4.1_Biodiversity
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Transcript 4.1_Biodiversity
The variety of life
Biodiversity Whiteboard Activity
A: Everyone will be one type of tree
1.
Douglas Fir (Write a D on your whiteb0ard)
2.
Walk around and write down 3 peoples names on your board
3.
Go back to you seat and remain standing
4.
A disease will now infect one and spread among the trees
B: We will now be different trees (Repeat Steps in A)
Douglas Fir
(D)
Nobel Fir
(N)
Western Red Cedar
(C)
Maple
(M)
Hemlock
(H)
White fir
(W)
Lodge Pine
(L)
White Pine
(WP)
Western Dogwood
(WD)
Important Terms
Biodiversity: The
amount of different
species living in an area.
Genetic Diversity:
Different genetic
characteristics of a
species.
Cheetah populations have
very low diversity, due to
inbreeding
Important Terms
Species Diversity:
The number of species or
organisms per unit area
found in different habitats
of the planet.
Important Terms
Habitat Diversity: The amount of habitats or niches in a
given area
Variety of forests, deserts, grasslands, lakes, oceans,
coral reefs, wet lands, and other biological communities.
Chaparral
Coniferous forest
dessert
grasslands
deciduous forest
Biodiversity: Why should we care?
Diverse ecosystems are more stable and more healthy
More resistant to damage from factors like climate
change and spread of disease
Provides important ecological services to humans
Biodiversity is useful to us as humans
Recreation
Food
Goods
Medicine
Pre-Assessment Questions
(Write on Loose leaf paper)
How do you think diversity changes during succession?
Do you think a more complex ecosystem is more or
less stable?
How could human activities (agriculture, mining…)
impact biodiversity?
What are the potential positive and negative results of
human activities that reduce diversity?
How might habitat diversity impact species diversity
and genetic diversity?
Ecological Services of
Biodiversity
Flow of material, energy in
the biosphere
Photosynthesis
Pollination
Soil formation and
maintenance
Nutrient cycling
Moderation of weather
extremes
Purification of air and water
Important “stuff” From biodiversity
Food, fuel, ecosystems, species, fiber, lumber, paper….
90% of all food crops
40% of all medicines and 85% of all antibiotics
Pacific Yew – Taxol
(cancer drug)
Willow Tree - Aspirin
Biodiversity of Species
Darwin Natural Selection
Important Terms
Evolution: A change in the gene
pool of a population over time
Natural Selection: Process by
which individuals that are better
suited to their environment
survive and reproduce more
successfully.
Adaptation: An inherited
characteristic that increases an
organism’s chance of survival.
Darwin's
Research
Studies 13 species of finches
on Galapagos Islands
Looked a beak size and shape:
Stout beaks for eating seeds
Short and sharp beaks for
eating insects.
Woodpecker-like beak for
eating insects from trees, but
instead of a long tongue it
uses a cactus spine held in its
beak to remove its prey.
Darwin’s Finches
Darwin’s Theory
Based on his observations he proposed
that the evolution of species occurs by
Natural selection.
Occurred due to:
Variation within populations (Genetic
Diversity)
Overproduction of offspring (J and S
curves)
Struggle for existence (Competition/
Limited resources)
Unequal survival and reproduction rates
(R and K)
Population of Organisms
Overproduction of Offspring
Mutations & Sexual Reproduction produces
variations among offspring.
Limited resources leads to a
struggle for survival between
offspring.
Survivors reproduce more
successfully.
Population changes over time.
What is a species?
Species: A group of interbreeding populations, with a
common gene pool, which are reproductively isolated.
It’s not all about looks!
Different Species:
They do not
Interbreed,
because they
have different
songs.
Western Medowlark
Eastern Medowlark
What is a species…
Species definition was made
by humans, and fails to fully
define nature.
These two ants look
different are the same
species of ant fulfilling
different roles in a colony.
Pheidole barbata
Species definition is not always
black and white
Are we the same?
+
ZONKEY
Photo: Wiki Commons/GNU
Are we the same?
+
LIGER!
Speciation due to isolation
The islands are close enough
to allow migration and cause
distinct island populations
to arise.
But the distances between
the islands is great enough
to reduce interbreeding
between islands
This has made possible the
formation of distinctive
species on the islands
Speciation in grand canyon
Speciation of salamanders due
to geographic isolation
Speciation occurred on the earth over a very long
period of time when the continents slowly drifted apart.
This leads to
geographic isolation
Continental Drift Animation
Process of Natural Selection
Organisms became isolated on various continents which
restricted interbreeding populations
Without the opportunity to interbreed and the slowly
changing climatic conditions organisms “evolve” into a
new species over time.
This leads to “survival of the fittest”
Fitness: Organisms that are better suited to survive and
reproduce
Discussion Question
Why does Australia have such strange animals??
Evolutionary Timeline of mammals
Platypus (Monotreme)
Kangaroo (Marsupial)
Dingo (Placental Mammal)