from one another. )

homology

Similarity in structure, physiology, or development of species of organisms based upon their descent from a common evolutionary ancestor

Ex: the limbs of a human and a cat

analogy

similarity of function and superficial resemblance of structures that have different origins

Ex. wings of a moth and a bird

Maximum parsimony

assumes the fewest evolutionary events is most likely ( apomorphies )

Principle of max likelihood

States given certain rules about DNA mutations over time, a tree can be found that reflects the most likely sequence of evolutionary events; “odds”

homologous genes

genes sharing the same evolutionary ancestry

orthologous genes

related genes that result from speciation into different species

paralogous genes

related genes that result from gene duplication in the same species

analogous genes

unrelated genes that evolved independently to do similar functions in two organisms

population

total number of species in a given definition

population density

amount of people per unit of land area

distribution

pattern of where things are found in an area

dispersion

the scattering of organism over periods within a given rea

how do you determine the overall population size of an organism?

Sampling

what are the 3 ways of sampling

1. extrapolation from small samples

2. using an index of population size ( # of nests for birds )

3. The mark re-capture of tagged individuals and estimate population size ( N ) by capturing 2nd sample ( n ) and determining % that are marked ( x )

what factors determine population size?

Birth rates, death rates, immigration and emigration

3 types of dispersion patterns

1. clumped

2. uniform

3. random

demography

study of vital statistics of a population ( ex. birth/death rates )

Life Table

is an age-specific summary of the survival in a population usually followed by the fate of a cohort ( group of individuals of the same age )

Survivor ship curve type 1

low death rates during early and middle life and an increase in death rates among older age groups ( ex. humans )

survivorship curve type 2

a constant death rate over the organisms life span ( ex. some lizards )

Survivorship curve type 3

high death rates for the young and lower death rates for survivors ( ex. turtles )

Life history traits

1. age of first reproduction

2. frequency of reproduction cycles

3. litter or clutch size

semelparous reproductions ( bing- bing )

reproduce once and die ( highly variable or unpredictable environments )

Iteroparous reproduction

reproduce repeatedly, dependable and less variable environments

exponential growth

idealized situation with no external limits; best case scenario; J shape curve

what is zero population growth?

when the birth rate equals the death rate

logistic growth

exponential growth unsustainable; more realistic model, limits growth by incorporating carrying capacity

Allee effect

when individuals have harder time surviving or reproducing if population size is too small

K- selection ( density dependent )

selection promotes life history traits sensitive to population density ( ex. elephant, whale, people )

r- selection ( density- independent )

Selection encourages life history traits that maximize reproduction; produce more, live shorter ( ex. frogs and mice )

what environmental factors stop a population from growing indefinitely

lack of food, natural disaster, predators, lack of space, disease, etc.

density- dependent

birth and death rates are negative feedback that regulates population growth

predation

as a prey population builds up, predators may feed preferentially on that species

toxic wastes

accumulation of toxic wastes can contribute to density- density regulation of population size

intrinsic factors

for some populations, intrinsic ( physiological ) factors appear to regulate population size

metapopulations

are groups of populations linked by immigration and emigration

age structure

is the relative number of individuals at each age

interspecific competition

( -/- ) occurs when species compete for a resource in short supply

intraspecific competition

drives population dynamics

competitive exclusion

two species competing for ALL the same limiting resources; cannot coexist in the same place ( sympatric )

sympatry

ex. if both species on an island, thier mean beak sizes would be different

allopatry

if only one species on an island, their is a best average beak size

Fundamental Niche

species can use all resources and play all of its roles

realized niche

can only use a subset of its resources due to other species, can to limit

ecological niche

species use of biotic and abiotic resources

aposematic

bright coloration

cryptic

camoflauge

batesian mimichry

one palatable or harmless species mimics an unpalatable or harmful species

mullerian mimicry

2+ unpalatable or harmful species resemble each other

symbiosis

relationship where two or more species live in direct and intimate contact with one another

parasitism ( symbiosis )

( +/-) harmful; one organism
derives direct nourishment
from another with the host
harmed

Mutualism ( symbiosis )

( +/+ ) helpful

commensalism ( symbiosis )

( +/0 ) neutral; where one species
benefits and other is
neither harmed nor
helped

disease

also ( +/- ) one organism
(pathogen) exerts harm on
another organism by fulfilling
part or all of life cycle

obligate mutualism

where one species cannot survive without the other

faculative mutualism

where both species can survive alone

a keystone species

Not always most abundant in a natural community but exert a strong effect on its health. ( think of brick in bridge ) ex. otters

species richness

number of different species

relative abundance

proportion each species of the total individuals

ecological sucession

is the sequence of
community and
ecosystem changes
after a disturbance

primary succession

occurs where no soil
exists when succession
begins

secondary sucession

begins in an area
where soil remains
after a disturbance

Minimum viable population (MVP)

is the minimum
population size at which a species can survive

movement corridor

is a narrow strip
connecting
otherwise isolated
patches (promote
dispersal)

bioremediation

is using
living organisms to
detoxify ecosystems; Most often used are
prokaryotes, fungi, or
plants; Absorb and sometimes
metabolize very toxic
molecules

Biological augmentation

uses
organisms to add
essential materials
to degraded
ecosystems