Human Evolution Essay Example For Students

Human Evolution Essay It has been over 100 years since English naturalistCharles Darwin first told the world hisrevolutionary concept about how livings thingsdevelop. Evolution through natural selection andadaptation was the basis of his argument as itremains to this day a debated subject by many. Across this nation, a return to traditional valueshas also brought the return of age old debatedtopics. One issue that truly separates Americans isthe issue of creation versus evolution. Since the19th century, this divisive topic has been debatedin school boards and state capitols acrossAmerica. In many instances religiousfundamentalists won the day by having banned theinstruction or even the mention of ungodlyevolutionary thinking in schools. With todayssocial and political climate, this question is backwith greater force than ever. This is why thissubject is more important now than ever. In JayGoulds book The Pandas Thumb, an overviewof and an argument for Charles Darwinsevolutionary thinking is conducted with flowingthoughts and ideas. This essay titled NaturalSelection and the Human Brain: Darwin vs. Wallace takes a look directly at two hard foughtbattles between evolutionists and creationists. Using sexual selection and the origins of humanintellect as his proponents, Gould argues hisopinion in the favor of evolutionary thought. In thisessay titled Natural Selection and The HumanBrain: Darwin vs. Wallace, Gould tells about thecontest between Darwin and another prominentscientist named Alfred Wallace over twoimportant subjects. These topics, one being sexualselection and the other about the origins of thehuman brain and intellect were debated by menwho generally held the same views on evolution. However on these two subjects, Wallace chose todiffer as he described it as his special heresy(53). The first of these two areas of debatebetween the two men was the question of sexualselection. Darwin theorized that there laid twotypes of sexual selection. First a competitionbetween males for access to females and secondthe choice exercised by females themselves (51). In this, Darwin attributed racial differences amongmodern human beings to sexual selection basedupon different criteria of beauty that arose amongvarious peoples (51). Wallace, however,disputed the suggestion of female choice. Hebelieved that animals were highly evolved andbeautiful works of art, not allowing the suggestionof male competition to enter his mind. The debateof sexual selection was but a mere precursor to amuch more famous and important question . . . thequestion of the origins of the human mind. Gouldsdiscussion of the origins of the human mind is onethat he in which he vocalizes his own opinions andfeelings in a much more critical manner. Gouldbegins the topic of human origins by brieflycriticizing Wallace for his different views on thissubject. Wallace believed that human intellect andmorality were unique and could not be the productof natural selection. Wallace suggested that somehigher power (53) must have intervened toconstruct this latest and greatest of organicin novations. Gould sharply chastises Wallace forsimple cowardice, for inability to transcend theconstraints of culture and traditional views ofhuman uniqueness, and for inconsistency inadvocating natural selection so strongly (53). Theargument that human intelligence was divine alongwith the belief that all people of all races have thesame capacity of intellect, but are limited only bytheir culture was at the heart of Wallacesopinions. Gould rebuts Wallace by going intoDarwins subtler view. Gould writes that ourbrains may have originated for some set ofnecessary skills . . . but these skills do not exhaustthe limits of what such a complex machine can do(57). Gould ends by describing Wallaces thinkingas having direct ties with creationist thought. Aschool of thought that Gould obviously portrays aswrong throughout his essay. Throughout ThePandas Thumb, Gould tells us about the debatebetween Darwin and Wallace over sexualselection and the origins of human intellect. Character Formation Essayerectus the major trends in human evolution continued. The brain sizes of earlyH. erectus fossils are not much larger than those of previous hominines, rangingfrom 750 to 800 cc (45.8 to 48.8 cu in). Later H. erectus skulls possess brainsizes in the range of 1100 to 1300 cc (67.1 to 79.3 cu in), within the sizevariation of Homo sapiens. Early Homo sapiens Between 200,000 and 300,000 years ago, H. erectus evolvedinto H. sapiens. Because of the gradual nature of human evolution at this time,it is difficult to identify precisely when this evolutionary transition occurred,and certain fossils from this period are classified as late H. erectus