Chapter 20 Flashcards
natural theology
A belief that knowledge of God may be acquired through study of natural phenomena
natural history
The branch of biology that examines the form and variety of organisms in their natural environments
taxonomy
The science of the classifications of organisms into an ordered system that indicates natural relationships
biogeography
The study of geographical distributions of plants and animals
morphology
The form or shape of an organism or of a part of an organism
vestigial structures
An anatomical feature of living organisms that no longer retains its function
fossils
The remains or traces of an organism of a past geologic age embedded and preserved in Earth’s crust
paleobiology
The study of ancient organisms
catastrophism
The theory that Earth has been affected by sudden, violent events that were sometimes worldwide in scope
gradualism
The view that Earth and its living systems changed slowly over its history
James Hutton
argued that slow continuous physical processes, acting over long periods of time produced Earth’s major geological features (gradualism)
uniformitarianism
The concept that the geological processes that sculpted Earth’s surface over long periods of time- such as volcanic eruptions, earthquakes, erosions, and the formation and movement of glaciers- are exactly the same as the processes observed today
Charles Lyell
wrote Principles of Geology
argued that the geological processes that sculpted Earth’s surface over on periods of time (uniformitarianism)
Why did the existence of vestigial structures make Buffon question the idea that living systems never changed?
Buffon did not understand how”anatomically perfect” animals could have useless structures
What were Lamarck’s contributions to an evolutionary worldview?
Lamarck proposed: 1) all species change through time
2) the changes are inherited by the next generation
3) the changes arise in response to environmental conditions
4) specific mechanisms caused the changes
How do the concepts of gradualism and uniformitarianism in geology undermine the belief that the Earth is only about 6,000 years for these features to assume their present forms?
The concept of gradualism and uniformitarianism suggest that Earth’s major geological features were produced by the very slow action of geological processes observed today. It must have taken more than 6,000 years for these features to assume their present forms
adaptive traits
A genetically based characteristic, preserved by natural selection, that increases an organism’s likelihood of survival or its reproductive output
evolutionary divergence
A process whereby natural selection or genetic drift causes populations to become more different over time
descent with modification
biological evolution
What observations that Darwin made on his round-the-world voyage influenced his later thoughts about evolution?
Darwin observed that living organisms often resemble fossils found in the same area; that organisms found on South America resembled one another, even if the occupied different environments; and that many species found on the Galapagos Islands resembled species from South American mainland
How did Darwin’s understanding of artificial selection enable him to envision the process of natural selection?
Darwin realized that the effects of competition for resources in nature were similar to the action of a plant or animal breeder who used only certain individuals as parents to produce the next generation
What were the four great intellectual triumphs of Darwin’s theory?
Darwin’s theory relied on physical explanations for the origin of biodiversity: he recognized that evolutionary change takes place within a population rather than in individuals; he recognized that natural selection is a multistage process; and he emphasized the importance of environmental conditions to the process of natural selection
population genetics
The branch of science that studies the prevalence and variation in genes among variation in gene among populations of individuals
modern synthesis
A unified theory of evolution developed in the middle of the twentieth century
microevolution
small-scale genetic changes within populations, often in response to shifting environmental circumstances or chance events
macroevolution
large-scale evolutionary patterns in the history of life, producing major change in species and higher taxonomic groups
biological lineages
An evolutionary sequences of ancestral organisms and their descendants
comparative morphology
Analysis of the structure of living and extinct organisms
homologous traits
Characteristics that are similar in two species because they inherited the genetic basis of the trait from their common ancestor
orthogenesis
An obsolete theory that evolution is goal oriented striving to perfect organisms
What two problems slowed the acceptance of Darwin’s theory among scientists?
Two problems that slowed the acceptance of Darwin’s theory are that Mendel’s genetic studies focused on simple traits and that these traits often changed in just a few generations
What is the difference between microevolution and macroevolution?
Microevolution refers to small, genetically based changes within populations. Macroevolution refers to larger-scale evolutionary changes observed in species and more inclusive groups. Current research suggests that microevolutionary change results from the same evolutionary processes
What type of data provide evidence that evolution has adapted organisms to their environments and promoted the diversification of species?
Evidence for evolution comes from studies of adaptation, the fossil record, historical biogeography, comparative morphology, and comparative molecular biology
20.1
- Ancient greek philosophers classified the natural world, ranking inanimate objects and living organisms form simple to complex
- natural theologians believed that all species were specially created and perfectly adapted; that existing species do not change or become extinct; and that new species do not arise. Studies in biogeography, comparative morphology, and paleontology led scientists to question whether species change through time
- Lamarck proposed that species evolved into more complex forms tha tfunctioned better in their environments. He hypothesized that structures in an organism changed when they were used, and htat those changes were inherited by the organism’s offspring. Experiments has refused Lamarck’s proposed mechanisms
- two geologists, Hutton and Lyell, recognized that major features on Earth were created by the long-term action of the very slow geological processes that scientists observe today. Their insights suggested that Earth was much older than natural theologians had supposed
20.2
- Darwin’s observations during his voyage on the Beagle provided much of the data and inspiration for the development of his theory of evolution
- Darwin based the theory of evolution by means of natural selection:
1) individuals within a population compete for limited resources
2) hereditary characteristics allow some individuals to survive longer and reproduce more than others
3) population’s characteristics change over time as advantageous heritable characteristics become more common - Darwin also proposed that the accumulation of difference fostered by natural selection could cause populations to diverge over time. Such evolutionary divergence can lead to the production of new species give rise to new evolutionary lineages
20.3
- scientists working in population genetics developed theories of evolutionary change by integrating Darwin’s ideas with Mendel’s research on genetics
- in 1930s and 1940s, the modern synthesis provided a unified view of evolution that drew on studies from many biological disciplines. It emphasized evolution within populations, the central role of variation in the evolutionary process, and the gradualism of evolutionary change
- studies of adaptation, the fossil record, historical biogeography, and comparative morphology provide compelling evidence of evolutionary change
- molecular techniques have extended the achievements of the modern synthesis, allowing precise analysis of the genetic basis of evolutionary change and the genetic relatedness of living and extinct organisms
