Threats to the koala
Between 1788 and 1921, 35.3 million hectares of forest were ring-barked and partially cleared, which corresponds with 44 of the land area of New South Wales.1 The fur trade was not the only threat the koala had to face during the late 1800s and early 1900s.2 Australia's native animals have always had to contend with natural disasters such as fire and drought, but other dangers are a direct result of human settlement. Habitat loss and fragmentation, disease, overpopulation, inbreeding, dog...
Liaoning a hot spot for fossil smuggling
The discovery in 1991 of the famous Liaoning sites of the Yixian Formation, marked the beginning of a series of important palaeontological discoveries that would change our views on the evolution of birds and the biology of dinosaurs. The sites yielded a series of extremely well-preserved early birds, with feather patterns intact see Ackerman 1998 , which bridged the longstanding hiatus in avian evolution from the oldest bird, the German Archaeopteryx, to modern birds. In 1996, a paper...
Ideal gas mixtures
Ideality in a multicomponent system means that the components interact with each other on a molecular level with the same intensity as the component molecules interact amongst themselves. In an ideal gas mixture, there are no intermolecular interactions in either the pure components or in the mixture. The mixing process starts from prescribed quantities of the pure components at specified temperature and pressure. The mixture is at the same T and p. If the mixture or solution is ideal, this...
Early vascular plants
The transition from aquatic to terrestrial habitats gradually took place over tens of millions of years. Plants steadily adapted to the environmental challenges of the land and became less dependent on aquatic habitats. The first true vascular plants are Middle Silurian, although resistant, cutinized spores are known from Upper Ordovician sediments, suggesting that they may have evolved earlier. Known from the mid-Silurian, early leafless and or rootless Sporangia borne on tips on terminal...
OneComponent Phase Diagrams
The most familiar graphical representation of the phase relationships of a pure substances is the p-T diagram, as illustrated for water and carbon dioxide in Fig. 5.4. The most familiar graphical representation of the phase relationships of a pure substances is the p-T diagram, as illustrated for water and carbon dioxide in Fig. 5.4. Fig. 5.4 p-T phase diagrams for water and carbon dioxide Fig. 5.4 p-T phase diagrams for water and carbon dioxide p-T diagrams are comprised of three lines that...
Internal Energy and Enthalpy
Consider the internal energy to be a function of temperature and specific volume, or u T,v . The total differential is The coefficient of dT is by definition the heat capacity at constant volume, CV. The coefficient of dv is obtained from the fundamental differential du Tds - pdv by dividing by dv and holding T constant Where the partial derivative involving the entropy has been replaced by the Maxwell relation of Eq 6.19 . The final result for du is This form is applicable to nonideal gases...
Excess properties 1
In this theory, the molecules mix randomly as they do in ideal solutions, so that That is, there is no tendency for either like or unlike molecules to cluster. When sex 0, the excess Gibbs free energy reduces to the excess enthalpy. The analytical formulation of hex in terms of composition is restricted by the limiting behavior of the solution enthalpy h as the solution approaches pure A and pure B. In these limits, h hA and h hB, respectively. Examination of Eq 7.21 shows that to satisfy these...
The Future of the Fossil Industry
Among palaeontologists and those who know, these things Ediacaran fossils are like ancient illuminated manuscripts. They are relics from the very beginnings of complex life on Earth. There's nothing like them anywhere else. So they're incredibly sought after, extremely valuable, expensive to buy and of course illegal to take out of the State Professor Tim Flannery, Director of South Australian Museum, ABC radio interview 19 10 00 . A sketch of my trilobite see page 205 . The specimen is 7 mm...
Chapter Spirits of the Otherworld Ghosts and Vampires
Ghosts 1 The word alone creates images of translucent and flowing spirits, spirits that have either failed to realize that they are no longer physically alive or who intend to exact revenge from those left living. Ghosts are feared the world over, and have been since humans began to recognize realities and dimensions outside of the present one. Are they creations of our own minds Native American lore is filled with legends about ghosts and the Other-world that they inhabit. Native Americans are...
The Seventh Extinction
As strange as it may sound, we could actually be living in the middle of a mass extinction right now. In recent times, there have been no colossal outpourings of lava, nor have there been any huge asteroid impacts, so what's the cause of this, the seventh, mass extinction We are. Humans almost certainly contributed to the demise of some of the Pleistocene animals, some of which appear in this book. More recently, around 780 species have become extinct since 1500, but as the vast majority of...
