Developing Theories to Explain Change 4:2

Question 1

If all organisms originated in their present forms during a single event, Darwin wondered, why was there a distinctive clustering of similar organisms in different regions of the world? Why were all types of organism not randomly distributed?

Answer 1

Darwin concluded that there was a force or forces at work in the regions that modified how the native organisms developed.

Question 2

Which of the following theories gives the best explanation of the pace of evolution?

Answer 2

Either Graduated or Punctuated Equilibrium, it depends on your view.

Question 3

Select all statements that describes the ideas of graduated equilibrium.

Answer 3

• Not supported by the fossil record but should be noted that not all species leave a fossil record
• Big changes (such as the evolution of a new species) occur as aresult of many small changes.
• Changes occur slowly and in a linear fashion.

Question 4

Select all statements that describes the ideas of punctuated equilibrium.

Answer 4

• Most species undergo most of their morphological changes when they first diverge from the parent species.
• There are periods of rapid change (i.e., rapid speciation after mass extinctions).
• Long periods of equilibrium interupted by periods of speciation
• After undergoing morphological changes, the species changes relatively little even as they evolve into a new species.

Question 5

A women spends much of her time by swimming pools and, as aresult has very tanned skin. What would the hypothesis of inheritance of acquired characteristics say about the skin of her children?

Answer 5

Because the woman’s ability to develop dark-tanned skin served a favourable purpose (adaptation) it would be passed onto her offspring.

Question 6

Charles Darwin’s observations were also supported by his knowledge of the breeding of dogs, pigeons, and flowers. His research here showed that variations are not usually passed on through sexual reproduction and that change happened thrugh random mutation. This helped emphasize that change could happen within a species over time.

Answer 6

false

Question 7

Darwin’s theory of evolution

Answer 7

• Weak organisms are killed off through natural slection
• Survival of the fittest does not include progressive development
• Variation in fin size occurs in the population of fish
• Those fish with the larger fins reproduced, and the advantageous trait was passed on to offspring
• At some point, the fish with the larger fins were able to survive, while fish with small fins did not.

Question 8

Lamarck’s theory of evolution

Answer 8

• Organisms strive toward complexity and perfection
• Survival of the fittest does include progressive development.
• Over time developed a large pectoral fin because they needed it to outrun predators or hunt for insects above the water
• Flying fish arose from a simpler fish
• Since the fin was used over and over, the fin got larger and larger, and the modifications were passed on to the next generations of offspring

Question 9

Both Lamarck’s and Darwin’s ideas about evolution

Answer 9

• Traits of organisms are slightly altered from generation to generation
• Organisms are always changing over time