PPT-Evolution by Natural Selection

Chapters 1418 Charles Darwin DOB 1809 On the Origin of Species by Means of Natural Selection HMS Beagle 183136 Greeks life arose in water and more complex followed simpler ones. Evolution. Believed to be 4.5 billion years old. Thought to have had a very anaerobic atmosphere. Earliest organisms were able to survive primitive environments. Prokaryotes that resemble today’s bacteria. Change over time…. Geology. Began to study rock layers called strata. George Cuvier. Studied fossils. Found extinct species and noticed the deeper the fossil the more unique. Catastrophism. Charles Lyell. How does natural selection change . a population?. P. 247-248 What are the five important principles of natural selection? . P. 250 . What are two sources of variation? . What is a niche? . P. 258 - 259. Evolution- changes in the characteristics of groups of organisms over time . Charles Darwin was the first to propose a feasible . mechanism. for evolution. It is called . natural selection. . . Evolution by Natural Selection is a theory. . The Importance of Evolution in Ecology. Ecologists study proximate or “how” questions:. How nutrients flow through ecosystems. Evolutionary biologists study ultimate or “why” questions:. Why does a stickleback fish have armor in one lake but not another?. The Smallest Unit of Evolution. A common misconception is that organisms evolve during their lifetimes. Natural selection acts on individuals, but only populations evolve. Consider, for example, a population of medium ground finches on Daphne Major Island. Danielle Donahue. Aa. A. daptation: a well fitted feature that aids in the survival of a population. Example: the blind cave salamander has no use for eyes because they live in complete darkness. Bb. What is natural selection?. It’s the . process whereby organisms better adapted to their environment tend to survive and produce more offspring. . The . theory. of its action was first fully . explained . 3 Mechanisms for selection and an introduction to . Hardy-Weinberg. Lyell’s Influence. In attempt to . explain the past in terms of present day processes. , Darwin went to local farmers and animal breeders and observed…. Motivation. Most powerful mode of evolution. Explains observation of Descent with Modification. Nonrandom survivorship/reproduction of individuals based on particular features of their phenotype. . Any environmental agent may be the cause of natural selection. Evolutionary Ideas. A. lthough Darwin is given much credit for evolutionary theory, he was not the first person to come up with the idea.. Evolution is the change in a population over time.. The concept of evolution had been discussed for more than 100 years prior to Darwin’s theory.. Unit:09. Lesson: 01. Be prepared to share your response to the following:. Biological evolution happens at the __________ level, not the individual organism level.. All three definitions mention genetic changes or changes in allele frequency within a population from one generation to the next.. Gibson. Geoscience Research Institute. www.grisda.org. Summary. Evolution is the theory that all organisms have descended from a common ancestor by unguided (natural) processes.. The Cambrian Explosion contradicts the pattern . wallace. and was explained in book “ on the origin of species by means of Natural Selection . . Darwin put the theory based on his observations as he travelled round the world on the ship Beagle..