midterm #1
Tuesday, January 28, 2020 2:09 PM
What is Evolution: the process by which different kinds of living organisms are thought to h
developed and diversified from earlier forms during the history of the earth.
- Describes change
- Selection and random change
- All species are impacted by evolution as it is an ongoing and constant event
- Descent with modification; when parents have offspring's they tend to look and act a
different from their parents and each other due to random genetic mutations
- Change in allele frequency in a population
- Common descent; all living things on earth are related from a common ancestor
Theory of Evolution: gene distribution changes overtime
What is a Hierarchy?
- An arrangement of items (objects, names, values, categories, etc) in which the items a
represented as being above, below, or at the same level as another based on relative
status or authority
Nested hierarchy: groups of related organisms share suites of similar characteristics and the
number of shared traits increases with relatedness
- Groups fit neatly and completely inside other higher groups
- As you move up the hierarchy categories get more general/broad and include more an
more lover level categories (aka inclusion hierarchy)
- "One fits within the next"
Unionidae: the largest family of freshwater mussels in the order
- 850 known species with 300+ being in North America and 41 different species apart of
Unionidae family in Ontario
1. Males release sperm into the water through exhalent
2. Females uptake sperm through inhalant siphon (fertilization is internal)
3. Embryo develops inside marsupium; pouches in female gills
4. Embryos mature to glochidia; parasitic life stage
5. It attaches to host fish to fully mature
6. Adult unionid mussels exhibit adaptations to attract a host fish; mantle tissue forming
Dioecious: meaning mussels have two halves and are separate for male and female
Larval: after fertilization the eggs develop into a larval stage with temporarily parasites fish b
attaching onto a fishes gills or fin
Glochidium: a type of larval form of a freshwater mussel that attaches as an external parasit
a vertebrate host (fish) where it grows into a juvenile mussel
Obligate parasitism: mussel cannot complete life cycle without exploiting a host (fish)
Conglutinates: glochidia enclosed in membranous capsules that mimic host prey (fish), allow
glochidia to infest tissue after the capsule is broken. The fish eats, glochidia attaches itself th
,e
he
re
to
for
n
, 4. Embryos mature to glochidia; parasitic life stage
5. It attaches to host fish to fully mature
6. Adult unionid mussels exhibit adaptations to attract a host fish; mantle tissue
forming lure
Dioecious: meaning mussels have two halves and are separate for male and female
Larval: after fertilization the eggs develop into a larval stage with temporarily
parasites fish by attaching onto a fishes gills or fin
Glochidium: a type of larval form of a freshwater mussel that attaches as an external
parasite to a vertebrate host (fish) where it grows into a juvenile mussel
Obligate parasitism: mussel cannot complete life cycle without exploiting a host (fish)
Conglutinates: glochidia enclosed in membranous capsules that mimic host prey (fish),
allows for glochidia to infest tissue after the capsule is broken. The fish eats, glochidia
attaches itself then the fish spits it out
Some host capture strategies unionids use are:
1. Simple and complex lures
2. Conglutinates
3. Mussels can physically grip the host with teeth and pump glochidia over the gills
Veliger Mussels Reproduce
1. Mussel releases gametes directly into the water where fertilization takes place
and once released it attaches to a piece of shell or rock with byssal threads for
stability
2. As it grows to adulthood it loses the need and ability to produce byssal threads
therefore it relies on it's weight for stability
Zebra Mussels: dreissena polymorpha
- Native to eastern Eurasia (black and Caspian sea)
- First reported in the Great Lakes in 1988 in Lake St. Clair and spread rapidly
- Migrated from original habitat across the Atlantic ocean by moving through
ballast water of ocean liner (current)
Inquiry Case
Advantage
- Zebra mussels are an invasive spices to lakes in Ontario. They allow for lake
water to be clear and filtered; less particle matter due to the huge abundance of
zebra mussels. They filter massive amounts of water everyday and can attach
themselves to almost any solid object and to each other. Sand does not show
the invasion but docks below the water do
Disadvantage
- Dead mussels wash up in large amounts on the beach reducing the quality
- Damage by zebra mussels have already cost billions of dollars in efforts to
control
- Can clog pipes and cover industrial equipment
- Impact the native mussels of the region (North America), fresh watch mussels
are among the most endangered organisms
Genetic Variation: differences at the DNA level among individuals within a population
Tuesday, January 28, 2020 2:09 PM
What is Evolution: the process by which different kinds of living organisms are thought to h
developed and diversified from earlier forms during the history of the earth.
