Scientists now know that Darwin had the right idea but the wrong animal. Instead of looking at bears, he should have instead been looking at cows and hippopotamuses. The story of the origin of whales is one of evolution's most fascinating tales and one of the best examples scientists have of natural selection. To understand the origin of whales, it's necessary to have a basic understanding of how natural selection works.
Natural selection can change a species in small ways, causing a population to change color or size over the course of several generations. This is called "microevolution. But natural selection is also capable of much more. Given enough time and enough accumulated changes, natural selection can create entirely new species, known as "macroevolution.
Take the example of whales — using evolution as their guide and knowing how natural selection works, biologists knew that the transition of early whales from land to water occurred in a series of predictable steps. The evolution of the blowhole, for example, might have happened in the following way:. Random genetic changes resulted in at least one whale having its nostrils placed farther back on its head. Those animals with this adaptation would have been better suited to a marine lifestyle, since they would not have had to completely surface to breathe.
Such animals would have been more successful and had more offspring. In later generations, more genetic changes occurred, moving the nose farther back on the head. Other body parts of early whales also changed. Front legs became flippers. Back legs disappeared. Their bodies became more streamlined and they developed tail flukes to better propel themselves through water. Darwin also described a form of natural selection that depends on an organism's success at attracting a mate, a process known as sexual selection. The colorful plumage of peacocks and the antlers of male deer are both examples of traits that evolved under this type of selection.
But Darwin wasn't the first or only scientist to develop a theory of evolution. Genetics: Study of traits and how they are passed down from generation to generation. Gradualism : Changes in species that happen over long periods of time. Homologous Structures : Body parts on different species that are similar and most likely evolved from a common ancestor.
Creation, Evolution, and Thomas Aquinas
Hydrothermal Vents : Very hot areas in the ocean where primitive life might have begun. Macroevolution: Changes in populations at the species level, including ancestral relationships. Mass Extinction : Event in which large numbers of species died out completely. Natural Selection: Characteristics that are favorable in an environment and are passed down while undesirable characteristics are bred out of the gene pool. Panspermia Theory : Early theory proposing that life came to Earth on meteors from outer space.
Prokaryote : Organism made up of the simplest type of cell; has no membrane-bound organelles. Primordial Soup: Nickname given to the theory that life started in the oceans from the synthesis of organic molecules.
Punctuated Equilibrium : Long periods of consistency of a species interrupted by changes that happen in quick bursts. Speciation: The creation of a new species, often from evolution of another species. Stabilizing Selection: Type of natural selection that favors the average of the characteristics. Theory of Evolution: Scientific theory about the origins of life on Earth and how it has changed over time. Vestigial Structures: Body parts that seem to no longer have a purpose in an organism. Share Flipboard Email.
Religion, or more appropriately religions, are cultural phenomena comprised of social institutions, traditions of practice, literatures, sacred texts and stories, and sacred places that identify and convey an understanding of ultimate meaning. Religions are very diverse. While it is common for religions to identify the ultimate with a deity like the western monotheisms — Judaism, Christianity, Islam or deities, not all do.
Darwin, Evolution, and Faith
There are non-theistic religions, like Buddhism. Although science does not provide proofs, it does provide explanations. Science depends on deliberate, explicit and formal testing in the natural world of explanations for the way the world is, for the processes that led to its present state, and for its possible future. When scientists see that a proposed explanation has been well confirmed by repeated observations, it serves the scientific community as a reliable theory.
Well-supported theories guide future efforts to solve other questions about the natural world. Religions may draw upon scientific explanations of the world, in part, as a reliable way of knowing what the world is like, about which they seek to discern its ultimate meaning. Religious understanding draws from both subjective insight and traditional authority. However, this is an erroneous judgment.
Virtually all of the historic religions include traditions of rational reflection. Science and religion both have historical traditions that exhibit development over time. Each has places for individual insight and communal discernment.
Analytic and synthetic reasoning can be found exhibited in both. Science and religion have been and continue to be formative elements shaping an increasingly global human society. Both science and religion have served to jeopardize and contribute to the common human good. Typical assumptions about this relationship fall into one of three forms: conflict, separation or interaction. A conflict approach assumes that science and religion are competitors for cultural authority. Either science sets the standard for truth to which religion must adhere or be dismissed, or religion sets the standard to which science must conform.
For example, some atheists adopt this approach and argue that science reduces religion to a merely natural phenomenon. Conversely, some religious adherents, while claiming to accept science, will identify specific points at which mainstream scientific findings must be distorted or abandoned for the sake of religious convictions.
Such an adversarial approach tends to rule out any constructive engagement between science and religion. Individuals who prefer a separation approach hold that science and religion use different languages, ask different questions and have different objects of interest e. By highlighting the differences between science and religion, conflict is avoided. While this approach allows a person to explore what science has learned about human origins without fear of conflict with religious beliefs, it also encourages that the science be left, so to speak, at the museum threshold so that it has no impact on other non-scientific explorations of what it means to be human.
A consequence of separation is that the science of human origins can be viewed as irrelevant to what might be the deepest of human concerns. It should be noted that it is true that science is practiced without reference to religion. God may be an ultimate explanation, but God is not a scientific explanation. This approach to science is called methodological naturalism. However, this method of isolating religious interests from scientific research is not an example of the separation approach. Historically, this bracketing out of religious questions in the practice of scientific inquiry was promoted by religious thinkers in the 18th and 19th centuries as the most fruitful way to discover penultimate rather than ultimate explanations of the structures and processes of nature.
A third possibility for the relationship between science and religion, one of interaction , at minimum holds that dialogue between science and religion can be valuable, more that science and religion can constructively benefit from engagement, and at maximum envisions a convergence of scientific and religious perspectives. Generally, this view encourages an effort to explore the significance of scientific understanding for religious understanding and vice versa. With this approach science remains relevant beyond the museum for many people who might otherwise ignore scientific findings.
The National Museum of Natural History of the Smithsonian Institution has a responsibility due to its charter to provide the public with an opportunity to explore for themselves the most recent scientific understandings of the natural world, including human origins. People are well aware that insights from the humanities, including the arts, literature and religious traditions, have much to say on this topic as well.
For some people an evolutionary account of human origins may be greeted with skepticism because it challenges their particular religious commitments. In contrast, other people find their religious perspectives are deepened and enriched by an evolutionary understanding of human origins. Although the questions below recognize this range of perspectives, many of the questions reflect expectations that are especially characteristic of people from those religious communities that are skeptical about the science of evolution.