DOCSLIB.ORG

Animal Evolution and Diversity

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Animal Evolution and Diversity Name Class Date Animal Evolution and Diversity Evolution Q: How have animals descended from earlier forms through the process of evolution? WHAT I KNOW WHAT I LEARNED SAMPLE ANSWER: Invertebrates SAMPLE ANSWER: The first animals 26.1 How did evolved before vertebrates, began evolving before the invertebrates millions of years ago. Cambrian Explosion. Over a evolve? period of 10–15 million years, animals evolved complex body plans, appendages, skeletons, and other hard body parts. By the end of the Cambrian Period, all the basic body plans of modern animal phyla had been established. SAMPLE ANSWER: Chordates SAMPLE ANSWER: Each time 26.2 How did evolved more recently than chordate ancestors evolved a chordates evolve? invertebrates. new adaptation in their body plan, a major adaptive radiation occurred. Today, there are six groups of modern chordates—one group of nonvertebrate chordates and five groups of vertebrate chordates (fishes, amphibians, reptiles, birds, and mammals). SAMPLE ANSWER: Primates SAMPLE ANSWER: Humans and evolved later than other other primates evolved from 26.3 How did animals. There are many a common ancestor that lived primates evolve? different kinds of primates, more than 65 million years including monkeys, apes, and ago. Many species of the humans. genus Homo existed before our species, Homo sapiens, appeared. Our genus originated in Africa and spread to the rest of the world. Chapter 26 • Workbook A • Copyright © by Pearson Education, Inc., or its affi liates. All Rights Reserved. 407 013368718X_CH26_407-420.indd 1 1/5/09 12:39:38 PM Name Class Date 26.1 Invertebrate Evolution and Diversity Lesson Objectives Explain what fossil evidence indicates about the timing of the evolution of the first animals. Interpret the cladogram of invertebrates. Lesson Summary Origins of the Invertebrates It is not known when the first multicellular animals evolved from single-celled eukaryotes. ▶ Animals probably evolved from ancestors they shared with choanoflagellates. Fossil evidence indicates that animals began evolving long before the Cambrian Explosion, which occurred between 530 and 515 million years ago. ▶ Fossils from the Ediacara Hills of Australia date from roughly 565 to 544 million years ago. Their body plans are different from those of anything alive today. Some seem to be related to invertebrates such as jellyfishes and worms. ▶ Cambrian fossils (dating back about 542 million years ago) show how animals evolved complex body plans over a span of 10–15 million years. Many had body symmetry, a front and back end, specialized cells, and appendages, structures such as legs or antennae protruding from the body. Some had hard body parts that became fossilized. ▶ By the end of the Cambrian, the basic body plans of the modern phyla were established. ▶ Today, invertebrates are the most abundant animals on Earth. Cladogram of Invertebrates The cladogram of invertebrates presents current hypotheses about evolutionary relationships among major groups of modern invertebrates. ▶ The major invertebrate phyla are the sponges, cnidarians, arthropods, nematodes (roundworms), flatworms, annelids, mollusks, and echinoderms. • Sponges have pores in their bodies. • Cnidarians are radially symmetrical animals with stinging tentacles. • Arthropods have segmented bodies, a hard external skeleton, jointed appendages, and cephalization. • Nematodes, or roundworms, are nonsegmented worms with pseudocoeloms. Their digestive tracts have two openings. • Platyhelminthes, or flatworms, are the simplest animals to have three germ layers, bilateral symmetry, and cephalization. • Annelids are worms with segmented bodies and a true coelom. ▶ Larvae are the immature stages of development in some animals, such as mollusks. Many mollusks have a free-swimming larval stage called a trochophore. The trochophore is also characteristic of many annelids, indicating that annelids and mollusks are closely related. • Mollusks are soft-bodied animals that usually have a shell. They also have a true coelom and complex organ systems. • Echinoderms have spiny skin and exhibit radial symmetry. Lesson 26.1 • Workbook A • Copyright © by Pearson Education, Inc., or its affi liates. All Rights Reserved. 