User:EvolutionMisconception

Scientific Misconceptions: Evolution

Misconception:

Evolution is progressive and/or progresses in a directional path leading to the improvement of organisms; “Evolution is like a climb up a ladder of progress; organisms are always getting better.”

Introduction

This article is aimed at investigating and analyzing one of the major misconceptions related to biology and evolution. It is in no way meant to offend or harm anyone or their beliefs. It is simply a compilation of factual data/evidence and general observations to provide a stronger counter argument to challenge the scientific misconception about evolution and show it to be false. The target age for this article is high school students, focusing on 9th grade students (approximately 14-15 years old) in their first year of high school who are taking an introduction/beginning level biology course and are learning about the concept of evolution and how it works. I chose this specific target age primarily because 9th grade students are introduced to the concept of evolution more in-depth if not already in middle school in their intro level biology course. The article is organized in a manner that aims to allow the student to first be introduced to the misconception about evolution and then providing evidence as well as examples to argue against the misconception. Through this article I hope to teach/inform these students at an early stage in their scientific education about misconceptions related to evolution and present an argument which illustrates the counter-point to the misconception and the actual truth and reality about the process of evolution.

Misconceptions related to/about Evolution

Many people have misconceptions about the process of evolution and how it works. While some misconceptions are simply misunderstandings; thoughts and ideas that develop/grow in the course of learning about evolution from a school education and/or information portrayed through the media. Other broader/general misconceptions branch from either refusing to believe in the process of evolution or purposeful efforts to challenge and/or interfere with the teaching of evolution and how it works.

The Concept of Evolution and How it Works

There are many misconceptions about the concept of evolution and how it works. Unfortunately, misunderstandings related to the history of life and how it has developed through the process of evolution are very widespread among many age groups ranging from middle and high school students to adults. One prominent misconception is based on the assumption that evolution proceeds in a directional path leading to the improvement of organisms, which is often metaphorically compared to climbing an evolutionary ladder. What probably causes such a misunderstanding to come about is that simpler and smaller organisms did appear before complex and larger organisms; however, this makes sense when one understands how multicultural organisms have evolved and how large complex organisms develop. Here we investigate/examine this scientific misconception as well as the concept of evolution and how it works.

Historical Background

The scientific misconception that evolution is progressive has a history long before Charles Darwin established/created his theory on evolution and natural selection. This misconception developed in the 18th and 19th century European cultures due to their conservative social and religious attitudes and beliefs. This misunderstanding, however, continued long after Darwin visited and researched the Galapagos Islands and is still a common misconception among many students today.

The Study of Evolution

The viewpoint that evolution is proceeds in a directional path from simple organisms to more complex organisms represents one of the most fundamental inaccuracies in understanding the history of life and how it came about. Studying evolution is not simply based on the study of progress and/or direction. Rather, studying evolution requires one to study change. There are many evolutionary examples where lineages evolved from “complex” to “simpler” forms of organisms which will be explained later on.

Evolution does not involve progression towards more complex forms of life. Related to the misconception that evolution is progressive, many people view humans as the height of the evolution ladder/pyramid; however, this is yet another misunderstanding related to the misconceptions about evolution. Humans are simply one more branch on the growing tree of life. The only general trend related to the evolution of life on Earth that has been observed is increasing biodiversity.

“Humans evolved from apes”

The statement that “humans evolved from apes” illustrates the most common misconceptions about evolution. This statement is false as it assumes that living organisms evolve through a step-by-step process from simple form to more complex forms and that one living species develops into another through direct transformation. However, evolution is not a progressive ladder, but can be viewed as a constantly growing tree as explained below.

Natural Selection

The common misconception that evolution is progressive is false because the process of evolution is driven by natural selection. The processes of evolution and natural selection have no long-term objectives and do not necessarily result in greater complexity. The only significant outcome is that any organism that is fit enough for the environment survives and reproduces to pass on its genes. Though over time complex species have evolved, the majority of organism on earth consists of simple forms of life. For example, the majority of species on Earth are microscopic organisms known as prokaryotes, which account for about half of the world’s biomass (dry weight) regardless of their small size compared to other organisms including eukaryotes and represent the majority of biodiversity on Earth. Therefore, simple organisms remain the dominant and/or prevailing life form on Earth though complex organisms appear to be more diverse.

Progressive evolution has not been observed

The concept of progress does not exist in the process of natural selection and/or evolution. No one has observed progressive evolution because it is an inaccurate misunderstanding about the process of evolution. Evolution occurs without direction and without purpose. Evolution deals more with change in species over time which has been observed by Darwin’s research as well as more modern/contemporary studies. Evolution is also directly related to adaptation; while some adaptations are observed as being “progressive” others are considered “regressive.” For example, various parasites are simple organisms that have lost features that their evolutionary ancestors had; e.g. nongreen parasitic plants lost their leaves and the ability to produce energy/ food from photosynthesis.

