CAMPBELL BIOLOGY CONCEPTS CONNECTIONS NINTH EDITION Power Point
CAMPBELL BIOLOGY: CONCEPTS & CONNECTIONS, NINTH EDITION Power. Point Lectures Chapter 15 Tracing Evolutionary History TAYLOR SIMON DICKEY HOGAN REECE © 2018 Pearson Education, Inc. Lecture by Edward J. Zalisko
Introduction • Bird feathers and flight are a marriage of structure and function. • Birds were not the first feathered animals on Earth —dinosaurs were. • The evolution of birds is an example of macroevolution, the major changes recorded in the history of life over vast tracts of time. © 2018 Pearson Education, Inc.
Figure 15. 0_2 Chapter 15: Big Ideas Early Earth and the Origin of Life Major Events in the History of Life Mechanisms of Macroevolution Phylogeny and the Tree of Life © 2018 Pearson Education, Inc.
EARLY EARTH AND THE ORIGIN OF LIFE © 2018 Pearson Education, Inc.
15. 1 Conditions on early Earth made the origin of life possible • Earth formed about 4. 6 billion years ago. © 2018 Pearson Education, Inc.
Figure 15. 1 Earth’s atomospheric oxygen changed over time O 2 build-up in the Earth's atmosphere. Red and green lines represent the range of the estimates while time is measured in billions of years ago (Ga). Stage 1 (3. 85– 2. 45 Ga): Practically no O 2 in the atmosphere. Stage 2 (2. 45– 1. 85 Ga): O 2 produced, but absorbed in oceans & seabed rock. Stage 3 (1. 85– 0. 85 Ga): O 2 starts to gas out of the oceans, but is absorbed by land surfaces. Stages 4 & 5 (0. 85–present): O 2 sinks filled and the gas accumulates. [3] © 2018 Pearson Education, Inc.
15. 2 SCIENTIFIC THINKING: Experiments show that the abiotic synthesis of organic molecules is possible • In 1953 Stanley Miller tested the Oparin-Haldane hypothesis using the apparatus in Figure 15. 2. • Scientists continue to generate alternative hypotheses for the origin of organic molecules on Earth. © 2018 Pearson Education, Inc.
Checkpoint question What would a scientist change in Miller’s apparatus to incorporate new evidence about Earth’s early atmosphere? © 2018 Pearson Education, Inc.
MAJOR EVENTS IN THE HISTORY OF LIFE © 2018 Pearson Education, Inc.
Checkpoint question For how long did life on Earth consist solely of single-celled organisms? © 2018 Pearson Education, Inc.
15. 6 The fossil record documents the history of life • The fossil record, the sequence in which fossils appear in rock strata, is an archive of evolutionary history. • Based on this sequence and the ages of rocks and fossils, geologists have established a geologic record. • In the geologic record, eras and periods are separated by major transitions in life-forms, often caused by extinctions. © 2018 Pearson Education, Inc.
Table 15. 6 © 2018 Pearson Education, Inc.
Table 15. 6_2 © 2018 Pearson Education, Inc.
Table 15. 6_1 © 2018 Pearson Education, Inc.
Animation: The Geologic Record © 2018 Pearson Education, Inc.
MECHANISMS OF MACROEVOLUTION © 2018 Pearson Education, Inc.
15. 7 Continental drift has played a major role in macroevolution • The history of life on Earth has been shaped by plate tectonics, theory that Earth’s crust is divided into giant, irregularly shaped plates that essentially float on the underlying mantle. • About 250 million years ago, plate movements brought all the previously separated landmasses together into the supercontinent Pangaea. • The formation and split-up of Pangaea affected the distribution and diversification of organisms. © 2018 Pearson Education, Inc.
Millions of years ago Figure 15. 7 c_1 1 Paleozoic 252 © 2018 Pearson Education, Inc. ea ga n Pa
Laurasia 135 2 1 Paleozoic 252 © 2018 Pearson Education, Inc. Gon dwa Mesozoic Millions of years ago Figure 15. 7 c_2 ea ga n Pa na
Cenozoic Figure 15. 7 c_3 66 a rth ic er Am No Africa 3 India Madagascar lia a str Au Antarctica Laurasia 135 2 Gon dwa Mesozoic Millions of years ago South America 1 Paleozoic 252 © 2018 Pearson Education, Inc. Eurasia ea ga n Pa na
66 4 Cenozoic Present Figure 15. 7 c_4 a rth ic er Am No Africa 3 India Madagascar lia a str Au Antarctica Laurasia 135 2 Gon dwa Mesozoic Millions of years ago South America 1 Paleozoic 252 © 2018 Pearson Education, Inc. Eurasia ea ga n Pa na
15. 8 CONNECTION: Plate tectonics may imperil human life • Moving crustal plates • cause continents to collide, pile up, and build mountain ranges and • produce volcanoes and earthquakes that often occur at the boundaries of Earth’s plates. Checkpoint question Volcanoes usually destroy life. How might undersea volcanoes create new opportunities for life? © 2018 Pearson Education, Inc.
