Biology Concepts and Investigations PDF

Because learning changes everything.® Chapters 13, 14, 15 Evidence of Evolution Speciation and Extinction The Origin and History of Life BIOLOGY: Concepts and Investigations Fifth Edition Mariëlle Hoefnagels © 2021 McGraw Hill. All rights reserved. Authorized only for inst...

Because learning changes everything.® Chapters 13, 14, 15 Evidence of Evolution Speciation and Extinction The Origin and History of Life BIOLOGY: Concepts and Investigations Fifth Edition Mariëlle Hoefnagels © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.  Life on Earth arose 3.8 billion years ago Scientists use the Geologic Timescale to divide the history of the Earth into Eons and Eras, based on evidence of biological and geographical events. Earliest evidence of life Section 13.1 Access the text alternative for slide images. Figures 1.2, 13.2 © McGraw Hill StockTrek/Getty Images 2  Avian Reptiles Theropods Archaeopteryx lithographica Stephen L. Brusatte et al. ; James Reece © Australian Museum 3 © McGraw Hill  Plants and animals of the past left plenty of evidence Paleontology is the study of Fossil remains or other clues to past life. Fossils, the remains of ancient organisms, provided the original evidence for Evolution. (plant): Johnathan Blair/National Geographic Image Collection; (wood): Bill Florence/Shutterstock; (embryo): Millard H. Sharp/Science Source; (coprolite): Sinclair Stammers/Science Source; (trilobite): Siede Preis/Getty Images; (fish): Alan Morgan; (leaf): Biophoto Associates/Science Source; (Triceratops): Francois Gohier/Science Source Section 13.1 Access the text alternative for slide images. Figure 13.1 © McGraw Hill 4  Fossils form in many ways: compression & petrification Organic Fossil Petrified Fossil Section 13.2 Access the text alternative for slide images. Figure 13.4 © McGraw Hill (a): Wong Hock Weng/123RF; (b): John Reader/Science Source 5  Fossils form in many ways: impressions and casting Trace Fossil Cast Fossil Section 13.2 Access the text alternative for slide images. Figure 13.4 © McGraw Hill (a): Wong Hock Weng/123RF; (b): John Reader/Science Source 6  Fossils form in many ways: intact preservation Rarely, intact organisms are preserved by being buried suddenly in the absence of oxygen. These conditions minimize decomposition and prevent scavenging. Section 13.2 Access the text alternative for slide images. Figures 13.4, 13.5 © McGraw Hill (Left image): Natural Visions/Alamy Stock Photo: (Right image): (a): Tim Boyle/Getty Images; (b, c): Dr. Luis M. Chiappe 7  Biogeography considers species’ distribution around the world. Earth’s geography has changed drastically over the last 200 million years due to Plate Tectonics. Section 13.3 Access the text alternative for slide images. Figure 13.7 © McGraw Hill 8  Plate tectonics theory explains why continents move According to the theory of plate tectonics, forces acting deep within the planet move Earth’s land masses. Section 13.3 Figure 13.7 © McGraw Hill 9  Continents are still moving today Continental movements are a strong force that shapes evolution. Earthquakes and volcanoes are evidence that Earth’s plates continue to move today. Section 13.3 Figure 13.7 © McGraw Hill 10  Species distributions reveal evolutionary events The location of various fossil species around 280 MYA tells geographers that Earth’s continents at that time were arranged into one large landmass called Pangaea (280-200 MYA). As the continents drifted apart, populations became isolated from each other leading to Speciation or the forming of new Species which are unique types of life on Earth. Section 13.3 Access the text alternative for slide images. Figure 13.8 © McGraw Hill 11  Biogeography sheds light on evolutionary events Animals on either side of Wallace’s line have been separated for millions of years, evolving independently. The result is a unique variety of organisms on each side of the line. Section 13.3 Access the text alternative for slide images. Figure 13.9 © McGraw Hill 12  Anatomical relationships reveal common descent Investigators often look for anatomical features to determine the evolutionary relationship of two organisms. Section 13.4 Access the text alternative for slide images. Figure 13.10 © McGraw Hill 13  Homologous structures are inherited from a common ancestor All these organisms have similar bones in their forelimbs. These bones are Homologous Structures, inherited from a common ancestor. Section 13.4 Figure 13.10 © McGraw Hill 14  Vestigial structures have lost their functions A Vestigial Structure is homologous to a functional structure in another species and has lost their function in some organisms. In Humans, our Appendix, Eyebrows, and Male Nipples are Vestigial Structures. Section 13.4 Access the text alternative for slide images. Figure 13.11 © McGraw Hill (a): Giel/Getty Images; (b): Pascal