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2 March Chapters 12.3, 12.4 & 12.6 Define these words: Phylogeny – Cladistics – Understand what the Cladogram – Theories are related to Derived characters – Cyanobacteria – the origin of live on Endosymbiosis – Earth Primate – Chapter 12.3 Prosimian – Anthropoids – Hominids – (for these vocabulary words and the topic of human evolution, look for similarities in skull shape between Australopithecus and Homo sapiens 3 March Chapters 12.3, 12.4, 12.6 Earth was very different billions of years ago. There have been many hypotheses of Earth’s origins. The most widely accepted hypothesis of Earth’s origins is the nebula hypothesis, where condensing gasses coalesced into planets 4.6 billion years ago. Several sets of hypotheses propose how life began on Earth. Nitrogen & carbon from the atmosphere. • There are two organic molecule hypotheses. – Miller-Urey experiment: demonstrated that organic molecules could be made by passing an electric current, simulating lightning, through closed system that held a mixture of gases Hydrogen & oxygen from the oceans. electrodes “atmosphere” water “ocean” heat source amino acids Early primordial earth – from 4.6 to 2 billion years ago Organic compounds could be made by passing an electrical current through a mixture of gasses (methane, ammonia, hydrogen and water vapor). • These atmospheric gasses comprise the carbon and nitrogen necessary for amino acids to be formed. • The oceans provided the elements of oxygen and hydrogen. Eukaryotic cells may have evolved through endosymbiosis. Endosymbiosis is a relationship in which one organism lives within the body of another. Mitochondria and chloroplasts may have developed through endosymbiosis. • A hypothesis proposes that RNA was the first genetic material. – Ribozymes are RNA molecules that catalyze their own replication. – DNA needs enzymes to replicate itself. • A cladogram is an evolutionary tree made using cladistics. – A clade is a group of species that shares a common ancestor. – Each species in a clade shares some traits with the ancestor. – Each species in a clade has traits that have changed. Which two plants Are most closely related? A B C D E • Derived characters are traits shared in different degrees by clade members. Useful for determining evolutionary relationships between species. – basis of arranging species in cladogram – more closely related species share more derived characters – represented on cladogram as hash marks 1 Tetrapoda clade 2 Amniota clade 3 Reptilia clade 4 Diapsida clade 5 Archosauria clade FEATHERS & TOOTHLESS BEAKS. SKULL OPENINGS IN FRONT OF THE EYE & IN THE JAW OPENING IN THE SIDE OF THE SKULL SKULL OPENINGS BEHIND THE EYE EMBRYO PROTECTED BY AMNIOTIC FLUID FOUR LIMBS WITH DIGITS DERIVED CHARACTER 1) Which two species are most closely related? 2) Which of the following would be used to determine the evolutionary relationships of these organisms? a) b) c) d) DNA sequences Analogous structures Homologous structures Occurring in a similar habitat A B C D E Humans share a common ancestor with other primates. • Primates are mammals with flexible hands and feet, forward-looking eyes and enlarged brains. • Primates evolved into prosimians and anthropoids. – Prosimians are the oldest living primates. – They are mostly small and nocturnal. – Anthropoids are humanlike primates, which are subdivided into the New World monkeys, Old World monkeys, and hominoids. – Homonoids are divided into hominids, great apes, and lesser apes. – Hominids include living and extinct humans. • Bipedal means walking on two legs. – foraging – carrying infants and food – using tools • Walking upright has important adaptive advantages. Can you list three advantages? There are many fossils of extinct hominids. • Most hominids are either the genus Australopithecus or Homo. • Australopithecines were a successful genus that lived for millions of years. • The Homo genus first evolved 2.4 million years ago. Modern humans arose about 200,000 years ago. • Homo sapiens fossils date to 200,000 years ago. • Human evolution is influenced by a tool-based culture. • There is a trend toward increased brain size in hominids. – Morphological changes in shape – Australopithecus afarensis Lucy – 4 mybp Homo habilis Homo neanderthalensis 1.5 mybp Homo sapiens 196,000 thousand ybp Page 381 in your textbook 4 March Finish your geologic clocks 5 March The Linnaean classification system has limitations. • Linnaeus taxonomy doesn’t account for molecular evidence. – The technology didn’t exist during Linneaus’ time. – Linnaean system based only on physical similarities. • Cladistics is a common method to make evolutionary trees. – classification based on common ancestry – species placed in order that they descended from common ancestor • Scientists estimate mutation rates by linking molecular data and real time. – an event known to separate species – the first appearance of a species in fossil record Mitochondrial DNA and ribosomal RNA provide two types of molecular clocks. Cladistics is classification based on common ancestry. • Phylogeny is the evolutionary history for a group of species. – shown with branching tree diagrams (cladograms) – Cladograms constructed by id’ing derived characters – evidence from living species, fossil record, and molecular data Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. – Until 