The Origin of Species
Charles Darwin in his work “Origin of Species”stated the idea that caused revolution in the world of biologic science – that plants and animals are not static biological entities, but dynamic lifeforms that exist in constant interaction with each other and with the environment, and that lifeforms change over time under the influence of other lifeforms and environmental factors.
These mutual influences, reactions to these influences and reaction of every organism to the influence of environment bring to life another idea – the idea of ties that bind everything in nature, the network of connections of different kinds.
More Essay Examples on Science Rubric
One kind of connections is connection between species through the common ancestor species: “ Therefore I cannot doubt that the theory of descent with modification embraces all the members of the same class” (Darwin 454). This kind of connections is confirmed and illustrated by similar principles of anatomical construction of even rather distant species – cats and dogs and horses still have head, body and tail, four legs and relatively similar set of internal organs, which differ in order to specialization and adaptation to different food types, environment and patterns of living. Another arguments that can illustrate and confirm the connection through common ancestor are rudimentary organs and structures that modern organisms have only in incompletely developed state, atavisms that sometimes arise during fetus formation and gestation, and fossil remains of now extinct transient species that bear primitive prototypical traits at different stages of development from the very beginning of differentiation from ancestor species to the current state.
Developing the idea of connection through single common ancestor to the extreme, Charles Darwin came to conclusion:
“I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number” (Darwin 454). “Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. … all living things have much in common, in their chemical composition, their germinal vesicles, their cellular structure, and their laws of growth and reproduction. We see this even in so trifling a circumstance as that the same poison often similarly affects plants and animals; or that the poison secreted by the gall-fly produces monstrous growths on the wild rose or oak-tree. Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed” (Darwin 455).
These ties of affinity penetrate all parts of the world of nature, connecting every creature to every other living being on the Earth. Ties are more or less evident dependently of how close two species are related. They are most evident when two creatures are of the very closely related species, but even in the most distant organisms common signs and traits may be found, though these common signs will be found on much more subtle levels of organization, sometimes at cellular, and sometimes at the level of cell organs and molecular complexes, if these species are very distant (e.g. fungus and plant or animal). Still, similarities exist and they confirm Darwin’s idea about one primitive life form which descendants differentiated and gave birth to multiplicity of species that exist today and to even larger number of life forms that are now extinct.
Other kinds of connections, like food chains, host-parasite relations inter- and intra-species competitions that form basics of modern ecology, are also consequent conclusions of Darwin’s idea. But these conclusions were drawn not by Darwin himself, but by his fellow scientists that developed and evolved his theories in following 150 years.
1.Darwin, Charles. On the Origin of Species. 1859. Penguin Books 1968