- Describes change
- Selection and random change
- All species are impacted by evolution as it is an ongoing and constant event
- Descent with modification; when parents have offspring's they tend to look and act a
different from their parents and each other due to random genetic mutations
- Change in allele frequency in a population
- Common descent; all living things on earth are related from a common ancestor
Theory of Evolution: gene distribution changes overtime
What is a Hierarchy?
- An arrangement of items (objects, names, values, categories, etc) in which the items a
represented as being above, below, or at the same level as another based on relative
status or authority
Nested hierarchy: groups of related organisms share suites of similar characteristics and the
number of shared traits increases with relatedness
- Groups fit neatly and completely inside other higher groups
- As you move up the hierarchy categories get more general/broad and include more an
more lover level categories (aka inclusion hierarchy)
- "One fits within the next"
Unionidae: the largest family of freshwater mussels in the order
- 850 known species with 300+ being in North America and 41 different species apart of
Unionidae family in Ontario
1. Males release sperm into the water through exhalent
2. Females uptake sperm through inhalant siphon (fertilization is internal)
3. Embryo develops inside marsupium; pouches in female gills
4. Embryos mature to glochidia; parasitic life stage
5. It attaches to host fish to fully mature
6. Adult unionid mussels exhibit adaptations to attract a host fish; mantle tissue forming
Dioecious: meaning mussels have two halves and are separate for male and female
Larval: after fertilization the eggs develop into a larval stage with temporarily parasites fish b
attaching onto a fishes gills or fin
Glochidium: a type of larval form of a freshwater mussel that attaches as an external parasit
a vertebrate host (fish) where it grows into a juvenile mussel
Obligate parasitism: mussel cannot complete life cycle without exploiting a host (fish)
Conglutinates: glochidia enclosed in membranous capsules that mimic host prey (fish), allow
glochidia to infest tissue after the capsule is broken. The fish eats, glochidia attaches itself th
,e
he
re
to
for
n
, 4. Embryos mature to glochidia; parasitic life stage
5. It attaches to host fish to fully mature
6. Adult unionid mussels exhibit adaptations to attract a host fish; mantle tissue
forming lure
Dioecious: meaning mussels have two halves and are separate for male and female
Larval: after fertilization the eggs develop into a larval stage with temporarily
parasites fish by attaching onto a fishes gills or fin
Glochidium: a type of larval form of a freshwater mussel that attaches as an external
parasite to a vertebrate host (fish) where it grows into a juvenile mussel
Obligate parasitism: mussel cannot complete life cycle without exploiting a host (fish)
Conglutinates: glochidia enclosed in membranous capsules that mimic host prey (fish),
allows for glochidia to infest tissue after the capsule is broken. The fish eats, glochidia
attaches itself then the fish spits it out
Some host capture strategies unionids use are:
1. Simple and complex lures
2. Conglutinates
3. Mussels can physically grip the host with teeth and pump glochidia over the gills
Veliger Mussels Reproduce
1. Mussel releases gametes directly into the water where fertilization takes place
and once released it attaches to a piece of shell or rock with byssal threads for
stability
2. As it grows to adulthood it loses the need and ability to produce byssal threads
therefore it relies on it's weight for stability
Zebra Mussels: dreissena polymorpha
- Native to eastern Eurasia (black and Caspian sea)
- First reported in the Great Lakes in 1988 in Lake St. Clair and spread rapidly
- Migrated from original habitat across the Atlantic ocean by moving through
ballast water of ocean liner (current)
Inquiry Case
Advantage
- Zebra mussels are an invasive spices to lakes in Ontario. They allow for lake
water to be clear and filtered; less particle matter due to the huge abundance of
zebra mussels. They filter massive amounts of water everyday and can attach
themselves to almost any solid object and to each other. Sand does not show
the invasion but docks below the water do
Disadvantage
- Dead mussels wash up in large amounts on the beach reducing the quality
- Damage by zebra mussels have already cost billions of dollars in efforts to
control
- Can clog pipes and cover industrial equipment
- Impact the native mussels of the region (North America), fresh watch mussels
are among the most endangered organisms
Genetic Variation: differences at the DNA level among individuals within a population
