DOCSLIB.ORG

Unmasking Natural Selection

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Unmasking Natural Selection BOOK REVIEWS || JOURNAL OF CREATION 32(2) 2018 Unmasking natural selection 40 Years of Evolution: Darwin’s finches on Daphne Major Island Peter and Rosemary Grant Princeton University Press, Princeton, NJ, 2014 Jean K. Lightner o many people, the word evolution Tis equated to humans descending from ape-like creatures, or all life originating from simpler life forms. However, if one studies biology, it quickly becomes apparent that the word has a much broader range of meanings. The Grants are evolu- tionary biologists, and the evolution In fact, this review is being written described in this book refers to the after the third time I went through change in heritable characteristics the whole book. I think that speaks of a population over time. This book highly to the value of the book: the presents the results of their 40 years basic concepts can be understood by observing patterns of change in several reading the book once, but a deeper populations of finches on an island in understanding is engendered by the Galápagos. No, the finches didn’t reading it multiple times a few years turn into a different kind of bird; apart. instead, the Grants’ observations are a gold mine for creationists wishing to under stand natural history in a biblical The draw of the finches worldview. on Daphne The book is very nicely illustrated, The preface and early chapters containing not only pictures but tables, charts, and boxes with more spend a lot of time providing the detailed information concerning context for their study, including what is discussed in the main text. It relevant information about the includes multiple appendices, a list of Galápagos in general, and Daphne abbreviations, a glossary, references, Major Island (hereafter, Daphne) in and a subject index. Despite their particular. As evolutionary biologists, best attempts to make the book as the Grants are interested in knowing lay-friendly as possible, some of how new species form—a topic of the chapters include rather technical great interest to creationary biologists population genetics concepts and as well. They discuss reasons for discussion of analyses. The summary choosing finches on an island at the end of each chapter is helpful (i.e. a small population of easily to gauge if the main concepts of the approachable birds that can be marked chapter were grasped. I found myself for individual identification and needing to reread portions of the book. tracked through time; figure 1). Their 37 JOURNAL OF CREATION 32(2) 2018 || BOOK REVIEWS method of tracking finch populations of a missing competitor. They list Heritable traits and through time is what makes their five assumptions of the character natural selection work so valuable. It steps away from release hypothesis, and spend several For evolution (in the change over the armchair philosophy and just-so chapters discussing how they went time sense, that no one denies) to stories that predominate when looking about demonstrating the veracity of occur, heritable variation must exist in at the current state of a population and those assumptions in their study on the population. The Grants demonstrate attempting to infer how it reached its the Galápagos finches. It is when that beak length, width, and depth are present condition. they list the five assumptions that the all highly heritable (and variable) in As the bird species and the foods proverbial elephant enters the room. the medium ground finch (G. fortis). they eat are being presented, the The listed assumptions are reasonable They also show that reproductive Grants explain what brought them to enough, but the variability to expand output varies with the amount of rain Daphne in particular. Many islands into a new niche has to come from and available food, and thus has a contain both the medium and small somewhere. This is the primary blind heritability close to zero. The primary ground finches Geospiza( fortis and spot of most evolutionary explanations. factor that affected successfully raising G. fuliginosa, respectively). Daphne That is, there is a hidden assumption offspring that themselves reproduced only harboured the former granivorous that appropriate variability is just was related to longevity. And longevity finch, but it was smaller than on other sort of going to magically be there was related to survival during the dry islands in the Galápagos. Thus, on and natural selection gets the credit season. Daphne, the medium ground finch for any adaptation. Now, to be fair to Four years into their study, the not only occupies the niche it does the Grants, they do discuss sources Grants observed natural selection on other islands, but also that of the of variability in the book (standing in action. There was a drought that small ground finch. The Grants were variation, interspecific hybridization, resulted in selective mortality. Beak intrigued, and wanted to know why. and mutation). However, they do not depth was the strongest contributor, Drawing on previous work, deal in depth with how appropriate as a greater beak depth was necessary particularly that of David Lack, they variation shows up in appropriate to effectively crack and consume the describe the concept of character timeframes, especially as it might larger seeds that remained available release, or expansion into the niche relate to mutation. well into the drought. This, and other related observations over the study, make it clear that natural selection does not always act slowly and imperceptibly bringing gradual changes for the good of the organisms involved, as Darwin had argued.1 The Grants found that natural selection occurs most strongly when the environment changes. In the Grants’ study of the finches, this was during the droughts. Not