Lecture 19 Evolution Intro Section 22 2 Understand the difference between natural selection and evolution Natural selection is a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits While evolution is descent with modification the idea that living species are descendants of ancestral species that were different from the present day ones also defined more narrowly as the change in the genetic composition of a population from generation to generation So the difference is natural selection is a process that drives evolution Understand the basic principle of natural selection The basic principles of natural selection is Variation Variations that increase reproductive success will be more common in the Heredibility Most variations are passed on from generation to generation they are following generations inherited Over production Animals have reproduced more young than what can actually survive on the available resources Survival of the fittest Since they are more young than resources the ones who are the most fit or most adapted to the environment will be the ones who survive and those favored traits that attribute to that success is what is passed on Natural selection is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals because of those traits Over time natural selection can increase the match between organisms and their environment If an environment changes or if individuals move to a new environment natural selection may result in adaptation to these new conditions sometimes giving rise to new species Be able to distinguish between evolutionary change and other kinds of changes Know the definition of evolution above no other change is quite like it since there is descent with modification Evolution is something that happens in populations and it leads to changes in the genetic nature of populations can lead to changes in the mean phenotype of populations Can lead to the differentiation of populations Can lead to the formation of new species Look for these changes Lecture 20 Introduction to Evolution Vocabulary Evolution is descent with modification the idea that living species are descendants of ancestral species that were different from the present day ones also defined more narrowly as the change in the genetic composition of a population from generation to generation Natural selection a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits Fitness The ability of a population usually a whole species or ecotype to survive reproduce and adapt genetically to a changing environment for many usually more than 50 generations Adaptation Inherited characteristic of an organism that enhances its survival and reproduction in a specific environment Phylogeny The evolutionary history of a species or group of related species Concepts Know that Darwin came up with his ideas after voyage on the Beagle Galapagos animals were influential Darwin went on a five year voyage on a ship called the Beagle His interest in the geographic distribution of species was peaked when he landed in the Galapagos There was very unique species here for the most part they did not exist anywhere else in the world Darwin realizes the importance of adaptation and how it is essential in defining evolution Darwin comes up with the idea of natural selection Know that Wallace independently came up with same idea He had nearly identical hypothesis concerning natural selection but Although Wallace had submitted his ideas for publication first he admired Darwin and thought that Darwin had developed the idea of natural selection so extensively that he should be known as its main architect Understand the five ideas in Darwin s theory 1 Evolution has happened 2 All life has a common ancestor 3 The diversity of life is the result of a series of splits in the lineage family tree of living things 4 Natural selection is the primary mechanism driving evolutionary change 5 Evolution occurs gradually over time Understand that exposure to the diversity of life around the world was an important influence Both Wallace and Darwin traveled the world before coming up with the hypothesis of natural selection Understand the basic process of natural selection 1 Mother reproduces more young than resources available 2 Certain traits allow the ones with said traits to survive 3 Those with favored traits are passed on since the ones processing the traits live long enough to reproduce Understand that evolution can be depicted as a branching tree Darwin viewed the history of life as a tree with multiple branchings from a common trunk out to the tips of the youngest twig The tips of the twigs represent the diversity of organisms living in the present Each fork of the tree represents the most recent common ancestor of all the lines of evolution that subsequently branch from that point Lecture 21 Evidence for Evolution and Modern Evolutionary Biology Vocabulary Homology Similarity in characteristics resulting from a shared ancestry Endemic Referring to a species that is confined to a specific geographic area Fitness The ability of a population usually a whole species or ecotype to survive reproduce and adapt genetically to a changing environment for many usually more than 50 generations Selection When something is favored or chosen Convergence A kind of evolution wherein organisms evolve structures that have similar analogous structures or functions in spite of their evolutionary ancestors being very dissimilar or unrelated Phylogeny The evolutionary history of a species or group of related species Non coding DNA Components of an organism s DNA sequences that do not encode for protein sequences Shared sequences of apparently non functional DNA are a major line of evidence of common descent Concepts Know the different types of evidence for evolution and understand their significance Life on Islands Species were similar to mainland but unique endemic this inferred that individuals arrived on the islands and then evolution of new forms occurred Fossil Record documents the pattern of evolution showing that past organisms differed from present day organisms and that many species have become extinct Fossils also show the evolutionary changes that have occurred in various groups
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