...Natural Selection Christine D. Bacon Abstract: There are factors in nature that determine whether or not an organism can live in certain environments and consequently, these same factors can lead to population decline and further extinction. With this information can, and how, do organisms adapt to their environments? Students will form hypotheses about processes of natural selection and expand with a discussion of what controls natural populations. The concept will be introduced using two islands with the same populations. Our study will test which species will experience extinction. Using various types of beans, students will test which kinds (species) are able to pass through their "time tunnel", a container with a hole in the bottom. Data collection and graphing will also be an emphasis of this laboratory exercise, enabling projection of ebbs and flows of ancient and future populations. Grade Level(s): 7th Objectives: • Form hypotheses, test, graph, and analyze results • Understand the process of natural selection and what may control populations, including the concepts of adaptation and extinction • Enforce reading skills of cause and effect though identifying factors that cause natural selection • Improve map interpretation skills by following the voyage of the HMS Beagle on a world map • Refine data collection strategies and management • Explore appropriateness of graphs National Standards: Standard A: Science as...
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...Microevolutionary Process Notes * 1) Natural selection works on individuals * 2) Individuals do not evolve, populations do * Insecticide application didn’t result in insecticide resistance: some insects carry trait of resistance in their genes * Processes in Microevolution -Mutation -Non-random mating -Genetic Drift -Natural Selection -Gene Flow * Hardy-Weinburg Theorem: Frequencies of alleles and genotypes are preserved from generation to generation in populations that are not evolving -p2 + 2pq + q2 = 1 * Hardy-Weinburg tells us that we will never get rid of bad genes and it’s used to figure how gene populations change over time * The Hardy-Weinberg theorem describes a pop’n that is not evolving. It has 5 assumptions: 1. Genetic Drift: This represents random changes in small gene pools due to sampling errors in propagation of alleles. The bottleneck effect and founder effect are prime examples of genetic drift. In either case the number of individuals in a population is drastically reduced distorting the original allelic frequencies. (H-W assumes large population) 2. Gene Flow: The movement of alleles into and out of a gene pool. Migration of an organism into different areas can cause the allelic frequencies of that population to increase. Most populations are not isolated, which is contrary to the Hardy-Weinberg Theorem. (H-W assumes the population isolated from others) 3. Mutations: These changes in the genome of an organism are an important...
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...Questions 10.1. What is a confounding variable, and why do confounding variables create problems in research studies? An extraneous variable is a variable that MAY compete with the independent variable in explaining the outcome of a study. A confounding variable (also called a third variable) is a variable that DOES cause a problem because it is empirically related to both the independent and dependent variable. A confounding variable is a type of extraneous variable (it’s the type that we know is a problem, rather than the type that might potentially be a problem). 10.2. Identify and define the four different types of validity that are used to evaluate the inferences made from the results of quantitative studies. 1. Statistical conclusion validity. • Definition: The degree to which one can infer that the independent variable (IV) and dependent variable (DV) are related and the strength of that relationship. 2. Internal validity. • Definition: The degree to which one can infer that a causal relationship exists between two variables. 3. Construct validity. • Definition: The extent to which a higher-order construct is well represented (i.e., well measured) in a particular research study. 4. External validity. • Definition: The extent to which the study results can be generalized to and across populations of persons, settings, times, outcomes, and treatment variations. 10.3. What is statistical conclusion validity, and what is the difference...
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...The peppered moth simulation gave me a better understanding of natural selection and how it causes populations to change and evolve. The method used to conduct this experiment was to use two different sheets of white and pink paper, small white and pink dots, and place the different colored dots on different colored paper, and pick the dots up with forceps in under eight seconds. The method also consisted of collecting data and graphing it. This method had high validity because it was accurate and can be validated with events that happen in real life. The events that the simulation accurately represents are the events of Manchester, England. It represents how earlier on in time, moths were light colored because the trunks of the trees in the...
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...Evolution occurs over time. Evolution occurs when the whole population changes due to certain events. The events that could cause evolution includes major changes in the environment, major changes in habitat, and major changes in the food chain. The Evidence For Evolution There are many different ways to observe the process of evolution. There are three main categories that show evolution. Those three categories are DNA, Fossils, and Comparative Anatomy. DNA is where scientists look at the DNA of modern animals and compare them to other modern animals and extinct animals. An example would be scientists looking at the DNA of a gorilla and comparing it to the DNA of an orangutan and being able to say when those two species became what they are today. Scientists use fossils to compare what an extinct species...