408 013368718X_CH26_407-420.indd 2 1/5/09 12:39:42 PM Name Class Date Origins of the Invertebrates 1. How much time passed between the appearance of the first prokaryotic cells and the emergence of multicellular organisms? About three billion years passed 2. What are choanoflagellates? What is their significance in animal evolution? They are single-celled eukaryotes that sometimes grow in colonies. They may have evolved from ancestors they shared with animals. 3. How old is our oldest evidence of multicellular life? roughly 600 million years old For Questions 4–9, write the letter of the correct answer on the line at the left. B 4. The first animals were tiny and soft-bodied, so A. no fossilized bodies exist. B. few fossilized bodies exist. C. fossilized bodies are plentiful. D. the only fossils that exist are “trace fossils.” B 5. Fossil evidence indicates that the first animals began evolving A. during the Cambrian Period. C. after the Cambrian Explosion. B. before the Cambrian Explosion. D. after the Cambrian Period. A 6. Why are the fossils of the Ediacara Hills of Australia important? A. Their body plans are different from those of anything alive today. B. Some had cells, tissues, and specialized organs. C. Some were differentiated into a front and back end. D. Some were autotrophic. C 7. Over a period of 10–15 million years in the Cambrian Period, animals evolved A. into eukaryotic, photosynthetic forms. B. the ability to survive on the bottom of shallow seas. C. complex body plans, including cells, tissues, and organs. D. into modern, vertebrate forms. B 8. Structures such as legs or antennae that protrude from the body are A. trace fossils. B. appendages. C. shells, skeletons, and other hard body parts. D. evidence of an extinct phylum. D 9. Which animals are the most abundant on Earth? A. arthropods C. sponges B. mollusks D. invertebrates Lesson 26.1 • Workbook A • Copyright © by Pearson Education, Inc., or its affi liates. All Rights Reserved. 409 013368718X_CH26_407-420.indd 3 1/5/09 12:39:44 PM Name Class Date Cladogram of Invertebrates 10. Write “yes” or “no” to indicate how certain features distinguish each phylum of multicellular invertebrates. The first row is completed as an example. Tissues Radial Bilateral symmetry Protostome Deuterostome development development Sponges no no no no no Cnidarians yes yes no no no Arthropods yes no yes yes no Nematodes (Roundworms) yes no yes yes no Flatworms yes no yes yes no Annelids yes no yes yes no Mollusks yes no yes yes no Echinoderms yes yes yes no yes 11. Describe three evolutionary trends you see in invertebrates. Invertebrates developed complex body plans, including specialized tissues; they also developed body symmetry such as bilateral or radial symmetry; arthropods, annelids, and mollusks developed a protostome, while echinoderms developed a deuterostome. Lesson 26.1 • Workbook A • Copyright © by Pearson Education, Inc., or its affi liates. All Rights Reserved. 410 013368718X_CH26_407-420.indd 4 1/5/09 12:39:46 PM Name Class Date 26.2 Chordate Evolution and Diversity Describe the most ancient chordates. Interpret the cladogram of chordates. Lesson Summary Origins of the Chordates Embryological studies suggest that the most ancient chordates were related to the ancestors of echinoderms. ▶ Fossils of the earliest chordates (Cambrian Period) show muscles arranged in a series, traces of fins, sets of feathery gills, a head with paired sense organs, and a skull and skeletal structures likely made of cartilage, a strong connective tissue that is softer and more flexible than bone. Cartilage supports all or part of a vertebrate’s body. ▶ Modern chordates are very diverse, consisting of six groups: the nonvertebrate chordates and the five groups of vertebrates—fishes, amphibians, reptiles, birds, and mammals. Cladogram of Chordates The cladogram of chordates presents current hypotheses about relationships among chordate groups. Major groups are: ▶ Nonvertebrate chordates: The tunicates and the lancelets lack backbones. ▶ Jawless fishes: Lampreys and hagfishes lack vertebrae and have notochords as adults. ▶ Sharks and their relatives: They have jaws and skeletons made of cartilage. ▶ Bony fishes: These animals have skeletons made of true bone. Most modern bony fishes are ray-finned fishes. One group of ancient lobe-finned fishes evolved into the ancestors of tetrapods, which are four-limbed vertebrates. ▶ Amphibians: Amphibians live in water as larvae but on land as adults. They breathe with lungs as adults, but most require water for reproduction. ▶ Reptiles: Reptiles have dry, scaly skin, well-developed