only did natural selection occur most strongly then, but it was inconsistent in the direction it acted. The first drought they observed resulted in a selective mortality affecting smaller-beaked birds. However, due to exceptionally wet intervening years that resulted in explosive growth of plants bearing smaller seeds, another drought resulted in selective mortality in the larger-beaked birds. This oscillating Figure 1. An example of the variation in beak size and shape among finches in the Galápagos. The large ground finch (1) and medium ground finch (2) were observed on the island of Daphne Major. pattern of natural selection removes The small tree finch and green warbler-finch (3 and 4, respectively) are found on other islands. useful variation and can potentially 38 BOOK REVIEWS || JOURNAL OF CREATION 32(2) 2018 put the finch population at risk of being The number of large ground breed with the medium ground finch extirpated from the island. finches increased slowly over the next (G. fortis). Hybrid offspring which As natural selection acted on decade, and then suddenly increased survived to reproduce would breed the medium ground finches during more dramatically. For many years with a medium ground finch, which the droughts, evolution resulted. there wasn’t much competition brought variation into the population. This simply means that in the next between them and the larger-beaked This was tremendously valuable, generation there was a shift in the medium ground finches (G. fortis). particularly after a drought which had average beak size. However, other That changed near the end of a two- selectively removed birds with smaller aspects of their study made it clear that year drought (2003–2005) when the beaks. Birds with smaller beaks are even in cases where natural selection large seeds they both consumed were much more efficient at consuming the appears to be acting, evolution does not depleted. The death toll was heavy for smaller seeds, and this hybridization always result. Instead, the net effect both species. In the medium ground allowed the resident medium ground of natural selection is influenced by finch G.( fortis), there was a size biased finch population to effectively exploit antagonistic selection, which can occur mortality (the larger-beaked birds were that resource again. on the same trait at different times, more severely affected), but in the Hybridization between these two or on different linked traits at the large ground finch (G. magnirostris) granivorous finches also explains mortality was not size biased. same time. Thus, it is incorrect to say the puzzle that brought the Grants The size biased mortality was an that natural selection is equivalent to to the island initially. The medium example of natural selection in action, evolution; it is merely one of several ground finch was relatively small on and evolution resulted. There was a possible causes. Daphne because it received genetic dramatic drop in the average beak material from the small ground finches size for the medium ground finch who occasionally stayed to breed. Character displacement population in the next generation. The Rather than establish a population, Grants point out that this example which could have eventually led to During the course of their study, of character displacement was not competition between the two species, the Grants also observed character from constant, ongoing competition. the small ground finch brought in displacement, the opposite of character Special conditions were required for useful variation. Since the medium release. In character displacement, it to occur. The reduction in average ground finch on Daphne never competition between species can beak size of the medium ground finch hybridized with the large ground finch result in divergence between the two. was dramatic, and this measurement (G. magnirostris), it had no way to The most striking example observed remained smaller throughout the rest regain the lost variation in the larger in their study is worth examining in of the study. size range after the drought depleted more detail. it in 2005. When their study began there A second factor that affects how were no large ground finches (G.
Load more

Recommended publications
  • Ecuador & the Galapagos Islands
    Ecuador & the Galapagos Islands - including Sacha Lodge Extension Naturetrek Tour Report 29 January – 20 February 2018 Medium Ground-finch Blue-footed Booby Wire-tailed Manakin Galapagos Penguin Green Sea Turtle Report kindly compiled by Tour participants Sally Wearing, Rowena Tye, Debbie Hardie and Sue Swift Images courtesy of David Griffiths, Sue Swift, Debbie Hardie, Jenny Tynan, Rowena Tye, Nick Blake and Sally Wearing Naturetrek Mingledown Barn Wolf’s Lane Chawton Alton Hampshire GU34 3HJ UK T: +44 (0)1962 733051 E: [email protected] W: www.naturetrek.co.uk Tour Report Ecuador & the Galapagos Islands - including Sacha Lodge Extension Tour Leader in the Galapagos: Juan Tapia with 13 Naturetrek Clients This report has kindly been compiled by tour participants Sally Wearing, Rowena Tye, Debbie Hardie and Sue Swift. Day 1 Monday 29th January UK to Quito People arrived in Quito via Amsterdam with KLM or via Madrid with Iberia, while Tony came separately from the USA. Everyone was met at the airport and taken to the Hotel Vieja Cuba; those who were awake enough went out to eat before a good night’s rest. Day 2 Tuesday 30th January Quito. Weather: Hot and mostly sunny. The early risers saw the first few birds of the trip outside the hotel: Rufous- collared Sparrow, Great Thrush and Eared Doves. After breakfast, an excellent guide took us on a bus and walking tour of Quito’s old town. This started with the Basilica del Voto Nacional, where everyone marvelled at the “grotesques” of native Ecuadorian animals such as frigatebirds, iguanas and tortoises.
