Chapter 15 - Darwin's Theory of Evolution

Question 1

What is evolution?

Answer 1

change over time

Question 2

How did Darwin’s trip to the Galapagos Islands help him with his theory of evolution? List 2 examples

Answer 2

1) the shape of the tortoise’s shell corresponds to the environment that they live in
2) the finches had beaks that corresponds to the food they eat

Question 3

What did James Hutton propose that helped Darwin shape his theory of evolution?

Answer 3

He proposed that Earth is shaped by geological forces that took place over extremely long periods of time. He estimated Earth to be millions-not thousands- of years old

Question 4

What did Charles Lyell propose that helped Darwin shape his theory of evolution?

Answer 4

Processes occurring now have shaped Earth’s geological features over long periods of time

Question 5

How did Lyell influence Darwin?

Answer 5

1) If Earth could change over time, might life change as well?
2) Earth had to be really old

Question 6

What did Jean-Baptiste Lamarck propose?

Answer 6

By selective use or disuse of organs, organisms acquired or lost certain traits during their lifetime. These traits could then be passed on to their offspring. Over time, this process led to change in a species.

Question 7

Who proposed that all organisms have an innate tendency toward complexity and perfection?

Answer 7

Lamarck

Question 8

Why is Lamarck’s theory wrong?

Answer 8

An organism’s behavior has no effect on its heritable characteristics

Question 9

What did Thomas Malthus propose?

Answer 9

If the human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone

Question 10

Who is Alfred Wallace?

Answer 10

A naturalist doing work in Malaysia who summarized the thoughts on evolution that Darwin had been thinking about for 25 years

Question 11

What year did Darwin publish On The Origin of Species?

Answer 11

1859

Question 12

What is artificial selection?

Answer 12

nature provided the variation, and humans selected those variations that they found useful

Question 13

What does struggle for existence mean?

Answer 13

members of each species compete regularly to obtain food, living space, and other necessities of life

Question 14

What is fitness?

Answer 14

the ability of an individual to survive and reproduce in its specific environment

Question 15

What is adaptation?

Answer 15

Any inherited characteristic that increases an organism’s chance of survival

Question 16

What is survival of the fittest?

Answer 16

Individuals that are better suited to their environment (with adaptations that enable fitness) survive and reproduce most successfully

Question 17

What is natural selection?

Answer 17

certain individuals of a population produce new individuals. the traits being selected contribute to an organism’s fitness in its environment; it also takes place without human control

Question 18

What happens over time due to natural selection?

Answer 18

results in changes in the inherited characteristics of a population. these changes increase a species’ fitness in its environment

Question 19

Can natural selection be seen directly?

Answer 19

no it can only be observed as changes in a population over many successive generations

Question 20

What is descent with modification?

Answer 20

each living species has descended with changes from other species over time

Question 21

What is common descent?

Answer 21

All species- living and extinct- were derived from common ancestors “tree of life”

Question 22

Where can evidence of evolution be found?

Answer 22

fossil record, geographical distribution of living species, homologous structures of living organisms, and similarities in early development or embryology

Question 23

What are homologous structures?

Answer 23

structures that have different mature forms but develop from the same embryonic tissues

Question 24

What evidence does homologous structures provide?

Answer 24

all four-limbed vertebrates have descended, with modifications from common ancestors

Question 25

What are vestiges?

Answer 25

traces

Question 26

What are vestigial organs?

Answer 26

homologous organs that have been reduced in size

Question 27

Why would an organism have a vestigial organ?

Answer 27

the presence of a vestigial organ may not affect an organism’s ability to survive and reproduce so natural selection would not cause the elimination of that organ

Question 28

Summarize Darwin’s theory of evolution

Answer 28

1) Individual organisms differ, and some of this variation is heritable
2) Organisms produce more offspring than can survive, and many that do survive do not reproduce
3) Because more organisms are produced than can survive, they compete for limited resources
4) survival of the fittest
5) descent with modification and common descent