BIO 1070- Inquiry Case 1: UNIT 1
- Zebra mussels were native to the Caspian see and the Black sea
- They were most likely transported here by the ballasts tanks of liners
- The zebra mussel was first discovered in 1988 in lake St. Claire.
- Around the world there are over 850 different species of mussels.
- Within North America there are 300 known species
- There are 41 species of mussels in Ontario.
Life cycle of a mussel:
- Unionids perform obligate parasitism meaning that they release there
eggs on another species of fish.
- Males release their sperm through the exhalant siphon and the females
take in the sperm with their inhalant siphon.
- Fertilization is internal and the embryos developed inside sacs called
- The embryos then mature into Glochidia and must be attached to the
gills of a fish host to continue to grow.
- The mantle tissue of the mussel can be in the shaoe of a smaller fish,
this allows for the bigger fish to go up close and get bitten by the
- At this time the mussel releases its glochidia and they attach to the
gills of the host.
Levels of biological organization: High to low
- DomainKingdomPhylum ClassOrderFamilyGenusSpecies
- Domain refers to organisms with eukaryotic cells
- Kingdom refers to animals
- Phylum refers to vertebrates
- Class refers to mammals
- Order refers to Primates
- Family refers to Hominidae
- Genus refers to Homo
- Species refers to Humans Genotype- same set of genes
Phenotype- differing physical features
Phenotypic Plasticity- when the same set of genes can cause differing
physical features according to environmental conditions.
Abundance- number of individuals
Diversity- number of species
Disparity- how physically different two species are
Genetic Variation- difference among individuals within among a species
Tree Thinking: Sister Taxa- 2 relatives from one recent ancestor
The Root- Common ancestor shared by all species depicted
Branches- Connections between ancestors and descendants
Terminal Nodes (tips)- living species
Internal Species- extinct ancestors
A clade is a section of the tree that contains both of the sister taxa, if one
of the taxa was cut off it would not be a clade.
Natural selection: Non-random differences in survival and/or reproduction
among individual entities on the basis of differences in heritable
Adaptation: 1) a characteristic that enhances the survival and/or
reproduction of organisms that bear it, relative to alternative (especially
ancestral) character states; 2) a physical, physiological, behavioural, or other
characteristic evolved through natural selection. Adaptation is NOT the
change undergone by an individual organism during its lifetime in response
to external conditions.
Population: for sexual species, a group of interbreeding individuals and
Alleles: alternate (i.e., different and mutually exclusive) forms of a gene.
e.g., “B” (brown eyes) versus “b” (blue eyes).
Genotype: the set of genes possessed by an organism.
Phenotype: the physical expression of the genotype (in combination with
Frequency: the proportional representation of a phenotype, genotype,
gamete, or allele in a population. e.g., 6 out of 10 have blue eyes = 60% = a
frequency of 0.6.
Mutation- the origin of new genetic variation
Gene Flow- movement of genes among populations Genetic Drift- changes due to chance, specifically founder effects and
population bottlenecks. Ex. Astroup moves from one island to another and
can no longer return to the 1 island.
4 rules of natural selection:
1. Individuals within populations are variable.
2. This variability among individuals is at least partly heritable.
3. Not everyone survives and reproduces, and some individuals
are more successful than others.
4. The differential survival and reproduction of individuals is
associated with the heritable variation among individuals (i.e., it
Natural selection can occur where there is a individual among a
population that can withstand a certain destroyer. As the population that is
not immune to this destroyer is killed off the ones that are immune can keep
reproducing until only that immune trait is left thus making the destroyer
useless against that new population.
Another way that natural selection can occur is when a mutation occurs
within a population causing a certain individual to be immune to the
destroyer. This causes the ones that aren’t immune to die off and the one that
is to reproduce and live on. This immune respones can also cause an
increased offspring count… meaning that for every one that dies two are
made compared to the ones that aren’t immune that produce 1 and die. This
causes the overall population to become more dominant in the immune
Genetic Isolation- genetically isolated groups can only form if some
factor(s) prevents gene flow between populations.
Extinction- a species has been removed from the earth.
Extirpation- extinction of a species may not be permanent if the species can
be re-introduced to its native range. BIO 1070- INQUIRY CASE 2:
Bio Diversity- biodiversity as “the variability among living organisms from
all sources including, terrestrial, marine and other aquatic ecosystems and
the ecological complexes of which they are part; this includes diversity
within species, between species and of ecosystems.”,
Species Richness- Number of species in an area.
Abiotic- non-living factors such as chemicals that affect the environment
and species within it
Biotic- living factors such as other animals or trees that affect the
environment and the species within it
Population- total number of individuals in an area at a given time
Community- the various species living in an are at a given time
Ecosystem- a system formed by the interaction of a community of
organisms with their physical environment.
Population Growth: growth rate = birth rate – death rate + immigration –
Carrying Capacity- the point in which a environment is at its maximum
level for supporting the species that inhabit it. If this point is crossed the
environment can no longer sustain the number of individuals living within it,
this causes individuals to die off. Species Interactions:
- Mutualism both individuals benefit from each other
- Neutralism two species interact but do n affect each other
- Amensalism one organism has a negative effect on another
- Antagonism one species benefits at the expense of the other
- Commensalism one organism benefits when the other is neither
benefited nor harmed
- Predation organism that hunts its prey
- Competition mutually determined interaction between two
Abiotic Variables: Abiotic factors are those non-living physical and
chemical factors that affect the ability of organisms to survive and
reproduce. This includes those inert factors of the ecosystem such as light,
temperature (heat), chemical products, water and atmosphere.
Realized Niche- is the set of environmental plus ecological conditions in
which a species actually lives
Fundamental Niche- is the set of environmental plus ecological
conditions in which a species could reside but doesn’t Habitat- regions in environmental space that are composed of multiple
dimensions, each representing a biotic or abiotic environmental variable;
that is, any component or characteristic of the environment related directly
(e.g. forage biomass and quality) or indirectly (e.g. elevation) to the use of a
location by the animal or plant.
Functional Trait: a term that is used to define a species role within its
Ecosystem Engineering: organisms that directly or indirectly modulate the
availability of resources to other species, by causing physical state changes
in abiotic or biotic variables.
Old Growth Forests:
relatively large trees – Large basal (please read) area and or tall
* meso/microhabitat diversification
presence of large logs and abundant coarse woody debris (CWD)
relatively old trees
* presence of large crown gaps (in some forest
* presence of tree hollows and/or fallen trees
* presence of indicator species
* presence of
certain growth forms, such as epiphytes in some forest types
* characteristic levels of gross and net productivity
* stable nutrient
cycles, high litter levels (in some vegetation classes)
* low or
negative biomass increment
* low rates of change in species, forest
structure and ecosystem functioning
* evidence of physical disturbance (like fire, logging, grazing,
* evidence of biological disturbance (such as introduced
weeds or pathogens)