Speaking Out for Paleontology: Out at supper that night, someone struck up a hymn. No voice was louder than that of Stephen Jay Gould: The new Creationists have recently started to break from their strategy of unrelenting attack.
Thanks to biochemist Michael J. The Biochemical Challenge to Evolution , they have started to lift the veil from their own beliefs about origins qua science. Are intellectuals allowing dogma in science but not in religion? Is Darwin in the Details? Allen Orr's critique of Darwin's Black Box is devastating and, assuming that there are some out there who find the book plausible and yet have open minds, might do some good.
For me, although I did not need convincing, there is the sheer pleasure in seeing an expert in his field take on the ignorant and arrogantly presumptuous. However, I do feel that Orr failed to raise the most important issue of all: Did Behe have the right, in the first place, to appeal to design? Forsdyke is unusual among modern essayists in science. While he has published a great deal in technical journals of science and has two recent books to his credit, his work as an essayist is presented almost exclusively on his own academic website in well written and highly illustrated pages.
It is to be hoped that this body of work will survive his tenure in academia. Selected Papers and Commentary: At the bottom of this page you will find a number of links to historical essays by Darwin, Hooker and others that Dr. Forsdyke has presented beautifully on his website. This amounts to a good introductory course in genetics. Theoretical Biology , . Given the great pharmaceutical industry interest in genes, this trend has continued in most subsequent texts.
These deal extensively with the exciting topic of gene discovery and searching databases, but hardly consider genomes as information channels through which multiple forms and levels of information, including genic information, have passed through the generations. This book identifies the types of information that genomes transmit, shows how competition between different types is resolved in the genomes of different organisms, and identifies the evolutionary forces involved.
The early chapters relate the form of information with which we are most familiar, namely written texts, to the DNA text that is our genome.
This lends itself well to introducing historical aspects dating back to the nineteenth century. Founded the discipline of Sociobiology, more commonly called Evolutionary Psychology today, and cofounded the study of island biogeography. A Global Biodiversity Map: Commentary in Science As genomics and biomedicine are to human health, so ecology and conservation biology are to the planet's health. Unfortunately, compared with their sister disciplines, ecology and conservation biology are still disadvantaged.
We have entered the Century of the Environment, in which the immediate future is usefully conceived as a bottleneck: Do we invent our moral absolutes in order to make society workable? Or are these enduring principles expressed to us by some transcendent or Godlike authority? Efforts to resolve this conundrum have perplexed, sometimes inflamed, our best minds for centuries, but the natural sciences are telling us more and more about the choices we make and our reasons for making them.
The Future of Life: The totality of life, known as the biosphere to scientists and creation to theologians, is a membrane of organisms wrapped around Earth so thin it cannot be seen edgewise from a space shuttle, yet so internally complex that most species composing it remain undiscovered.
Mayr helped establish the neodarwinian synthesis and was a tireless teacher of evolution. His work, combined with that of Dobzhansky and Simpson who are also represented here, established the basis for the modern theory of evolution. Ernst Mayr died on February 3, , at the age of What is a Species, and What is Not? The Old Man of American Biology reviews the variety of species concepts, especially his Biological Species Concept, and responds to his critics.
Originally published in Philosophy of Science Speciational Evolution or Punctuated Equilibria: The widespread neglect of the role of speciation in macroevolution continued until Niles Eldredge and Stephen Jay Gould proposed their theory of punctuated equilibria. Whether one accepts this theory, rejects it, or greatly modifies it, there can be no doubt that it had a major impact on paleontology and evolutionary biology. Great minds shape the thinking of successive historical periods.
Modern thought is most dependent on the influence of Charles Darwin. See my separate page What Evolution Is for commentary about Dr. Mayr, more of his essays, and a complete list of his books. Simpson was a paleontologist and taxonomist whose influential text The Principles of Classification and a Classification of the Mammals  remained the standard for treatment of the subject for many years.
His was the last of a series of major publications, by authors from several different disciplines, that became known as the neodarwinian synthesis, the foundation for modern-day evolutionary biology.
