Term
| What is the definition of evolution? |
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Definition
| Change over time in the characteristics of population. |
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Term
| Describe the Pre-Darwinian Scientific views. What were these views mainly based on? |
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Definition
| All organisms were created simultaneously by God and that each life form remained fixed and unchanging from the moment of creation. They were based on the Catholic church. |
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Term
| What discoveries during the 18th century caused the static views of creation to be changed? |
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Definition
| Naturalists discovered that each area had unique species and that some species were very similar to one another. Georges Louis LeClerc or Comte de Buffon, suggested that some species had changed over time through natural processes. The study of fossils, pollen, burrows, traces, eggs, and feces also suggests this. |
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Term
| What conclusion did scientists draw from these observations? |
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Definition
| Different types of organisms had lived at different times in the past. |
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Term
| What is a fossil? What are fossils made of? List different types of fossils. |
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Definition
| Fossils are the remains of a dead organism, normally preserved in rock; may be petrified bones or wood; shells; impressions of body forms; feathers, skin, leaves, or markings made such as footprints. |
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Term
| Name and describe the hypothesis developed by Georges Cuvier to account for the multitude of species while preserving the notion of creation by God. |
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Definition
| Cuvier advanced the idea of catastrophism and hypothesized that a vast supply of species was created initially and that successive catastrophes produced layers of rock and destroyed many species, fossilizing their remains in the process. The organisms of the modern world were the species that existed/. |
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Term
| What was wrong with Cuvier's explanation? |
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Definition
| Great catastrophes such as floods would have effects on the Earth such as layers of sediment, basalt, etc. The concept that Earth's present landscape was produced by past action of gradual geographical processes is called uniformitarianism. |
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Term
| How well did Charles Lyell's work explain the present landscape? |
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Definition
| Lyell concluded that layers of rock are evidence of ordinary natural processes. |
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Term
| What is uniformitarianism and what implication did it have for the age of the earth? |
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Definition
| It is the concept that Earth's present landscape was produced by past action of the same gradual geographical processes. It implies that the Earth is very old. |
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Term
| How old was the earth estimated to be in the early 1700s? What was this based on? |
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Definition
| It was estimated to be no more than a few thousand years on. This was based on the Old Testament. |
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Term
| Why was a young earth a problem for evolution? |
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Definition
| Deer, wolves, lions, etc. were identical to those present in Europe more than 2,000 years later. |
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Term
| What do modern geologists estimate the age of the Earth to be? |
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Definition
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Term
| Who was the early scientists that proposed a mechanism for how evolution occurs? |
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Definition
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Term
| Name and describe Lamarck's mechanism for how evolution occurs. |
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Definition
| He hypothesized that organisms evolved through the inheritance of acquired characteristics, a process in which borders of living are modified through the use or disuse of parts and the offspring inherit the modifications. He proposed that all organisms possess a drive for perfection. Inheritance by acquired characteristics. |
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Term
| What is wrong with Lamarck's mechanism for evolution? |
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Definition
| Acquired characteristics are not inherited by the offspring. |
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Term
| Which two scientists proposed the same mechanism for how evolution occurs? What was this mechanism? |
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Definition
| Darwin and Wallace proposed the same mechanism for how evolution occurs. This mechanism was natural selection. |
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Term
| What is natural selection? |
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Definition
| The unequal survival and reproduction of organisms with different phenotypes, caused by environmental forces. |
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Term
| Describe the four postulates of the theory of natural selection. |
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Definition
1. Individual members of a population differ from one another in many respects.
2. At least some of the differences among members of a population are due to characteristics that may be passed down from parent to offspring.
3. In each generation, some individuals in a population survive and reproduce successfully but others do not.
4. The fate of individuals is not determined by chance or luck, instead, as an individual's likelihood of survival and reproduction depends on its characteristics. Individuals with advantageous traits survive longest and leave the most offspring in a process called natural selection. |
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Term
| What was the weakness in Darwin's theory? |
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Definition
| The principles of genetics had not yet been discovered, therefore, Darwin/Wallace had no scientific evidence of Postulate 2. |
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Term
| At what level does natural selection act? What evolves over time? |
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Definition
| It acts on the population level. Over time, the population changes as the percentage of individuals inheriting favorable traits increases. An individual cannot evolve but a population can. It might evolve into an entirely new species. |
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Term
| What evidence demonstrates that evolution has occurred? |
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Definition
| Fossils provide evidence of evolutionary change over time. |
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Term
| How does the fossil record provide evidence that evolution has occurred? Provide an example. |
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Definition
| We might expect to find progressive series of fossils that start with an ancient organism, progress several intermediate stages, and culminate in a modern species. For example, fossils of the ancestors of modern whales illustrates stages in the evolution of an aquatic species from land-dwelling ancestors. |
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Term
| What can be revealed by comparing the bodies of different organisms? |
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Definition
| It can reveal similarities that can be explained only by shared ancestry and differences that could result only form evolutionary change during descent from a common ancestor. |
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Term
| What are homologous structures? Give some examples of homologous structures. |
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Definition
| Structures that may differ in function but that have similar anatomy, presumably b/c the organisms that possess them have descended from common ancestors. The forelimbs of birds and mammals are an example. |
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Term
| What are vestigial structures? Provide some examples. |
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Definition
| Structures that serve no apparent purpose but is homologous to functional structures in related organisms and provides evidence of evolution. Ex: molar teeth in bats and pelvic bones in whales and snakes. |
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Term
| What is convergent evolution? |
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Definition
| The independent evolution of similar structures among unrelated organisms as a result of similar environmental pressures. |
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Term
| What are analogous structures? Provide an example. |
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Definition
| Structures that have similar functions and superficially similar appearance but very different anatomies, such as wings of insects and birds. These result of similar environmental pressures rather than a common ancestry. Ex: Wings |
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Term
| Why do vertebrates have such similar developmental stages as embryos? |
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Definition
| Ancestral vertebrates possessed genes that directed the development of gills and tails. Their descendants still have those genes. |
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Term
| What biochemical evidence suggests that all life forms share a common ancestor? |
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Definition
All cells have DNA as the carrier of genetic information.
All cells use RNA, ribosomes, and approximately the same genetic code to translate the genetic information into proteins.
All cells use roughly the same set of 20 amino acids to build proteins.
All cells use ATP as a cellular energy carrier. |
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Term
| What is artificial selection? |
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Definition
| A selective breeding procedure in which only those individuals with particular traits are chosen as breeders; used mainly to enhance desirable traits in domesticated plants and animals; may also be used in evolutionary biology experiments. |
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Term
| How does artificial selection act as evidence that populations evolve by natural selection? |
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Definition
| By breeding organisms with desired organisms for enough time, a new species may be produced. |
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Term
| Provide and explain one example of natural selection that is occurring today. |
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Definition
| One example is on the island of Trinidad where brightly colored guppies have a higher chance of mating with females in predator-free areas, but have a lower chance in areas with predators. |
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Term
| How are variations produced on which natural selection acts? |
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Definition
| They are produced by chance mutations. |
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Term
| Why is natural selection not a mechanism for producing ever greater degrees of perfection? |
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Definition
| It does not select the "best" in any absolute sense, but only for what is best in the context of a particular environment, which varies from place to place and may change over time. A trait that is advantageous in one area may be a disadvantage in another or if conditions change. |
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Term
| 4 Parts of Natural Selection |
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Definition
1. Genetic variation exists
2. Traits are inherited - descent with modification
3. Competition -> some live and some die
4. Survival of the fittest |
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