Bryozoan morphology
The hard parts of an individual zooid are called the zooecium plural zooecia , and the skeletal colony the zoarium Fig. 5.2 . The zooecia of stenolaemates are tube shaped and are often studied in thin section. In branching colonies, the mature parts of the zooecia usually grow at a high angle to the axis of colony growth. Zooecia may change in shape as they grow. They share common skeletal walls with adjacent zooids. In cross-section these tubes can be identified along with the shared hard...
The German police and fossil seizures
Wednesday 12 September. We visit Chief Superintendent Eduard Amrien, a member of the environmental division for the state region. His jurisdiction spreads over the whole country on matters of fauna, flora, fossils or other environmental issues. Steve chatted with Amrien in German, explaining that he too was a law enforcement officer, a specialist in fossil-related crime. Amrien seemed very surprised that fossil-related crime in the USA was serious enough to warrant its own specialist policeman....
The Chemical Potential
The thermodynamic terms heat and work can be viewed as the product of a capacity factor or quantity of something and a difference in a potential. Table 7.1 lists several examples of this breakdown of heat work expressions for mechanical, electrical, thermal, and chemical processes. Although rate processes are not within the purview of thermodynamics, they involve the same potentials as those responsible for producing heat or work. The basic rate laws are of the form flux coefficient x potential...
Tetrapod evolution and climate change
It is tempting to think of climate change as a recent phenomenon. However, in some ways the only predictable thing about climate is the certainty of change. There have been at least four major glaciations during the Phanerozoic icehouse periods and in between there is usually little or no evidence for permanent ice existing at the poles these are called greenhouse periods . In addition to climatic oscillations, there have been unique changes caused by tectonics or by biological evolution. These...
The Garden of Ediacara 1
Copyright 1998 Columbia University Press All rights reserved Library of Congress Cataloging-in-Publication Data McMenamin, Mark A. The garden of Ediacara discovering the first complex life Mark A. S. McMenamin. p. cm. Includes bibliographical references and index. Casebound editions of Columbia University Press books are printed on permanent and durable acid-free paper. Printed in the United States of America c 10 9 8 7 6 5 4 3 2 1 p 10 9 8 7 6 5 4 3 2 1 Some images in the original version of...
A complex phase diagram ironuranium
Eutectic features often appear in parts of more complex phase diagrams, as shown in the iron-uranium diagram of Fig. 8.14. If the diagram is divided into three parts at 1 3 and 6 7 mole fraction uranium, the result is two simple eutectic diagrams and a more complex diagram. The Fe-rich side resembles Fig. 8.11 with two added features. The first is the number of phases of the pure components. The left hand ordinate of Fig. 8.14 makes provision for three crystallographic modifications of iron The...
Seedbearing plants angiosperms
Angiosperms are the most diverse and widespread group of living plants Fig. 12.13 . Leaf impressions of angiosperm-like plants are known from the Triassic. The first true angiosperm fossils are from the Cretaceous Fig. 12.14 . During this period angiosperms diversified rapidly, particularly in low latitudes, and dominated most habitats by the end of the Cretaceous. Paralleling the rise of the angiosperms, spore-bearing plants and gymnosperms declined through the Cretaceous. Abundance and...
The Dinosaur Dealers
Copyright Dr John Long, Alley Kat Productions Pty Ltd, Electric Pictures Pty Ltd, Australian Film Finance Corporation Limited, All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without prior permission in writing from the publisher. The Australian Copyright Act 1968 the Act allows a maximum of one chapter or 10 of this book,...
Ethological behavioral classification
This fundamental classification is founded on the supposed or inferred behavioral characteristics represented by the trace fossils Table 14.1 . The most important categories relate to feeding, dwelling, and locomotion. As the units are divided on the basis of activity there maybe some overlap between them if the organism performed more than one behavior for example, feeding and crawling at the same time. Also, different parts of the trace fossil structure may fall into different categories....
Effect of Pressure on GasPhase Chemical Equilibria
Instead of partial pressures, mixture compositions are often more conveniently expressed in terms of the mole fractions of the species present, as in the previous example. The following formulation illustrates how total pressure affects the equilibrium composition. Using Dalton's Rule Eq 7.3 , pi where xi is the mole fraction of species i and p is the total pressure, Eq 9.21 becomes K p reactants products k Products 9 24 Although KP is a function of temperature only, the equilibrium constant in...