lungs, strong limbs, and shelled eggs that do not develop in water. ▶ Birds: Birds can regulate their internal body temperature. They have an outer covering of feathers, strong yet lightweight bones, two legs covered with scales that are used for walking or perching, and front limbs modified into wings. ▶ Dinosaurs and birds are now considered to be in one clade, which is part of the larger reptiles clade. Modern birds are, therefore, reptiles. The traditional class Reptilia, which is not a clade, includes living reptiles and dinosaurs but not birds. ▶ Mammals: Mammals produce milk from mammary glands, have hair, breathe air, have four-chambered hearts, and regulate their internal body temperature. Origins
Load more

Recommended publications
  • Timeline of Natural History
    Timeline of natural history This timeline of natural history summarizes significant geological and Life timeline Ice Ages biological events from the formation of the 0 — Primates Quater nary Flowers ←Earliest apes Earth to the arrival of modern humans. P Birds h Mammals – Plants Dinosaurs Times are listed in millions of years, or Karo o a n ← Andean Tetrapoda megaanni (Ma). -50 0 — e Arthropods Molluscs r ←Cambrian explosion o ← Cryoge nian Ediacara biota – z ←Earliest animals o ←Earliest plants i Multicellular -1000 — c Contents life ←Sexual reproduction Dating of the Geologic record – P r The earliest Solar System -1500 — o t Precambrian Supereon – e r Eukaryotes Hadean Eon o -2000 — z o Archean Eon i Huron ian – c Eoarchean Era ←Oxygen crisis Paleoarchean Era -2500 — ←Atmospheric oxygen Mesoarchean Era – Photosynthesis Neoarchean Era Pong ola Proterozoic Eon -3000 — A r Paleoproterozoic Era c – h Siderian Period e a Rhyacian Period -3500 — n ←Earliest oxygen Orosirian Period Single-celled – life Statherian Period -4000 — ←Earliest life Mesoproterozoic Era H Calymmian Period a water – d e Ectasian Period a ←Earliest water Stenian Period -4500 — n ←Earth (−4540) (million years ago) Clickable Neoproterozoic Era ( Tonian Period Cryogenian Period Ediacaran Period Phanerozoic Eon Paleozoic Era Cambrian Period Ordovician Period Silurian Period Devonian Period Carboniferous Period Permian Period Mesozoic Era Triassic Period Jurassic Period Cretaceous Period Cenozoic Era Paleogene Period Neogene Period Quaternary Period Etymology of period names References See also External links Dating of the Geologic record The Geologic record is the strata (layers) of rock in the planet's crust and the science of geology is much concerned with the age and origin of all rocks to determine the history and formation of Earth and to understand the forces that have acted upon it.
    [Show full text]
  • Chordates (Phylum Chordata)
    A short story Leathem Mehaffey, III, Fall 201993 The First Chordates (Phylum Chordata) • Chordates (our phylum) first appeared in the Cambrian, 525MYA. 94 Invertebrates, Chordates and Vertebrates • Invertebrates are all animals not chordates • Generally invertebrates, if they have hearts, have dorsal hearts; if they have a nervous system it is usually ventral. • All vertebrates are chordates, but not all chordates are vertebrates. • Chordates: • Dorsal notochord • Dorsal nerve chord • Ventral heart • Post-anal tail • Vertebrates: Amphioxus: archetypal chordate • Dorsal spinal column (articulated) and skeleton 95 Origin of the Chordates 96 Haikouichthys Myllokunmingia Note the rounded extension to Possibly the oldest the head bearing sensory vertebrate: showed gill organs bars and primitive vertebral elements Early and primitive agnathan vertebrates of the Early Cambrian (530MYA) Pikaia Note: these organisms were less Primitive chordate, than an inch long. similar to Amphioxus 97 The Cambrian/Ordovician Extinction • Somewhere around 488 million years ago something happened to cause a change in the fauna of the earth, heralding the beginning of the Ordovician Period. • Rather than one catastrophe, the late-Cambrian extinction seems to be a series of smaller extinction events. • Historically the change in fauna (mostly trilobites as the index species) was thought to be due to excessive warmth and low oxygen. • But some current findings point to an oxygen spike due perhaps to continental drift into the tropics, driving rapid speciation and consequent replacement of old with new organisms. 98 Welcome to the Ordovician YOU ARE HERE 99 The Ordovician Sea, 488 million years 100 ago The Ordovician Period lasted almost 45 million years, from 489 to 444 MYA.
