chapter 1 Flashcards
What is ecology?
The scientific study of the natural environment and the relationships of organisms to eachother and their surroundings
What does oikos mean
-greek word for house
Population
a group of indivduals of the same speices living together in a certain area
community
all pop of species living together in an area
ecosystem
one or more comunities interacting with their non-living physical and chemical environments
What is an species?
a group of organisms that naturally interbreed with eachother and produce fertile offspring
what is an indidividual
a living being, most fundamental unit of eco
biosphere
all of the ecosystems on earth
Evolution
change in genetic compositon of a pop. over time
individual approach
the individuals morphology, physiology, and behaviour enable it to survive its environment
adaption
a characteristic of an organism that makes it wellsuited to its environment
population approach
variation over time and space in the number, density, and the composition of individuals
community approach
the diversity and relative abundances of different kinds of organisms living together in the same place
ecosystem approach
the storage and transfer ofi energy and matter, inlcuding the various chemical elements essential to life
biosphere approach
largest scale in the hierarchy of eco. systems. (movements of air and water)
natural selection
change in frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes
Could there be natural selection operating even
without interactions between species?
Yes, adaptions to non-living conditions ex, climate change
Phenotypes
colour, behaviour, ect
genotype
genes carried
fitness
the survivial and reproduction of an individual (purple caterpillers had low fitness)
what do eukaryotes have?
organelles
ex, autotrophs, heterotrophs, mixotrophs
law of conservation of matter
matter cannot be created or destroyed, can only change form
first law of thermodynamics
energy cannot be created or destroyed, it can only change form
dynamic steady state
when the gains and losses of ecological systems are in balance
What are the types of species interactions
herbivore
predator
competition
mutualism
Producer
an organism that uses photosynthesis to convert solar energy into organic compounds or uses chemosynthesis to convert chemical energy into oganic compounds.
(autotroph)
consumer
an organism that obtains its energy from other organisms
(heterotroph)
mixotroph
organism that obtains its energy from more than one source
predator
an organism that kills and partially or entirely consumes another individual
Herbivore
consumes producers (plants/algae)
Competition
interaction with negative effects between 2 species
that depend on the same limiting resource to survive, grow, and reproduce
mutalism
an interaction between 2 species in which each species recieves benefits from the other
(bees and flowers)
parasitoid
an organism that lives within and consumes the tissues of a living host, eventually killing the host
parasite
an organism that lives in or on another organsim but rarely kills it
pathogen
a parasite that causes disease in its host
what is lichen an example of?
mutalism and symbiosis
symbiosis
2 different species living closely together, like hyphae and algal cells
commensalism
interaction between 2 species that live close and one species receives the benefit while the other has a cost or no benefit
habitat
the place, or physical setting, in which an organism lives
fish= stream
NICHE
The range of biotic and abiotic conditions that an organism can tolerate
NICHE principle
no 2 species can have exactly the same niche due to compeition
sacvenger
an organism that consumes dead animals
detritivore
an organism that feeds on dead organic matter and waste products that are collectively known as detritus
decomposer
organism that breaks down dead organic material into simpler elements and compounds that can be recycled through the ecosystem
How do we do eco
1: do natural history (go out and observe nature- why a big wont eat something
2:make a hypo -
3: make a prediction (IF/THEN)
4: design an experiment to test hypo
5: measure response and analyze results - was the prediction correct?
Why is it important to randomize?
prevent bias/ influence of unmeasured factors
mean
the average
variance
the spread of the data around the mean
What does it mean if a sample has greater variance?
it does not mean that the data are inaccurate or unreliable
what does it mean if there is an overlap?
means there is greater variance
natural experiments
experiments that rely on natural variation in the environment
ex; places with more trees have more plants then those without
manipulative experiment
a process by which the hypo is tested by alternating a factor
-50/100 forests were cut down and now we wait to see what happens
control
a manipulation that includes all aspects of an experiment except the factor of interest
experimental unit
the object to which we apply an experimental manipulation
replication
being able to produce a similar outcome multiple times
What is a gene
a region of DNA that codes for a particular protein
What is an allele?
different forms of a particular gene
(gene pool)
natural experiments pros and cons
pros:
more realistic
more ethical
less expensive
can study longterm
cons:
less control (underlying factors)
relay on varation available
manipulative experiments pros and cons
pros:
more control
more easily repeatable
cons:
expensive
have to wait
could be unethical
what are gene pools
all the different alleles from all individuals in a pop
Polygenic
when a single gene trait is affected by several genes
ex height
pleiotropy
when a single gene affects multiple traits
ex: frizzle gene in chickens make weird feathers but also makes them have fewer eggs and slower digestion
epistatsis
when the expression of one gene is controlled by another gene
1 gene = brown or black fur
2 gene = no colour (white fur)
heterozygous
when an individual has 2 different alleles of a particular gene
homozygous
when an indivual has 2 identical alleles of a particular gene
how do we get genetic variation?
