Variations over time / Charles Darwin Theory / Grade 6 Science
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Resources:- Macmillan/McGraw-Hill Glencoe Grade 6 , Reading in Science It defines the meaning of Variation and Mutations. Charles Darwin studied different types of finches while visiting the Galapagos Island. Variations that Favor Survival are more likely to be passed on to the next generation. Darwin noticed that each species of finches was well adapted to its particular environment. In nature organisms compete for natural selection such as food, water, space, and sunlight. Another names of natural selection Antibiotics are medicines people take for diseases If you have any comments please write them down
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Natural selection
Darwin proposed the theory of natural selection to explain evolution. Natural selection is the process by which organisms better adapted to their environment are more likely to survive and reproduce, passing on their favorable traits. It involves overproduction of offspring, variation among individuals, and competition for limited resources. Those individuals possessing variations that increase chances of survival will be selected through surviving and reproducing, passing these traits to subsequent generations over long periods of time.
Darwins Finches
Darwin discovered 13 species of finches on the Galapagos Islands that all descended from a common ancestor. The finches have adapted to their environments by developing differences in beak type, color, and size to eat various foods like seeds, insects, or use tools. Peter and Rosemary Grant studied the finches to show there is enough natural variation within each species for natural selection to lead to changes over time, such as documenting changes in finch beak and body traits during drought.
Modern concept of natural selection
This document discusses the concept of natural selection and provides examples. It describes three patterns of natural selection: directional selection which favors advantageous traits, stabilizing selection which reduces variability, and disruptive selection which favors extreme traits. Examples provided include industrial melanism in moths due to pollution, control of Australian rabbits through myxomatosis virus, and selective breeding experiments increasing traits like body weight and disease resistance in salmon.
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The document summarizes key concepts in evolution including Darwin's theory of natural selection. It discusses early theories of evolution from Jean-Baptiste Lamarck and how Darwin's voyage on the HMS Beagle and observations of species on the Galapagos Islands led him to propose natural selection in his 1859 book On the Origin of Species. Natural selection proposes that individuals with favorable traits are more likely to reproduce and leave more offspring, gradually changing the traits of a population over generations. The document also outlines evidence of evolution such as fossils, taxonomy, and molecular biology as well as mechanisms of microevolution like genetic drift and gene flow that can lead to speciation, the evolution of new species.
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The document summarizes key aspects of Charles Darwin's theory of evolution by natural selection. It describes how Darwin observed variation among finch species on the Galapagos Islands and concluded that small populations of an original finch species from South America adapted over generations to different food sources and environments on each island, leading to the emergence of new species through natural selection. The document also contrasts Darwin's theory with Lamarck's idea of the inheritance of acquired characteristics, stating that Darwin believed advantageous traits were passed on to offspring through inheritance rather than acquisition during an organism's lifetime.
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This document discusses the four types of natural selection: directional selection which favors an extreme trait, stabilizing selection which favors average traits, disruptive selection which favors extreme traits over average traits, and sexual selection which favors traits that increase reproductive success such as traits used in mate choice or competition. Examples are given for each type of selection.
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Overproduction leads to competition because there are more individuals than resources available. Competition leads to selection because individuals with variations better suited to the environment are more likely to survive and reproduce, passing on their favorable variations.
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Darwin proposed the theory of natural selection to explain evolution. Natural selection is the process by which organisms better adapted to their environment are more likely to survive and reproduce, passing on their favorable traits. It involves overproduction of offspring, variation among individuals, and competition for limited resources. Those individuals possessing variations that increase chances of survival will be selected through surviving and reproducing, passing these traits to subsequent generations over long periods of time.
Darwins Finches
Darwin discovered 13 species of finches on the Galapagos Islands that all descended from a common ancestor. The finches have adapted to their environments by developing differences in beak type, color, and size to eat various foods like seeds, insects, or use tools. Peter and Rosemary Grant studied the finches to show there is enough natural variation within each species for natural selection to lead to changes over time, such as documenting changes in finch beak and body traits during drought.