Nonideal Liquid and Solid Solutions
Although gas mixtures can for most purposes be treated as ideal, liquid and solid solutions are generally significantly nonideal. The strong intermolecular interactions that are responsible for the existence of pure condensed phases are also the source of their deviations from ideality when mixed in solutions. A binary solution of A and B is ideal if the average of the A-A and B-B intermolecular forces is just equal to the strength of the A-B interaction Ref. 1 contains a thorough explanation...
Problems for Chapter
10.1 The solid-state electrochemical cell NbO Nb Ru electrolyte Ta2 O5 Ta consists on the right of a Ta Ta2O5 couple that produces a fixed electrode potential and on the left a half cell containing a mixture of NbO and Nb dissolved in ruthenium. Ru is inert electrochemically and serves only to dilute the active niobium metal component. The cell operates at 1000 K with various mole fractions of Nb dissolved in ruthenium. For the overall cell reaction NbO Ta Nb 1 Ta2O5 , the standard free energy...
Reactive gas in contact with a reactive metal
The values of the 02 pressure required for coexistence of M and M02 are usually quite small, because, except for the noble metals, oxides are much more stable than the elemental metals. Reaction 9.3 releases substantial heat, so AHo is large and negative. This term dominates AGo, which is also large and negative. For instance, if AGo -200 kJ mole at 1000 K, Eq 9.33a gives p0 3.6x10-11 atm. From practical considerations, such a low pressure of 02 is difficult to produce and control in a process...
Phase Separation
The single-phase solid and liquid phase regions in Fig. 8.3 show no structure because the A-B solutions were assumed to be ideal. However, if the components exhibit positive deviations from ideality i.e., if the A-B molecular interaction is weaker than the average of the A-A and the B-B interactions , the single-phase solutions separate into two distinct phases, either both liquid or both solid. The system in which phase separation has 3 See Sect. 2.6 for application of the lever rule in...
Binary phase diagrams analytical construction
Binary phase diagrams depict the stable condensed phase or phases formed by a two-component system as a function of temperature and overall composition. The ordinate of a phase diagram is the temperature and the overall composition is the abscissa1. The phase rule Eq 1.21 for a two component system permits F 4 - P degrees of freedom for a two-component system. Since the diagrams deal only with condensed phases, they are minimally affected by total pressure2. Ignoring the total pressure reduces...
Paleoceneeocene Climate And Flora
The world of the Paleocene and Eocene was very different from that of today. It was much warmer and more equable during most of that interval than at any other time during the Cenozoic Wing and Greenwood, 1993 . Temperatures varied little seasonally or latitudinally, mid-latitudes were largely frost-free, and there were no polar ice caps. Conditions were generally wet or humid. A paleotemperature curve reconstructed from deep-sea oxygen isotope records Zachos et al., 2001 shows that early...
A case of stolen Scottish fossils
31 October 2000. Silurian fish and invertebrate fossils from Scotland are stolen from a protected site, and sold to a museum in Germany. Scottish Natural Heritage are alerted in February 2001 after an academic reports seeing the 430-million-year-old remains in a museum in Berlin. A team of Scottish Natural Heritage geologists decided to visit the Humboldt University Museum in Berlin, to discuss the possible return of the rare fossils. Jamoytius kerwoodi, an anaspid one of the eel-like jawless...
Eutectic Phase Diagram
The binary systems treated in the preceding sections were either ideal melting-solidification or deviated positively from ideality according to regular solution theory phase separation . These simple types are rarely found in real binary systems. First, there may be more than one solid phase, each with a distinct crystal structure, just as there are in pure substances see Sect. 5.6 . Second, the liquid phase and the solid phase s are generally nonideal. The extent of deviation from ideality is...
Chapter An Overview of the Little People in Native America
When we think of Fairy lore, many of us in the US naturally think of Ireland. However, Fairies appear in the folklore of most every culture and on every continent. The similarities are striking and some have suggested that a common source memory exists or existed widely among people at one time. John Rhys advanced this theory at the beginning of the 20th century. Rhys thought that the lore of the Fairy were ancient stories of the original inhabitants of Britain. They were called the Corannians...
The Ancient Mass Extinctions And Evolution
For the organisms that experience them, cataclysmic events bring death and devastation, but mass extinctions have their positive side, too. Indeed, if it wasn't for mass extinction, we would not be here. Mass extinctions wipe the biological slate clean and leave the door open to organisms that have been kept in the shade. If we travel back in time, the Permian-Triassic mass extinction created an opportunity for the dinosaurs to rise to dominance, following the demise of the large synapsids,...
