The variety of life. Biodiversity Whiteboard Activity A: Everyone will be one type of tree 1....
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Transcript of The variety of life. Biodiversity Whiteboard Activity A: Everyone will be one type of tree 1....
4.1.1 BiodiversityThe variety of life
Biodiversity Whiteboard ActivityA: 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
board3. Go back to you seat and remain standing4. 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 TermsBiodiversity: 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
Species Diversity: The number of species
or organisms per unit area found in different habitats of the planet.
Important Terms
Important TermsHabitat Diversity: The amount of habitats or
niches in a given areaVariety of forests, deserts, grasslands, lakes,
oceans, coral reefs, wet lands, and other biological communities.
Chaparral Coniferous forest dessert grasslandsdeciduous forest
Biodiversity: Why should we care? Diverse ecosystems are more stable and
more healthyMore resistant to damage from factors like
climate change and spread of diseaseProvides important ecological services to
humansBiodiversity is useful to us as humans
RecreationFood 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 BiodiversityFlow of material, energy
in the biospherePhotosynthesisPollinationSoil formation and
maintenance Nutrient cycling Moderation of weather
extremes Purification of air and
water
Important “stuff” From biodiversityFood, fuel, ecosystems, species, fiber, lumber,
paper….90% of all food crops40% of all medicines and 85% of all
antibioticsPacific Yew – Taxol (cancer drug) Willow Tree - Aspirin
Biodiversity of Species
4.1.2-.5 Natural Selection
Darwin Natural SelectionImportant TermsEvolution: 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
seedsShort 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)
Survivors reproduce more successfully.
Mutations & Sexual Reproduction produces variations among offspring.
Population changes over time.
Limited resources leads to a struggle for survival between offspring.
Overproduction of Offspring
Population of Organisms
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!
Western Medowlark Eastern Medowlark
Different Species:They do not Interbreed, because they have different songs.
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 whiteAre we the same?
+
ZONKEY
Photo: Wiki Commons/GNU
Are we the same?
+
LIGER!
Speciation due to isolationThe 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 occurred on the earth over a very long period of time when the continents slowly drifted apart.
This leads to geographic isolation
Speciation of salamanders due to geographic isolation
Process of Natural SelectionOrganisms 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)