Why is evolution referred to as a theory?
It is well-supported testable explanation that occurs in the natural world
What two ideas from geology were important to Darwin's thinking?
First, he asked himself: If the Earth could change over time, might life change as well? Second, he realized that it would have taken many years for life to change the way he suggested. This would mean the Earth was extremely old.
According to Malthus, what factors limited population growth?
Malthus reasoned that if the human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone
How did Lyell's "Principles of Geology" influence Darwin?
Allowed Darwin to understand geology. First, he asked himself: If the Earth could change over time, might life change as well? Second, h realized that it would have taken many years for life to change the way he suggested. This would mean the Earth was extremely old.
How is artificial selection dependent on variation in nature?
In artificial selection, nature provides the variation and humans select those variations they find most useful
What types of evidence did Darwin use to support his theory of change over time?
Evidence for this process could be found in the fossil record, the geographical distribution of living species, homologous structures of living organisms, and similarities in early development, or embryology
What idea proposed by Lamarck was later found to be incorrect?
Acquired characteristics can be inherited
What are three of Darwin's observations about animals in South America and on the Galãpagos Islands.
1. Was intrigued by the fact that so many plants and animals seemed remarkable well suited to whatever environment they inhabited
2. Discovered fossils
3. Was fascinated by the fact that species varied form island to island
What is Lamarck's principle of use and disuse?
Lamarck proposed that organisms could alter the size or shape of particular organs by using their bodies in new ways
How does natural variation affect evolution?
Over time, natural selection results in changes in the inherited characteristics of a population.
What evidence of evolution can be found in the geographic distribution of living animals?
The existence of similar but unrelated species showed that similar animals in different locations were the produce of different lines of evolutionary descent
Summarize the main ideas of Darwin's theory
~Individual organisms differ, and some of this variation is heritable
~Organisms produce more offspring than can survive, and many do not reproduce
~Each organisms has different advantages and disadvantages in the struggle for existence. Those best suited survive and others die. Causing changes over time.
~Species alive today are descended with modification from ancestral species that lived in the distant past.
Which two scientists helped Darwin and others recognize how old Earth?
James Hutton and Charles Lyell
What ideas were proposed by Hutton?
Layers of rock are moved by forces beneath Earth's surface and most geological processes operate extremely slowly