Evidence of Evolution
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution.
The genetic variation within a population of organisms may cause some individuals to survive and reproduce more successfully than others. Factors that affect reproductive success are also important, an issue that Charles Darwin developed in his ideas on sexual selection.
Natural selection acts on the phenotype, or the observable characteristics of an organism, but the genetic (heritable) basis of any phenotype that gives a reproductive advantage will become more common in a population (see allele frequency). Over time, this process can result in adaptations that specialize populations for particular ecological niches and may eventually result in the emergence of new species. In other words, natural selection is an important process (though not the only process) by which evolution takes place within a population of organisms. As opposed to artificial selection, in which humans favor specific traits, in natural selection the environment acts as a sieve through which only certain variations can pass.
Natural selection is one of the cornerstones of modern biology. The term was introduced by Darwin in his influential 1859 book On the Origin of Species, in which natural selection was described as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of heredity; at the time of Darwin's writing, nothing was known of modern genetics. The union of traditional Darwinian evolution with subsequent discoveries in classical and molecular genetics is termed the modern evolutionary synthesis. Natural selection remains the primary explanation for adaptive evolution.
Theodosius Dobzhansky, a geneticist whose work influenced 20th century research on evolutionary theory, said, "Nothing in biology makes sense, except in light of evolution." This quote emphasizes the role of evolution as the most important unifying principle in biology. Living things might, at first, seem very diverse, but closer inspection reveals a surprising unity. This unity, or common ancestry, can be explained by evolutionary theory. With such an important theory at stake, it is essential to understand the evidence upon which it is based.
The Task
In this Evolution WebQuest you will investigate a variety of types of evidence for evolution. Your team will be responsible for learning about fossil evidence, structural evidence, and genetic evidence for evolution and presenting this information to the class.
The Process
1. You will be assigned to a group of researchers
2.Each group will have specialists in anatomy and physiology, paleontology, and molecular biology. Anatomists study the structure of organisms, physiologists study the function of organisms, molecular biologists study genetics, and paleontologists study fossils.
3. Review the sites that apply to your specialty
4. Find four to five examples of evidence for evolution. Try to find specific examples, so that when you present to the class you will all have different examples to share. Also, try to find the date on which the evidence was discovered.
5. The recommended sites are just examples. Feel free to search for your own.
Anatomists
• Evidence Supporting Biological Evolution (see "Common Structures")
• How Scientists Study Evolution
• What Is Morphology and Why Is It Important?
• Fossils Can Show How Certain Features Evolved
• It's a Bird, It's a Dinosaur?
Molecular Biologists
• Evolution Makes Sense of Homologies
• Axing the Family Tree
• Evidence of Evolution
• Chemical Clues to Darwin's Abominable Mystery
• Salvaged DNA Leads to Neanderthals' Mystique
Paleontologists
• Fossils Can Show How Certain Features Evolved
• Transitional Vertebrate Fossils FAQ
• Mother of All Mammals
• Shaking the Family Tree
• Evolution Makes Sense of Homologies
• The Nature of Fossils
• Dating Fossils
• Getting into the Fossil Record
6.Reconvene with your group, or work on your own, to create a presentation chart that looks like this
Special Areas of Interest Evidence Significance
(descriptions or drawings)
Anatomy
Molecular Biology
Paleontology
7. Present data to class
Conclusion
This WebQuest was designed to help you locate evidence for evolution from different areas of science. New evidence for evolution is being discovered every day. No evidence has been found which cannot be explained by evolution. If the future continues as in the past, we can look forward to more information about the genomes of earth's creatures, new discoveries in the fossil record, and the finding of new species in places like the ocean depths and the tropical rainforests. One thing is certain, more evidence will be added to support the theory of evolution.
The genetic variation within a population of organisms may cause some individuals to survive and reproduce more successfully than others. Factors that affect reproductive success are also important, an issue that Charles Darwin developed in his ideas on sexual selection.
Natural selection acts on the phenotype, or the observable characteristics of an organism, but the genetic (heritable) basis of any phenotype that gives a reproductive advantage will become more common in a population (see allele frequency). Over time, this process can result in adaptations that specialize populations for particular ecological niches and may eventually result in the emergence of new species. In other words, natural selection is an important process (though not the only process) by which evolution takes place within a population of organisms. As opposed to artificial selection, in which humans favor specific traits, in natural selection the environment acts as a sieve through which only certain variations can pass.
Natural selection is one of the cornerstones of modern biology. The term was introduced by Darwin in his influential 1859 book On the Origin of Species, in which natural selection was described as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of heredity; at the time of Darwin's writing, nothing was known of modern genetics. The union of traditional Darwinian evolution with subsequent discoveries in classical and molecular genetics is termed the modern evolutionary synthesis. Natural selection remains the primary explanation for adaptive evolution.
Theodosius Dobzhansky, a geneticist whose work influenced 20th century research on evolutionary theory, said, "Nothing in biology makes sense, except in light of evolution." This quote emphasizes the role of evolution as the most important unifying principle in biology. Living things might, at first, seem very diverse, but closer inspection reveals a surprising unity. This unity, or common ancestry, can be explained by evolutionary theory. With such an important theory at stake, it is essential to understand the evidence upon which it is based.
The Task
In this Evolution WebQuest you will investigate a variety of types of evidence for evolution. Your team will be responsible for learning about fossil evidence, structural evidence, and genetic evidence for evolution and presenting this information to the class.
The Process
1. You will be assigned to a group of researchers
2.Each group will have specialists in anatomy and physiology, paleontology, and molecular biology. Anatomists study the structure of organisms, physiologists study the function of organisms, molecular biologists study genetics, and paleontologists study fossils.
3. Review the sites that apply to your specialty
4. Find four to five examples of evidence for evolution. Try to find specific examples, so that when you present to the class you will all have different examples to share. Also, try to find the date on which the evidence was discovered.
5. The recommended sites are just examples. Feel free to search for your own.
Anatomists
• Evidence Supporting Biological Evolution (see "Common Structures")
• How Scientists Study Evolution
• What Is Morphology and Why Is It Important?
• Fossils Can Show How Certain Features Evolved
• It's a Bird, It's a Dinosaur?
Molecular Biologists
• Evolution Makes Sense of Homologies
• Axing the Family Tree
• Evidence of Evolution
• Chemical Clues to Darwin's Abominable Mystery
• Salvaged DNA Leads to Neanderthals' Mystique
Paleontologists
• Fossils Can Show How Certain Features Evolved
• Transitional Vertebrate Fossils FAQ
• Mother of All Mammals
• Shaking the Family Tree
• Evolution Makes Sense of Homologies
• The Nature of Fossils
• Dating Fossils
• Getting into the Fossil Record
6.Reconvene with your group, or work on your own, to create a presentation chart that looks like this
Special Areas of Interest Evidence Significance
(descriptions or drawings)
Anatomy
Molecular Biology
Paleontology
7. Present data to class
Conclusion
This WebQuest was designed to help you locate evidence for evolution from different areas of science. New evidence for evolution is being discovered every day. No evidence has been found which cannot be explained by evolution. If the future continues as in the past, we can look forward to more information about the genomes of earth's creatures, new discoveries in the fossil record, and the finding of new species in places like the ocean depths and the tropical rainforests. One thing is certain, more evidence will be added to support the theory of evolution.
