Biodiversity and Science Learning Objectives
• Define Biodiversity
• Explain why biodiversity is important
• Explain how biodiversity came about, including the principles of
natural selection and mutation
• Define biogeography
• List the characteristics of terrestrial and aquatic biomes
What is biodiversity?
What is biodiversity?
• Variety of life in the world or a particular region
Biodiversity
• Our world is so diverse
• From the microscopic to the blue whale
• Everything is connected
Biodiversity
• Our world is so diverse
• From the microscopic to the blue whale
• Everything is connected
• From the beginning of life
• Over millions of years
• Now: estimated 8.7 million species on
the planet
• Scientists have only classified about 2
million of those
Biodiversity
• Biodiversity has steadily increased
over time
• Punctuated by periods of mass
extinction
• More on that later
Levels of Biodiversity
• Genetic
• Within a population or a species, how much variation exists between
individuals
• Ecosystem
• Within a region, how many species are there
• Earth
• On our planet, how many species exist
Levels of Biodiversity
• Refers to the number of different species in an area
• Species richness
• And how many individuals of each species are in that area
• Species abundance and community composition
Why do we care about biodiversity?
Why do we care about biodiversity?
• All life depends on it
• Interconnectedness between organisms must be maintained so that
ecosystems can function
• Benefits to humans directly and indirectly
• Food, building supplies, medicine, aesthetic, spiritual, cultural enrichment
Biodiversity and Interconnectedness
• Even the microscopic organisms play a vital role in ecosystems
• Photosynthesis and decomposition
• Because of the many, many years over which organisms live, evolve,
and interact, many species are interdependent
• Pollinators and flowers
• Because of this interdependence, losing one species can throw off the
entire ecosystem
Keystone Species
• Species that are critical for maintaining overall ecosystem balance
• Sea Otters
Keystone Species
• Species that are critical for maintaining overall ecosystem balance
• Sea Otters
Biodiversity and Resilience
• More diverse ecosystems are more resilient
• The ability of an ecosystem to recover to its pre-disturbance state
following a disturbance.
Ecosystems Services
• Natural processes by which the environment produces services and
resources
Ecosystems Services
• Natural processes by which the environment produces services and
resources such as clean water and air, crops, timber, fisheries,
pollination of native and agricultural plants, oxygen production,
carbon dioxide uptake, decomposition of dead matter, soil
stabilization, etc.
Ecosystems Services
How do we get biodiversity?
• Over time (many, many, many years) changes accumulate in species
and they become fit to their environment
• Evolution
• Primarily through:
• Mutation
• Natural Selection
How do we get biodiversity?
• Mutations
• Genetic basis for change
• Occur randomly
• Some change in the DNA, which sometimes results in a change in different
traits of an organism
• Sometimes that change is beneficial
• Sometimes that change is detrimental
• Sometimes that change is neutral
How do we get biodiversity?
• Mutations
How do we get biodiversity?
• Natural Selection
• Because of genetic diversity, there is variation in a population
• Individuals look different
• Some of these differences might cause advantages for the organisms that
possess them
• These organisms then have a better chance of surviving and reproducing
• They pass on that trait
• Adaptation- the trait that allows a better chance of survival
How do we get biodiversity?
• Natural Selection
Natural Selection
• https://phet.colorado.edu/sims/html/naturalselection/latest/natural-selection_en.html
Natural Selection
• https://phet.colorado.edu/sims/html/naturalselection/latest/natural-selection_en.html
• Click “Intro”
• Add a mate, press play, and watch for two generations
• Now add a mutation for fur color
• Watch for two more generations
• Now add wolves and watch for a few more generations
• What happens to the population?
Natural Selection
• Mutations are the ultimate
source of variation
• Dominant vs Recessive
• Did you choose a dominant or a
recessive mutation?
• What is the difference in
outcome?
Natural Selection
• Predators
• Here, wolves and limited food
are selection pressures
• What did you notice about the
wolf population as the rabbit
population grew?
Natural Selection
• The environment also affects the
population
• What do you think will happen
to the rabbit fur color if we flip
to a winter background?
Natural Selection
• The environment also affects the
population
• What do you think will happen
to the rabbit fur color if we flip
to a winter background?
• Try it and see!
Natural Selection and Climate Change
• Imagine that we have all white
rabbits in a winter landscape
with wolves present
• Would the wolves eat all of the
rabbits?