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...What is the most significant set of theories that explain the evolutionary history of our natural world and ongoing environmental change? The origin of life and earth is still one of the greatest mysteries scientists have yet to solve. Modern day science and technology allow us to make theoretically correct assumptions about the past. According to research, it is evident that the earth’s environment and life have been evolving since the beginning of time, which is still evident today as ecosystems and environments continue to change. Three theories that help explain the evolutionary history of our natural world and ongoing environmental change include natural selection, neutral theory of molecular evolution, and the transition into the Anthropocene epoch. Natural selection theory argues that life forms evolve in response to the changes in the environment. Neutral theory of molecular change argues that changes occur in organisms at a constant rate over time without the influence of the environment. Anthropocene is a relatively new term that suggests we have transitioned from the Holocene era to the Anthropocene, which is characterized human dominated activity. These theories are presented in various works, but this paper will focus on Life and the Evolution of Earth’s Atmosphere by Stephen J. Mojzsis, The Anthropocene: a new epoch of geological time? by Jan Zalasiewicz, Mark Williams, Alan Haywood, and Michael Ellis, and The Modern Molecular Clock by Lindell Bromham and David...
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...gene flow between two populations ceases, the potential for _____ exists. Speciation Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the myrtle warbler and Audubon's warbler _____. A) Successfully interbreed and produce fertile offspring successfully interbreed and produce fertile offspring Imagine that part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the reconnection of the island with the mainland. Members of the formerly isolated island finch population can now interact freely with members of the original mainland population. Which of the following observations would, by itself, lead you to conclude unequivocally that the island finch population had evolved into a distinct species, according to the biological species concept? A) Individuals from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. Which of the following conditions is necessary for speciation to occur? D) Reproductive isolation At which point in the adaptation of a population is it clear that speciation has occurred? B) Gene pool changes establish reproductive...
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...Aquinas All things have an order or arrangement, and work for an end. (Again, note that the argument proceeds from empirical evidence of adaptation of ends to means of such natural processes as sensory organs, the food chain, the nitrogen cycle, the Krebs cycle, and so forth; hence, Thomas' argument is à posteriori or inductive.) The order of the universe cannot be explained by chance, but only by design and purpose. Design and purpose is a product of intelligence. Therefore nature is directed by a Divine Intelligence or Great Designer. Paley 1.)Human artifacts are products of intelligent design. 2.)The universe resembles human artifacts. 3.)Therefore the universe is a product of intelligent design. 4.)But the universe is complex and gigantic, in comparison to human artifacts. 6.)Therfore, there probably is a powerful and vastly intelligent designer who created the universe Tennant • Physical matter gathers together in galaxies, stars and planets because of gravity. The gravity balance is perfect for us to survive.• Therefore, the universe has been so ‘finely tuned’ it could not have been a matter of chance.• Humans could only survive in this kind of universe. R – RATIONALITY Life and the world is all about being rational: it seems rationally true to Tennant that God is the designer and creator as the world is comprehensible as such. For him it is the logical and sensible conclusion. Criticism: This is very debatable. Others have claimed that they have...
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...Session 1.3: The Evolution of Cellular Life Exam review view in a separate window In this session we focus on the natural history of cells and the evolutionary timelines of their appearance. The modern phylogenetic classification of domains is used to categorize the different types of cells: bacteria, archea, and eukarya. The names of periods and organisms and certain dates are often helpful in remembering or understanding events that occur in the natural history of evolution. However, we do not expect you to know the names of all organisms mentioned nor all dates (you may find some of the sound attachments on complicated figures useful for review). Those names and dates mentioned below are the ones to key on. The focus in this session is macroevolution which looks broadly at the time lines and changes over long intervals of time. Remember that small changes over millions of years are the framework for evolving complexity from simplicity. Summary of concepts and idea An initial step in covering this material is an understanding of the different types of cells (prokaryotic, eukaryotic animal and plant), their differences, and their place in the phylogeny of life. 1. Information from pre-class reading, Bioflix animations and briefly summarized in class discusses the fundamental components of the prokaryotic and eukaryotic cells. You need to know the differences and understand the basic functions of the cellular components as cells as they are the fundamental...
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...*Q: What is Evolution? - Descent from modification * Macro Evolution (Large Scale Evolution) * Common Ancestor - descent of different species over many generations * OVER LARGER TIMESCALE (ex. Speciation) * Micro Evolution (Small Scale Evolution) * Changes in gene (allele) frequency in population from one generation to the next * May be over shorter time period (generations) * BOTH OF THESE IMPLY: * 1. Common Ancestry * 2. Changes through time *Natural selection occurs when 3 conditions are met; results in evolution * 1. There is variation in a trait * (Ex. Beetle color) * 2. The trait is heritable * (Ex. Brown beetles tends to have brown babies) * 3. There is differential reproductive success, and not all individuals reproduce to their full potential * (Ex. Green beetles are selected against by natural and Brown beetles are selected for- so they reproduce more) *Adaption: A trait that increases the ability of an individual to survive and reproduce compared with individuals without the trait Adaption in an evolutionary context: An inherited trait that makes an organism more fit in its abiotic and biotic environment, and that has arisen as a result of the direct action of natural selection for its primary function. Ex. Mimicry of the non-toxic king snake to evade predators Natural selection leads to Adaptions * Adjustments or changes In behavior, physiology...
