Misconceptions About Evolution And The Mechanisms Of Evolution

Misconceptions about Evolution and the Mechanisms of Evolution

Adapted from Understanding Evolution, a website developed by the University of California Museum of Paleontology with support provided by the National Science Foundation and the Howard Hughes Medical Institute.

Unfortunately, people have misconceptions about evolution •Some are simple misunderstandings •Some are ideas that develop in the course of learning about evolution, possibly from school experiences and/or from the media. •Other misconceptions may stem from purposeful attempts to interfere with the teaching of evolution.

Evolution and How it Works •Misconceptions are unfortunately very common. •Most of these misunderstandings have to do with assumptions that evolution proceeds in a particular direction or that individual living things can choose to adapt.

“Evolution is a theory about the origin of life.”

•Evolution deals mainly with how life changed after its origin. •Science does try to investigate how life started but not as the central focus of evolutionary theory. •Whether or not we understand how life began, we do understand a lot about what happened during the history of life.

“Evolution is like a climb up a ladder of progress; organisms are always getting better.” •Natural selection weeds out individuals that are unfit in a particular situation. •For evolution, “good enough” is good enough. No organism has to be perfect. •They are not marching up a ladder of progress but need to be fit enough to survive and reproduce. •Other taxa may have changed and diversified a great deal—but that doesn’t mean they got “better.” •What works “better” in one location might not work so well in another. Fitness is linked to environment, not to progress.

“Evolution means that life changed ‘by chance.’ ” •Chance is certainly a factor in evolution, but there are also non-random evolutionary mechanisms. •Random mutation is the ultimate source of genetic variation •Natural selection, the process by which some variants survive and others do not, is not random. •To say that evolution happens “by chance” ignores half of the picture.

“Natural selection involves organisms ‘trying’ to adapt.” •Natural selection leads to adaptation, but the process doesn’t involve “trying.” •Natural selection involves genetic variation and selection among variants present in a population. •An individual has genes that are good enough to survive and reproduce, or it does not.

“Natural selection gives organisms what they ‘need.’ ” •Natural selection has no intentions or senses. •If genetic variation allows some individuals to survive a particular challenge better than others, they will have more offspring in the next generation, and the population will evolve. •If not in the population, the population may still survive (but not evolve much) or it may die out. •But it will not be granted what it “needs” by natural selection.

Evidence Regarding Evolution Many of the misconceptions about the evidence supporting evolution have been planted in the minds of the public through antievolution propaganda. The following notions may appear compelling at first glance, but are easily debunked with a little information.

“Evolution is ‘just’ a theory.”

Scientific theories are explanations that are based on lines of evidence, enable valid predictions, and have been tested in many ways. In contrast, there is also a popular definition of theory—a “guess” or “hunch.” These conflicting definitions often cause unnecessary confusion about evolution.

“Evolution is a theory in crisis and is collapsing as scientists lose confidence in it.” Debate is not whether evolution (descent with modification) took place, but how it took place. Details of the processes and mechanisms are vigorously debated. Evolution is sound science and is treated accordingly by scientists and scholars worldwide. ‘Project Steve’ and bogus lists of scientists who don’t support evolution

“Gaps in the fossil record disprove evolution.” There are lots of transitional forms. What counts as transitional? When has something changed ‘enough?’ That transitional fossils are not preserved does not disprove evolution. Science actually predicts that for many evolutionary changes there will be gaps in the record.

“Evolutionary theory is incomplete and is currently unable to give a total explanation of life.” Evolutionary science is a work in progress. New discoveries & new hypotheses made to explain them —just like other sciences We can’t know everything about evolution but… We do know a great deal about the history of life Evolution is the only well-supported explanation for life’s diversity.

“The theory of evolution is flawed, but scientists won’t admit it.” No support for creationists claims about flaws. Usually they are misunderstandings of evolution or misrepresentations of evidence. Scientific refinement process doesn’t mean there are flaws. Scientific method is mean to point out any real flaws.

