Chapter 16 - Evolution

Question 1

What conclusions did Hutton and Lyell draw about Earth’s history?

Answer 1

Hutton introduced a concept called “deep time” which is the idea of our planet’s history stretching back so long that the human mind finds it difficult to comprehend. Lyell introduced uniformitarianism, the concept of geological processes affecting the Earth millions of years ago while the same ones operate presently.

Question 2

What was Charles Darwin’s contribution to science?

Answer 2

The theory of evolution was Darwin’s contribution to science.

Question 3

What were the three patterns of biodiversity noted by Darwin?

Answer 3

Darwin noted that species vary globally, species vary locally, and species vary over time.

Question 4

Describe Lamarck’s hypothesis regarding evolution.

Answer 4

Lamarck proposed that all organisms have an inborn urge to become more complex and perfect, and to change and acquire features that help them live more successfully in their environments. He thought that organisms could change the size or shape of their organs by using their bodies in new ways.

Question 5

What was Malthus’s view on population growth?

Answer 5

Malthus reasoned that if the human population grew unchecked, there wouldn’t be enough living space and food for everyone. The human population can be checked by famine, disease, or war.

Question 6

How is inherited variation used in artificial selection?

Answer 6

In artificial selection, nature provides the variations, and humans select those they find useful.

Question 7

Under what conditions does natural selection occur?

Answer 7

Natural selection occurs in any situation in which more individuals are born than can survive (the struggle for existence), there is natural heritable variation (variation and adaptation), and there is variable fitness among individuals (survival of the fittest).

Question 8

What is common descent?

Answer 8

Common descent is a principle that states that all species, living and extinct, are descended from ancient common ancestors.

Question 9

How does the geologic distribution of species today relate to their evolutionary history?

Answer 9

Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors.

Question 10

What is biogeography?

Answer 10

Biogeography is the study of where organisms live now and where they and their ancestors lived in the past.

Question 11

How do fossils help to document the descent of modern species from ancient ancestors?

Answer 11

Many recently discovered fossils form series that trace the evolution of modern species from extinct ancestors.

Question 12

What do homologous structures and embryology suggest about the process of evolutionary change?

Answer 12

Evolutionary theory explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.

Question 13

How can molecular evidence be used to trace the process of evolution?

Answer 13

At the molecular level, the universal genetic code and homologous molecules provide evidence of common descent.

Question 14

What is evolution?

Answer 14

Evolution is change over time

Question 15

What is an adaptation?

Answer 15

An adaptation is a heritable characteristic that increases an organism’s ability to survive and reproduce.

Question 16

What is fitness?

Answer 16

Fitness is how well an organism can survive and reproduce. In natural selection, the environment influences fitness.

Question 17

What are homologous, vestigal, and analogous structures?

Answer 17

Homologous structures have the same structure, but occasionally different functions. Vestigal structures, such as the hip bones on whales, are inherited from ancestors, but have lost their original function due to selection pressures on their descendants. Analogous structures share a common function but not structure.

Question 18

What was the name of Darwin’s ship?

Answer 18

It was named HMS Beagle.

Question 19

What characteristic did Darwin observe about the finches on the Galapagos Islands?

Answer 19

He observed their beaks.

Question 20

How did the finches and tortoises on the Galapagos Island influence Darwin’s thinking?

Answer 20

The little brown birds that he saw were actually all species of finches, also found nowhere else, though they resembled a South American finch species. He noted that the finches were isolated from their peers and adapted by evolving their beaks into a new version that was more suitable for the fruit of the Galápagos.
The same was true for Galápagos tortoises.