• Probably not
Natural Selection and Climate Change
• Imagine that we have all white
rabbits in a winter landscape
with wolves present
• What if the environment
warmed and the snow melted?
Natural Selection and Climate Change
• Imagine that we have all white
rabbits in a winter landscape
with wolves present
• What if the environment
warmed and the snow melted?
Natural Selection and Climate Change
• This is what is happening:
organisms have adapted to one
environment and the
environment is changing
• Adapt to new environment or
perish
Natural Selection and Climate Change
• This is what is happening:
organisms have adapted to one
environment and the
environment is changing
• Adapt to new environment or
perish
• Can organisms adapt by willing
the adaptation?
Natural Selection and Climate Change
• This is what is happening:
organisms have adapted to one
environment and the
environment is changing
• Adapt to new environment or
perish
• Can organisms adapt by willing
the adaptation?
• No- need genetic basis for
variation (mutation), which affects
rates of survival and reproduction
• Even behaviors have a genetic
basis
Questions?
Biodiversity and Science Learning Objectives
• List the characteristics of terrestrial and aquatic biomes
• Explain human impacts on biomes
• List causes of biodiversity decline
Biogeography
• Study of plant and animal
distributions over the globe
Biogeography
• Study of plant and animal
distributions over the globe
• Influenced by:
• Movement of land masses over
Earth’s history
Biogeography
• Study of plant and animal
distributions over the globe
• Influenced by:
• Movement of land masses over
Earth’s history
• Current climate
• Precipitation and Temperature
Biogeography
• Biomes: large area of land with
characteristic climate
(precipitation and temperature),
flora, and fauna
• We’re in the Temperate Forest
biome
Biomes
• Explore the characteristics of a
few terrestrial biomes
• Forest
• Desert
• Savanna/Grassland
• Tundra
Forests
• Dominated by trees and woody
plants
• Near equator
• Average 50 degrees
• Lots of insects and birds
• Very high biodiversity
Deserts
•
•
•
•
•
•
•
•
Very little rainfall (lots of lava
• Lots of marine life that went extinct were shallow water marine
inverts
Triassic/Jurassic Extinction
• 200 MYA
• Land and ocean life were both affected
• 50% of species disappeared because of rising sea levels and increase
in CO2 in atmosphere because of volcanic activity
• During this time, dinosaurs dominated
Cretaceous Extinction
• 66 MYA
• Asteroid is thought to be the cause– impact either killed off species or
created an artificial winter because of ash that went into atmosphere
and stopped photosynthesis
• 75% of species killed off
• Surviving dinosaurs were Aves, some reptiles survived but no larger
land-living organisms
Mass Extinction in the Anthropocene?
Mass Extinction in the Anthropocene?
Mass Extinction in the Anthropocene?
Mass Extinction in the Anthropocene?
• Primary cause: loss of habitat
• Endemic species are most threatened
Mass Extinction in the Anthropocene?
• Do some research in your groups
• Are we in the middle of the 6th
Mass Extinction?
• Spend some time researching
now so that if a question
appears on the test, you’ll be
ready
• We’ll also come back and discuss
Invasive Species Learning Objectives
• Define invasive species
• List the typical characteristics of an invasive species
• Explain typical management practices for invasive species
• Explore the complexity of invasive species
What is an invasive species?
What is an invasive species?
• Non-native species that spread rapidly through an ecosystem and
negatively impacts native organisms in that ecosystem
• Definition varies depending on who you talk to:
• Human introduced
• Degree of harm
• Non-native/exotic/alien species- can be synonymous or might be used
to refer to non-native species that don’t do harm
Invasive Species in the Great Lakes
What makes a species invasive?
What makes a species invasive?
• Usually:
•
•
•
•
•
•
•
Few natural enemies
Quick reproduction and produce many offspring
Long lived
High dispersal ability
Phenotypic plasticity
Tolerant
Generalist
Why do we care about invasive species?
Why do we care about invasive species?
IUCN
How do we stop invasive species?
How do we stop invasive species?
• Biological controls- the intentional manipulation of natural enemies
by humans for the purpose of controlling pests
• Mechanical controls- physical removal or removal of pieces of the
habitat
• mowing, hoeing, cultivation, and hand pulling, etc
• Chemical control- the use of pesticides/herbicides/fungicides
Kudzu in the US
• Complete Part 1
Kudzu in the US
Kudzu in the US
• Complete Part 2
Kudzu in the US
• Complete Part 3
Name_____________________________________________________________________
Part I – The Beginnings
What a beautiful morning! As I traveled across Philadelphia’s new Girard Avenue Bridge
towards Fairmont Park, my pace quickened. This area was jammed packed. All bridges were
filled with trains, steam and horse-drawn street cars, carriages, cabs, and pedestrians. They, like
myself, were making their way towards America’s first world fair. Surely this May 10th, 1876 will
be a historic day for our nation and our world.
