The Evolution of Populations and Speciation
... • How common is genetic variation? – Only about 5% of all vertebrate genes have 2 or more alleles ...
... • How common is genetic variation? – Only about 5% of all vertebrate genes have 2 or more alleles ...
I. Evolution- A brief overview
... 4) Charles Darwin = credited for the accepted theory of evolution (natural selection) • In 1831 was recommended as a naturalist on HMS Beagle, a ship chartered for a five year collecting and mapping expedition to South America and the South Pacific. Developed a hypothesis based on observations, spec ...
... 4) Charles Darwin = credited for the accepted theory of evolution (natural selection) • In 1831 was recommended as a naturalist on HMS Beagle, a ship chartered for a five year collecting and mapping expedition to South America and the South Pacific. Developed a hypothesis based on observations, spec ...
Biology B – Test 3 Study Guide
... Explain the roles that Malthus, Lyell and Wallace played in the development and publication of Darwin’s theory of natural selection. Compare and contrast Darwin and Lamarck’s theories of evolution. ...
... Explain the roles that Malthus, Lyell and Wallace played in the development and publication of Darwin’s theory of natural selection. Compare and contrast Darwin and Lamarck’s theories of evolution. ...
Honors Evolution Power Point
... related populations or species become more and more dissimilar. Divergence is nearly always a response to differing habitats and can result in new species – A) adaptive radiation: many related species evolve from a single ancestral species ex: ...
... related populations or species become more and more dissimilar. Divergence is nearly always a response to differing habitats and can result in new species – A) adaptive radiation: many related species evolve from a single ancestral species ex: ...
What was Darwin trying to explain?
... • Why should these strings of code, or genes, be the same across dissimilar organisms? ...
... • Why should these strings of code, or genes, be the same across dissimilar organisms? ...
BiomoW04Week2
... • long periods of stability with abrupt periods of change and appearances of new species • splitting off of daughter species (cladogenesis), rather than transformation of species as a whole ...
... • long periods of stability with abrupt periods of change and appearances of new species • splitting off of daughter species (cladogenesis), rather than transformation of species as a whole ...
Evolution
... which suggested that inherited variations favorable to survival tend to be preserved, while unfavorable ones are eliminated because of a struggle for resources. • The result is adaptation, an evolutionary modification that improves the chances of survival and reproductive success in a given environm ...
... which suggested that inherited variations favorable to survival tend to be preserved, while unfavorable ones are eliminated because of a struggle for resources. • The result is adaptation, an evolutionary modification that improves the chances of survival and reproductive success in a given environm ...
The Man with the Plan
... Natural variation meant that some finches had slightly different beaks. These finches would have been able to eat different types of food and avoid competition. They would therefore have survived and passed on their genes. 9 of 7 ...
... Natural variation meant that some finches had slightly different beaks. These finches would have been able to eat different types of food and avoid competition. They would therefore have survived and passed on their genes. 9 of 7 ...
BIOLOGY 160 Lecture OBJECTIVES Assessment 5
... 10. Explain gene frequency and genotype ratios. 11. What is meant by gene pool? 12. Know when the Hardy-Weinberg law fails and why. 13. Explain genetic drift. 14. Explain the bottle neck effect and the founder effect and how they change and modify populations. 15. Explain gene flow and how it contri ...
... 10. Explain gene frequency and genotype ratios. 11. What is meant by gene pool? 12. Know when the Hardy-Weinberg law fails and why. 13. Explain genetic drift. 14. Explain the bottle neck effect and the founder effect and how they change and modify populations. 15. Explain gene flow and how it contri ...
Key Question answers
... Animals appeared to change over time (giant fossils vs. regular sized living organisms) 2. Darwin’s thoughts on the differences between species The organisms changed over many generations and became better suited to their environment Differences in organisms were the result of their environmen ...
... Animals appeared to change over time (giant fossils vs. regular sized living organisms) 2. Darwin’s thoughts on the differences between species The organisms changed over many generations and became better suited to their environment Differences in organisms were the result of their environmen ...
Evolution Notes
... Female chooses male with brightest feet and best dance Sexual selection! Sexual selection is a trait or behavior that acts on an organism's ability to obtain a mate ...
... Female chooses male with brightest feet and best dance Sexual selection! Sexual selection is a trait or behavior that acts on an organism's ability to obtain a mate ...
Evolution
... event, perhaps because of the increased availability of their food sources. At the end of the Cretaceous there seem to have been no purely herbivorous or carnivorous mammals. Mammals and birds that survived the extinction fed on insects, worms, and snails, which fed on dead plant and animal matter. ...
... event, perhaps because of the increased availability of their food sources. At the end of the Cretaceous there seem to have been no purely herbivorous or carnivorous mammals. Mammals and birds that survived the extinction fed on insects, worms, and snails, which fed on dead plant and animal matter. ...
PPEvolution_notes_01_April
... -Fish in caves don’t use their eyes so they ________________________________r -Elephants use their trunks a lot so they get longer Although false, his theory ____________________________________________ to explain how organisms adapted to their environment over time ...
... -Fish in caves don’t use their eyes so they ________________________________r -Elephants use their trunks a lot so they get longer Although false, his theory ____________________________________________ to explain how organisms adapted to their environment over time ...
15.1 Notes
... • Vestigial structures, such as pelvic bones in the baleen whale, are evidence of evolution because they show structural change over time. ...
... • Vestigial structures, such as pelvic bones in the baleen whale, are evidence of evolution because they show structural change over time. ...
