Population Ecology Flashcards
Provided mechanisms of evolutionary change in
population. Population descended from a common ancestor
whose descendants had changed after reaching
each island
Darwin’s Theory of Evolution
process that changes populations of
organisms over time.
Evolution
characteristics producing that advantage
preserved
unfavorable
characteristics of other individuals
destroyed
First draft of theory of natural selection
1842
proposed that differential
survival and reproduction of individuals would
produce changes in species populations over
time
Darwin (1859)
an evolutionary process that
changes anatomy, physiology, or behavior, resulting in an improved ability of the members
of a population to live in a particular
environment.
Adaptation
rare traits, no matter
how favorable, would be blended out of a
population, preventing change as a
consequence.
Blending inheritance
Augustinian monk, developing the facility with
mathematics necessary to complete theory of
natural selection. - uncovered the basic mechanisms of
inheritance. - probability and statistics
Gregor Mendel
garden pea SN
Pisum sativum
consists of its observable characteristics, which result in interactions between the genetic makeup of the individual and their environment.
phenotype
the substrate upon which the environment acts during the process of natural selection determining the extent of sources in variation within population is one of the most fundamental consideration in evolutionary studies
Phenotypic variations
sticky cinquefoil SN
Potentilla glandulosa
variation among individuals in form and function as a result of environmental influences
Phenotypic plasticity
locally adapted and genetically distinctive populations within a species.
Ecotypes
Acts to impede changes or to stop changes in population
Acts against extreme phenotypes and as a consequence it favors the average phenotype
Stabilizing population
have lower rates of reproduction and survival
Extreme phenotypes
Favors an extreme phenotype over other
phenotype in the population
The larger individuals in the population would
have higher rate of survival and reproduction
The average and small individuals would have
lower rates
Directional Selection
It favors two or more extreme phenotypes over
the average phenotypes in a population. Individuals with average body size have lower
rate of survival and reproduction than
individuals of either large or small body
Disruptive Selection
that the environment
determines the evolution of the anatomy, physiology, and behavior of organism
theory of natural selection
the proportion of total phenotypic variation in a trait, such as body size or pigmentation, that is attributable to genetic variance
heritability
the environment has a substantial effect on many aspects of the phenotype of organisms. Food, amount of light, temperature, and other environmental factors
Environmental variance (VE)
with intermediate size beaks is
relatively uncommon or very few. High level of
immigrating and high mortality
Geospiza fortis
change in the frequency of an
existing gene variant in the population due to
random chance.
Genetic drift
the original population
undergoes a random event
bottleneck event
number of individuals in a
particular population is isolated from that
population
founding event
predicts that
small population size will be more subject to
genetic drift, which can result in a loss of
genetic variation
Hardy-Weinberg principle
who compared the
genetic diversity of Island and Mainland
the population of both animals and plants
Richard Frankham (1997)
organisms are solely found in a particular area or habitat
Endemic
lower in isolated and generally small, island populations
Genetic variation
cannot be eliminated as a contributor to the higher extinction rates observed on islands.
Genetic factors
Host for Melitaea cinxia
Plantago lanceolata and Veronica spicata
mating between close relatives, is more likely in small populations,
Inbreeding
indicator of genetic variability
Heterozygosity
animal and plant breeders have produced thousands of varieties of domesticated plants and animals from a wild ancestor
Artificial selection
alteration of the genetic makeup of an organism through the introduction or deletion of genes.
genetic engineering
The weeds in fields planted with genetically modified, herbicide-resistant soybeans can be controlled with herbicides, in a system of cultivation called
no-till agriculture
Reduced production cost, higher crop yield, reduced soil erosion, and better weed control.
benefits
the world’s most widely used herbicide, commonly sold under the trade name of Roundup.
Glyphosate
Defined as a group of individuals
of a single species inhabiting a specific area. It may consist of highly localized groups of
individuals representing a fraction of the total
the population of species or it may consist of all
the individuals of a species across its entire
range
Population
Ecologists study populations for many reasons:
- Saving endangered species
- Controlling pest populations
- Managing fish and game populations
- Offer clues to understanding and controlling
disease epidemics - Growth of the human population
summarizes the
environmental factors that influenced the
growth, survival, and reproduction of species
niches
centered around the influences of the
physical environment
Grinnell
included biological interactions, as well
as abiotic factors.
