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Dinosaurs and Their Relatives
Dinosaurs and Their Relatives

... o Origin of a new lineage; in other words, species 1 branches into species 1 and species 2; called cladogenesis or branching  Speciation itself refers to the origin of a new lineage, includes many mechanisms, and involves allopatric speciation  New species form (allopatrically) when populations di ...
Ch 12 - Mr. Neason`s Earth Science
Ch 12 - Mr. Neason`s Earth Science

... Geologists had noticed that fossil from older rock layers were very different from the fossils in younger rocks. In 1859, Darwin set forth the theory of evolution, which states that life forms have changed over time, or evolved, from simpler to more complex forms. To explain why evolution occurs, Da ...
14. Natural Selection
14. Natural Selection

... are called adaptations. Organisms have developed many different kids of adaptations that help them survive in their environments. Charles Darwin observed many species of animals and plants in the Galapagos Islands that were unique to the islands, but still similar to species he had seen elsewhere. Da ...
The Evolution of Evolutionary Thinking in Chile
The Evolution of Evolutionary Thinking in Chile

... activities that caught the attention of Darwin and reinforced his idea of a world in continuous change (Darwin 1846; Moorehead 1969). Naturalists were not rare in Chile at that time, as indicated by Darwin himself in a letter to Henslow in October 28, 1834 “I had hoped during this time to have ...
Chapter 13 PPT
Chapter 13 PPT

... Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings ...
migration and genetic drift as mechanisms
migration and genetic drift as mechanisms

... clear the graph, reset all parameters to their default values, print your graph, and quit. More details on using AlleleA1 can be found in the manual, available both as a separate PDF file and online, under the Help menu, while you are running AlleleA1. ...
Migration and Drift
Migration and Drift

... your graph, and quit. More details on using AlleleA1 can be found in the manual, available both as a separate PDF file and online, under the Help menu, while you are running AlleleA1. ...
Instructional Design Project
Instructional Design Project

... Grade Level Indicators:  Recognize that ecosystems change when significant climate changes occur or when one or more new species appear as a result of immigration or speciation. ...
Apomictic Parthenogenesis and the Pattern of the
Apomictic Parthenogenesis and the Pattern of the

... diapause determination and other seasonal constraints need specific attention, as they may interfere with geographical dispersal, and only life-cycles of one or more years seem possible. In rich biotic communities, which evolve continuously, evolutionary rigidity of apomicts may lead to their extinc ...
life sciences examination guidelines senior certificate
life sciences examination guidelines senior certificate

...  DNA replication takes place  Single-stranded chromosomes become double stranded  Each chromosome will now consist of two chromatids joined by a centromere  DNA replication helps to double the genetic material so that it can be shared by the new cells arising from cell division ...
Taxonomy ppt
Taxonomy ppt

... • Was invented by Carolus Linnaeus • Is the modern system of naming and classifying organisms • Provides the genus is capitalized while the species is not and both are italicized • Combines the genus and species of an animal to give it a name ...
journal questions
journal questions

... predictions about the outcome of this event. With a basic knowledge of amphibians (but lacking specific knowledge of this species), you base your predictions on historical information about climate and reports on the topography of this island. After your visit to Santa Cruz, you compare your previou ...
Class: - 09 Chapter: - Diversity in Living Organisms
Class: - 09 Chapter: - Diversity in Living Organisms

... i) Diploblastic - organisms which derived from two embryonic germ layers (ecto and endo). ii) Triploblastic - organisms which derived from all the three embryonic germ layers. 3. Coelom: Body cavity or coelom is important for proper functioning of various organs. For example, heart which has to cont ...
PowerPoint Chapter 4 - Bakersfield College
PowerPoint Chapter 4 - Bakersfield College

... behaviors of their social group.  Two closely related African species of chimpanzee: common chimpanzees and bonobos, provide models to reconstruct the behavior of evolving humans ...
Canine Evolution - Fuchs Foundation
Canine Evolution - Fuchs Foundation

... place over 100,000 years ago. The study further showed that dogs do not share DNA with either the coyote or jackal and have only one common ancestor - the wolf. Although there is evidence to support the theory that domestic dogs originated from multiple wolf populations over a wide geographic area, ...
B1 Revision Cards - All Saints Academy Dunstable
B1 Revision Cards - All Saints Academy Dunstable

... Take a fixed set of values – categories (e.g shoe size, blood group, gender) Discontinuous variation is usually caused by instructions within cells and is called genetic variation Discontinuous data is plotted on a bar graph ...
classification - All Saints Academy Dunstable
classification - All Saints Academy Dunstable

... Speciation is the formation of a new species as a result of geographical isolation Example of speciation: • Darwin noted that although mockingbirds on different Galapagos islands were very closely related, each island had its own species of bird • Darwin guessed that originally individuals from one ...
pdf of programe and abstracts.
pdf of programe and abstracts.

... changes, involving marine dispersal. Here we test these alternate scenarios for a species that exhibits morphologically distinguishable lineages between Tasmania and the Australian mainland, but also has marine dispersal potential – the wedge-tailed eagle Aquila audax. Genetic variation was surveyed ...
Chapter 10: Natural Selection
Chapter 10: Natural Selection

Science 8 Unit B – Section 1.0
Science 8 Unit B – Section 1.0

...  Analyze the general structure and function of living things  Explain how living things have different structures for similar functions  Show how the body is organized into systems ...
The Battle of Beginnings: Why Neither Side is Winning the Creation
The Battle of Beginnings: Why Neither Side is Winning the Creation

... thinking skills involved in science. Scientists employing these critical thinking skills have made numerous advances in the scientific understanding of the nature of genetic variation. Scientific analyses have provided us with a better understanding of the power of natural information carried (inclu ...
Adaptive Evolution
Adaptive Evolution

... the t phenotypes are those that are similar, natural selection will result in stabilizing selection, and an overall decrease in the population's variation. Directional selection works to shift a population's variance toward a new, t phenotype, as environmental conditions change. In contrast, diver ...
Social Evolution
Social Evolution

... increasing complexity of all things based on the “all-pervading principle” that “[e]very active force produces more than one change—every cause produces more than one effect” (1857: ¶22). Evolution, then, is a process of increasing complexity over time. In his 1860 essay on “The Social Organism” Spe ...
Introduction to Evolution
Introduction to Evolution

Evolution and Biodiversity: Origin and
Evolution and Biodiversity: Origin and

... predation. ...
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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.
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