1: sexual reproduction
2: mutation
3:recombination
mutation
random change in the sequence of nucleotides in the DNA
Recombination
exchange of DNA between homologous chromosomes during meiosis
recipe for evolutionary change
we need genetic variation that leads to phenotype variation
selection or random processes
selection
process by which certain phenootypes are favoured to survive and reproduce over others
-natural or artifical
relationship between fitness and phenotype
can be used to predict what type of selection will occur
Strength of selection
the difference between the mean of the phenotype distribution before and after selection
heritability
the proportion of the phenotype that is controlled by genes
response to selection
strength of selection x heritability
Evolutionary change can also occur with-
genetic drift
bottleneck effect
founder effect
Genetic drift
changes in allele frequencies due to random variation in mating, mortality, fecundity and inheritance
-more common in small populations
bottleneck effects
a reduction of genetic diversity in a population due to a large reduction in population size
Founder effects
small number of individuals leave a large pop to colonize a new area and bring with them only a small amount of genetic variation
-higher rates of alleles that cause certain diseases
microevolution
the evolution of populations (changes in gene frequencies over time)
macroevolution
-evolution at higher levels (species)
-includes speciation
speciation
the evolution of new species
Phylogentic trees
show hypothesized patterns of relatedness among species or higher taxonomic groups
types of speciation
allopatric and sympatric
allopatric
evolution of new species through the process of geographic isolation
sympatric
evolution of new species
WITHOUT geographic isolation
industrail melanism
cause habitats to become darker due to pollution and individuals start pocessing darker phenotypes are favoured by selection
polyploid
a species that contains three or more sets of chromosome
Life history:
the schedule of an
organism’s growth, development, reproduction, and survival
reproduction: ogranisms can differ in-
-time to reach sexual maturity
-fecudity
-parity
-parental investment
what is the point of life?
-live, reproduce, and die
fecundity
the number of offpring produced by an organism per reproductive episode
parity
the number of reproductive episodes an organism experiences
perental investment
the amount of time and energy given to an offspring by its parents
longevity
the life span of an organism
(life expectancy)
types of Growth:
determinate
indeterminate
determinate
stop growing once reaching sexual maturity
-most birds and mammals
inderteminate
keep growing even after reaching sexual maturity and starting to reproduce
overall goal
to maximize fitness (survial and reproduction)
BUT there are trade-offs
one organism can’t produce lots of offspring AND large offspring AND give them lots of parental care AND grow fast AND live a long time
Why not? trade offs for overall goal
- physical constants
size of uterus, cant birth an elephant
-genetic contrants
-plecotropy
-finate time, energy, nutrients
principle of allocation
When resources are used for one body structure,
physiological function, or
behaviour, they cant also be used for something else
life history strategies are related to…:
envirnomental conditions
Consider a species with a fast potential growth rate, reproduction at a relatively
early age, allocation of a small proportion of net production to seeds, and reliance on vegetative spread. According to Grime’s classification of life history traits, this species fits the profile of a-
competitor
Annuals
live 1 year (or less)
perennials
live more than 1 year
Which is more likely to be a ruderal, annual or perennial
annuals, everything done fast, then they die
semiparity
when organisms reproduce only once during their life
lteroparity
when organisms reproduce muiltple times during their life
senescence
a gradual decrease in fecundity and an increase in the probability of mortality
parental care
more babies, less care
trade offs between # babies and parental care per baby
extra effort of feeding extra chicks = reduced survival for parents = lower fitness as they cant reproduce anymore if they are dead
photoperiod
the amount of light that occurs each day
trade-off between growth and reproduction
if life expectany is long
-grow first and get big, then have babies (bigger or more babies)
if life is short
-reproduce ASAP
Environmental conditions can affect life history strategies. can be due to-
1) the availability of resources
2) presence or abundance of predators
timing is important
organisms need to time their life history events to occur at the right time
- need CUES to know when is the right time to: e.g. migrate, reproduce, hibernate, etc.
