Presentation on theme: "DARWINS THEORY of NATURAL SELECTION (Survival of the Fittest)"— Presentation transcript:
DARWINS THEORY of NATURAL SELECTION (Survival of the Fittest)
HOW DID DARWIN EXPLAIN THE DIFFERENCES BETWEEN SPECIES ON THE GALAPAGOS ISLANDS AND ON MAINLAND SOUTH AMERICA? HOW DOES NATURAL SELECTION LEAD TO EVOLUTION? HOW DO NEW SPECIES FORM? In this section you will want to find the answers for:
In 1831, Charles Darwin set sail on the HMS Beagle for a 5 year trip around the world Darwin collected and studied numerous marine organisms during this famous voyage...
Observations he made on the Beagle expedition also provided him with the ideas that he later used to formulate his theory of evolution and natural selection.
Group of similar organisms that can mate and produce offspring VOCABULARY a well tested concept (idea) that explains a wide range of observations SCIENTIFIC THEORY : SPECIES: What is the difference between an idea, theory and fact?
DARWINS THEORY : Species gradually change over many generations and become better adapted to new conditions
THE GALAPOGOS ISALNDS ARE A GROUP OF VOLCANIC ISLANDS
HOW DID DARWIN THINK PLANTS...
...AND ANIMALS ORIGINALLY CAME TO GALAPAGOS ISLAND?
Ancestors of todays plants & animals on the islands were brought from the mainland by wind, currents, or on floating debris...
ONCE THEY REACHED ILSANDS, THEY REPRODUCED & OFFSPRING BECAME DIFFERENT FROM MAINLAND RELATIVES DUE TO RESOURCES AVAILABLE. Mainland Turtle Island Turtles
THIS BRINGS US TO DARWINS THEORY OF NATURAL SELECTION
Natural Selection Individuals that are better adapted to their environment are more likely to survive.
WHAT ARE FACTORS THAT AFFECT SURVIVAL? Differences in species (variations) SURVIVAL OF THE FITTEST Competition for resources Over production of same species
SO…. HOW DOES THIS APPLY TO THE GALAPAGOS ISLANDS?
Organisms that were on the Islands first had NO competition for resources (food, shelter, H2O) because no other species was there.
Darwin studied finches found on these islands. This played an important role in his recognition of the evolutionary process.
by studying the finches - Darwin showed how species are related to other species
...And over long periods of time natural selection can lead to evolution. HOW? VARIATIONS IN ORGANISMS GRADUALLY ACCUMULATE WHILE UNFAVORABLE ONES DISAPPEAR.
As you can see in the next photos, Darwin's finches share similar size color, and habits - the difference is size and shape of their beak.
The F I N C H E S
Lava Finch Galapagos Volcanoes
WHAT ARE SOME OTHER WAYS NEW SPECIES COULD HAVE FORMED? CONTINENTAL DRIFT
SEPARATION by: RIVERS
SURVIVAL of the FITTEST
How is each organism suited to play a certain role in a certain habitat? ADAPTATIONS: inherited features that let organisms survive & produce young
Camouflage: Adaptations that allow organisms to blend in w/environment.
Whats right w/these pics?
Whats the problem here?
Whats wrong w/this pic?
MIMICRY ANOTHER ADAPTATION SEEN IN ANIMALS AND PLANTS:
WHICH IS WHICH? CORAL KING
CRITICAL THINKING WHAT MAKES AN IDEA A THEORY? HOW IS A THEORY DIFFERENT FROM A FACT? UPON WHAT FACTS DID DARWIN BASE HIS THEORY OF EVOLUTION?