Figure 15. 8 Pacific Plate North American Plate San Francisco San Andreas Fault Los Angeles California © 2018 Pearson Education, Inc.
15. 9 Five mass extinctions have altered the course of evolution • Over the last 500 million years, five mass extinctions have occurred, and in each event, more than 50% of Earth’s species went extinct. • The ones marking the ends of the Permian and Cretaceous have received the most attention. • The Permian extinction is linked to the effects of extreme volcanic activity. • The Cretaceous extinction, which included most dinosaurs, may have been caused by the impact of an asteroid. © 2018 Pearson Education, Inc.
15. 9 Five mass extinctions have altered the course of evolution • During mass extinctions, large numbers of species are lost. • The loss of species that are now at critical risk of extinction would push our planet into a sixth mass extinction. • The fossil record shows that it typically takes 5– 10 million years for the diversity of life to return to previous levels. © 2018 Pearson Education, Inc.
Figure 15. 9 Asteroid North America Chicxulub crater Yucatán Peninsula © 2018 Pearson Education, Inc.
15. 10 Adaptive radiations have increased the diversity of life • Adaptive radiations are periods of evolutionary change in which many new species evolve from a common ancestor. • Adaptive radiations often occur following the colonization of new, unexploited areas or the appearance of evolutionary innovations. © 2018 Pearson Education, Inc.
Figure 15. 10 Extinction of dinosaurs Ancestral mammal Monotremes (5 species) Reptilian ancestor Marsupials (324 species) Eutherians (placental mammals; 5, 010 species) 250 200 150 100 66 50 Time (millions of years ago) © 2018 Pearson Education, Inc. 0
15. 10 Adaptive radiations have increased the diversity of life Checkpoint question Why did marsupial mammals undergo more diversification on the continent of Australia than elsewhere in the world? © 2018 Pearson Education, Inc.
15. 11 Genes that control development play a major role in evolution Checkpoint question Research shows that many differences in body form are caused by changes in gene regulation and not changes in the nucleotide sequence of the developmental gene itself. Why might this be the case? © 2018 Pearson Education, Inc.
Figure 15. 11 b Chimpanzee infant Chimpanzee fetus © 2018 Pearson Education, Inc. Human fetus Chimpanzee adult Human adult
Animation: Allometric Growth © 2018 Pearson Education, Inc.
15. 12 EVOLUTION CONNECTION: Novel traits may arise in several ways • Complex structures may evolve in stages from simpler versions with the same basic function or from the gradual adaptation of existing structures to new functions (exaptations). • Figure 15. 12 illustrates the range of complexity in the structure of eyes among molluscs living today. © 2018 Pearson Education, Inc.
Figure 15. 12 Patch of pigmented cells Eyecup Pigmented cells (photoreceptors) Pigmented cells Simple pinhole eye Eye with primitive lens Complex camera lens-type eye Transparent protective tissue (cornea) Fluid-filled cavity Cornea Lens Eyecup Nerve fibers Limpet © 2018 Pearson Education, Inc. Nerve fibers Abalone Optic nerve Nautilus Layer of pigmented cells (retina) Retina Optic nerve Marine snail Squid
15. 13 Evolutionary trends do not mean that evolution is goal directed • The fossil record seems to show trends in the evolution of many species, for example, toward larger or smaller body size. • An evolutionary trend may be a result of species selection or natural selection in changing environments. © 2018 Pearson Education, Inc.
30 35 40 45 50 55 © 2018 Pearson Education, Inc. Epihippus Archaeohippus Hypohippus Pliohippus Hyracotherium Equus Callippus Hippidion and close relatives Nannippus Neohipparion Hipparion Parahippus Miohippus Megahippus 20 Haplohippus Anchitherium Sinohippus 10 Palaeotherium Pachynolophus 15 Propalaeotherium 5 Orohippus 25 Millions of years ago Present Figure 15. 13 Merychippus Mesohippus Grazers: teeth adapted for grazing Browsers: teeth adapted for browsing
PHYLOGENY AND THE TREE OF LIFE © 2018 Pearson Education, Inc.
15. 14 Taxonomy names and classifies the diversity of life • Taxonomy is the branch of biology concerned with identifying, naming, and classifying species. • Taxonomists assign each species a two-part scientific name, or binomial. • The first part of a binomial is the genus. • The second part of a binomial, the specific epithet, is used to distinguish each species within a genus. • Genera are grouped into progressively broader categories. © 2018 Pearson Education, Inc.