- CUES could include things like: temperature, photoperiod
-birds lay eggs at a certain time so when they hatch there is plenty of food
If birds are laying their eggs earlier in response to the
temp warming up earlier, why wouldn’t the caterpillars shift their life history earlier as well?
they dont use temperture as a cue for their life history timing
sexual reproduction gametes
fusion of 2 haploid gametes
asexual
no fusion of haploid gametes, DNA inherited from 1 parent only
asexual types
-vegetative reproduction
-parthenogenesis
vegitative reproduction
-offspring comes from non-sexual tissues
-exact clones
parthenogenesis
embryoo produced without fertilization
-if meiosis occurs first- not clones
-if no meiosis- clones
pros and cons for asexual reproduction
pros:
no cost for meiosis
dont have to find a mate
dont have to spend energy on sexual displays/mating rituals/ sexual organs
cons:
less genetic varability
harmful mutations are harder to get rid of (can be passed on)
pros and cons for sexual reproduction
pros:
purging deleterious mutations
increased genetic variation
-increased ability to adapt to changing conditions
-parasites or predators
cons:
more energy for sexual organs, mating rituals
cost of meiosis
increase risk of predational herbivory (making noise to attract mates but also attracting predators)
Red queen hypo
Sexual reproduction allows
hosts to evolve at a rate just
fast enough to match the rapid evolution of their parasites
binary fission
reproduction throuigh duplication of genes followed by divition of cell into 2 identical cells
Prediction: If the Red Queen Hypothesis is true, then…
asexual populatinos will have significantly higher parasite loads than sexual populations
Different ways to do sexual
reproduction:
seperate sexes vs both sexes in one individual = hermaphrodite
plants can be hermaphrodites in two different ways:
1: each flower has both male and female parts (perfect flowers)
2: one plant has some flowers that are male and some that are female
2/3 flowers are perfect
Hermaphrodites can self-fertilize
female and male gametes from the same individual
- potential problem:
inbreeding depression:
what is inbreeding depression
a decrease in fitness caused by mating, between close relatives
how to prevent selfing (inbreeding)
1: male and females parts can mature at different times
2: self-incompatibilty
simultaneous hermaphrodies
individuals that possess male and female reproductive functions at the same time
seqyential hermaphrodites
individuals that possess male or femal reproductive function and then switch to possess the other function
monoecious
plants that have seperate male and female flowers on the same individual
dioecious
plants that contain either only male flowers or only female flowers on a single individual
When do plants want to self fertilize (inbreed)
1: when resources are low or far cuz outcrossing flowers cost more energy to produce
2: when mates are hard to find (pop density is low)
Sex determination
1:in mammals, birds, some others: inheritance of specific chromosomes
-male birds zz,
-female birds zw
(2) in some turtles, lizards, alligators: determined by the environment the egg is in
-phenotypic plasticity (egg with SAME genotype can turn out either male OR female)
The degree of environmental sex determination can vary across environments
ex fish
bigger females = more eggs (= greater fitness)
IF growing season is LONG, females that hatch earlier can get really BIG (best for females)
IF growing season is SHORT – short time to grow, no matter when they hatch.
-no benefit, females or males
In many populations of species with separate sexes, the ratio is 1:1.. why?
Frequency dependent selection: when the rarer phenotype in a population is favored by natural selection.
-if males are less common, newborn males have greater chance of mating cuz there is less males
local mate competition
when competition for mates occurs in a very limited area and only few males are required to fertillze all of the females
mating systems
the number of mates each
individual has, and the permanence of the relationship
PROMISCUITY:
-leaving it to chance
males mate with many females, females mate with many males
-no lasting bond
Polygamy
single individual of one sex forms a long-term socail bond with more than one individual of the opposite sex
monogamy
usually (relatively) permanent
– favoured when males make important contributions to raising offspring
selection
the process by which certain phenotypes are favoured to survive and reproduce over other phenotypes
sexual selection
natural selection for sex-specific traits related to reproduction
-female choice
-life history difference
-conflicts between males
sexual dimorphism
the difference in the phenotype between males and females of the same spieces
bigger females for eggs, smaller males cuz sperm is small
-spiders
Male conflict
larger antlers = more likely
to win conflict = more likely to get to mate with females = selection for larger conflict in males
examples of sexual selection
sexual dimorphism
male conflict
female choice
female choice
- females mate with males that have longer tails more often than they mate with males that have short tails
- therefore, greater fitness for longer tailed males
- therefore, sexual selection for longer and longer tails
why do males prefer longer tails
indication of good health or genes
What females are looking for:
Material benefits:
place to raise chicks, high quality territory, abundant food
Non-material benefits:
indicator of superior genes or health
good gene hypo
females choose mates based on indicators of good
genes
good health hypo
females choose mates based on indicators of good
health
When would selection for longer and longer tails stop?