Elton
defines the physical
conditions under which a species might live, in
the absence of interactions with other species.
fundamental niche
the actual niche of a species
whose distribution is limited by biotic
interactions such as competition, predation, disease, and parasitism.
realized niche
described how along the coast of Scottland, adult Chthamalus stellatus is restricted to the upper levels of the intertidal zone while adult Balanus balanoides are limited to the middle and lower levels
Joseph Connell (1961)
suffer higher mortality
Balanus balanoides
appear to be more vulnerable to desiccation or drying
Balanus
refers to small distances over which there is little environmental change significant to the organism under study
Small scales
refers to areas over which there is substantial environmental change. Patterns over an entire continent or patterns along a mountain slope or environmental gradient.
Large scale
Three Basic Patterns of Distribution observed on Small Scales
random, regular, and clumped
an individual has an equal probability of occurring anywhere in an area
- neutral interactions between individuals, and between individuals and the local environment.
Random
individuals are uniformly spaced through the environment - antagonistic interactions between individuals or local depletion of resources.
Regular
individuals live in areas of high local abundance, separated by areas of low abundance.
Clumped
The young shrubs tend to be clumped for three
reasons:
- Seeds germinate at a limited number of “safe sites”
- Seeds are not dispersed far from the parent
plant. - Asexually produced offspring are
necessarily close to the parent plant.
who map patterns of bird
abundance across North America using the
Christmas Bird Counts (begin in 1900)
Terry Root
High density and appear as red
patches
Hot spots
he produces one of the clearest demonstrations of the relationship between body size and population density (Herbivorous mammals).
John Damuth (1981)
pointed out that plant
Ecologists have been studying the relationship
between plant size and population density for a
longer time
James White (1985)
one of the most fundamental aspects of
population biology.
relationship bet. size and density
add individuals to populations
births and immigration
remove
individuals from populations
deaths and emigration
concerned with the
factors influencing the expansion, decline, or
maintenance of populations
Population dynamics
Honey bee SN
Apis mellifera
Can increase or decrease local
population densities. It is an important aspect of population dynamics.
Dispersal
dispersed by winds, water or
transported by a variety of mammals.
Plant seeds
may spend their lives attached to rocks
Barnacle
travel the high seas on far
ranging ocean currents
Larvae
often disperse from
the area where they are born and may join
other local populations
Young mammals and birds
changes in the density
of predator populations in response to
increased prey density.
Numerical responses
part of a larger population, with
which it sustains a limited exchange of individuals
through immigration and emigration. (ex. population
of butterflies that lives in a specific place and then
scattered)
subpopulation
group of subpopulations living on such patches
connected by exchange of individuals among
patches
metapopulation
Rocky mountain parmesan butterfly
Parnassius smintheus
summarizes the pattern of
survival in a population.
survivorship curve
bookkeeping devices that list both the survivorship and the deaths, or mortality, in populations.
life tables
A group born during the same time period; for
example, the same year
Cohort
A life table made from data collected in this way is
called
cohort life table
Record the age at death of
a large number of individuals. The method
involves a Snapchat of survival within a
population during a short interval of time
Static life table
consists of the proportion
of individuals of different ages within a
population
age distribution
indicate periods of successful
reproduction, periods of high and low survival,
and whether the older individuals in a
population are replacing themselves or if the
population is declining.
age distribution
population reflects its
history of survival, reproduction, and potential
for future growth.
age distribution
A relatively high rate of survival among young
and middle-aged individuals followed by a high
rate of mortality among the aged
type one survivorship
Constant rates of survival throughout life
produced this straight line pattern survival
type 2 survivorship curve
period of extremely high rates of
mortality among the young is followed by a
relatively high rate of survival
type 3 survivorship curve
Three types of Survivorship Curves
type one, type two, type three
the number of young born per female in
a period of time
birthrate
The tabulation of birthrates for females of
different ages in a population
fecundity schedule
Fluctuation is
produce by large scale climatic system
El nino
Two complementary approaches
- Mathematics to model population growth
- Studies of laboratory and natural populations
grows slowly at first then faster and faster.