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The document summarizes key concepts in evolution including Darwin's theory of natural selection. It discusses early theories of evolution from Jean-Baptiste Lamarck and how Darwin's voyage on the HMS Beagle and observations of species on the Galapagos Islands led him to propose natural selection in his 1859 book On the Origin of Species. Natural selection proposes that individuals with favorable traits are more likely to reproduce and leave more offspring, gradually changing the traits of a population over generations. The document also outlines evidence of evolution such as fossils, taxonomy, and molecular biology as well as mechanisms of microevolution like genetic drift and gene flow that can lead to speciation, the evolution of new species.
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The document summarizes key aspects of Charles Darwin's theory of evolution by natural selection. It describes how Darwin observed variation among finch species on the Galapagos Islands and concluded that small populations of an original finch species from South America adapted over generations to different food sources and environments on each island, leading to the emergence of new species through natural selection. The document also contrasts Darwin's theory with Lamarck's idea of the inheritance of acquired characteristics, stating that Darwin believed advantageous traits were passed on to offspring through inheritance rather than acquisition during an organism's lifetime.
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This document discusses the four types of natural selection: directional selection which favors an extreme trait, stabilizing selection which favors average traits, disruptive selection which favors extreme traits over average traits, and sexual selection which favors traits that increase reproductive success such as traits used in mate choice or competition. Examples are given for each type of selection.
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Overproduction leads to competition because there are more individuals than resources available. Competition leads to selection because individuals with variations better suited to the environment are more likely to survive and reproduce, passing on their favorable variations.
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Charles Darwin developed the theory of natural selection after making observations on his voyage on the Beagle and gathering evidence that species adapt to their environments over generations. Through natural selection, individuals with traits better suited to the environment are more likely to survive and pass on those traits, causing populations to evolve over time. Darwin's observations of related but different species on the Galapagos Islands provided evidence that all life shares a common ancestor that diverges through this process of descent with modification.
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2. Individual variations over time include age variations, seasonal variations within an individual's lifetime, and seasonal variations across generations.
3. Social variations occur in social insects where there are distinct castes or groups within a colony serving different functions.
4. Ecological variations arise from differences in habitat, climate conditions, host organisms, population density, growth patterns, and neurogenic responses to the environment.
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This document discusses many examples of convergent evolution across different species and environments. Some key examples mentioned include:
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Types of evolution notes
There are three main types of evolution:
1. Coevolution occurs when two species evolve together due to their close relationship, such as flowers and pollinating insects.
2. Divergent evolution happens when species with a common ancestor become more different and evolve into separate species, often in different environments like the finches of the Galapagos Islands.
3. Convergent evolution is when species with different ancestors evolve similar traits for the same environment, like dolphins and fish developing flippers for swimming.
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Charles Darwin studied medicine at Edinburgh University but was repulsed by surgery without anesthesia. He then studied to become a clergyman at Cambridge University. After Cambridge, he was recommended for a surveying trip on the HMS Beagle where he worked as a naturalist for 5 years sailing around the world. His observations and evidence collected on this voyage, especially from the Galapagos Islands, led to his theory of evolution by natural selection, which challenged the prevailing views that species were fixed and unchanging and had been created only a few thousand years ago.
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1. Evolution is the accumulation of genetic changes within populations over time through natural selection. It refers to changes in characteristics of populations over generations, not changes within individuals' lifetimes.
2. Early Greek philosophers like Plato and Aristotle proposed ideas about organisms changing over time, but creationism was dominant until the 1700s. Georges Buffon proposed evolution through natural processes. Jean-Baptiste Lamarck proposed the first natural mechanism of evolution.
3. Charles Darwin developed the theory of evolution by natural selection, proposing that organisms evolve through gradual adaptation to their environments and that species share common ancestry.
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2) Zygomycetes, which are terrestrial decomposers with hyphae that lack septa.
3) Glomeromycetes, which form important mycorrhizal relationships with plants.
4) Ascomycetes, which include yeasts, molds, morels and truffles and help digest plant materials. Many form lichens.
5) Basidiomycetes, which include important decomposers and ectomycorrhial fungi and reproduce sexually through mushrooms.
