Download Environmental Science Introduction

Environmental Science
Earth and Ecosystems
What is a watershed?
• A watershed is the area of land where all
of the water that is under it or drains off of
it goes into the same place like an ocean!
Earth Spheres
Earth Layers
Earth’s Layers
Earth Layers
Atmosphere
The Ozone Layer
Levels of Organization
Ecological Levels of Organization
Water Cycle
Water Cycle
Evolution
• The processes that have transformed life on
earth from it’s earliest forms to the vast
diversity that characterizes it today.
• A change in the genes!!!!!!!!
Charles Darwin
• Darwin set sail on the H.M.S. Beagle (1831-1836)
to survey the south seas (mainly South America
and the Galapagos Islands) to collect plants and
animals.
• On the Galapagos Islands, Darwin observed
species that lived no where else in the world.
• These observations led Darwin to write a book.
Charles Darwin
• Two main points:
1. Species were not created in their
present form, but evolved from
ancestral species.
2. Proposed a mechanism for
evolution: NATURAL SELECTION
Natural Selection
• Individuals with favorable traits are more
likely to leave more offspring better suited for
their environment.
• Example:
English peppered moth (Biston betularia)
- light and dark phases
Peppered moths rest on trees and depend
on camouflage for protection.
Evolution by Natural Selection
•
Evolution by Natural Selection
– Struggle for existence – competition for resources
– Survival of the fittest (natural selection)– Fitness is
a result of adaptations
• Adaptation – any inherited characteristic that
increases an organism’s chance of survival
Artificial Selection
• Artificial selection – nature provides the
variation, but humans select the variations
they find useful, e.g. breeding the largest
hogs, fastest horses
– The selective breeding of domesticated plants and animals
by man.
• Question:
What’s the ancestor of the domesticated dog?
• Answer: WOLF
Evolution of Resistance
• Resistance – the ability of one or more organism
to tolerate a particular chemical designed to kill
it.
• Pesticide resistance –
– The survivors (insects usually) live because they have
a gene that protects them.
– Each time the pesticide is used, there is selection for
insects with this gene.
– Eventually, the pesticide has little effect on the insect
population.
The Diversity of Living Things
Kingdoms
• Archaebacteria and Eubacteria
– Microscopic, single celled, have a cell wall and divide
by splitting in half.
– Kingdom Archaebacteria – found in extreme places
– Kingdom Bacteria – common bacteria
• Fungi
– Cell nuclei and walls
– Examples: mushrooms, yeast, Athletes Foot
The Diversity of Living Things
Kingdoms
• Protists – diverse group of simple animallike, fungi-like and plant-like organisms.
– Examples: Amoeba, diatoms, green algae,
kelp
The Diversity of Living Things
Kingdoms
• Plants – many-celled organisms with cell walls
that make their own food using the sun’s energy
(photosynthesis)
– Lower plants (mosses, ferns)
– Gymnosperms – woody plants that produce seeds
that are not in fruits. Examples: Pine Trees
– Angiosperms – flowering plants that produce seeds in
fruits Examples: Oaks, cotton, roses, daisies,
dandelions, corn, tomatoes
The Diversity of Living Things
Kingdoms
• Animals – many-celled organisms without
cell walls that must consume their food
– Invertebrates – lack backbones Examples:
insects, crabs, oysters, jellyfish, corals,
sponges, octopus, snail, starfish
– Vertebrates – have a backbone Examples:
humans and mammals, fish, frogs,
salamanders, snakes, turtles, lizards, birds