Goetgheluck/Science Source 15  Analogous structures evolved independently Anatomical Structures are analogous (similar function) if they are superficially similar but did not derive from a common ancestor. Both wings are used for the same function, flight. However, wing structure in birds and insects is very different. Section 13.4 Figure 13.12 © McGraw Hill 16  Analogous structures result from convergent evolution These similarities arose by convergent evolution, which produces similar structures in organisms that don’t share the same lineage. Section 13.4 Access the text alternative for slide images. Figure 13.13 © McGraw Hill (a, both): Danté Fenolio/Science Source (b, Cardon): Fuse/Getty Images; (b, Euphorbia): Digital Vision/Getty Images 17  Evolution produces life’s diversity Small evolutionary changes that accumulate in a population are called microevolution. These can occur quickly, in just a few generations. Eventually, this leads to macroevolution, which is slower and results from large-scale changes. Section 14.1 Access the text alternative for slide images. Figure 14.1 © McGraw Hill Photos: (bacteria): S. Lowry/University Ulster/Getty Images; (tree): Sieboldianus/E+/Getty Images; (bird): Erich Kuchling/Westend61/Getty Images 18  What is a species? In Evolution, new species form while others become extinct. Species are distinct groups of organisms, but the definition of “species” has changed over time. Section 14.1 Figure 14.1 © McGraw Hill Photos: (bacteria): S. Lowry/University Ulster/Getty Images; (tree): Sieboldianus/E+/Getty Images; (bird): Erich Kuchling/Westend61/Getty Image 19  Linnaeus and Darwin defined species based on appearance In the 1700s, Carolus Linnaeus created the Taxonomic system of Binomial Nomenclature. Each species’ name combines the broader Gharial, American classification Genus alligator, Gavialis with the term species. gangeticus Alligator mississippiensis Section 14.1 Figure 14.2 © McGraw Hill (gharial): RichLindie/Getty Images; (alligator): McGraw-Hill Education 20  Modern biologists define species by reproduction More recently, the Biological Species Concept defines “species” based on their potential to interbreed and produce fertile offspring. New species form when some individuals can no longer interbreed with the rest of the group. Section 14.1 Figure 14.3 © McGraw Hill IT Stock Free/Alamy Stock Photo 21  The Origin of Species is the source of Biological Diversity Speciation is the process by which one species splits into two or more species. Each time speciation occurs, the diversity of life increases. Over the course of 3.5 billion years, an ancestral species first gave rise to two or more different species, which then branched to new lineages, which branched again, until we arrive at the millions of species that live, or once lived, on Earth.  The Biological Species Concept can be problematic. Some pairs of clearly distinct species do occasionally interbreed. The resulting offspring are called Hybrids. An example is the Grizzly Bear (Ursus arctos) and the Polar Bear (Ursus maritimus), whose hybrid offspring have been called “Grolar Bears”. + = Horse + Donkey = Mule  Reproductive barriers cause speciation If the potential to interbreed defines species, reproductive isolation results in new species. Reproductive Isolation can be either Prezygotic (barriers prevent the formation of an embryo before reproduction occurs) or Postzygotic (after reproduction has occurred, hybrid individuals have reduced fitness decreasing the size of future generations). Section 14.2 Figure 14.4 © McGraw Hill IT Stock Free/Alamy Stock Photo 25  Prezygotic reproductive barriers prevent fertilization Barrier Description Example Illustration PREZYGOTIC REPRODUCTIVE ISOLATION Ladybugs feed on different Habitat isolation Different environments plants. Temporal Active or fertile at Field crickets mature at isolation different times different rates. Behavioral Different courtship Frog mating calls differ. isolation activities Mechanical Mating organs or Sage species use different isolation pollinators incompatible pollinators. Sea urchin gametes are Gametic isolation Gametes cannot unite. incompatible. Section 14.2 Access the text alternative for slide images. Figure 14.4 © McGraw Hill 26  Postzygotic reproductive barriers prevent development of fertile offspring Barrier Description Example Illustration POSTZYGOTIC REPRODUCTIVE ISOLATION Hybrid offspring fail to Hybrid eucalyptus seeds and Hybrid inviability reach maturity. seedlings are not viable. Hybrid infertility Hybrid offspring unable Lion-tiger cross (liger) is (sterility) to reproduce infertile. Second-generation hybrid Offspring of hybrid Hybrid offspring have reduced mosquitoes have abnormal breakdown fitness. genitalia.. Section 14.2 Figure 14.4 © McGraw Hill 27  Spatial patterns define three types of speciation Reproductive