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How does evolution happen
Charles Darwin developed the theory of natural selection after observing variations in finch beaks on the Galapagos Islands. Natural selection has four parts: overproduction of offspring, inherited variation of traits, struggle for survival, and successful reproduction of adapted organisms. Darwin lacked an understanding of genetics and the source of variations, but we now know traits are inherited from parents and variations arise from gene combinations. Natural selection can act through factors like hunting, resistance, and competition to change population levels over time and potentially lead to the formation of new species.
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1. Variation is necessary for a species' survival as it allows some individuals to adapt to environmental changes while others perish, helping the species as a whole to survive.
2. Evidence for evolution includes homologous and analogous structures in different species, fossils that show increasingly complex forms over time, and similarities in early embryo development - all of which point to shared ancestry.
3. Speciation, or the formation of new species, occurs through mechanisms like the accumulation of variations when populations are isolated, natural selection acting on heritable traits, and migration to new environments.
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Here are some examples of radioactive elements commonly used in radiometric dating and their half-lives:
- Potassium-40 to Argon-40: Half-life of 1.25 billion years
- Rubidium-87 to Strontium-87: Half-life of 48.8 billion years
- Thorium-232 to Lead-208: Half-life of 14 billion years
- Uranium-235 to Lead-207: Half-life of 704 million years
- Uranium-238 to Lead-206: Half-life of 4.47 billion years
The key is that each radioactive element decays at a known rate, allowing scientists to determine the age of a material by knowing
Natural selection
Darwin proposed the theory of natural selection to explain evolution. Natural selection is the process by which organisms better adapted to their environment are more likely to survive and reproduce, passing on their favorable traits. Darwin identified three factors that influence natural selection: overproduction of offspring, variation among individuals, and competition for limited resources. Those individuals possessing variations that increase their chances of survival will be selected through this process to pass on their genes over many generations.
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1) Evolution is the process of change over many generations where organisms become better suited to their environment or more likely to die out.
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This document discusses biological variation and its role in evolution. It defines variation as differences between individuals of a species. Variation can be continuous, with a range of values, or discontinuous with only a few categories. Variation arises from genetic and environmental factors. Natural selection acts on this variation, favoring adaptations that help organisms survive and reproduce, leading to evolution over time as beneficial traits become more common. The document provides examples of anatomical, physiological and behavioral adaptations.
Classification of cat
1. The domestic cat is a small carnivorous mammal that is found globally and primarily lives in areas of human habitation.
2. Domestic cats come in over 100 breeds but generally have a similar body shape, weighing between 4-5 kg and measuring around 76 cm long.
3. Cats are polygynandrous, meaning both males and females can mate with multiple partners, and gestation typically lasts 60-67 days resulting in litters of kittens that are dependent on their mother for care.
Charles darwin & Natural Selection
Charles Darwin developed the theory of natural selection after making observations on his voyage on the Beagle and gathering evidence that species adapt to their environments over generations. Through natural selection, individuals with traits better suited to the environment are more likely to survive and pass on those traits, causing populations to evolve over time. Darwin's observations of related but different species on the Galapagos Islands provided evidence that all life shares a common ancestor that diverges through this process of descent with modification.
Intrapopulation variation
1. Intrapopulation variations can be genetic or non-genetic. Non-genetic variations include individual, social, ecological, and traumatic variations.
2. Individual variations over time include age variations, seasonal variations within an individual's lifetime, and seasonal variations across generations.
3. Social variations occur in social insects where there are distinct castes or groups within a colony serving different functions.
4. Ecological variations arise from differences in habitat, climate conditions, host organisms, population density, growth patterns, and neurogenic responses to the environment.
Isolating mechanism and speciation in time 1
This document discusses isolating mechanisms and theories of speciation. It defines isolating mechanisms as any factors that prevent interbreeding between related groups. There are two main types of mechanisms: pre-mating (preventing mating) and post-mating (preventing hybrid formation). Theories of speciation include gradualism, where new species evolve slowly over long periods, and punctuated equilibrium, where species remain largely unchanged apart from brief periods of rapid change leading to speciation. The key differences between these theories are that gradualism involves continuous small changes while punctuated equilibrium involves long periods of stasis punctuated by sudden speciation events.