Relationships of Local and Continental Mammalian Faunas: Antarctica as a Faunal Migration Route: Mammals and Land Bridges: Mammals and the Nature of Continents: Dobzhansky emigrated to the USA where his research with fruit flies led to many publications in genetics. He was one of the principle founders of the neodarwinian synthesis and trained many students in biology, genetics and evolutionary theory. In contradististinction to some other noted scientists of his time, Dr. Dhobzhansky never relinquished his religious orthodoxy.
Evolution in the Tropics: American Scientist 38 2: Natural selection augments the frequency of favorable types and reduces the frequency of unfavorable types. Populations thus react to changes in their environment by adaptive modifications. This is one of the rare occasions when evolutionary changes taking place in nature under the influence of natural selection can actually be observed in the process of happening.
American Biology Teacher . Unfortunately, not many of his writings are currently on the Internet. Those that are tend toward his viewpoints on politics and religion. On Being the Right Size: Haldane's essay is widely anthologized and frequently quoted, at least when the subject of biological scaling crops up. Daedalus, or, Science and the Future: As I sit down to write these pages I can see before me two scenes from my experience of the late war. The first is a glimpse of a forgotten battle of It has a curious suggestion of a rather bad cinema film.
Evolution is pretty generally accepted as an historical fact. But some biologists and many popularizers of biology believe that Darwin's account of how and why it happened is incorrect. This is of course true in one sense. Darwin was not infallible. The difficulties which biologists encounter in explaining evolution are of two kinds. One arises from the time scale. The other is more serious. Discoveries of different workers seem to contradict each other flatly. See also this thorough analysis of Haldane's Rule at Donald R.
His book The Genetical Theory of Natural Selection in helped pave the way for the modern Darwinian synthesis, giving it strong mathematical and statistical support. He ended his career in Australia. Collected Papers of R.
Fisher Relating to Genetics, Evolution and Eugenics: These are all large files in. Fisher edited by J. Bennett and published in five volumes by the University of Adelaide between and In most cases the papers are highly technical and might not be of interest to the general reader. One might at least view the list of titles to see the breadth of research that Fisher conducted. He was also a tireless advocate for secular public education and the professionalization of science.
Wallace he was outspoken on a wide range of issues. He is credited with having coined the term agnosticism. Thirty-two Essays by Thomas H. A fair library of Huxley's writings. The Origin of Species: A review in The Westminster Review .
An early review in the London Times . On the Reception of On the Origin of Species: A retrospective written 20 years later. Agassiz between and on variation and geographic distribution. His discovery of close affinities between East Asian and North American floras was a key piece of evidence in favor of evolution. Natural Science and Religion: I am invited to address you upon the relations of science to religion, in reference, as I suppose, to those claims of natural science which have been thought to be antagonistic to religion, and to those assumptions connected with the Christian faith which scientific men in our day are disposed to question.
Review of On the Origin of Species: Excerpts from Darwiniana [New York. Darwin's philosophy may be, or whether he has any, is a matter of no consequence at all, compared with the important questions, whether a theory to account for the origination and diversification of animal and vegetable forms through the operation of secondary causes does or does not exclude design Forest Geography and Archeology: Arts 16 3rd ser.
Here, then, we have reached a fair answer to the question how the same or similar species of our trees came to be so dispersed over such widely separated continents. He acquiring funding for and built the Museum of Comparative Zoology in He urged the creation of a National Academy of Sciences, becoming a founding member in , and was appointed a regent of the Smithsonian Institution.
Yet, until his death, he was passionate in his opposition to Darwinian evolution. Geographical Distribution of Animals: Christian Examiner and Religious Miscellany 48 2: Darwinism - Classification of Haeckel: This is chapter 7 from De l'Espece et de la Classification en Zoologie. From The Atlantic Monthly, pp. Many of his arguments published posthumously , are central tenets of creationism today.
Oddly his statement "Philosophers and theologians have yet to learn that a physical fact is as sacred as a moral principle," did not lead him to infer from the facts of the fossil record that it is a record of ancestry, even though he drew branching diagrams of lineages. Fossils and Geologic Time: An interesting depiction of the distribution of fossils in the geological strata. Professor Agassiz on the Origin of Species: This appears to be a collection of substantial excerpts from an originally longer essay.