barriers can arise in three ways, depending on spatial patterns. Section 14.3 Figure 14.5 © McGraw Hill 28  Populations can be geographically separated In allopatric speciation, a barrier physically separates a population into two groups that cannot interbreed. With no gene transfer between the two populations, each proceeds down its own evolutionary line. Section 14.3 Figure 14.5 © McGraw Hill 29  Allopatric speciation is common and well documented For example, Galápagos tortoises diverged into several subspecies on different islands. Section 14.3 Figure 14.7 © McGraw Hill 30  Parapatric speciation occurs in neighboring regions In Parapatric Speciation, part of a population shares a border with another population. Some breeding between populations occurs, but most individuals mate within their own population. Section 14.3 Figure 14.5 © McGraw Hill 31  Sympatric speciation occurs in a shared habitat In sympatric speciation, populations diverge genetically while living together. Although the habitat may appear uniform, often it consists of many microenvironments that select for different phenotypes. Section 14.3 Figure 14.5 © McGraw Hill 32  Cichlid fish may be going through sympatric speciation One species of Cichlid fish has diversified in this small African lake into two types of fish because the bottom is different in the center and near the shore, creating two different habitats for eating and breeding. Section 14.3 Figure 14.9 © McGraw Hill 33  Aneuploidy and Polyploidy Many organisms, such as plants, can survive having too many or too few chromosomes. This is called Aneuploidy. This condition can lead to some genes being repeated and expressed in the offspring making them “bigger”, “faster”, “more drought tolerant”, etc. Many plant species have evolved by Polyploidy in which cells have more than two complete sets of chromosomes. © McGraw Hill 34  Cotton plants went through sympatric speciation Sympatric speciation also occurs when gametes unite to form polyploid offspring with more chromosomes than either parent. Section 14.3 Access the text alternative for slide images. Figure 14.10 © McGraw Hill 35  Polyploidy can form “instant” new species A polyploid organism is reproductively isolated from diploids, because the chromosome numbers differ, creating hybrid inviability. Section 14.3 Figure 14.10 © McGraw Hill 36  Speciation can occur at different paces Evidence from the fossil record supports two models of speciation: gradualism and punctuated equilibrium. Section 14.4 Access the text alternative for slide images. Figure 14.11 © McGraw Hill 37  Speciation can occur after a mass extinction Major environmental changes can cause Mass Extinctions. The surviving organisms exploit new resources in the changed environment, so they diversify after the others die. Section 14.4 Access the text alternative for slide images. Figure 14.13 © McGraw Hill 38  Adaptive radiation of mammals followed the extinction of nonavian dinosaurs Section 14.4 Figure 14.13 © McGraw Hill 39  Extinction marks the end of the line A species is extinct when all of its members have died. Most extinctions occur as part of the background extinction rate, the pace at which species go extinct due to gradually changing environments. Section 14.5 Figure 14.13 © McGraw Hill 40  Many species are lost quickly in mass extinctions The fossil record shows evidence of five mass extinctions in the last 600 million years, due to major environmental changes. Section 14.5 Figure 14.13 © McGraw Hill 41  The sixth mass extinction is happening right now Current extinction rates are accelerating due to Human Population Explosion, especially in vulnerable areas such as islands. Humans profoundly alter the environment by: Causing habitat loss and fragmentation Creating pollution Introducing nonnative species Overharvesting Section 14.5 Access the text alternative for slide images. Figure 14.A © McGraw Hill 42  Taxonomy is Based on Common Descent Taxonomic Aloe vera Number of Biologists try to organize all group plant found in: species species into a classification Domain Eukarya Several million system that reflects evolutionary history. Kingdom Plantae –375,000 Phylum Anthophyta –235,000 Class Liliopsida –65,000 Order Liliales –1200 Family Asphodelaceae 785 Genus Aloe 500 Species Aloe vera 1 Section 14.6 Figure 14.15 © McGraw Hill 43  Taxonomy is the science of describing, naming, and classifying species Taxonomic Aloe vera Number of group plant found in: species The taxonomic Several Domain Eukarya hierarchy organizes million species Kingdom Plantae –375,000 into progressively Phylum Anthophyta –235,000 larger groups. Class Liliopsida –65,000 Order Liliales –1200 Family Asphodelaceae 785 Genus Aloe 500 Species Aloe vera 1 Section 14.6 Figure 14.15 © McGraw Hill 44  Three Domains Domain Bacteriae – unicellular, prokaryotic, common bacteria Domain Archaea – unicellular, prokaryotic, bacteria which live in extreme environments (very hot, very cold, very salty, very acidic) Domain Eukarya – unicellular or multicellular, eukaryotic, Protistans, Fungi, Plants, and Animals © McGraw Hill 45  Six Kingdoms Domain Bacteriae, Kingdom Bacteria - unicellular, prokaryotic, common bacteria. Domain Archaea, Kingdom Archaea - unicellular, prokaryotic, ancient, extreme-living bacteria. Domain Eukarya: Kingdom Protista - unicellular or multicellular, eukaryotic animal-like Protozoans, plant-like Algae, and fungus-like Molds. Kingdom Fungi - unicellular or multicellular, eukaryotic, saprophytic or parasitic. Kingdom Plantae - multicellular, eukaryotic, autotrophic, non-motile. Kingdom Animalia - multicellular, eukaryotic, heterotrophic, motile. © McGraw Hill 46  Life’s origin remains mysterious Life arose on Earth about 3.8 Billion Years Ago. Scientists use the Geologic Timescale to describe major events in the history of life. Section 15.1 Access the text alternative for slide images. Figure 15.1 © McGraw Hill 47  Early Earth was not hospitable to life Geology and Astronomy tells us that the Universe is about 13.7 Billion years old and that Earth and other planets in our solar system formed about 4.6 Billion Years Ago. Atmospheric Pressure and Temperature were too high to sustain life when it was first formed. Section 15.1 Figure 15.2 © McGraw Hill 48  Organic molecules formed from simple precursors For about 500 million years, the harsh conditions on Earth made it possible for small molecules to combine with each other. Scientists think this is how the biological macromolecules formed, in a sort of chemical “soup.” Section 15.1 Access the text alternative for slide images. Figure 15.3 © McGraw Hill 49  The first cells were prokaryotes The earliest microfossil evidence of prokaryotic cells is from around 3.5 BYA. Section 15.2 Figure 15.6 © McGraw Hill 50  Eukaryotes evolved next Fossil evidence of eukaryotic cells dates to around 1.9–1.4 BYA. Section 15.2 Figure 15.6 © McGraw Hill 51  Some organelles evolved by endosymbiosis Endosymbiosis explains the origin of mitochondria and chloroplasts. Section 15.2 Access the text alternative for slide images. Figure 15.8 © McGraw Hill 52  Endosymbiosis occurred more than once Endosymbiont theory proposes that mitochondria and chloroplasts originated as free-living bacteria that were engulfed by other microbes. Section 15.2 Figure 15.8 © McGraw Hill 53  Modern-day organelles developed from ancient bacteria Mitochondria originated as aerobic proteobacteria. Chloroplasts originated as photosynthetic cyanobacteria. Section 15.2 Figure 15.8 © McGraw Hill 54 Ediacarans Lived in the Precambrian Supereon (4.54 BYA to 543 MYA) During the Precambrian Supereon, Photosynthesis evolved, O2 accumulated in the Earth’s atmosphere, Eukaryotic cells, multicellular Algae and Animals appeared. Ediacarans might have been animals, but no one really knows. They lived about 550 MYA and are the most complex known examples of Precambrian life. Section 15.3 Figure 15.12 © McGraw Hill (a): De Agostini Picture Library/Getty Images; (b): The Natural History Museum/The Image Works 55  The Paleozoic era spans 543–248 MYA The Paleozoic era is divided into periods: Cambrian Ordovician Silurian Devonian Carboniferous Permian Access the text alternative for slide images. Figure 15.1 © McGraw Hill 56  Paleozoic Era © McGraw Hill Searra Matt 57  Invertebrate animals flourished during the Cambrian period The Cambrian period lasted from 543–490 MYA. During this time, there is fossil evidence of many different sea animals, including sponges, jellyfish, worms, and the first animals with hard bodies. Section 15.3 Figure 15.13 © McGraw Hill O. Louis Mazzatenta/National Geographic Image Collection 58  Life on Land Developed During the Ordovician and Silurian Periods Paleozoic Era The first land plants and vertebrates appeared during the Ordovician Period (490–443 MYA). During the Silurian Period (443– 417 MYA), land animals and plants continued to diversify and expand. The first plants with vascular tissue arose, as shown in the fossil to the right. Section 15.3 Figure 15.14 © McGraw Hill The Natural History Museum/The Image Works 59  The Devonian Period was the “Age of Fish” Fish with skeletons of bone or cartilage dominated the Devonian Period (417–354 MYA), which ended when a mass extinction of sea life took place. Paleozoic Era Fish with powerful fins and primitive lungs moved onto land. Section 15.3 Figure 15.15 © McGraw Hill (a): Jan Sovak/Stocktrek Images, Inc./Alamy Stock Photo; (c): DEA Picture Library/Getty Images 60  The Carboniferous Period was the “Age of Amphibians” Amphibians were the dominant animals in the Carboniferous Period (354–290 MYA). Ferns and early seed plants flourished. Paleozoic Era Section 15.3 Figure 15.16 © McGraw Hill (a): Richard Bizley/Science