Darwin

1
Darwins Theory

• Chapter 7, Section 1

2
Vocabulary

• Species group of similar organisms that can
  mate with each other and produce fertile
  offspring
• Fossil preserved remains or traces of an
  organism that lived in the past
• Adaptation a trait that helps an organism
  survive and reproduce in its environment
• Evolution gradual change in species over time

3

• Scientific Theory well-tested concept that
  explains a wide range of observations
• Natural Selection individuals that are better
  suited to their environment are more likely to
  survive and reproduce (Survival of the fittest)
• Variation difference between individuals of the
  same species

4
Gold Keys

• Darwins important observations include - 1.
  diversity of organisms 2. remains of ancient
  organisms (fossils) 3.
  characteristics of organisms on the
  Galapagos Islands

5

• Darwin reasoned that plants or animals that
  arrived on the Galapagos Islands faced
  environmental factors that were different from
  those on the mainland. Perhaps, Darwin
  hypothesized, the species gradually changed over
  many generations and became better adapted to the
  new environment.
• Darwin proposed that, over a long time, natural
  selection can lead to change. Helpful variations
  may gradually accumulate in a species, while
  unfavorable ones may disappear.

6
General Notes

• Darwin made comparisons, noted similarities and
  differences, between organisms on the mainland
  and organisms on the islands. Also, within the
  different islands. Led to his belief in
  adaptations due to environment.
• Examples of adaptations structure different
  beaks coloration used to attract (helps in
  reproduction) or hide (camouflage) toxic
  poisons prevents organism from being eaten

7

• Darwins ideas are often referred to as the
  theory of evolution
• Selective Breeding choosing the characteristics
  you want an organism to have and then breeding
  for them. Example sheep with fine wool
• Factors that affect the process of natural
  selection overproduction variation
  competition

8

• Overproduction too many organisms are produced,
  not enough food, space or water to allow them to
  all survive
• Variation a difference within a species allows
  one organism to survive better than another
• Competition competing with other organisms in
  order to survive
• Organisms can sometime survive in situations
  where they shouldnt because of mutations.
  (Monkey flowers near copper mines)