Owen was later a leading opponent of Darwin's ideas about evolution and engaged in lengthy and acrimonious public debates with Thomas Huxley, Darwin's principle defender. Owen's review of On the Origin of Species is available here. In the Edinburgh Review 3: The bomb took the form of a page book with the grand title Vestiges of the Natural History of Creation, presenting a comprehensive account of the history of the Earth, from the formation of the Solar System through the development of plant and animal life, up to the origins of humankind.
Strangely, there was no author's name on the cover. Vestiges of the Natural History of Creation: This was a book that everyone seemed to criticize.
A number of noted personalities were "evolutionists" before Darwin published, based on the reading of this book. President Abraham Lincoln was one of them. Also available as Vestiges of the Natural History of Creation: Few people realize that Darwin's original contributions to science were mainly books on geology. Lyell was Darwin's main sounding board during the 20 years he spent developing the Theory of Evolution, but Lyell never completely agreed with Darwin about natural selection or the descent of man.
The Progress Of Geology: A chapter from Lyell's classic Principles of Geology [ and many revisions]. Another chapter from the same work. The Student's Elements of Geology: This is a complete downloadable book. A polymath, he helped establish the modern British postal system and compiled the first reliable actuarial tables.
He also participated in the pre-Darwinian debates in natural theology, contributing to the Bridgewater Treatises. Many scholars were involved with the exciting project of trying to develop a better understanding of the relations among living things. The name most often associated with the application of the model of ancestral forms and branchings is of course Charles Darwin, although Darwin did not satisfactorily explain everything involved or all of the implications.
For one thing, he lacked a modern understanding of genetics. For another, he had very little fossil evidence showing what extinct life forms looked like.
Biological evolution as it is understood today involves populations of plants or animals with slight genetic variation from one individual to the next. Genetic variation in the population can increase through occasional, non-lethal genetic mutations. And it naturally decreases with lethal genetic mutations birth defects or when any individual dies. An individual organism or a population that produces offspring is referred to as "successful. That is the ONLY meaning of "success" in this technical application of the word.
Biological evolution consists of a heritable change in the genetic make-up of a genetically diverse population. A population containing little or no genetic diversity has little capacity to evolve.
An example is sorghum, discussed in the Neolithic essay of the this web site. Link Two processes are responsible. Over time, a single initial population timber wolves — Canis lupus — for example , subjected to different environmental constraints including deliberate manipulation by humans , can produce a wide range of very different populations varieties of domestic dogs — Canis lupus familiaris.
None of this was particularly new. People had been breeding dogs and cultivating varieties of corn and cabbage and tulips for centuries. What was new was proposing that the process was evolutionary that is, that it eventually produced permanent differences , and that it was an inevitable characteristic of all living forms, including ourselves.
This led to opposition from religious "creationists. Something else was new: In this model, evolution is held to be the origin of new species out of increasingly separate biological varieties, just as linguistic evolution posits the gradual development of new languages out of increasingly separate dialects. The working definition of a species in biology is that it is a plant or animal form, in which male and female members can mate to produce fertile offspring.
Pigs and goats are different species because they cannot be crossed. But Irish setters and German shepherds are two variants of the same species, since they can produce fertile puppies. The model of biological evolution holds that if a population is divided into two non-interacting sub-populations in different environments, then the differences in the genotypes in the two populations will eventually become so great that members of the first population will not be able to mate and produce fertile offspring with members of the second population.
That is, that the two populations will have become two species. Darwin proposed that over the vast reaches of time available, this happened over and over, eventually producing the range of modern and extinct life forms. The logic of the argument is quite similar to the logic that guided the model of linguistic evolution. The idea of changes in the composition of a population being attributable to changes in its environment has been an extremely useful.
With this perspective, we can coherently account for the distribution of forms in the fossil record, for example. However, great interest also lies in species-formation speciation , which occurs when populations that for some reason cease to interbreed become different enough to lose all ability to interbreed. In actual life, the boundaries between species are not always absolute —varieties only gradually evolve into species, after all— and it has been found that occasional fertile crosses between closely similar species do occur, if rarely.
The rule-of-thumb of fertile offspring as defining species remains the way most biologists think of it, but the possible exceptions have generated complexities in classification and in modeling gene flow.
A population split in half by an uncrossable barrier can over time develop substantial differences between its two parts. The most famous example of this process, called "allopatric" —"different country"— speciation, is the squirrels of the Grand Canyon, who have diverged into different species on the two sides of the Canyon.