    [Show full text]
  • A Paleontological Perspective of Vertebrate Origin
    http://www.paper.edu.cn Chinese Science Bulletin 2003 Vol. 48 No. 8 725-735 Cover: The earliest-known and most primitive vertebrates on the A paleontological perspective Earth---Myllokunmingia fengjiaoa ， (upper) Zhongjianichthys rostratus of vertebrate origin （ middle ）， Haikouichthys ercaicunensis (lower left and lower right). They were SHU Degan Early Life Institute & Department of Geology, Northwest products of the early Cambrian Explosion, University, Xi’an, 710069, China; School of Earth excavated from the famous Chengjiang Sciences and Resources, China University of Geosciences, Beijing, 100083, China Lagersttat, which was formed in the (e-mail:[email protected]) eastern Yunnan about 530 millions of years ago. These ancestral vertebrates not only Abstract The Early Cambrian Haikouichthys and Haikouella have been claimed to be related to contribute in an important developed primitive separate vertebral way to our understanding of vertebrate origin, but there have elements, but also possessed principal been heated debates about how exactly they are to be interpreted. New discoveries of numerous specimens of sensory organs, including a pair of large Haikouichthys not only confirm the identity of previously lateral eyes, nostril with nasal sacs, then described structures such as the dorsal and the ventral fins, and chevron-shaped myomeres, but also reveal many new had led to the transition from acraniates to important characteristics, including sensory organs of the head craniates (true vertebrates). The (e.g. large eyes), and a prominent notochord with differentiated vertebral elements. This “first fish” appears, discoveries of these “naked” agnathans however, to retain primitive reproductive features of have pushed the earliest record of acraniates, suggesting that it is a stem-group craniates.
    [Show full text]
  • Vertebrate Innovations
    Perspective Vertebrate innovations Sebastian M. Shimeld* and Peter W. H. Holland* School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, United Kingdom Vertebrate innovations include neural crest cells and their derivatives, neurogenic placodes, an elaborate segmented brain, endoskeleton, and an increase in the number of genes in the genome. Comparative molecular and developmental data give new insights into the evolutionary origins of these characteristics and the complexity of the vertebrate body. ll chordates, at some stage in their life of both amphioxus (5) and ascidian (6) minded specifically disrupts an early mi- Acycle, possess a hollow neural tube embryos, although the expression pattern grating cell population that contributes to dorsal to a notochord, plus lateral muscle differs in detail between taxa. Lateral spinal ganglia, without affecting later- blocks. These characters unite tunicates (in- neural plate cells in amphioxus embryos migrating neural crest cells (13). Further- cluding ascidians), amphioxus, and verte- express members of the Msx (7), more, this mutant also affects Rohon- brates in the phylum Chordata. Compara- slug͞snail (8), and Distalless (9) gene Beard cells; these are not considered to be tive molecular and developmental analyses families whereas the latter gene is also neural crest derivatives but are a dorsal have refined this anatomical picture, sug- expressed in ectoderm adjacent to (and neural population of cells involved in gesting that the neural tube of the
    [Show full text]
  • Head and Backbone of the Early Cambrian
    _________________________________________________________________________www.paper.edu.cn letters to nature 12. Bokelmann, G. H. R. & Harjes, H.-P. Evidence for temporal variation of seismic velocity within the upper continental crust. J. Geophys. Res. 105, 23879–23894 (2000). 13. Ratdomopurbo, A. & Poupinet, G. Monitoring a temporal change of seismic velocity in a volcano: Application to the 1992 eruption of Mt. Merapi (Indonesia). Geophys. Res. Lett. 22, 775–778 (1995). 14. Hill, D. P. et al. Seismicity remotely triggered by the magnitude 7.3 Landers, California, earthquake. Science 260, 1617–1623 (1993). 15. Brodsky, E., Karakostas, V. & Kanamori, H. A new observation of dynamically triggered regional seismicity: earthquakes in Greece following the August, 1999 Izmit, Turkey earthquake. Geophys. Res. Lett. 27, 2741–2744 (2000). 16. Knopoff, L., Levshina, T., Keilis-Borok, V. I. & Mattoni, C. Increased long-range intermediate- magnitude earthquake activity prior to strong earthquakes in California. J. Geophys. Res. 101, 5779–5796 (1996). 17. Bowman, D. D. & King, G. G. C. P. Accelerating seismicity and stress accumulation before large earthquakes. Geophys. Res. Lett. 28, 4039–4042 (2001). 18. Price, E. & Sandwell, D. T. Small-scale deformations associated with the 1992 Landers, California, earthquake mapped by synthetic aperture radar interferometry. J. Geophys. Res. 103, 27001–27016 (1998). 19. Fialko, Y., Simons, M. & Agnew, D. The complete (3-D) surface displacement field in the epicentral region of the 1999 Mw7.1 Hector Mine earthquake, southern California, from space geodetic observations. Geophys. Res. Lett. 28, 3063–3066 (2001). Figure 4 Model of velocity as a function of time owing to damage from the Landers 20. Kilb, D., Gomberg, J.