by somescientists and as early H. sapiens by others. Although placed in the same genusand species, these early H. sapiens are not identical in appearance with modernhumans. New fossil evidence suggests that modern man, H. sapiens sapiens, firstappeared more than 90,000 years ago. There is some disagreement among scientistson whether the hominine fossil record shows a continuous evolutionarydevelopment from the first appearance of H. sapiens to modern humans. Thisdisagreement has especially focused on the place of Neandertals (or Neandertals),often classified as H. sapiens neanderthalis, in the chain of human evolution. The Neandertals (named for the Neander Valley in Germany, where one of theearliest skulls was found) occupied parts of Europe and the Middle East from100,000 years ago until about 35,000 to 40,000 years ago, when they disappearedfrom the fossil record. Fossils of additional varieties of early H. sapiens havebeen discovered in other parts of the Old World. The dispute over theNeandertals also involves the question of the evolutionary origins of modernhuman populations, or races. Although a precise definition of the term race isnot possible (because modern humans show continuous variation from onegeographic area to another), widely separate human populations are marked by anumber of physical differences. The majority of these differences representadaptations to local environmental conditions, a process that some scientistsbelieve began with the spread of H. erectus to all parts of the Old Worldsometime after a million years ago. In their view, human development since H. erectus has been one continuous, in-position evolution; that is, localpopulations have remained, changing in appearance over time. The Neandertals andother early H. sapiens are seen as descending from H. erectus and are ancestralto modern humans. Other scientists view racial differentiation as a relativelyrecent phenomenon. In their opinion, the features of the Neandertalsa low,sloping forehead, large brow ridge, and a large face without a chinare tooprimitive for them to be considered the ancestors of modern humans. They placethe Neandertals on a side branch of the human evolutionary tree that becameextinct. According to this theory, the origins of modern humans can be found insouthern Africa or the Middle East. Evolving perhaps 90,000 to 200,000 years ago,these humans then spread to all parts of the world, supplanting the local,earlier H. sapiens populations. In addition to some fragmentary fossil findsfrom southern Africa, support for this theory comes from comparisons ofmitochond rial DNA, a DNA form inherited only from the mother, taken from womenrepresenting a worldwide distribution of ancestors. These studies suggest thathumans derived from a single generation in sub-Saharan Africa or southeasternAsia. Because of the tracing through the material line, this work has come to becalled the Eve hypothesis; its results are not accepted by mostanthropologists, who consider the human race to be much older. See also RACES,CLASSIFICATION OF. Whatever the outcome of this scientific disagreement, theevidence shows that early H. sapiens groups were highly efficient at exploitingthe sometimes harsh climates of Ice Age Europe. Further, for the first time inhuman evolution, hominines began to bury their dead deliberately, the bodiessometimes being accompanied by stone tools, by animal bones, and even by flowers. Modern Humans Although the evolutionary appearance of biologically modernpeoples did not dramatically change the basic pattern of adaptation that hadcharacterized the earlier stages of human history, some innovations did takeplace. In addition to the first appearance of the great cave art of France andSpain See CAVE DWELLERS, some anthropologists have argued that it was duringthis time that human language originated, a development that would have hadprofound implications for all aspects of human activity. About 10,000 years ago,one of the most important events in human history took placeplants weredomesticated, and soon after, animals as well. This agricultural revolution setthe stage for the events in human history that eventually led to civilization. Modern understanding of human evolution rests on known fossils, but the pictureis far from complete. Only future fossil discoveries will enable scientists tofill many of the blanks in the present picture of human evolution. Employingsophisticated technological devices as well as the accumulated knowledge of thepatterns of geological deposition, anthropologists are now able to pinpoint themost promising locations for fossil hunting more accurately. In the years aheadthis will result in an enormous increase in the understanding of humanbiological history. Daniel Mokari