“Evolution is not science because it is not observable or testable.” •Evolution is observable and testable. •Science is not limited to controlled experiments Actually, much is accomplished by gathering evidence from the real world and inferring how things work. •Multiple lines of evidence allow valid and useful inferences

“Most biologists have rejected ‘Darwinism’ (i.e., no longer really agree with the ideas put forth by Darwin and Wallace).” •Evolution generally proceeds at a slow, deliberate pace but can proceed at a relatively rapid pace under some circumstances. •In this sense, “Darwinism” is continually being modified. •Modification is how things work in science. •No credible challenges to the basic Darwinian principles so far. •Scientists have not rejected Darwin’s natural selection, but have improved and expanded it.

‘Project Steve’ and bogus lists of scientists who don’t support evolution The statement: Evolution is a vital, well-supported, unifying principle of the biological sciences, and the scientific evidence is overwhelmingly in favor of the idea that all living things share a common ancestry. Although there are legitimate debates about the patterns and processes of evolution, there is no serious scientific doubt that evolution occurred or that natural selection is a major mechanism in its occurrence. It is scientifically inappropriate and pedagogically irresponsible for creationist pseudoscience, including but not limited to "intelligent design," to be introduced into the science curricula of our nation's public schools.

As of a year ago, 688 scientists with some version of Steve in their name had signed the document.

Implications of Evolution Evolution has one implication—it explains the history of life. Other implications allegedly derived from evolutionary theory have been used to support the denial of evolution or to justify inhumane behavior. .

“Evolution leads to immoral behavior. If children are taught that they are animals, they will behave like animals.” •Humans are animals. •We share anatomical and biochemical traits as well as behaviors, with other animals •Some behaviors are specific to particular animals. •Linking immoral or inappropriate behavior to evolution makes no sense. •Morality is not based on what is, but on what ought to be.

“Evolution supports the idea that ‘might makes right’ and rationalizes the oppression of some people by others.” •“Social Darwinism” arose from a misguided effort to apply lessons from biological evolution to society. •Pre-existing prejudices were rationalized to promote social and political agendas. •The “science” of Social Darwinism was refuted. •Biological evolution has stood the test of time, but Social Darwinism has not.

Evolution and Religion The alleged incompatibility of religion and evolution has been used as a way of persuading people to deny the history of the Earth.

“Evolution and religion are incompatible.” •Religion and science (evolution) are very different things. •In science only natural causes are used to explain natural phenomena. •Religion deals with beliefs that are beyond the natural world. •The misconception that one has to choose between science and religion is divisive.   

Teaching Evolution Misconceptions about what should be taught in the science classroom stem from confusion about the nature of science itself. Science is about figuring out how things work and relies on empirical knowledge, not faith. Antievolutionists have tried to confuse science and religion, leading to the following misconceptions in the minds of some members of the public.

“Teachers should teach ‘both sides’ and let students decide for themselves. ” •Given the wide variety of religious views about creation, there are not simply “two sides” to be compared. •In science class, students should have opportunities to discuss the merits of arguments within the scope of science. •The “fairness” argument has been used a great deal by creationist activists attempting to insinuate their religious beliefs into science curricula.                                                 

“Evolution is itself ‘religious,’ so requiring teachers to teach evolution violates the First Amendment.” •Evolution is science. •The study of evolution relies on evidence and inference from the natural world. •Thus it is not a religion.

Why is Evolution Relevant and Important to Study?

Solving biological problems •Biological systems evolve, which means that variables always change and history always matters. •If we don’t take evolution into account, our solutions to biological problems are likely to fail. •Understanding evolution helps solve biological problems that impact our lives.

Understanding how diseases evolve helps us administer vaccines most effectively.

Understanding the evolution of insects helps us devise more effective methods of pest control.

Medical Science Vaccine development

A researcher examines a gel used in DNA analysis

Agriculture & Economics

The mass production of genetically-similar foods (like the grain being harvested here, and these red onions) makes our groceries inexpensive, but leaves them vulnerable to diseases and pests.

Irish Potato Famine

Grape phylloxera

Conservation

Kemp's Ridley sea turtle

Right whale

Hairy-nosed wombat