    [Show full text]
  • Lack of Support for Deuterostomia Prompts Reinterpretation of the First Bilateria. Authors and Affiliations Paschalia Kapli1, Pa
    bioRxiv preprint doi: https://doi.org/10.1101/2020.07.01.182915; this version posted July 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Lack of support for Deuterostomia prompts reinterpretation of the first Bilateria. 2 3 Authors and Affiliations 4 Paschalia Kapli1, Paschalis Natsidis1, Daniel J. Leite1, Maximilian Fursman1,&, Nadia Jeffrie1, 5 Imran A. Rahman2, Hervé Philippe3, Richard R. Copley4, Maximilian J. Telford1* 6 7 1. Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, 8 University College London, Gower Street, London WC1E 6BT, UK 9 10 2. Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK 11 3. Station d’Ecologie Théorique et Expérimentale, UMR CNRS 5321, Université Paul Sabatier, 12 09200 Moulis, France 13 4. Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), Sorbonne 14 Université, CNRS, 06230 Villefranche-sur-mer, France 15 & Current Address: Geology and Palaeoenvironmental Research Department, Institute of 16 Geosciences, Goethe University Frankfurt - Riedberg Campus, Altenhöferallee 1, 60438 17 Frankfurt am Main 18 19 20 21 22 23 *Correspondence: [email protected]. 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.07.01.182915; this version posted July 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • Downloaded from Brill.Com09/29/2021 09:36:32AM Via Free Access 318 Cotoras & Allende – Origin of Fin Developmental Program
    Contributions to Zoology, 84 (4) 317-328 (2015) Was the tail bud the ancestral centre where the fin developmental program evolved in chordates? Darko D. Cotoras1, 2, 3, Miguel L. Allende1 1 FONDAP Center for Genome Regulation, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile 2 Department of Integrative Biology, University of California, Berkeley, CA 94720, USA 3 E-mail: [email protected] Key words: Archipterygium hypothesis, co-option, fin fold hypothesis, limb bud Abstract phologists proposed two explanations for the origin of the limbs/fins: The ‘Archipterygium Hypothesis’ and The structural origin of the vertebrates’ paired limbs is still an the ‘Fin Fold Hypothesis’ (both reviewed by Cole and unsolved problem. Historically, two hypotheses have been raised Currie, 2007). Later, it was suggested that the extremi- to explain the origin of vertebrate limbs: the Archipterygium ties were related with side folds in the Cambrian verte- Hypothesis and the Fin Fold Hypothesis. Current knowledge Myllokunmingia Haikouichthys provides support for both ideas. In the recent years, it has been brates and . This has also suggested that (1) all appendages correspond to body axis been rejected due to lack of evidence of a skeletal and duplications and (2) they are originated by the ventralization of muscular support, which are the distinctive features of the developmental program present in the median fins. The tail true limbs (Coates, 2003). bud is also a relevant structure in the attempt to understand the The oldest known paired fin-like appendages were origin of the vertebrates’ limbs. Due to their similarities in gene expression and general organization, both structures should be present in the jawless Thelodonta, however it is not studied more closely to understand their potential evolutionary obvious they had an endoskeletal support (Coates link.