Source; (b): Kevin Schafer/Corbis Documentary/Getty Images 61  The Permian period saw many different adaptations to dry land During the Permian Period (290– 248 MYA), reptiles and seed plants became more common. The Permian Period ended with the largest mass extinction in the history of the Earth. The global climate altered drastically due to accumulation of carbon dioxide, rising temperatures, and depletion of oxygen. Section 15.3 Page 316 © McGraw Hill 62  The Mesozoic era spans 248–65 MYA Reptiles and flowering plants dominated the Mesozoic era, which is divided into periods: Triassic Jurassic Cretaceous Figure 15.1 © McGraw Hill 63  The Mesozoic era was the “age of reptiles” Dinosaurs and giant reptiles lived in water, on land, and in the air throughout the Mesozoic Era. Meanwhile the first birds, mammals, and flowering plants developed during the Jurassic Period (206-144 MYA). Section 15.3 Figure 15.17 © McGraw Hill cowardlion/Shutterstock 64 The Cretaceous Period was a Time of great Biological Change Mesozoic Era Many famous dinosaurs lived during the Cretaceous Period (144–65 MYA). A powerful asteroid impact caused extinction of the dinosaurs and a great many other species, ending the era. Section 15.3 Figure 15.14 © McGraw Hill The Natural History Museum/The Image Works 65  The Cenozoic era spans 65 MYA - present Figure 15.1 © McGraw Hill 66  The Cenozoic era was the “age of mammals” With large reptiles gone, mammals diversified rapidly. During the Paleogene (65-23 MYA) and Neogene (23–2.58 MYA) periods, marsupials, monotremes, and placental mammals became common. Section 15.3 Figure 15.18 © McGraw Hill (a): National Geographic/Getty Images; (b): Kevin Schafer/NHPA/Photoshot/Newscom 67  Ice ages came and went during the Pleistocene epoch Many organisms of the Quaternary Period (2.58 MYA–present) look like those that live today, but others went extinct at the end of the last ice age 10,000 years ago. Homo sapiens appeared about 200,000+ years ago. Section 15.3 Figure 15.19 © McGraw Hill Julie Dermansky/Science Source 68  Fossils and DNA tell the human evolution story Monkeys, Apes, and Humans are in a group of Placental Mammals called Primates. Section 15.4 Figure 15.28 © McGraw Hill RollingEarth/E+/Getty Images 69  Humans are primates All primates share a group of physical characteristics not seen in other mammals. Opposable thumbs, long arms, and upright locomotion are notable adaptations in one or more primate groups. Section 15.4 Access the text alternative for slide images. Figure 15.20 © McGraw Hill 70  Primates originated about 60 MYA Humans (Hominins) evolved from common ancestors just as the other groups of Primates did. Primates are divided into three main lineages: Prosimians, Monkeys, Hominoids Section 15.4 Access the text alternative for slide images. Figure 15.21 © McGraw Hill 71  Humans are a type of ape The human lineage of hominids (great apes) are called hominins. Modern humans are the only hominin species that is not extinct. Section 15.4 Figure 15.21 © McGraw Hill 72  Human evolution is studied using fossils and DNA Hominin fossils fall into four groups: Ardipithecus, 4.4 MYA Australopithecus, 4–2.5 MYA Paranthropus, an evolutionary dead end, 3–1.5 MYA Homo, at least eight different human species, 2.5 MYA–present Section 15.4 Access the text alternative for slide images. Figure 15.24 © McGraw Hill 73  Paleoanthropology Paleoanthropology is the study of Human origins and evolution, the brief history of time since the divergence of Human and Chimpanzee lineages. Paleoanthropologists are Scientists who study Human origins. They have unearthed about 20 species of extinct Hominins. © McGraw Hill 74 Because learning changes everything. ® www.mheducation.com © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.  Accessibility Content: Text Alternatives for Images © McGraw Hill 76  Life on Earth arose 3.8 billion years ago - Text Alternative Return to parent-slide containing images. An image shows a color spectrum which represents time duration from the origin of the earth up till present into six-time fragments. The origin of the earth (first fragment) dates back to 4.6 billion years ago, second fragment dates back to 3.8 billion years ago, third fragment dates back to 2.5 billion years ago, fourth fragment dates back to 543 million years ago, fifth fragment dates back to 248 million years ago and sixth fragment dates back to 65 million years ago. Return to parent-slide containing images. © McGraw Hill 77  Plants and animals of the past left plenty of evidence - Text Alternative Return to parent-slide containing images. A photo shows eight images of fossil which are fossil of a plant, pile of wood, fossil of a dinosaur egg, fossil of a snake, fossil of trilobite, fossil of a fish, an unknown fossil and fossil of a triceratops Return to parent-slide containing images. © McGraw Hill 78  