-when it lowers male fitness
-when genetic variation runs out
polygyny
a mating system in which a male mates with more than one female
polyandry
when a female mates with more than one male
extra-pair copulations
when an individual that has a socail bond with a mate also breeds with other individuals
mate guarding
a behaviour in which one partner prevents the other partner from doing extra-pair copulations
primary sexual charcateristics
traits related to fertilization
secondary sexual characteristics
traits related to differences between the sexes in terms of body size, ornaments, colour, and courtship
runaway sexual selection
when selection for preference of a sexual trait and selection for that trait continue to reinforce each other
the handicap principle
the greater the handicap an individual carries, the greater its ability must be to offset that handicap
Why do organisms often live in groups? What are the benefits and costs of group living?
-help finding and killing food/prey
-easier to find mates
benefits:
increased survival
-defend against predators and watch for them
dilution effect
-reduced probability of predation for a single animal when in a group
social behaviours
interactinos with members of ones own speices, including mates, offspring, other relatives, and unrelated individuals
cost of living in a group
-competition for food and other resources
-greater risk of parasites and disease (easier to spread)
-big groups= easier to find
what is a territory
an area defended by one or more individuals against the intrusion of others
- can be transient (temporary) or permanent
A male bird establishes his territory in an area with lots of food resources for his future chicks.
What kind of benefits does this provide for his mate?
Material benefits
dilution effect
the reduced or diluted probability of predation to a single animal when it is in a group
Lek
the location of an animal aggregation to put on display attract the opposite sex
co-operation vs multualism
multualism is when 2 from 2 different species benefit eachother
co-operation= when 2 of the SAME species benefit eachother
co-operation
when the donor and the recipient both experience increased fitness from an interaction
-lions work together to find and kill prey
dominance hierachy
a socail ranking among individuals in a group, typically determined through contests such as fighting or other contests of strength or skill
donor
the individual who directs a behaviour towards another individual as part of a socail interaction
recipient
the individual who recives the behaviour of a donor in a social interaction
selfishness
when the donor of a social behaviour experiences increased fitness and the recipent expereiences decreased fitness
-one lion steals all of the prey the pack killed
spitefulness
when a social interaction reduces the fitness of both donor and recipeint
-none known for ex
alturism
a socail inteaction that increases the fitness of recipient and decreases the fitness of the donor
-one bee works to tend the
Queen bee’s offspring, and
doesn’t have its own offspring
How could altruism evolve?
fitness can be divided into DIRECT and INDIRECT fitness
fitness = survival and reproduction of an individual
higher fitness = pass on more of your genes
Direct fitness
fitness gained from passing your genes on to your offspring
indirect fitness (kin)
indirectly passing down some of your genes by helping your relatives raise their offspring (who share some of your genes)
inclusive fitness
direct fitness + indirect fitness
Coefficients of relatedness (r)
the probability of sharing the same copy of a gene
in diploid organisms, half of genes come from dad and half from mom therefore, r for mom and her offspring =0.5
r for full siblings = 0.5
direct selection
selection that favours direct fitness
indirect selection
selection that favours indirect fitness, also known as kin selection
indirect fitness for math stuff
if the recipient is not related
to the donor, r = 0, and indirect fitness = 0
For altruism to be favoured by evolution, need:
B x r > C
eusocial
social animal in which individuals live in large groups with overlapping generatins, co-opperation in nest building and brood care, and reproduction dominance by one or a few individuals
-Ants, bees
caste
individuals within a socail group sharing a specialized form of behaviour
haplodiploid
a sex-determination syetem in which one sex is haploid and the other sex is diploid
queen
the dom, egg-flying female in eusocial insect societies
calc indirect fitness
b x r
calc direct fitness
b x r x p
to get inclusive fitness
direct + indirect
Eusociality:
at least several adults living
together
- overlapping generations
- co-operation in nest building, taking care of young
- only one or a few individuals reproduce – the rest are sterile
- favoured by haplodiploid sex determination