    [Show full text]
  • A Global Overview of Protected Areas on the World Heritage List of Particular Importance for Biodiversity
    A GLOBAL OVERVIEW OF PROTECTED AREAS ON THE WORLD HERITAGE LIST OF PARTICULAR IMPORTANCE FOR BIODIVERSITY A contribution to the Global Theme Study of World Heritage Natural Sites Text and Tables compiled by Gemma Smith and Janina Jakubowska Maps compiled by Ian May UNEP World Conservation Monitoring Centre Cambridge, UK November 2000 Disclaimer: The contents of this report and associated maps do not necessarily reflect the views or policies of UNEP-WCMC or contributory organisations. The designations employed and the presentations do not imply the expressions of any opinion whatsoever on the part of UNEP-WCMC or contributory organisations concerning the legal status of any country, territory, city or area or its authority, or concerning the delimitation of its frontiers or boundaries. TABLE OF CONTENTS EXECUTIVE SUMMARY INTRODUCTION 1.0 OVERVIEW......................................................................................................................................................1 2.0 ISSUES TO CONSIDER....................................................................................................................................1 3.0 WHAT IS BIODIVERSITY?..............................................................................................................................2 4.0 ASSESSMENT METHODOLOGY......................................................................................................................3 5.0 CURRENT WORLD HERITAGE SITES............................................................................................................4
    [Show full text]
  • Beak of the Pinch: Anti-Parasite Traits Are Similar Among Darwin's Finch
    Evolutionary Ecology https://doi.org/10.1007/s10682-018-9949-0 Beak of the pinch: anti‑parasite traits are similar among Darwin’s fnch species Scott M. Villa1 · Jennifer A. H. Koop1,2 · Céline Le Bohec1,3,4 · Dale H. Clayton1 Received: 6 July 2018 / Accepted: 17 August 2018 © Springer Nature Switzerland AG 2018 Abstract Darwin’s fnches are an iconic example of adaptive radiation. The size and shape of the beaks of diferent fnch species are diversifed for feeding on diferent size seeds and other food resources. However, beaks also serve other functions, such as preening for the control of ectoparasites. In diverse groups of birds, the efectiveness of preening is governed by the length of the overhanging tip of the upper mandible of the beak. This overhang functions as a template against which the tip of the lower mandible generates a pinching force sufcient to damage or kill ectoparasites. Here we compare feeding versus preening components of the beak morphology of small, medium, and large ground fnches that share a single para- site community. Despite adaptive divergence in beak morphology related to feeding, the three species have nearly identical relative mandibular overhang lengths. Moreover, birds with intermediate length overhangs have the lowest feather mite loads. These results sug- gest that Darwin’s fnches maintain an optimal beak morphology to efectively control their ectoparasites. Keywords Preening · Feather mites · Geospiza · Principal component analysis · Overhang Introduction In his Pulitzer Prize-winning book “Beak of the Finch”, Jonathan Weiner (1994) features Peter and Rosemary Grant’s classic work on the adaptive radiation of Darwin’s fnches in the Galápagos Islands (Grant and Grant 2014).
    [Show full text]
  • Isotopic Niche Segregation Among Darwin's Finches on Santa
    diversity Article Isotopic Niche Segregation among Darwin’s Finches on Santa Cruz Island, Galápagos Mariana Villegas 1,2,*,†, Catherine Soos 1,2 , Gustavo Jiménez-Uzcátegui 3, Shukri Matan 4 and Keith A. Hobson 2,4 1 Department of Veterinary Pathology, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada; [email protected] 2 Environment and Climate Change Canada, Science & Technology Branch, Saskatoon, SK S7N 0X4, Canada; [email protected] 3 Charles Darwin Research Station, Charles Darwin Foundation, Puerto Ayora, Galápagos 200350, Ecuador; [email protected] 4 Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada; [email protected] * Correspondence: [email protected]; Tel.: +1-591-71294780 † Current address: Instituto de Ecología, Universidad Mayor de San Andrés, Calle 27 Campus Universitario de Cota Cota, 0001 La Paz, Bolivia. Abstract: Darwin’s finches are a classic example of adaptive radiation involving differential use of dietary resources among sympatric species. Here, we apply stable isotope (δ13C, δ15N, and δ2H) analyses of feathers to examine ecological segregation among eight Darwin’s finch species in Santa Cruz Island, Galápagos collected from live birds and museum specimens (1962–2019). We found that δ13C values were higher for the granivorous and herbivorous foraging guilds, and lower for the insectivorous finches. Values of δ15N were similar among foraging guilds but values of δ2H were higher for insectivores, followed by granivores, and lowest for herbivores. The herbivorous Citation: Villegas, M.; Soos, C.; guild generally occupied the largest isotopic standard ellipse areas for all isotopic combinations Jiménez-Uzcátegui, G.; Matan, S.; and the insectivorous guild the smallest.