Criterion of Chemical Equilibrium
As in any system constrained to constant temperature and pressure, the equilibrium of a chemical reaction is attained when the free energy is a minimum. Specifically, this means that dG 0, where the differential of G is with respect to the composition of the mixture. In order to convert this criterion to an equation relating the equilibrium concentrations of the reactants and products, the chemical potentials are the essential intermediaries. At equilibrium, Eq 7.27 provides the equation where...
Golden Toad
Golden Toad The golden toad was restricted to the cloud forest above the city of Monteverde in Costa Rica. It was last seen in 1989. Renata Cunha Golden Toad The golden toad was restricted to the cloud forest above the city of Monteverde in Costa Rica. It was last seen in 1989. Renata Cunha Scientific name Bufo periglenes Scientific classification Phylum Chordata Class Amphibia Order Anura Family Bufonidae When did it become extinct No golden toads have been seen since May 1989. Where did it...
Protecting fossil sites in China
China has always valued its heritage, yet measures to protect its fossil heritage have only been in place since the early 1960s. I asked Professor Zhu Min, current Director of the Institute of Vertebrate Palaeontology and Palaeoan-thropology, for his views on Chinese laws pertaining to fossil protection. He replied by email on 9 April 2002 First, I would like to point out that all Chinese vertebrate fossils for sale in the international fossil markets are illegal according to the Chinese law....
THE MAJOR EXTINCTIONS AND THEIR CAUSES CambrianOrdovician
Geologists use a series of extinction events that occurred around 490 million years ago to define the end of the Cambrian period and the beginning of the Ordovician. These events led to the demise of many types of marine animal. The brachiopods marine mol-lusks resembling bivalves were very numerous before this event, but whatever occurred all that time ago had a drastic effect on their numbers. The trilobites, ancient forerunners of today's numerous creepy crawlies, could also be found in...
Standard Free Energy of Formation
Even though the thermochemical database need contain only AGo or, equivalently, AHo and ASo , the number of reactions that would have to be included in such a compilation is intractably large. The key to reducing data requirements to manageable size is to provide the standard free energy changes of forming the individual molecular species from their constituent elements. Particular reactions are constructed from these so-called formation reactions. For molecular compounds containing two or more...
Solving for the Equilibrium Composition
The law of mass action for a particular reaction Eq 9.24 is but a single equation with more than one variable. As an example, Eq 9.21a contains three unknown mole fractions. There are two principal methods for incorporating the conservation equations into the analysis the element conservation method and the reaction progress variable method. Both of these methods require the following input information The temperature and total pressure AHo and ASo of the reaction This information fixes KP by...
Chapter Werewolves Not Just in Transylvania
Werewolves have been a fear of humankind since the Neolithic age and may have originated in the shamanic rituals that seemingly transformed men into wolf-like creatures. During the Middle Ages, legends of the werewolf expanded into tales of daily occurrences. There are places in the world that even today the werewolf remains a feared creature that decimates livestock and threatens the lives of local inhabitants. The interesting thing about the folklore surrounding the werewolf is that, like the...
Stability diagrams
Equations 9.33a and 9.33b are plotted in Fig. 9.6. These plots are called stability diagrams because the lines separate regions in which only one of the two phases is present. The line represents the p - T combinations where both the metal and its oxide coexist. The oxide-metal stability diagram is similar to the p-T phase diagram of a single substance such as water, where lines separate existence regions of solid, liquid, and vapor phases see Figs. 5.1 and 5.3 . The zones above and below the...
A famous German fossil site
Saturday 15 September. Steve calls Broome Prison again, but Michael Latham still isn't available. We visit the famous Messel fossil quarry near Darmstadt. One of the world's most important sites, the 49-million-year-old oil shales of Messel, preserves a great diversity of insects, plants, fishes, frogs, reptiles, mammals and birds. The preservation of these fossils is truly extraordinary and like no other site on Earth. The mammals often have their fur preserved, stomach contents intact, even...
European LandMammal Ages
As mentioned earlier, standard ages are more widely used for biochronology of European faunas than are the European Land-Mammal Ages ELMAs , and are therefore used in this text. This preference for the former may have come about because the ELMAs are for the most part equivalent in time to the standard ages Dano-Montian Danian Cernaysian Selandian and Thanetian Neustrian most of the Ypresian Rhenanian the rest of the Ypre-sian through the Bartonian and Headonian Priabonian McKenna and Bell,...