Fossils form in many ways: compression & petrification - Text Alternative Return to parent-slide containing images. An image shows fossil form by compression with four images, first image shows leaf sinks in the water, second image shows fine sediment covers leaf; third image shows sediment compresses, forming sedimentary rock and fourth image shows a full form of leaf fossil. An image shows fossil form by petrifaction with four images, first image shows a skull is buried in the ground, second image shows water containing dissolved minarets seeps through, third image shows organic matter replaced by minerals turns to stone and forth image shows a broken skull fossil. Return to parent-slide containing images. © McGraw Hill 79  Fossils form in many ways: impressions and casting - Text Alternative Return to parent-slide containing images. An image shows fossil form by impression with four images, first image shows an animal dies on the mud, second image shows animal decays away, third image shows mud hardens to rock and fourth image shows a full form of animal fossil. An image shows fossil form by cast with four images, first image shows a carrot sinks in the water, second image shows carrot decays away, third image shows imprint fills with mud and fourth image shows full form of carrot fossil. Return to parent-slide containing images. © McGraw Hill 80  Fossils form in many ways: intact preservation - Text Alternative Return to parent-slide containing images. An image shows fossil form by intact preservation with two images, first image shows a mosquito trap in a liquid substance of a tree, second image shows mosquito which is trap on a liquid substance. Return to parent-slide containing images. © McGraw Hill 81  Biogeography considers species’ geographical locations - Text Alternative Return to parent-slide containing images. An illustration shows four images of earth which represents Biogeography consider species’ geographical locations. First image shows earth when 280-200 million years ago where All continents are joined into one supercontinent, Pangaea. Second image shows earth when 100-65 million years ago where Present-day continents form and begin to drift apart. Third image shows earth when 181-135 million years ago where two major continents form. Fourth image shows earth when 181-135 million years ago where Continents continue to drift apart. Return to parent-slide containing images. © McGraw Hill 82  Species distributions reveal evolutionary events - Text Alternative Return to parent-slide containing images. The Earth’s continents during 200 MYA time were arranged into one large landmass called Pangaea. It shows Triassic land reptile, Cynognathus found in South America, Permian freshwater reptile, Mesosaurus found in lower part of South America, Triassic land reptile, Lystrosaurus found in Africa and Permian ferns, Glossopteris found in Australia. Return to parent-slide containing images. © McGraw Hill 83  Biogeography sheds light on evolutionary events - Text Alternative Return to parent-slide containing images. The different types of animals found in Asia are bear, thrushes (Java), rhino, bear, leopard (Sumatra), woodpeckers, elephants (Malay Peninsula), orangutans, pheasants and tigers (Borneo). The different types of animals found in Australia are tree kangaroos, deer, cockatoos (Sulawesi), sugar gliders (Philippines), brush turkeys, deer (New Guinea), and sugar gliders, tree kangaroos, cockatoos, honey suckers (Australia). Return to parent-slide containing images. © McGraw Hill 84  Anatomical relationships reveal common descent - Text Alternative Return to parent-slide containing images. The organs marked in the image for all the organism is the fore limb. The organs marked in the image are different in structure but have their common use. The organisms are human, lion, bat, falcon and seal. Return to parent-slide containing images. © McGraw Hill 85  Vestigial structures have lost their functions - Text Alternative Return to parent-slide containing images. The first image shows vestigial eyes of a blind mole, the second image shows a snake (python), the third image shows whale ancestor where limbs are marked which represents more like a hand, and next image shows a modern whale where flipper and vestigial hand limb are marked. Return to parent-slide containing images. © McGraw Hill 86  Analogous structures result from convergent evolution - Text Alternative Return to parent-slide containing images. First photo shows an axolotl fish, second photo shows a white crab, third photo shows Armatocereus oligogonus cactus plant and fourth photo shows a desert cactus. Return to parent-slide containing images. © McGraw Hill 87  Evolution produces life’s diversity - Text Alternatives Return to parent-slide containing images. It show evolution produces three types of domains domain bacteria, domain