    [Show full text]
  • Diversity and Movement Patterns of Passerine Birds Near an Urban Center on Santa Cruz, Galapagos Islands Ana M
    University of Massachusetts Amherst ScholarWorks@UMass Amherst Masters Theses 1911 - February 2014 January 2007 Diversity And Movement Patterns Of Passerine Birds Near An Urban Center On Santa Cruz, Galapagos Islands Ana M. Gabela University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/theses Gabela, Ana M., "Diversity And Movement Patterns Of Passerine Birds Near An Urban Center On Santa Cruz, Galapagos Islands" (2007). Masters Theses 1911 - February 2014. 20. Retrieved from https://scholarworks.umass.edu/theses/20 This thesis is brought to you for free and open access by ScholarWorks@UMass Amherst. It has been accepted for inclusion in Masters Theses 1911 - February 2014 by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. DIVERSITY AND MOVEMENT PATTERNS OF PASSERINE BIRDS NEAR AN URBAN CENTER ON SANTA CRUZ, GALAPAGOS ISLANDS A Thesis Presented By ANA MARIA GABELA Submitted to the Graduate School of the University of Massachussetss Amherst in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 2007 Graduate Program in Organismic and Evolutionary Biology © Copyright by Ana Maria Gabela 2007 All Rights Reserved DIVERSITY AND MOVEMENT PATTERNS OF PASSERINE BIRDS NEAR AN URBAN CENTER ON SANTA CRUZ, GALAPAGOS ISLANDS A Thesis Presented by ANA MARIA GABELA Approved as to style and content by: ____________________________________ Jeffrey E. Podos, Chair ____________________________________
    [Show full text]
  • Hybridization Increases Population Variation During Adaptive Radiation
    Hybridization increases population variation during adaptive radiation Peter R. Granta,1 and B. Rosemary Granta aDepartment of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544 Contributed by Peter R. Grant, September 27, 2019 (sent for review August 6, 2019; reviewed by Leonardo Campagna and J. Albert Uy) Adaptive radiations are prominent components of the world’s bio- with Geospiza scandens (cactus finch, ∼21 g), a common resident, diversity. They comprise many species derived from one or a small and Geospiza fuliginosa (small ground finch, ∼12 g), an occasional number of ancestral species in a geologically short time that have immigrant; G. scandens and G. fuliginosa do not interbreed on this diversified into a variety of ecological niches. Several authors have island. Significantly, none of them hybridize with the much larger proposed that introgressive hybridization has been important in Geospiza magnirostris (large ground finch, ∼30 g). We measured the generation of new morphologies and even new species, but large samples of hybrid and nonhybrid finches annually from 1973 how that happens throughout evolutionary history is not known. until 2012 (33). Within this period breeding was documented in Interspecific gene exchange is expected to have greatest impact on detail from 1976 to 1998 (34). Hybridization was first observed in variation if it occurs after species have diverged genetically and 1976 (35, 36), but it only led to breeding of the hybrids and phenotypically but before genetic incompatibilities arise. We use a backcrossing in 1983 after a climatically induced change in the dated phylogeny to infer that populations of Darwin’s finches vegetation that was favorable to hybrid survival.
