I Evolutionary Patterns A 3 5 million years ago evolution started B How did this take place 1 Phylogeny II Phylogeny A III Phylogeny of Vertebrates B Species living today A B C C Node Common ancestors of the two species D Root Oldest common ancestor of the species A Phylogenetics study of phylogenic trees B Taxonomy naming of organisms two part name 1 Genus Homo 2 Species sapiens italicized or underlined C IV Sister Groups A Groups of organisms that share a common ancestor Sister Groups B V Monophyletic Paraphyletic and Polyphyletic Groups A Monophyletic includes a common ancestor and all of its descendants 1 Ex Lungfish B Paraphyletic includes a common ancestor and some but not all of its descendants 1 Ex Reptile Group does not include birds C Polyphyletic does not include the common ancestor 1 BE ABLE TO RECOGNIZE THE DIFFERENCE BETWEEN THEM AND IDENTIFY THEM D Which of the following is a common ancestor of birds and crocodiles 1 Sauropods 2 Archeoptryx 3 Dinosaurs 4 Coelocanths E Are fish a monophyletic group 1 Yes 2 No It would be a paraphyletic group because it includes some ancestors but not all F VI Classification A Taxonomy naming process classification B Multiple Phylum KINGDOM DOMAIN 1 Ex Humans a Homosapiens Genus Species C VII Homologous and Analogous Features A Homologous amniotic egg things that evolve and we can see evidence of that evolution throughout history 1 Common throughout a common ancestor and then throughout all the organisms in that group 2 More helpful when trying to read phylogenic trees B Analogous wing evolved separately and there is not a common ancestor 1 More info given when looked at C VIII Synapomorphies A Synapomorphies 1 A characteristic present in an ancestral species and shared exclusively in more or less modified form by its evolutionary descendants 2 Possession by two or more organisms of a characteristic inherited exclusively from their common ancestor 3 Characters that have evolved independently in two separate groups are called 1 Homologous Characters 2 Analogous Characters 3 Synapomorphies 4 Evolutionary Innovations 4 IX Construction of a Tree A B Out group organism A then look at B and C and then look at Synapomorphies branch to B because of wings X XI Using Molecular Data to Build Phylogenetic Trees A Can use gene sequences amino sequences genomes etc Practical Uses of Phylogenetic Trees A Dentist accused of transferring HIV to his patients 1 HIV positive 2 Didn t use gloves and proper precautions when treating patients 3 Few patients came down with HIV with no history of it except dentist 4 RED people who had to have contracted it from the dentist B Which molecular detail can be used to construct phylogenetic histories o A Individual Nucleotides o B RNA o C Amino Acids o D All of the Above XII Using Fossils to Create Phylogenies A Allow us to calibrate phylogenies in terms of time B Provide a record of extinct species C Place evolutionary events in context with the Earth s history XIII Fossils A Fossils the remains of ancient organisms that have been preserved in rocks 1 Must be buried in sediments 2 Must not be exposed to a lot of oxygen a Bones and teeth fossilize the best XIV Formation of the Fossil Record A B Find fossils in sedimentary rock 1 Layers of rock the deeper or older the layers older the organisms 2 Location helps with evolutionary evidence XV Trace Molecular Fossils Used if there isn t a true fossil A Trace Fossils 1 Many animals leave tracks and trails as they move about or burrow into sediments 2 These trace fossils from dinosaur tracks to the feeding trails of snails and trilobites preserve a record of both anatomy and behavior 3 Sometimes it can identify the presence of a track footprint B Molecular Fossils 1 Organisms can also contribute molecular fossils to the rocks 2 Most biomolecules decay quickly after death 3 Proteins and DNA for example generally break down before they can be preserved XVI Burgess Shale XVII Messel Shale A Area where we have found a huge number of fossils A Formed 50 million years ago in a lake B Things died very quickly and were fossilized C Helps us better understand how mammals develop A Area between Permian and Triassic Pangea formed B XVIII Geologic Timescale XIX Radioactive Decay A B Carbon 14 Dating 1 Isotope of Carbon 13 2 After an organism dies the C 14 begins to decay 3 Amount of it decreases 4 Then proceeds to Nitrogen 14 C Half Life 1 The amount of time it takes for half of the radioactive isotope to decay 2 Second half life 1 4 of the time XX Pangaea A When all the continents came together and formed a single continent B Caused mass eruptions of volcanoes C Mass extinction of paleozoic XXI Dinosaur and Bird Phylogeny A B C Confirmed relationship between dinosaurs and birds XXII Fish to Tetrapod Vertebrates A B Lungfish can live on land for a short period of time XXIII Mass Extinctions A 1 Phylogeny and Fossils Together A CHAPTER SUMMARY 23 1 A PHYLOGENETIC TREE IS A REASONED HYPOTHESIS OF THE EVOLUTIONARY RELATIONSHIPS OF ORGANISMS The nested pattern of similarities seen among organisms is a result of descent with modification and can be represented as a phylogenetic tree The order of branches on a phylogenetic tree indicates the sequence of events in time Sister groups are more closely related to one another than they are to any other group A node is a branching point on a tree and it can be rotated without changing evolutionary relationships A monophyletic group includes all the descendants of a common ancestor and it is considered a natural grouping of organisms based on shared ancestry A paraphyletic group includes some but not all of the descendants of a common ancestor A polyphyletic group includes organisms from distinct lineages based on shared characters but it does not include a common ancestor Organisms are classified into domain kingdom phylum class order family genus and species 23 2 A PHYLOGENETIC TREE IS BUILT ON THE BASIS OF SHARED DERIVED CHARACTERS Characters or traits existing in different states are used to build phylogenetic trees Homologies are similarities based on shared ancestry while analogies are similarities based on independent adaptations Homologies can be ancestral unique to a particular group or present in some but not all of the descendants of a common ancestor shared derived characters Only shared derived characters or synapomorphies are useful in constructing a phylogenetic tree Molecular data provide a wealth of characters that complement
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