But when the genotype of a single, inbreeding population changes gradually over time, at what point should we say it has turned into a new species? Our "rule of thumb" about producing fertile offspring can hardly be applied to two different points in the history of the same population. And yet if the differences between early and late specimens are substantial, can we be confident in calling them the same species?
As an intellectual matter, it is difficult to know when one continuously changing population should be regarded as a different species from its remote ancestors. As a practical matter, it is also difficult to know how specimens available for study are actually related to each other anyway.
If two fossil snake teeth look similar, but neither looks exactly like any modern snake, were they separate species, or were they merely two slightly different variants of the same species?
And is either of them ancestral to any modern snake? Many specialists in prehistoric life —paleontologists— tend to assume that speciation occurs relatively easily when plant or animal communities are separated, and they argue that the default assumption should be that two specimens should be assumed to be different species until they can be convincingly shown to be the same which is hard to demonstrate with extinct forms.
Others argue that speciation is in fact relatively difficult. Barring intervention with atomic bombardment, we have not succeeded in changing a genotype sufficiently to make it a whole new species just through selective breeding alone. That is why all dogs are still the same species. The best assumption when looking at prehistoric forms should therefore be that two similar specimens should be considered to belong to the same species until shown to have more variation between them than is exhibited in a modern population of similar animals, if there is one.
All of this becomes particularly controversial in the case of proto-humans. Darwin did not explore the evolution of humans — indeed only one clearly pre-human hominid fossil had been discovered when he published The Origin of Species Through Natural Selection in Since humans look a lot like modern Great Apes, it seemed logical that we should have a common ancestor with them, but that was about as much as one could say. In some respects, the exact ways in which we draw the lines among species may not make much difference.
The more we learn about genetics, the more obvious it becomes that what matters most is not the label given to a form, but our understanding of the over-all process of evolutionary transformation that is continually going on.
Geneticists are ever refining more detailed "family trees" of biological forms based on the inheritance of specific gene mutations. In these family trees, it makes no significant difference where one species stops and the next begins. What matters is where mutations occur that are inherited by future generations. Since Darwin's time, many fossil forms have turned up that look more like us than they or we look like modern apes. It is impossible to say that any given bone is ancestral to any modern creature, of course, but there is a clear sequence of forms: Earlier ones tend to look more like the hypothetical common ancestor that we might share with modern apes; more recent ones look more and more like us.
Chancy as biological classification is with the incomplete fragments of extinct animals, virtually all biologists today are satisfied:. Some fossil forms are objects of great controversy. For example, the Neanderthals that roamed Europe in the last ice age and before are clearly Homo , but it was not clear whether they were a separate species or should be classed as Homo sapiens.
If Neanderthals counted as Homo sapiens , then they belonged to the sub-species " Homo sapiens neanderthalensis " and we were of the sub-species " Homo sapiens sapiens. In a logically similar way, the recently discovered Homo floresiensis forms have an unclear relationship to Homo erectus , with which they overlapped in time.
This essay will focus on: the early evolution of our eukaryote ancestor during Precambrian period, plastids origin along the algae family due to second endosymbiosis; discuss the evidence that supports the theory, including further examples of endosymbiosis.
May 16, · Evolution Essay Evolution is the theory that all living forms came from ancient ancestors. Through a series of mutations, genetic drift, migration, and natural selection today’s descendants show an amazing amount of similarities and diversity.
Essay on Evolution There are many mechanisms that lead to evolutionary change. One of the most important mechanism in evolution is natural selection which is the differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment. Sample Essay - Week 4: Speciation and the Fossil Record This essay was developed for the AMNH online course Evolution. Evolution is a part of Seminars on Science, a program of online graduate-level professional development courses for K educators.
An essay on evolution can be quite an interesting topic to work on. It is a topic that is being debated upon a lot in many academic circles. Evolution essays are details of different theories proposed by academicians who are advocates of different schools of thoughts. Creationism vs. evolution essay is popular for evolution research papers. Essays in Natural History and Evolution: THE ESSAY in science is an art form as well as a means of communicating ideas. All scientists publish their findings somewhere, but relatively few produce books or monographs. Even fewer produce essays.