    [Show full text]
  • FACT SHEET Giant Tortoise
    FACT SHEET Giant Tortoise The Galápagos giant tortoise (Chelonoidis nigra and related species) is one of the most famous animals of Fun Facts the Galápagos Islands. Indeed, that’s where the name comes from - galápago is old Spanish for “tortoise." • Giant tortoises can go up to a year without Giant tortoises live on only six islands now - driven to eating or drinking. extinction on others by hunting, habitat destruction • They are really slow. and invasive species. They walk at .16 mph (for perspective, Whalers used to take hundreds of tortoises at a time humans walk at about and stack them upside down on their ships to serve as 3 mph). fresh meat later in the voyage. Over 200,000 tortoises were taken this way before the 20th century. • Giant tortoises live over 100 years. One The Galápagos population bottomed out at a lived over 150 years! few thousand in the mid-1970s, but has partially recovered to about 20,000 today. Lonesome George, the last tortoise originally from Pinta Island, died in 2012. FACT SHEET Marine Iguana The marine iguana (Amblyrhynchus Fun Facts cristatus) is found only in the Galápagos Islands. It is the only sea- • They can dive as deep as 100 ft and going lizard in the world - it dives in the stay underwater for up to an hour. ocean to forage for algae. • They expel extra salt (the result of a high-salt diet) by sneezing - thus their Scientists believe it is descended from heads are often white. the Central American land iguana and adapted to life in the Galápagos Islands • Males turn partly red during mating by eating algae along the shore, slowly season and butt heads to establish developing diving skills.
    [Show full text]
  • Roadkill of Birds in Galapagos Islands: a Growing Need for Solutions
    VOLUME 15, ISSUE 1, ARTICLE 19 García-Carrasco, J.-M., W. Tapia and A.-R. Muñoz. 2020. Roadkill of birds in Galapagos Islands: a growing need for solutions. Avian Conservation and Ecology 15(1):19. https://doi.org/10.5751/ACE-01596-150119 Copyright © 2020 by the author(s). Published here under license by the Resilience Alliance. Short Communication Roadkill of birds in Galapagos Islands: a growing need for solutions José-María García-Carrasco 1, Washington Tapia 2 and Antonio-Román Muñoz 1 1University of Málaga, 2Galapagos Conservancy ABSTRACT. A major step in the development of conservation measures would be to study and understand the sources of non-natural mortality in wild fauna. The implementation of such measures should be a priority in oceanic islands because biodiversity hotspots are concentrated in these locations. Furthermore, anthropogenic changes have a greater impact on island species than on their mainland relatives. This situation is of particular relevance in the Galápagos Archipelago, owing to its rapid population growth and the striking increase in the number of vehicles. The latter aspect is due to attempts by the tourist industry to stimulate the economy in this area. Thus, the environment and biota are under new pressures. There are few studies on the effects of wildlife roadkill in the Galápagos. We surveyed two stretches of a 13.8-km road in two different vegetation zones on the island of Santa Cruz. This island has the highest population and the greatest number of tourists in the archipelago. We determined the spatial patterns of bird roadkill using counts, which were conducted via bicycle rides.
    [Show full text]
  • Bird Mortality by Vehicles
    GALAPAGOS REPORT 2007-2008 Bird mortality by vehicles Charles Darwin Foundation Introduction Highways are an indispensable part of socioeconomic development (Coelho et al. , 2005) but they can have negative impacts on natural habitats (Granizo et al. , 2002). One impact is habitat fragmentation, which produces a barrier effect, which can divide populations and lead to extinctions of subpopulations (Arroyave et al. , 2006), and a border effect, which includes changes i n temperature, humidity, radiation, and wind that penetrates the ecosystem up to 50 m from the roadway (Arroyave et al. , 2006), resulting in a change in species distribution and abundance. A more direct and visible impact is that vehicles traveling on these highways can kill animals, with the frequency and velocity of vehicles representing the primary factors affecting population size and animal behavior (Taylor & Goldingay, 2004). Santa Cruz Island is the tourism and economic center of Galapagos. It is an island where transportation plays an important role in day-to-day life and also affects the fauna of the island. Construction of the highway that crosses the island north-south (connecting Puerto Ayora and the Itabaca Canal) began in 1972 (Loza, 1981), was completed in 1974 (Carvajal, 1980), and finally paved in 2000 (Tanner & Perry, 2005). Meanwhile, the number of vehi - cles in Santa Cruz has increased from 28 in 1980 (Márquez, 2000) to 1276 in 2006 (Villa, 2007). A total of 177 bird species have been registered in Galapagos (CDF, 2008), including 56 endemic or native species (Jiménez-Uzcátegui et al. , 2007). Of this group, 23 are on the Red List (IUCN, 2007) due to their low population numbers (two endemic species have fewer than 150 individuals) and to anthro - pogenic problems (Wiedenfeld & Jiménez-Uzcátegui, 2008).