1866: only two kingdoms, Animalia and Plantae Animalia Plantae Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. – Until 1866: only two kingdoms, Animalia and Plantae Animalia – 1866: all single-celled organisms moved to kingdom Protista Plantae Protista Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. – Until 1866: only two kingdoms, Animalia and Plantae Animalia – 1866: all single-celled organisms moved to kingdom Protista Plantae Protista – 1938: prokaryotes moved to kingdom Monera Monera Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. – Until 1866: only two kingdoms, Animalia and Plantae Animalia – 1866: all single-celled organisms moved to kingdom Protista Plantae Protista – 1938: prokaryotes moved to kingdom Monera – 1959: fungi moved to own kingdom Monera Fungi Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. – Until 1866: only two kingdoms, Animalia and Plantae Animalia – 1866: all single-celled organisms moved to kingdom Protista Plantae Protista – 1938: prokaryotes moved to kingdom Monera – 1959: fungi moved to own kingdom Archea Fungi Bacteria – 1977: kingdom Monera split into kingdoms Bacteria and Archaea The three domains in the tree of life are Bacteria, Archaea, and Eukarya. • Domains are above the kingdom level. – Carl Woese: studied rRNA of prokaryotes and found they were two separate groups, genetically speaking – domain model more clearly shows prokaryotic diversity Please do Study Guide questions: Pages 125 126 127 128 131 132 all questions all questions all questions all questions all questions all questions 6 March http://www.pbs.org/wgbh/nova/evolution/ becoming-human.html#becoming-humanpart-1 PBS – Becoming Human 9 March Define these words, please: Autotroph Heterotroph Binomial nomenclature Species Study guide pages Taxonomy 175, 176, 177, & 182 All questions • Domain Bacteria includes prokaryotes in the kingdom Bacteria. – one of largest groups on Earth – classified by shape, need for oxygen, and diseases caused spirilla bacteria • Domain Archaea includes prokaryotes in the kingdom Archaea. – cell walls chemically different from bacteria – differences discovered by studying RNA – known for living in extreme environments Cocci archaea • Bacteria and archaea can be difficult to classify. – transfer genes among themselves outside of reproduction – blurs the line between “species” – more research needed to understand prokaryotes bridge to transfer DNA • Domain Eukarya includes all eukaryotes. – Kingdom Protista • Domain Eukarya includes all eukaryotes. – Kingdom Protista – Kingdom Plantae • Domain Eukarya includes all eukaryotes. – Kingdom Protista – Kingdom Plantae – Kingdom Fungi • Domain Eukarya includes all eukaryotes. – – – – Kingdom Protista Kingdom Plantae Kingdom Fungi Kingdom Animalia • Binomial nomenclature is a two-part scientific naming system. – uses Latin words – scientific names always written in italics – two parts are the genus name and species descriptor • A genus includes one or more physically similar species. – Species in the same genus are thought to be closely related. – Genus name is always capitalized and italisized. • A species descriptor is the second part of a scientific name. – always lowercase – always follows genus name; never written alone Tyto alba Barn owl • Advantages: unique name for each species, scientists around the world recognize them – Some species have very similar common names. – Some species have many common names. Linnaeus’ classification system has seven levels, called taxa. • Each level is included in the level above it. • Levels get increasingly specific from kingdom to species. • Physical similarities are not always the result of close relationships. • Genetic similarities more accurately show evolutionary relationships. 10 March Review for Test 9 – Evolution (10), Mechanisms of Change (11), and taxonomy (17) Using our study guide, make sure you understand the following concepts: Chapters 10 & 12– Study Guide Questions on pages 99 through 108. • • • • Darwin’s observations – Theory of natural selection Evidence of evolution Explain the evidence supporting the scientific theory of the origin of eukaryotic cells (ch 12) Describe scientific explanations of the origin of life on Earth as those posed Miller and Urey (chapter 12) • Origin of primates (chapter 12) • Identify conditions contributing to the origin of life on Earth, such as: organic molecule synthesis, Earth’s early atmosphere, primordial soup Chapter 11 – Study Guide Questions on pages 109 (questions 1 & 2), 110 (questions 7 & 8), 113 (all questions), 117 (all questions) , and 118 (all questions) • Describe the conditions required for natural selection that result in differential reproductive success, including: • Discuss mechanisms of change other than natural selection, such as: genetic drift, gene flow, and non‐random mating 11 March Geographic isolation Variation Punctuated equilibrium Kingdom Protista Phylogeny Archaea Behavioral isolation Kingdom Fungi Homologous structures Convergent evolution Vestigal structure Gene flow Bottleneck effect Reproductive isolation Kingdom Animalia Cladogram Endosymbiosis Geographic isolation Adaptive radiation Intersexual Genetic Drift Anthropoids Embryology Natural Selection Intrasexual Eukarya Biogeography Bacteria Fossils Coevolution Cladistics Evolution Kingdom Plantae Hominid Speciation Prosimians Primate