    [Show full text]
  • Chapter 34 Vertebrates
    Chapter 34 Vertebrates Lecture Outline Overview: Half a Billion Years of Backbones • In the early Cambrian period, 540 million years ago, slender 3-cm-long animals swam in the oceans. • These animals lacked armor and appendages, but they left behind a remarkable legacy. • They were the ancestors of the vertebrates, one of the most successful groups of animals ever to swim, walk, slither, or fly. • Vertebrates derive their name from vertebrae, the series of bones that make up the vertebral column, or backbone. • For nearly 200 million years, vertebrates were restricted to the oceans, but about 360 million years ago, the evolution of limbs in one lineage of vertebrates set the stage for these vertebrates to colonize land. ○ On land, vertebrates diversified into amphibians, reptiles (including birds), and mammals. • There are about 52,000 species of vertebrates, far fewer than the 1 million insect species on Earth. • What vertebrates lack in species diversity, however, they make up for in disparity. ○ Plant-eating dinosaurs, at 40,000 kg, were the heaviest animals to walk on land. ○ The biggest animal that ever existed is the blue whale, at 100,000 kg. ○ A fish discovered in 2004 is only 8.4 mm long and has a mass roughly 100 billion times smaller than that of a blue whale. Concept 34.1 Chordates have a notochord and a dorsal, hollow nerve cord. • Vertebrates belong to one of the two major phyla in the Deuterostomia, the chordates. • Chordates are bilaterian animals belonging to the Deuterostomia clade. ○ Two phyla of invertebrate deuterostomes—the urochordates and the cephalochordates—are most closely related to the vertebrates.
    [Show full text]
  • 1 Vertebrates
    Vertebrates Chapter 34 • Objectives • List the derived traits for: chordates, craniates, vertebrates, gnathostomes, tetrapods, amniotes, birds, mammals, primates, humans • Explain what Haikouella and Myllokunmingia tell us about craniate evolution • Describe the trends in mineralized structures in early vertebrates • Describe and distinguish between Chondrichthyes and Osteichthyes, noting the main traits of each group • Define and distinguish among gnathostomes, tetrapods, and amniotes 2 • Describe an amniotic egg and explain its significance in the evolution of reptiles and mammals • Explain why the reptile clade includes birds • Explain the significance of Archaeopteryx • Distinguish among monotreme, marsupial, and eutherian mammals • Define the term hominin • Describe the evolution of Homo sapiens from australopith ancestors, and clarify the order in which distinctive human traits arose • Explain the significance of the FOXP2 gene 3 1 Introduction • Half a Billion Years of Backbones – By the end of the Cambrian period, some 540 million years ago an astonishing variety of animals inhabited Earth’s oceans – One of these types of animals gave rise to vertebrates, one of the most successful groups of animals 4 • The animals called vertebrates get their name from vertebrae, the series of bones that make up the backbone • There are approximately 52,000 species of vertebrates which include the largest organisms ever to live on the Earth 6 2 Chordates have a notochord and a dorsal, hollow nerve cord • Vertebrates are a subphylum of the phylum
    [Show full text]
  • Phylogenetic Relationships of the Cretaceous Frog Beelzebufo from Madagascar and the Placement of Fossil Constraints Based on Temporal and Phylogenetic Evidence
    doi: 10.1111/j.1420-9101.2010.02164.x Phylogenetic relationships of the Cretaceous frog Beelzebufo from Madagascar and the placement of fossil constraints based on temporal and phylogenetic evidence S. RUANE* ,R.A.PYRONà & F. T. BURBRINK* *Department of Biology, The College of Staten Island, The City University of New York, New York, NY, USA Department of Biology, The Graduate School and University Center, The City University of New York, New York, NY, USA àDepartment of Ecology and Evolution, Stony Brook University, Stony Brook, NY, USA Keywords: Abstract Beelzebufo; The placement of fossil calibrations is ideally based on the phylogenetic Ceratophrys; analysis of extinct taxa. Another source of information is the temporal dating error; variance for a given clade implied by a particular constraint when combined divergence time estimation; with other, well-supported calibrations. For example, the frog Beelzebufo fossil calibration; ampinga from the Cretaceous of Madagascar has been hypothesized to be a Gondwanaland; crown-group member of the New World subfamily Ceratophryinae, which Madagascar. would support a Late Cretaceous connection with South America. However, phylogenetic analyses and molecular divergence time estimates based on other fossils do not support this placement. We derive a metric, Dt, to quantify temporal divergence among chronograms and find that errors resulting from mis-specified calibrations are localized when additional nodes throughout the tree are properly calibrated. The use of temporal information from molecular data can further assist in testing phylogenetic hypotheses regarding the placement of extinct taxa. Estimating the ages of clades by integrating fossil data supported constraints placed throughout the tree. Using and molecular phylogenies has become commonplace other calibrations, one can predict the age of the targeted and expands the range of evolutionary hypotheses that node for the uncertain fossil.