Checkpoint question How much of the classification in do we share with the leopard? © 2018 Pearson Education, Inc.
Animation: Classification Schemes © 2018 Pearson Education, Inc.
15. 15 Phylogenies based on homologies reflect evolutionary history • The evolutionary history of a species or group of species is called phylogeny. • Systematics, which includes taxonomy, is a discipline of biology that focuses on • classifying organisms and • determining their evolutionary relationships. • A phylogenetic tree is a hypothesis of evolutionary relationships. © 2018 Pearson Education, Inc.
Figure 15. 15 a Genus Species Panthera pardus (leopard) Mustela frenata (long-tailed weasel) Lutra lutra (European otter) Mustelidae Carnivora Family Felidae Order Canis Canidae © 2018 Pearson Education, Inc. Canis latrans (coyote) Canis lupus (wolf)
15. 15 Phylogenies based on homologies reflect evolutionary history • Homologous structures and molecular sequences provide the evidence of common ancestry used to determine phylogeny. • However, some similarities are due to similar adaptations in organisms from different evolutionary lineages, a process called convergent evolution. • Similarity due to convergent evolution is called analogy. © 2018 Pearson Education, Inc.
Figure 15. 15 b © 2018 Pearson Education, Inc.
15. 15 Phylogenies based on homologies reflect evolutionary history Checkpoint question Human forearms and a bat’s wings are _____. A bat’s wings and a bee’s wings are _____. © 2018 Pearson Education, Inc.
15. 16 Shared characters are used to construct phylogenetic trees • Cladistics groups organisms by common ancestry. • Each clade is a monophyletic group that consists of an ancestral species and all its evolutionary descendants—a distinct branch in the tree of life. © 2018 Pearson Education, Inc.
Figure 15. 16 a TAXA CHARACTERS Frog Iguana Duck-billed platypus Kangaroo Beaver Amnion Frog 0 1 1 Iguana Amnion Hair, mammary glands 0 Gestation 0 0 0 1 1 Long gestation 0 0 1 0 1 1 Character Table © 2018 Pearson Education, Inc. Duck-billed platypus 1 Hair, mammary glands Gestation Kangaroo Beaver Long gestation Phylogenetic Tree
15. 16 Shared characters are used to construct phylogenetic trees Checkpoint question To distinguish a particular clade of mammals within the larger clade that corresponds to class Mammalia, why is hair not a useful character? © 2018 Pearson Education, Inc.
Checkpoint question According to this phylogenetic tree, which protists are most closely related to animals? © 2018 Pearson Education, Inc.
15. 17 An organism’s evolutionary history is documented in its genome • The more recently two species have branched from a common ancestor, the more similar their DNA sequences should be. • Molecular systematics uses DNA or other molecules to infer relatedness. • Homologous genes are found across distantly related species. © 2018 Pearson Education, Inc.
© 2018 Pearson Education, Inc.
Figure 15. 17 Giant panda Spectacled bear Sloth bear Sun bear American black bear Asian black bear Polar bear Brown bear 20 © 2018 Pearson Education, Inc. 15 10 5 Millions of years ago
15. 17 An organism’s evolutionary history is documented in its genome • The remarkable commonality of molecular biology • demonstrates that all living organisms share many biochemical and developmental pathways and • provides overwhelming support for Darwin’s theory. © 2018 Pearson Education, Inc.
15. 17 An organism’s evolutionary history is documented in its genome Checkpoint question Why is the DNA that specifies r. RNA useful for determining whether fungi are more closely related to plants or to animals? © 2018 Pearson Education, Inc.
15. 18 Molecular clocks help track evolutionary time • The longer two groups have been separated, the greater the divergence of their genes. • Biologists have found that some genes or other regions of genomes appear to accumulate changes at constant rates. • Such observations form the basis for the concept of a molecular clock, a method that estimates the time required for a given amount of evolutionary change. © 2018 Pearson Education, Inc.
15. 19 Constructing the tree of life is a work in progress • Life is currently classified into three domains: 1. Bacteria, 2. Archaea, and 3. Eukarya. © 2018 Pearson Education, Inc.
Figure 15. 19 a Domain Eukarya © 2018 Pearson Education, Inc. Archaea Domain Bacteria Domain Common ancestor of all life Stramenopiles Alveolates Rhizarians Excavata Amoebozoans Fungi Animals Red algae Green algae Land plants Methanogens, halophiles Thermophiles Proteobacteria (Mitochondria) Chlamydias Spirochetes Gram-positive bacteria Cyanobacteria (Chloroplasts)
15. 19 Constructing the tree of life is a work in progress • Multiple horizontal gene transfers occurred during the early history of life, and was possibly a major driver of evolution. © 2018 Pearson Education, Inc.
- Slides: 58