Population grow accelerate
maximum rate
which successive
generations differ in size by a constant ratio.
geometric population growth
express the rate of
population growth which is the change in
numbers with change in time as per the capita rate
of increase
exponential growth
have a tremendous
capacity for increase, and unlimited population
growth cannot be maintained in any
population for very many generations
Natural populations
estimate population sizes in growth by
counting the number of pollen grain of each
tree species deposited within lake sediments.
By counting the number of pollen grains per
square centimeter deposited each year
Bennett (1983)
which first appeared in the pollen record of the
study lake about 9,500 years ago.
Pinus sylvestris
Eurasian collared dove
Streptopelia decaocto
Environmental limitation
is incorporated into another model of
population growth
population growth
The population size at which
growth stops, which is the number of
individuals of a particular population that the
environment can support.
carrying capacity or K
obtained sigmoidal growth curves
for populations of several species of yeast and
protozoa
Gause (1934)
Because the effects of biotic factors, such as
disease and predation, are often influenced by
population density, biotic factors are often
referred to
density-dependent factors
Abiotic factors, such as floods and extreme
temperature, can exert their influences
independently of population density and so are
often called
density-independent factors
can influence populations in a
density-dependent fashion.
Abiotic factors
can affect
populations in a density-independent way
Biotic factors
one of the main sources of
food for cactus finches on Genovesa Island
Opuntia helleri
the most populous countries
on the planet.The remainder of the human
population is spread across Africa, Europe ,
North America , and South and Central America
and the Caribbean . The remainder live in
Oceania (Australia, New Zealand, and scattered
oceanic islands)
China and India
projected
to decline to less than 0.5% by 2050.
Global growth rate
Redwood tree SN
Sequoia sempervirens
consists of the adaptations of an
organism that influence aspects of its biology
such as the number of offspring it produces, its
survival, and its size and age at reproductive
maturity.
Life history
underscores the fact
that if an organism uses energy for one function
such as growth, it reduces the amount of
energy available for other functions such as
reproduction.
principle of allocation
who pointed out that fish show
more variation in many life history traits than
any other group of animals
Winemiller (1995)
ranges from the one or
two large live young produced by mako sharks
to the 600,000,000 eggs per clutch laid by the
ocean sunfish
clutch size
interested in determining the relationship between egg size and egg number, or fecundity, and the extent of
gene flow among populations.
Turner and Trexler (1998)
simply the number of eggs
or seeds produced by an organism
Fecundity
are small, stream-lined benthic
fishes that live in rivers and streams
throughout eastern and central North
America
Darters
an important face of the
population biology of all organisms,
including plants.
dispersal
Species with woody
thickening of their tissues were considered as
woody plants
climbing plants and vines were classified as
climbers
If seeds had hooks, spines, or barbs,
they were classified as
adhesion-adapted
seeds with wings, hairs, or other
structures that provide air resistance
were assigned to
wind-dispersed category
a structure on the surface of some
seeds generally containing oils attractive to
ants, as ant-dispersed
elaiosome
Seeds with an aril, a fleshy covering of some
seeds that attracts birds and other vertebrates,
or with flesh were classified as
vertebrate dispersed
those seeds known to be
gathered by mammals and stored in scattered
caches or hoards.
scatterhoarded
the allocation of energy,
time, and other resources to the production
and care of offspring.
Reproductive effort
explored life history
variation among snakes and lizards to
determine whether generalizations developed
through studies of fish and marine
invertEbrates could be extended to another
group of animals living in very different
environments.
Shine and Charnov (1992)
limited energy supplies are allocated to
three functions:
maintenance, growth, and reproduction
explored patterns in adult survival and reproductive
effort among 28 populations of fish.
- strong relationship between adult
mortality in populations and reproductive
effort because some combinations of
mortality and reproductive effort have a
higher probability of persisting than others.
Donald Gunderson (1997)
was taken as the ovary weight of each
species divided by the species body
weight and adjusted for the number of
batches of offspring produced by each
species per year
Gonadosomatic index or GSI
studied the influence
of adult survival on pumpkinseed sunfish life
histories
Bertschy and Fox (1999)
which refers to the per
capita rate of increase, as selection favoring a
higher population growth rate.
R selection
refers to the carrying capacity of the
logistic growth equation
K selection
developed the concept of r and K selection
further in two important papers.
that r selection and K selection are the
endpoints on a continuous distribution and that
most organisms are subject to forms of
selection somewhere in between these
extremes.
Eric Pianka (19970, 1972)