    [Show full text]
  • Shared Developmental Programme Strongly Constrains Beak Shape Diversity in Songbirds
    ARTICLE Received 13 Nov 2013 | Accepted 20 Mar 2014 | Published 16 Apr 2014 DOI: 10.1038/ncomms4700 Shared developmental programme strongly constrains beak shape diversity in songbirds Joerg A. Fritz1,*, Joseph Brancale2,*, Masayoshi Tokita2,*, Kevin J. Burns3, M. Brent Hawkins2, Arhat Abzhanov2 & Michael P. Brenner1 The striking diversity of bird beak shapes is an outcome of natural selection, yet the relative importance of the limitations imposed by the process of beak development on generating such variation is unclear. Untangling these factors requires mapping developmental mechanisms over a phylogeny far exceeding model systems studied thus far. We address this issue with a comparative morphometric analysis of beak shape in a diverse group of songbirds. Here we show that the dynamics of the proliferative growth zone must follow restrictive rules to explain the observed variation, with beak diversity constrained to a three parameter family of shapes, parameterized by length, depth and the degree of shear. We experimentally verify these predictions by analysing cell proliferation in the developing embryonic beaks of the zebra finch. Our findings indicate that beak shape variability in many songbirds is strongly constrained by shared properties of the developmental programme controlling the growth zone. 1 School of Engineering and Applied Sciences and Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts 02138, USA. 2 Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA. 3 Department of Biology, San Diego State University, San Diego, California 92182, USA. * These authors contributed equally to this work. Correspondence and requests for materials should be addressed to A.A.
    [Show full text]
  • Adaptive Radiation: Darwin Finches Core Course: ZOOL3014 B.Sc. (Hons’): Vith Semester
    Adaptive radiation: Darwin Finches Core course: ZOOL3014 B.Sc. (Hons’): VIth Semester Prof. Pranveer Singh Macroevolution Factors of large evolutionary changes (Macroevolution) Macroevolutionary studies focus on change that occurs at or above the level of species This is in contrast with microevolution, which refers to smaller evolutionary changes (typically described as changes in allele frequencies) within a species or population Adaptive radiation The term adaptive radiation was coined by H.F. Osborn (1902) Adaptive radiation is the process through which a single ancestor is evolved into multiple descendants with a great variety of adaptations to different niches It is the diversification of a dominant evolutionary group into a large number of subsidiary types adapted to more restrictive modes of life (different adaptive zones) within the range of the larger group According to George Gaylord Simpson (1940, 1953), adaptive radiation is the rapid proliferation of new taxa (species) from a single ancestral group Certain authors of evolution biology such as Savage (1969),Stanley (1979) and Volpe (1985) have used an entirely new term macroevolution for the Osborn’s law of adaptive radiation Adaptive radiations are best exemplified in closely related groups that have evolved in a relatively short time A striking example is the radiation, beginning in the Paleogene Period (beginning 66 million years ago), of basal mammalian stock into forms adapted to- Running Leaping Climbing Swimming, and Flying Other examples include Australian marsupials,
    [Show full text]
  • The Galapagos Avifauna
    THE GALAPAGOS AVIFAUNA M. P. HARRIS Edward Grey Institute of Field Ornithology Oxford University and Charles Darwin Research Station Gakpagos, Ecuador The last review of the birds of the Galhpagos Haematopus ostralegus ( H. palliatus) , Himan- archipelago was made by Swarth (1931) al- topus himantopus (H. mexicanus), Tyto alba though L&&que et al. (1966) summarized the (T. punctatissima), Asio flammeus (A. gala- migrants on and near the islands. Several pagoensis), Pyrocephalus rubinus ( P. nanus authors (Brosset 1963; Curio and Kramer 1964; and P. dubius). The nomenclature and se- Harris 1968, 1969a,b,c,d, 1970a,b; L&$que quence of the migrants follows that used by 1963,1964; Nelson 1968; Snow and Snow 1969) LBv&que et al. (1966). Overall, the order of have published distribution maps and/or species is very close to that of the 1957 edition counts of several species of resident birds but of the A.O.U. Checklist of North American the status of the birds needs to be looked at as Birds. a whole to determine recent changes, due The naming of the islands is as much a either to man or other factors or to gaps in our problem as naming the birds (see Bowman knowledge. This paper attempts to document 1960). Most islands have several names, En- the past and present status of all the birds glish and Spanish. I hope that this summary known to have occurred within the islands or will be useful to field workers, therefore I have in the seas immediately surrounding them, and used the names now in common usage, but to suggest some possible reasons for the dis- give below a list of alternatives.
    [Show full text]