archaea and domain eukaeya. Domain bacteria produce SEM and domain eukaeya produces animals, fungi and plants. Return to parent-slide containing images. © McGraw Hill 88  Prezygotic reproductive barriers prevent fertilization - Text Alternatives Return to parent-slide containing images. It shows total four columns labeled as Barrier, Description, Example, and Illustration. The values are shown below: Row 1: Barrier: Habitat isolation; Description: Different environments; Example: Ladybugs feed on different plants; Illustration: In this section, it shows two images. The first image shows a flower where a ladybug is sitting on the leave. The second image shows three leaves where a ladybug is sitting on the middle leave. Return to parent-slide containing images. © McGraw Hill 89  Cotton plants went through sympatric speciation – Text Alternatives Return to parent-slide containing images. At the extreme left it shows a cotton plant. At the right side of the plant, it shows two gametes labeled as old world cotton n equals 13 (2n equals 26) and south and central American cotton n equals 13 (2n equals 26). Both the gametes fused together to form a single one and the process is known as fertilization which is labeled as sterile hybrid (diploid) 2n equals 26. After this step the chromosome number doubles and forms a gamete labeled as cultivated American cotton (polyploid) 4n equals 52. Return to parent-slide containing images. © McGraw Hill 90  Speciation can occur at different paces – Text Alternatives Return to parent-slide containing images. The illustration shows two models of speciation: gradualism and punctuated equilibrium. In the model gradualism, it shows a purple flower at the initial stage. The flower is divided into three sub parts in the first stage where the first part of the flower turns into light purple, second part turns into dark purple with increase in size and the third part turns into purple with slight reddish in the middle portion. The first part then turns into light yellow in the second stage, second part turns into dark purple with increase in size and the third part turns into combination of red and slight purple. The first part turns into fully yellow at the final stage, the second part turns into fully purple and the third part turns into fully red with slight yellow in colour. In the model Punctuated equilibrium, it shows a purple flower at the initial stage. The flower is divided into three sub parts in the first stage where the first part of the flower turns into yellow in colour, second part turns into dark purple with increase in size and the third part turns into combination of red and yellow colour. The first part then turns into yellow in the second stage, second part turns into dark purple with increase in size and the third part turns into combination of red and slight purple. Return to parent-slide containing images. © McGraw Hill 91  Speciation can occur after a mass extinction – Text Alternatives Return to parent-slide containing images. It shows a chart with x-y plane. Its x-axis represents millions of years ago range from 140 to 0 in decrements of 20 units where from 140 to 80 ranges are labeled as Mesozoic and from 60 to 0 ranges are labeled as Cenozoic. Its y-axis represents relative number of taxonomic groups. At the range from 140 to 80 which is Mesozoic, it shows Nonavian dinosaur families where in the middle it is labeled as major extinction event with a rightward arrow. At the range from 60 to 0 which is Cenooic, it shows Mammal families where three different mammals are shown. Return to parent-slide containing images. © McGraw Hill 92  The sixth mass extinction is happening right now – Text Alternatives Return to parent-slide containing images. Its x-axis represents Number of extinct species. A graph shows the sixth mass extinction. Its x-axis represents two bars labeled as Vertebrate animals and plants. Its x-axis represents Number of extinct species ranges from 0 to 300 in increments of 50 units. The first bar in the graph has two sections. The section is represented as Islands from 0 to 200 and from 200 to approx. 275, it is represented as Mainlands. The second bar in the graph has two sections. The section is represented as Islands from 0 to 50 and from 50 to approx. 