Biogeography is the study of the distribution of organisms. biogeographical dist
ID: 134222 • Letter: B
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Biogeography is the study of the distribution of organisms. biogeographical distributions. Try to remember what Europeans knew of the World in which we live in the 1200s-1800s In 1831 Charles Darwin -age 22-set off for a five year journey to explore parts of the world far, far away from patrician English landed gentry of his youth. Alfred Russel Wallace set sail in 1948, at the age of 25. Biographers of both naturalists have stated that immersion in the world so different from which they were raised, at an age and with an education where they were open to new knowledge yet had significant base learning, was essential for both individuals. Someday you will want to read Darwin's "ourney of the Beagle." This book is highly entertaining, easy to read, and provides insight into Darwin's thoughts as he viewed these wondrous sites. 1. Darwin was an early observer of Wallace's line separates Asian and Australian ecozone organisms. What types of plants and animals characterize each ecozone? Look at Darwin's travels and Wallace's work in the Malay Archipelago. Do additional research and determine where they were closest together in this area, when they were in this region, when Darwin would have seen the Asian ecozone organisms and when he would have seen the Australian ecozone organisms. COMPARE Darwin and Wallace's work on biogeography, identifying the common features and the unique features of each. Except for birds and bats, there are almost no native land vertebrates in New Zealand. One native frog species, a few lizard species, and several species of flightless birds are native. No snakes, freshwater fishes, or terrestrial mammals are native. What might explain this situation? is the biota more likely derived by dispersal from another region or by vicariance? (explain). What is the significance of the missing freshwater fishes? b. C. d.Explanation / Answer
a)1.Acrocephalidae, Aegithalidae, Certhiidae, Cettiidae, Chloropseidae, Dromadidae, Eupetidae, Eurylaimidae, Hemiprocnidae, Hypocoliidae, Ibidorhynchidae, Muscicapidae, Phasianidae, Pityriaseidae, Podargidae, Tichodromadidae and Turdidae. Also characteristic are pittas, bulbuls, Old World babblers,cuckooshrikes, drongos, fantails, flowerpecker, helmetshrikes, hornbill, nuthatch, orioles, parrotbills, shrikes, sunbirds and woodswallows.
2.Two orders of mammals, the colugos (2 species) and treeshrews (19 species), are endemic to the Indomalaya ecozone, as are families Craseonycteridae (Kitti's hog-nosed bat), Diatomyidae, Platacanthomyidae, Tarsiidae (tarsiers) and Hylobatidae (gibbons). Large mammals characteristic of Indomalaya include the Asiatic lions,tigers, wild Asian water buffalos, Asian elephant, Indian rhinoceros, Javan rhinoceros, Malayan tapir. The other endemic Asian families include Ursidae (giant panda), Calomyscidae (mouse-like hamsters) and Ailuridae (red pandas). The Asian ungulates include bharal, gaur, blackbuck, the wild yak and the Tibetan antelope, four-horned antelope, ox-sheep (Ovibovini), takin, kting voar, several species of muntjac, Bubalus and others. The goat-antelopes (Rupicaprini) are represented by the goral and the serow. Asia's tropical forests accommodate one of the world's three principal primate communities, about 45 species including lorises, tarsiers, leaf-eating langurs, the orangutan of Borneo and Sumatra, and the gibbon.
3.Thelizardsinclude geckos (Agamura, Alsophylax, Asaccus, Calodactylodes, Cyrtodactylus, Chondrodactylus, Cnemaspis, Cyrtopodion, Dixonius, Gehyra, Gekko, Gonydactylus, Hemidactylus, Hemiphyllodactylus,Lepidodactylus,Luperosaurus,Perochirus,Pristurus,Teratolepis,etc.), Xenosauridae (Shinisaurus), monitor lizards, skinks. There are also about 100 species of turtles and tortoises.
b) The preface summarises Wallace's travels, the thousands of specimens he collected, and some of the results from their analysis after his return to England. In the preface he notes that he travelled over 14,000 miles and collected 125,660 specimens, mostly of insects: 83,200 beetles, 13,100 butterflies and moths, 13,400 other insects. He also returned to England 7,500 "shells" (such as molluscs), 8,050 birds, 310 mammals and 100 reptiles.
The book is dedicated to Charles Darwin, but as Wallace explains in the preface, he has chosen to avoid discussing the evolutionary implications of his discoveries. Instead he confines himself to the "interesting facts of the problem, whose solution is to be found in the principles developed by Mr. Darwin"so from a scientific point of view, the book is largely a descriptive natural history. This modesty belies the fact that while in Sarawak in 1855 Wallace wrote the paper On the Law which has Regulated the Introduction of New Species, concluding with the evolutionary "Sarawak Law", "Every species has come into existence coincident both in space and time with a closely allied species", three years before he fatefully wrote to Darwin proposing the concept of natural selection.
c) Darwin and Wallace both seemed to think that small changes over time would result in new species, Alfred Wallace seems to have concentrated his efforts a different cause for speciation!
Historians of science have noted that, while Darwin considered the ideas in Wallace's paper to be essentially the same as his own, there were differences.
Darwin emphasized competition between individuals of the same species to survive and reproduce, whereas Wallace emphasized environmental pressures on varieties and species forcing them to become adapted to their local conditions, leading populations in different locations to diverge.
Some historians, notably Peter J. Bowler, have suggested the possibility that in the paper he mailed to Darwin, Wallace was not discussing selection of individual variations at all but rather group selection. However, Malcolm Kottler has shown that this notion is incorrect and Wallace was indeed discussing individual variations.
Others have noted that another difference was that Wallace appeared to have envisioned natural selection as a kind of feedback mechanism keeping species and varieties adapted to their environment.
They point to a largely overlooked passage of Wallace's famous 1858 paper:
The action of this principle is exactly like that of the centrifugal governor of the steam engine, which checks and corrects any irregularities almost before they become evident; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any conspicuous magnitude, because it would make itself felt at the very first step, by rendering existence difficult and extinction almost sure soon to follow.
Alfred Wallace pursued other subjects, like the colorization of animals as a warning, and the possible effect on Naturalization known as the Wallace Effect:
Reinforcement (sometimes called secondary contact) is a process of speciation where natural selection increases the reproductive isolationbetween two populations of species. This occurs as a result of selection acting against the production of hybrid individuals of low fitness. The idea was originally developed by Alfred Russel Wallace and is sometimes referred to as the Wallace effect.
Both Darwin and Wallace seem agreed that evolution takes place, but they seem to hold different ideas for the mechanism that brings about these changes.
d) The fossil has been called SB mammal. It is not known when, or why, land mammals became extinct in New Zealand but there were none present on New Zealand for several million years before the arrival of man. The short-tailed bats (from the monotypic family Mystacinidae), first arrived in the Oligocene or before.
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