This Centennial Exposition, as it was more commonly called, was held in honor of the 100th
anniversary of the signing of the Declaration of Independence. From May through October, close
to ten million people came to Fairmont Park in Philadelphia to see more than 30,000 exhibits
from all over the world. Some of the products first displayed included the Corliss Steam Engine,
Alexander Graham Bell’s telephone, the Remington Typograph Machine, Heinz ketchup, and
Hires Root Beer. Lady Liberty’s arm and torch was on display as part of a fundraising effort to
help pay for the completion of the statue. This event was quite historic for the United States.
However, it would also be historic in an ecological sense.
Plant exhibitions were widely popular among gardeners. The Japanese delegation drew the most
attention with the construction of a garden filled with some of Japan’s beautiful native plants. In
particular, American gardeners were instantly attracted to the large leaves and sweet aromatic
blooms of Pueraria lobata, commonly known as kudzu. There is no evidence that kudzu
exchanged hands during this fair in 1876. It would not be surprising if it was distributed to
gardeners in small amounts. What is known is that seventeen years later, in 1893, another world
fair would serve as a launching point for this plant.
Chicago hosted the world fair in 1893 to celebrate the 400th anniversary of Columbus’ arrival in
the New World in 1492. It was there in Chicago that two plant nursery operators, Earl and Lillie
Pleas, would see the beautiful purple blooms of kudzu for the first time. During the 1920s, Earl
and Lillie discovered that animals would eat kudzu. They began selling it and sending samples
throughout the United States. During the Great Depression of the 1930s, kudzu was promoted
and used for erosion control by the U.S. Soil Conservation Service because of its rapid growth
and underground root systems. In the 1940s farmers were paid as much as eight dollars an acre to
plant fields of kudzu. The problem, of course, is that kudzu grows too well in some places and
has rapidly spread throughout the Southeast.
Questions
1. List several initial thoughts you have after reading this brief historical account. Include
whether or not you think there was anything wrong with people immediately getting
excited about the potential benefits of this particular plant.
2. How would you define an invasive species?
3. If kudzu was shipped all over the United States, why is it only prevalent in the Southeast?
Why did it not establish itself all over the country?
4. List some pros and cons of kudzu
5. Should kudzu have been introduced into the United States?
Part II – The Solution?
Another Asian import, Megacopta cribaria, was first observed in Georgia in 2009. This insect is
now commonly referred to as the “kudzu bug.” Since 2009, this bug has moved through most of
Georgia and South Carolina and has been confirmed in almost every county in North Carolina.
The rapid spread is amazing, and initially, people were hopeful because these bugs feed on
kudzu and non-native wisterias. The voracious appetites and prolific breeding ability could
potentially slow down the spread of kudzu vines.
However, these bugs also feed on soybeans and other bean crops. This has caused farmers
throughout the south to become very concerned. Besides destroying crops, these bugs also pose a
potential nuisance to homeowners. When cold weather approaches, large numbers of these
insects look for shelter in which to overwinter, and a warm house becomes the perfect place.
Questions
1. List several initial thoughts you have about the kudzu bug. Does this species provide hope
for eradicating kudzu? Why or why not?
2. How would you explain the spread of the kudzu bug? Is it a coincidence that the bug looks
to be establishing itself in the same areas as kudzu?
3. List some pros and cons of the “kudzu bug”.
Part III – Invasive or Not?
Questions
1. Even though the kudzu bug probably was not intentionally introduced, would there be
anything wrong with introducing a non-native (or invasive) species to attempt to get rid
of another invasive species?
2. If a non-native species in an area seems to not cause any ecological problems, should it
still be defined as invasive?
3. Kudzu has been here in the U.S. since 1876. How do ecologists define a native species?
When does a non-native (even if it is invasive) species become a native species? What do
we do with native species that are also invasive?
Case copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State
University of New York. Originally published November 17, 2017. Please see our usage guidelines, which outline
our policy concerning permissible reproduction of this work. Licensed photograph in title block © Robhainer |
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