75, it is represented as Mainlands. Between both the bars, a deer is shown and above the second bar few plants are shown. Return to parent-slide containing images. © McGraw Hill 93  Life’s origin remains mysterious - Text Alternative Return to parent-slide containing images. First the origin of life started 4.6 billion years ago. Then the earth's crust formed 4.2 billion years ago. Then the prokaryotic life originated from 4.2 billion to 3.8 billion years ago. This time is known as the hadean eon. After which the photosynthesis originated 3.7 billion years ago. This period is known as the archean eon. Next the oxygen accumulated in atmosphere about 2.4 billion years ago. Then the oldest eukaryotic fossils formed about 1.5 billion years ago. The first multicellular organisms formed 1.2 billion years ago. The first animals in the ocean formed about 570 million years ago. This period is known as the proterozoic eon. Then the first plants on land formed about 475 million years ago. First vertebrate on land formed about 375 million years ago. This era is known as paleozoic era. Then the nonavian dinosaurs went extinct about 65 million years ago. This era is known as phanerozoic era. At last the earliest homo sapiens formed about 6 million years ago. This era is known as cenozoic era. Return to parent-slide containing images. © McGraw Hill 94  Organic molecules formed from simple precursors - Text Alternative Return to parent-slide containing images. An image shows precursor chemicals like Lipids, Monosaccharides, Nucleotides, and amino acids with their molecular structure react to form small organic molecules. Five precursors- Carbon dioxide, hydrogen, water, methane and ammonia are shown. They combine together to form lipids, monosaccharides, nucleotides and amino acids. The monosaccharides again form polysaccharides. Nucelotides form RNA then complimentary DNA. The amino acids form polypeptides. Return to parent-slide containing images. © McGraw Hill 95  Some organelles evolved by endosymbiosis - Text Alternative Return to parent-slide containing images. A common ancestor is shown. Then three arrows points towards host cell, aerobic bacterium and photosynthetic bacterium. Host cell form membrane folding. Then membrane folding and aerobic bacterium points towards endosymbiosis. After endosymbiosis non-photosynthetic eukaryotes are formed. Endosysmbiosis also forms chloroplast which in turn forms photosynthetic eukaryotes. Aerobic bacterium also directly forms bacteria. Some photosynthetic bacterium directly forms bacteria, and some undergoes chloroplast process to form photosynthetic eukaryotes. Host cell also directly forms archaea. Return to parent-slide containing images. © McGraw Hill 96  The Paleozoic era spans 543–248 MYA - Text Alternative Return to parent-slide containing images. The oldest eukaryotic fossils formed about 1.5 billion years ago. The first multicellular organisms formed 1.2 billion years ago. The first animals in the ocean formed about 570 million years ago. This period is known as the proterozoic eon. Then the first plants on land formed about 475 million years ago. First vertebrate on land formed about 375 million years ago. This era is known as Palaeozoic era. Then the nonavian dinosaurs went extinct about 65 million years ago. This era is known as phanerozoic era. At last the earliest homo sapiens formed about 6 million years ago. This era is known as cenozoic era. Return to parent-slide containing images. © McGraw Hill 97  Humans are primates - Text Alternative Return to parent-slide containing images. Tarsier, gorilla and homo sapiens grasp objects with opposable thumbs and flat nails. Human brains are also larger than chimpanzee brains. The binocular vision of human eyes has excellent depth perception. The overlapping field of view is almost 120 degree. Return to parent-slide containing images. © McGraw Hill 98  Primates originated about 60 MYA - Text Alternative Return to parent-slide containing images. First the prosimians formed. Then the new world monkeys and old-world monkeys evolved. These three are the ancestral primate having opposable thumbs, flat nails, binocular vision and large brain. Then the lesser apes like gibbons evolved. The gibbons had long arms, short legs and no tail. Then the great apes like orangutans, gorillas, bonoboas and common chimpanzees evolved. The orangutans were the first walking primates. The gorillas were knuckle walking primates. The bonobos and common chimpanzees had long legs. At last the humans evolved. Return to parent-slide containing images. © McGraw Hill 99  Human evolution is studied using fossils and DNA - Text Alternative Return to parent-slide containing images. Human fossils fall into four groups- Ardipithecus which was dated 4.4 million years ago. Australopithecus which was dated 4-2.5 million years ago. Australopithecus is divided into four types as- Australopithecus anamensis, Australopithecus afarensis, Australopithecus garhu and Australopithecus africanus. Paranthropus was dated 3-1.5 million years ago. Paranthropus is divided into three types as- paranthropus robustus, paranthropus aethiopicus, and paranthropus boisei. At last homo which was dated 2.5 million years ago- present. The homo group is divided into four types as Homo habilis, homo rudolfensis, Homo erectus, homo floresiensis, homo ergaster, homo heidelbergensis, homo neanderthalensis and Homo sapiens. Return to parent-slide containing images. © McGraw Hill 100