Isentropic process
Isentropic expansion of an ideal gas was treated in Sect. 3.5. Here, the same process is analyzed without the restriction of ideality. Equation 6.23b is divided by dv while holding s constant, which produces the relation To illustrate the effect of gas nonideality on property changes during an isentropic expansion, the right hand side of Eq 6.30 is evaluated for a Van der Waals gas obeying the equation of state in the form given by Eq 2.5 Substituting the above EOS into Eq 6.28 yields In the...
Heat Capacities
Subtracting Eq 6.23b from Eq 6.24b gives Dividing by dv and holding p constant gives Inverting the partial derivative on the left hand side yields For an ideal gas, the product of T and the two partial derivatives is equal to the gas constant. For nonideal gases, on the other hand, the two heat capacities can differ significantly from R see problem 6.8 . For condensed phases, the first partial derivative in Eq 6.25 is replaced by av and the second by Eq 6.8 , yielding For solids or liquids with...
Thermodynamic Relations for Nonideal Behavior
In Chapters 2 and 3, numerous property relations were presented for ideal gas and idealized solids. The latter are characterized by constant coefficients of thermal expansion and compressibility and obey the equation of state given by Eq 2.18 . For these substances, the specific heats and hence the internal energy and enthalpy are functions of temperature but are independent of pressure or specific volume the entropy of the ideal gas varies with T and v or p according to Eqs 3.9 and 3.10 . The...
Equilibrium
The equal sign in Eq 9.5 signifies that the equilibrium state has been achieved. By convention, the molecular species on the left-hand side of the reaction are called reactants and those on the right hand side are termed products. At equilibrium, there is no fundamental distinction between reactants and products Eq 9.5 could just as well have been written with C and D on the left and A and B on the right. As long as the element ratios are the same, the equilibrium composition does not depend on...
Chemical Potentials in Gas Mixtures
The analysis in Sect. 7.2.2 of the entropy change associated with mixing of ideal gases at fixed T and p was based on the absence of an entropy change if the pure gases are at the partial pressures that they will have in the mixture. Since the gases are ideal, neither is there an enthalpy change in the mixing process. With both the enthalpy and entropy of each species unaltered, the Gibbs free energy must also remain constant during this mode of mixing. Since the partial molar Gibbs free energy...
Timing Of The Crowntherian Radiation
The question of when the therian radiation took place is a contentious issue, whose answer depends on the kind of data employed paleontological morphological or molecular. There are three principal models of the timing of origin and diversification of placental mammals Archibald and Deutschman, 2001 , which also apply generally to the therian radiation Fig. 1.2 1. The explosive model, in which mammalian orders both originated and diversified in a short period of about 10 million years after the...
Herbivory in arthropods
Most of our knowledge of herbivory in arthropods comes from coprolites, feeding marks on leaves and other plant parts, wood borings sometimes containing coprolites , and inferences based on comparisons of fossils with their living counterparts. Plant-bearing arthropod coprolites are oval to cylindrical in shape and can be as much as 1 mm long, although most are smaller. Those that have been analysed contain the remains of various plant parts e.g. leaves, stems, spores, pollen derived from a...
Methods for the study of paleosols
Just as soil individuals pedons are studied as soil columns in soil pits, paleosols are studied in columnar stratigraphic sections of the sort also used in sedimen-tology and stratigraphy O Figure 13.3 . Grain size is emphasized because it is important to soil formation, as weathering transforms sand and silt grains to clay. A graphical representation of grain size profiles conveys important information on the abruptness of horizon transitions. Color from a Munsell chart should also be...
Continental Drift 1
Although the theory of the new global tectonics, or plate tectonics, has largely been developed since 1967, the history of ideas concerning a mobilist view of the Earth extends back considerably longer Rupke, 1970 Hallam, 1973a Vine, 1977 Frankel, 1988 . Ever since the coastlines of the continents around the Atlantic Ocean were first charted, people have been intrigued by the similarity of the coastlines of the Americas and of Europe and Africa. Possibly the first to note the similarity and...
Tarpan
Tarpan A pair of tarpan stallions fight during the breeding season. This hardy animal is widely considered to be the ancestor of most modern horses. Renata Cunha Tarpan A pair of tarpan stallions fight during the breeding season. This hardy animal is widely considered to be the ancestor of most modern horses. Renata Cunha Scientific name Equus ferus Scientific classification Phylum Chordata Class Mammalia Order Perissodactyla Family Equidae When did it become extinct The last known pure-bred...