Convergent evolution
This document discusses many examples of convergent evolution across different species and environments. Some key examples mentioned include:
- Mimicry complexes that have evolved independently in insects like butterflies and snakes. Mimicry provides protection from predators for palatable species.
- Convergent evolution of traits like wings, flight, body forms adapted for swimming/flying, and defensive adaptations like spines in plants from arid regions.
- Convergent evolution of traits in lizards like burrowing, toe pads for sand, and color patterns as defenses against predators across different continents.
- Convergent camera-like eye structures in vertebrates and cephalopods providing an example of complex traits evolving
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There are three main types of evolution:
1. Coevolution occurs when two species evolve together due to their close relationship, such as flowers and pollinating insects.
2. Divergent evolution happens when species with a common ancestor become more different and evolve into separate species, often in different environments like the finches of the Galapagos Islands.
3. Convergent evolution is when species with different ancestors evolve similar traits for the same environment, like dolphins and fish developing flippers for swimming.
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Charles Darwin studied medicine at Edinburgh University but was repulsed by surgery without anesthesia. He then studied to become a clergyman at Cambridge University. After Cambridge, he was recommended for a surveying trip on the HMS Beagle where he worked as a naturalist for 5 years sailing around the world. His observations and evidence collected on this voyage, especially from the Galapagos Islands, led to his theory of evolution by natural selection, which challenged the prevailing views that species were fixed and unchanging and had been created only a few thousand years ago.
Introduction to darwinian evolution
1. Evolution is the accumulation of genetic changes within populations over time through natural selection. It refers to changes in characteristics of populations over generations, not changes within individuals' lifetimes.
2. Early Greek philosophers like Plato and Aristotle proposed ideas about organisms changing over time, but creationism was dominant until the 1700s. Georges Buffon proposed evolution through natural processes. Jean-Baptiste Lamarck proposed the first natural mechanism of evolution.
3. Charles Darwin developed the theory of evolution by natural selection, proposing that organisms evolve through gradual adaptation to their environments and that species share common ancestry.
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A simple description of how natural selection and evolution works, in very simple, bullet point style steps, followed by an example.
Groups and phyla of fungi
The document summarizes the five major phyla of fungi:
1) Chytrids, which are the only fungi with flagellated cells and mostly live in water.
2) Zygomycetes, which are terrestrial decomposers with hyphae that lack septa.
3) Glomeromycetes, which form important mycorrhizal relationships with plants.
4) Ascomycetes, which include yeasts, molds, morels and truffles and help digest plant materials. Many form lichens.
5) Basidiomycetes, which include important decomposers and ectomycorrhial fungi and reproduce sexually through mushrooms.
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Genetic variations are passed on through reproduction. Natural selection leads to evolution as organisms best adapted to their environment have a better chance of surviving and reproducing. Our understanding of evolution has changed over time from pre-Darwin beliefs that species did not change to Darwin's theory that organisms evolve from common ancestors through natural selection and adaptation to their environment. Evidence for evolution includes homologous structures between species, vestigial organs, embryonic development, and the fossil record.
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How does evolution happen
Charles Darwin developed the theory of natural selection after observing variations in finch beaks on the Galapagos Islands. Natural selection has four parts: overproduction of offspring, inherited variation of traits, struggle for survival, and successful reproduction of adapted organisms. Darwin lacked an understanding of genetics and the source of variations, but we now know traits are inherited from parents and variations arise from gene combinations. Natural selection can act through factors like hunting, resistance, and competition to change population levels over time and potentially lead to the formation of new species.
Heredity and evolution
1. Variation is necessary for a species' survival as it allows some individuals to adapt to environmental changes while others perish, helping the species as a whole to survive.
2. Evidence for evolution includes homologous and analogous structures in different species, fossils that show increasingly complex forms over time, and similarities in early embryo development - all of which point to shared ancestry.
3. Speciation, or the formation of new species, occurs through mechanisms like the accumulation of variations when populations are isolated, natural selection acting on heritable traits, and migration to new environments.
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This document provides background information on key terms related to evolution such as species, artificial selection, and natural selection. It also discusses an experiment conducted by Charles Darwin to test the effects of saltwater immersion on seed germination. The document outlines instructions for students to design a controlled experiment testing this effect using different types and varieties of seeds. It prompts analysis of the data to determine which plant species survived best and whether results help explain plant colonization of islands.