    [Show full text]
  • On the Origin of Vertebrate Body Plan: Insights from the Endoderm Using the Hourglass Model
    University of Massachusetts Amherst ScholarWorks@UMass Amherst Veterinary & Animal Sciences Department Faculty Publication Series Veterinary & Animal Sciences 2020 On the origin of vertebrate body plan: Insights from the endoderm using the hourglass model Chunpeng He Tingyu Han Xin Liao Rui Guan J.-Y. Chen See next page for additional authors Follow this and additional works at: https://scholarworks.umass.edu/vasci_faculty_pubs Authors Chunpeng He, Tingyu Han, Xin Liao, Rui Guan, J.-Y. Chen, Kimberly D. Tremblay, and Zuhong Lu Gene Expression Patterns 37 (2020) 119125 Contents lists available at ScienceDirect Gene Expression Patterns journal homepage: www.elsevier.com/locate/gep On the origin of vertebrate body plan: Insights from the endoderm using the hourglass model Chunpeng He a,*,1, Tingyu Han a,1, Xin Liao b, Rui Guan a, J.-Y. Chen c,**, Kimberly D. Tremblay d,***, Zuhong Lu a,**** a State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China b Guangxi Academy of Sciences, Guangxi Mangrove Research Center, Guangxi Key Lab of Mangrove Conservation and Utilization, Beihai, 536000, China c Nanjing Institute of Paleontology and Geology, 39 East Beijing Road, Nanjing, 210008, China d Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, 661 North Pleasant Street, Amherst, MA, 01003, USA ARTICLE INFO ABSTRACT Keywords: The vertebrate body plan is thought to be derived during the early Cambrian from a worm-like chordate ancestor. Chordata While all three germ layers were clearly involved in this innovation, the role of the endoderm remains elusive. Vertebrata According to the hourglass model, the optimal window for investigating the evolution of vertebrate endoderm- Endoderm derived structures during cephalochordate development is from the Spemann’s organizer stage to the opening of Hourglass model the mouth (Stages 1–7, described herein).
    [Show full text]
  • Head and Backbone of the Early Cambrian Vertebrate Haikouichthys
    letters to nature 12. Bokelmann, G. H. R. & Harjes, H.-P. Evidence for temporal variation of seismic velocity within the upper continental crust. J. Geophys. Res. 105, 23879–23894 (2000). 13. Ratdomopurbo, A. & Poupinet, G. Monitoring a temporal change of seismic velocity in a volcano: Application to the 1992 eruption of Mt. Merapi (Indonesia). Geophys. Res. Lett. 22, 775–778 (1995). 14. Hill, D. P. et al. Seismicity remotely triggered by the magnitude 7.3 Landers, California, earthquake. Science 260, 1617–1623 (1993). 15. Brodsky, E., Karakostas, V. & Kanamori, H. A new observation of dynamically triggered regional seismicity: earthquakes in Greece following the August, 1999 Izmit, Turkey earthquake. Geophys. Res. Lett. 27, 2741–2744 (2000). 16. Knopoff, L., Levshina, T., Keilis-Borok, V. I. & Mattoni, C. Increased long-range intermediate- magnitude earthquake activity prior to strong earthquakes in California. J. Geophys. Res. 101, 5779–5796 (1996). 17. Bowman, D. D. & King, G. G. C. P. Accelerating seismicity and stress accumulation before large earthquakes. Geophys. Res. Lett. 28, 4039–4042 (2001). 18. Price, E. & Sandwell, D. T. Small-scale deformations associated with the 1992 Landers, California, earthquake mapped by synthetic aperture radar interferometry. J. Geophys. Res. 103, 27001–27016 (1998). 19. Fialko, Y., Simons, M. & Agnew, D. The complete (3-D) surface displacement field in the epicentral region of the 1999 Mw7.1 Hector Mine earthquake, southern California, from space geodetic observations. Geophys. Res. Lett. 28, 3063–3066 (2001). Figure 4 Model of velocity as a function of time owing to damage from the Landers 20. Kilb, D., Gomberg, J. & Bodin, P.
    [Show full text]