bio 2200 exam 1

ecology definition

the scientific study of the natural environment and relationships of organisms to one another and their surroundings

population

a group of individuals of the same species living in an area

populations are the unit of

evolution

ecosystem is a flow of

energy and matter

individuals are the unit of

natural selection

community

all populations of different species living together in an area

ecosystem

one or more communities interacting with their nonliving physical and chemical environments

what is an individual

genetically identical organism that survives and reproduces

what is a species

same biological features that can reproduce. some species can interbreed and produce hybrids

examples of communities

plant community, forest plant community

community features

no distinct boundaries, defined by researchers

evolution

change in the genetic composition of a population over time

ecology and evolution are linked by

natural selection

natural selection

change in frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes

predation leads to … leads to …

predation leads to differential survival, leads to adaptation via natural selection

why can there be natural selection operating even without interactions between species

it can arise from abiotic conditions

phenotype

morphology, behavior, physiology

fitness

the survival and reproduction of an individual

genotype

genes carried by an individual

protists

red algae, green algae, other protists

eukaryotes

protists, plants, fungi, animals

prokaryotes

bacteria (eubacteria) and archaea (archaebacteria)

eukaryotes have

organelles

autotroph

can convert abiotic sources of energy into stored energy in organic compounds, which can be used by other organisms.

heterotroph

an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly matter from other organisms. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but not producers.

mixotroph

an organism that uses a mix of different sources of energy and carbon, instead of having a single trophic mode.

herbivore

consumer producers- eat plants or algae

predator

kill and partially/entirely consume another individual

competition

interaction with negative effects between 2 species that depend on the same limiting resource to survive, grow, and reproduce

mutualism

interactions in which each species receives benefits from the other

lichen

example of mutualism and symbiosis- algae and fungi

symbiosis

2 different species living very closely together

habitat

the physical setting in which an organism lives

niche

the range of biotic and abiotic conditions that an organism can tolerate. multidimensional

principle of niches

no two species can have exactly the same niche

steps of ‘doing’ ecology

1. observe nature

2. make hypothesis

3. make prediction

4. do an experiment and test the hypothesis (randomize too)

5. measure response and analyze results- was the prediction correct?

mean

average

variance

the spread of data around the mean

natural experiments

experiments that rely on natural variation in the environment

2 experiment types

natural and manipulative

manipulative experiment pros

more control

manipulative experiment cons

less realistic

harder to test long processes

if large scale, costly

natural experiment pros

more realistic

easier to get permission

larger scale with less cost

natural experiment cons

not as much control

harder to get direct causation

what is a gene

a region of DNA that codes for a particular protein, affecting the traits

what is an allele

different versions of a particular gene

gene pool

all the different alleles from all individuals in a population

codominant alleles

Alleles that are both fully and simultaneously expressed in the phenotype of a heterozygote.

polygenic traits

traits that are affected by more than 1 gene

pleipotropy

when a single gene affects multiple traits

epistasis

when the expression of one gene is controlled by another gene

3 methods of getting genetic variation

1. sexual reproduction

2. mutation

3. recombination

mutation

random change in the sequence of nucleotides in DNA

recombination

exchange of DNA between homologous chromosomes during meiosis

what are the 2 needs for evolutionary change

genetic variation that leads to phenotypic variation

and

random/natural/artificial selection

selection

a process by which certain phenotypes are favored to survive and reproduce over others

directional selection

favors one end of the phenotypic range

stabilizing selection

favors the averages of the phenotypic range rather than the extremes

disruptive selection

favours extreme phenotypes

what can the relationship between fitness and phenotype be used to predict

what type of selection will occur

strength of selection (s)

the difference between the mean of the phenotype distribution before and after selection

heritability

the proportion of the phenotype that is controlled by genes

formula for response to selection

strength of selection (s) x heritability

random processes that can cause evolutionary change

1. genetic drift

2. founders effect

3. bottleneck effect

genetic drift

changes in allele frequencies due to random variation in mating, mortality, fecundity and inheritance

bottleneck effects

a reduction of genetic diversity in a population due to a large reduction in population size

founder effects

a few individuals colonize a new area, and bring only a small amount of genetic variation

microevolution

the evolution of populations (changes in gene frequencies over time)

macroevolution

evolution at higher levels

example of macroevolution

speciation

speciation

evolution of new species

what do phylogenetic trees show

hypothesized patterns of relatedness among species or higher taxonomic groups

two types of speciation

allopatric and sympatric

allopatric speciation

evolution of new species through the process of geographic isolation

sympatric speciation

evolution of new species without geographic isolation

life history

the schedule of an organisms growth, development, reproduction, and survival

fecundity

number of offspring produced per reproductive episode

parity

number of episodes of reproduction, can be semelparous or iteroparous

semelparous

1 reproductive episode per lifetime

iteroparous

many reproductive episodes per lifetime

parental investment

how much time/energy is given to offspirng

determinate growth

stop growing once reaching sexual maturity

indeterminate growth

keep growing even after reaching sexual maturity and starting to reproduce

overall goal of life

maximize fitness- survival and reproduction

trade-offs for fitness

1. physical constraints

2. genetic constraints

3. finite time/energy/nutrients

principle of allocation

when resources are used for one body structure, physiological function, or behavior, they cant also be used for something else

grimes classification of life history traits in plants

competitors → ruderals → stress toleratos

competitors (grimes)

low stress, low disturbance = fast growth, early maturity, low perc. of energy to seeds, often veg. reproduction

ruderals (grimes)

low stress, lots of disturbance = fast growth, early maturity, lots of energy towards making seeds

stress tolerators

high stress, low disturbance = slow growth, late maturity, low perc. of energy to seeds, lot of veg. reproduction

annuals

live one year only

perrenials

live > 1 year

what happens to parental care with more offspring

less parental care per offspring (ex- food, protection)

an individual can use energy for 2 things

growth and reproduction

reproduction style of a long life expectancy

growth first, get large, then reproduce since bigger bodies have more babies

environmental conditions can affect life history strategies due to…

1. the availability of resources

2. the presence/abundance of predators

organisms need … to know when it is the right time to migrate, reproduce, hibernate, etc

CUES, such as temperature or photoperiod

sexual reproduction

fusion of 2 haploid gametes

asexual reproduction

no fusion of haploid gametes, DNA inherited from 1 parent only

2 types of asexual reproduction

parthogenis and vegetative reproduction