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...CHAPTER 6 POPULATION GENETICS SELECTION 1. Which of the following options factually completes the statement, "If a population is in Hardy-Weinberg equilibrium..."? a. There can be no more than two alleles. b. The two alleles will be present at equal frequency. c. Allele frequencies will not change from one generation to the next. d. The dominant allele will be more common. |Correct Answer: |C, Allele frequencies will not change from one generation to the next. | [pic] 2. If allele frequencies do not change from one generation to the next, is the population definitely in Hardy-Weinberg equilibrium? Why or why not? No, it might not be in Hardy-Weinberg equilibrium. Any process that selectively targets heterozygotes can affect genotype frequencies without necessarily changing allele frequencies in the next generation. Examples are nonrandom mating, overdominance, and underdominance. [pic] 3. The Hardy-Weinberg equilibrium principle yields which of the following conclusions? a. If the allele frequencies in a population are given by p and q, the genotype frequencies are given by p2, 2 pq and q2. b. The allele frequencies in a population will not change over time. c. If the allele frequencies in a population are given by p and q, the genotype frequencies are given by p2 and q2. d. The first and third answers are correct. e. The first and second choices are correct. |Correct Answer:...
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...responsive to change.” (Charles Darwin). One of the more controversial pieces ever written was Darwin’s Natural Selection. The controversy is evolution vs. creation. Religion says earth and mankind, and life in general was created by god (as told in the creation story) with a design and purpose. Darwin says life all descends from a common ancestor with modifications over time in an undirected manor. It is not outside the realm of possibility that Darwin may be right considering he was trained as a minister and allowed himself to step outside the general consensus. Much like he did, we may need to accept that there may be some truth to the work he has done over his life I feel that Darwin's work was impactful because it shows us that there are alternative reasoning’s behind how we got here. I agree with Darwin's work and his theory of evolution because it is actually supported by evidence. I don't know about you but I've never been religious. I also think that his theory should be taught because religion has no place in public classrooms. Let parents teach religion, schools teach science, and allow the child to decide what to believe. I believe that evolution is real because it explains why there are so many different types of certain species. Natural selection is the gradual process by which biological traits become either more or less common in a population. Variation exists within all populations of organisms. This occurs partly because random mutations cause changes in the genome...
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...by: Riley Buenaventura The theory of evolution incorporates a logical view that natural life on our planet has changed over time and continues to change by a process known as "natural selection". Charles Darwin, a nineteenth century naturalist, is given credit for this hypothesis, not just because he was the first person to suggest that evolution occurs. Natural selection is where organisms that are most best suited to their habitat or surroundings, survive and pass on their hereditary attributes for future generations. Charles Darwin “It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.” Therefore, the fittest survive and multiply. Natural...
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...Karl J. Niklas The modern theory of biological evolution: an expanded synthesis Published online: 17 March 2004 Springer-Verlag 2004 Abstract In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwin’s Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwin’s perspective. Weismann’s neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwin’s dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the “modern synthesis” is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and molecular evolution, experimental bacterial evolution, and computer simulations (in silico evolution...
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...researcher avoids influencing subjects in any way and tries to be as inconspicuous as possible. 2 Four Main Types of Research Historical research - describes what was-mostly nonobtrusive Descriptive research - describes what is-mostly nonobtrusive Correlation research - makes comparisons, looking for trends or tendencies Experimental research - describes what will be - mostly obtrusive 3 Historical Research A systematic process of searching for information and fact to describe analyze or interpret the past Value-can provide prospective for decision making about current problems -issues are often better understood if we understand the historical perspective Sources-must have good backed sources to protect from criticism -most common sources are past records Descriptive Research Describes, interprets, and clarifies what in the present -often done with surveys -may be done by observation or an observational instrument Developmental Research is one common type of descriptive research which involves the study of changes in behavior over a period of time 4 Correlation Research The purpose is to find relationships between two or more variable so to: - Better understand the conditions and events that we encounter (what goes with what) - To predict future conditions and events. - Correlations do not show cause and effect Coefficients of Correlation...
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