Evolutionary Theory 3
... • Speciation is the formation of new species by evolution from preexisting species. • Speciation rarely occurs overnight-it usually occurs in stages over generations. • Speciation has occurred when the net effects of evolutionary forces result in a population that has unique features and is ...
... • Speciation is the formation of new species by evolution from preexisting species. • Speciation rarely occurs overnight-it usually occurs in stages over generations. • Speciation has occurred when the net effects of evolutionary forces result in a population that has unique features and is ...
Evolution as a Statistical Process
... Each paired trait has a different survival probability If Ecosystem remains largely unchanged, end result is a distribution of most probable values http://homework.uoregon.edu:8080/chimer a/worksheet.jnlp ...
... Each paired trait has a different survival probability If Ecosystem remains largely unchanged, end result is a distribution of most probable values http://homework.uoregon.edu:8080/chimer a/worksheet.jnlp ...
Notes
... reduced genetic variation from the original population. a non-random sample of the genes in the original population. For example, the Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of th ...
... reduced genetic variation from the original population. a non-random sample of the genes in the original population. For example, the Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of th ...
Notes
... reduced genetic variation from the original population. a non-random sample of the genes in the original population. For example, the Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of th ...
... reduced genetic variation from the original population. a non-random sample of the genes in the original population. For example, the Afrikaner population of Dutch settlers in South Africa is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of th ...
NOTES 2 Ideas Shaped Darwin ch 16_2
... A. Thomas Malthus 1. Humans were being born faster than people were dying, causing overcrowding. 2. The forces that work against population growth, include war, famine, and disease. 3. If the human population grew unchecked, there wouldn’t be enough living space and food for everyone. 4. Darwin real ...
... A. Thomas Malthus 1. Humans were being born faster than people were dying, causing overcrowding. 2. The forces that work against population growth, include war, famine, and disease. 3. If the human population grew unchecked, there wouldn’t be enough living space and food for everyone. 4. Darwin real ...
Evolution
... make them best suited to their environment are passed on to offspring. Individuals whose characteristics are not as well suited to their environment die or leave fewer offspring. • Species change over time. Over long periods, natural selection causes changes in the characteristics of a species, such ...
... make them best suited to their environment are passed on to offspring. Individuals whose characteristics are not as well suited to their environment die or leave fewer offspring. • Species change over time. Over long periods, natural selection causes changes in the characteristics of a species, such ...
Theory of Evolution
... Compare these two examples of change in beetle populations. Which one is an example of evolution 1. Beetles on a diet Imagine a year or two of drought in which there are few plants that these beetles can eat. All the beetles have the same chances of survival and reproduction, but because of food res ...
... Compare these two examples of change in beetle populations. Which one is an example of evolution 1. Beetles on a diet Imagine a year or two of drought in which there are few plants that these beetles can eat. All the beetles have the same chances of survival and reproduction, but because of food res ...
Introduction to evolution
Evolution is the process of change in all forms of life over generations, and evolutionary biology is the study of how evolution occurs. Biological populations evolve through genetic changes that correspond to changes in the organisms' observable traits. Genetic changes include mutations, which are caused by damage or replication errors in an organism's DNA. As the genetic variation of a population drifts randomly over generations, natural selection gradually leads traits to become more or less common based on the relative reproductive success of organisms with those traits.The age of the Earth is about 4.54 billion years old. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old metasedimentary rocks discovered in western Greenland. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.Evolution does not attempt to explain the origin of life (covered instead by abiogenesis), but it does explain how the extremely simple early lifeforms evolved into the complex ecosystem that we see today. Based on the similarities between all present-day organisms, all life on Earth originated through common descent from a last universal ancestor from which all known species have diverged through the process of evolution. All individuals have hereditary material in the form of genes that are received from their parents, then passed on to any offspring. Among offspring there are variations of genes due to the introduction of new genes via random changes called mutations or via reshuffling of existing genes during sexual reproduction. The offspring differs from the parent in minor random ways. If those differences are helpful, the offspring is more likely to survive and reproduce. This means that more offspring in the next generation will have that helpful difference and individuals will not have equal chances of reproductive success. In this way, traits that result in organisms being better adapted to their living conditions become more common in descendant populations. These differences accumulate resulting in changes within the population. This process is responsible for the many diverse life forms in the world.The forces of evolution are most evident when populations become isolated, either through geographic distance or by other mechanisms that prevent genetic exchange. Over time, isolated populations can branch off into new species.The majority of genetic mutations neither assist, change the appearance of, nor bring harm to individuals. Through the process of genetic drift, these mutated genes are neutrally sorted among populations and survive across generations by chance alone. In contrast to genetic drift, natural selection is not a random process because it acts on traits that are necessary for survival and reproduction. Natural selection and random genetic drift are constant and dynamic parts of life and over time this has shaped the branching structure in the tree of life.The modern understanding of evolution began with the 1859 publication of Charles Darwin's On the Origin of Species. In addition, Gregor Mendel's work with plants helped to explain the hereditary patterns of genetics. Fossil discoveries in paleontology, advances in population genetics and a global network of scientific research have provided further details into the mechanisms of evolution. Scientists now have a good understanding of the origin of new species (speciation) and have observed the speciation process in the laboratory and in the wild. Evolution is the principal scientific theory that biologists use to understand life and is used in many disciplines, including medicine, psychology, conservation biology, anthropology, forensics, agriculture and other social-cultural applications.