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Charles Darwin traveled around the world on the HMS Beagle from 1831-1836, collecting biological specimens. This provided the foundation for his theory of evolution by natural selection, published in 1859. His theory proposed that species evolve over generations through natural selection acting on inherited variation between individuals. Variations that aid survival and reproduction in a given environment become more common, leading to evolution of new species over time. This document provides background on Darwin's voyage and life, an overview of his theory of evolution by natural selection, and various evidence that supports the theory, including fossils, anatomical similarities, embryology, biochemistry and observations of natural selection in action.
Darwin’s theory of evolution
Darwin proposed four main ideas about evolution: 1) Common descent - all organisms are related through descent from a common ancestor; 2) Gradualism - new species arise gradually through accumulation of small adaptations over time; 3) Multiplication of species - populations tend to increase in size, leading to new species; 4) Natural selection - individuals with traits better suited to the environment will leave more offspring, driving evolution.
Evolution review ppt
This document contains vocabulary terms and definitions related to natural selection and evolution. It includes 14 key terms such as mutation, evolution, fossil, species, adaptation, and natural selection. Interactive questions and definitions are provided to help the learner understand and practice these important concepts.
Darwinism
Darwinism is Charles Darwin's theory of evolution by natural selection, which he published in 1859. The theory proposes that all species of life have evolved over time from common ancestors through the natural selection of small, inherited variations that increase the individual's ability to survive and reproduce in their environment. Criticisms of Darwin's theory led to the modern synthesis of Darwinism with genetics in the 1930s and 1940s, forming the foundation of modern evolutionary theory.
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Compound A
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Compound B
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Compound C
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Products
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Variations over time / Charles Darwin Theory / Grade 6 Science
- 2.
- 4. Darwin studied different types of finches while visiting the Galapagos Island. All the birds were similar in size, color, shape, and habitat (aspects) except they had different beaks. Darwin thought all finishes might come from one ancestor
- 5. Variations that favor survival are more likely to be passed to the next generation. Those variations do not favor survival are less like to be passed on to the next generation. Variations can help a species live long enough to successfully reproduce. Same thing also occur in plants. Many plants are suited to live in particular climates.
- 6. • Darwin noticed that each species of finches was well suited to its particular environment • Each beak of finch enabled the finches to eat particular seed or insect. • Each beak type is called Variation or differences among members of the same species. • Differences are caused by change in an organism genetic which is called Mutation
- 7. Cause Mutation Disorder in organisms DNA Variations Changes in organisms genetic setup Effect Different beaks in finches
- 8. Enables species to live longer Which enables in reproduction A variation that favors survival Pass the traits to offspring's How are variations passed down through generations?
- 9. QUESTION: Why do most organisms produce more off springs than survive in the environment Answer: producing more offspring to ensure that at least a few will survive and reproduce
- 10. In nature organisms compete for natural resources such as food, water and space sunlight Survival of fittest is another way to describe natural selection Plant and animals have more offspring than their environments can support to ensure that enough will survive to carry the species into the future Animals whose fur or skin color blend in with their environments are much likely to hide from or escape their predators than are more noticeable animals( camouflage) In some species Vivid (strong)coloring can warn predator that an organism is dangerous, tasted bad , or is poisonous
- 11. What is another name for natural selection Survival of fittest How does variations help an organism survive in its environment Organisms with a traits that are better suited for survival in environment, are more likely to reproduce and pass these traits to their offspring
- 12. How can an animal‘s coloring affect its chances of survival? Color Camouflage in animals Could make animal more noticeable Helps it to attract and mate Cause Effect
- 13. Antibiotic are medicines people take for diseases Anti means against. Biotic means life This medicine kills live bacteria
- 14. Q/ Why should people complete a course of anti biotic? A/ The strongest bacteria take the longest time to be killed by anti biotic Q/ What some process enable some bacteria to resist the anti biotic? A/ Natural selection Q/ What do you think might happen if more bacteria become resistance to antibiotic? A/ New strong medicine will be needed
- 15. Science Grade 6 Mrs. Deema Anabosi