Variations may occur in all different directions

The misconception that evolution is progressive is contrary to the method of evolutionary processes. Variations may occur in any group of organisms in any direction, and in theory they can be “backwards”/retrogressive or “forward”/progressive. From a Protozoan point of view, we humans might be considered a retrogressive development in the sense that our cells have lost their capacity to sustain independent life and have to live and work together to survive. Variations may occur in all different directions and it has often been observed that the path to adaptation has resulted in a the direction of a simple structure meaning the exclusion of more complex structures, in order to better adapt the organism its surrounding environment.

Examples

• Crayfish (habitat: American caverns)

    o	Lost their eyes, but adapted to living a life in total darkness

• Sessile Ascidians

    o	Lose almost all their resemblance to vertebrates, which they acquire in 
       the larval stage, by their adaptation to their specific environment

• Whales and seacows

    o	Lost their hind limbs, but developed a fish-like 
       structure in adapting to their aquatic environment

• Tape-worm

    o	Lacks an intestinal tract

• Parasitic barnacle Rhizocephala

These regressive developments which bring about the loss of simple structures are just as much the product of evolution as are the complex organized social life of ants and bees, the multi-faceted and intricate human brain, or the adaptation/modification of a fore limb to a wing on a species of birds.

“Can evolution make things less complicated?”

In a recent article/study, scientist suggested that cell origins involved a forward-and-backward process. The article mentions that the idea that life starts simple and gets more complex over time persists even among scientists. According to recent research, however, the origin of the cell that make up the tissue in our bodies, one of the biggest events in the evolutionary history, may be a case of life developing less complicated structures. David Penny, a molecular biologist at Massey University in new Zealand, stated that” “We do think there is a tendency to look at evolution as progressive. We prefer to think of evolution as backwards, sideways, and occasionally forward.” Referencing numerous examples of bacteria, Chuck Kurland of Sweden’s Lund University, who worked with Penny, concludes by mentioning that the examples “illustrate the Darwinian view of evolution as a reversible process in the sense that ‘eyes can be acquired and eyes can be lost.’ Genome evolution is a two-way street.”

To view the article, click the link below: http://www.msnbc.msn.com/id/12853798/

Oxymoron: “Evolutionary ladder”

The evolutionary ladder is a misconception and misunderstanding as evolution does not work in a directional path. Rather, organisms are presented with two choices: either adapt to their surrounding environment which is always undergoing change or risk extinction. The ladder concept may reassure some people especially since it justifies humans as being the most complex of organisms as they are at the top of the ladder. However, natural selection not does work this way. Nature works in a very efficient manner as it utilizes what is available, maintains what works, and removes the rest; in fact, the genetic material is not literally “thrown away,” but is turned off, like a switch, and maybe turned on later time if it fits the environment. Nature flourishes with different organisms each adapted to its specific environment. The sponge and jellyfish are examples of creatures with simple cell structures that have persevered from the Precambrian period, and have developed very little. Other ancient creatures that have survived due to their specialized adaptation(s) are: • Fungi, • Mosses, • Sharks, and • Horseshoe crabs.

Thus, according to natural selection, fitness is linked to the environment as adaptations are linked to changes, and not to progress or direction. The term “evolutionary ladder” is in reality an oxymoron.

The Ladder vs. the Tree Concept/Metaphor

Natural selection does weed out individuals that are unfit for a particular environment. However, for evolution, no organism has to be perfect. For example, many taxa have changed little over time such as some: • Mosses, • Protists, • Fungi, • Sharks, • Opossums, and • Crayfish.

However, these organisms are not climbing up a ladder of progress; rather they are stemming out onto different branches of a tree or bush as they are fit enough to survive and reproduce, which is all that is required to ensure they live long enough to pass on their genes.

Though other taxa may have changed and adapted over time, it does not necessarily mean that they improved or got “better.” Nevertheless, environments are constantly changing also: climates change, rivers alter their direction, and new competitors invade. Also, what was considered “better” a million years ago may not be considered “better” today, and what works “better” in one environment might not work well in another. Accordingly, fitness is linked directly to environment, not to progress.

Conclusion

Evolution is not progressive in the sense that it results in a fixed goal. Evolution makes organisms “better” only in the sense of improving their adaptation to their surrounding environment. However, in doing this, complex organisms may sometimes evolve less complex structures (for example, the ancestors of snakes had legs). Humans, monkeys, insects, and bacteria all are successful in their own methods according to their environment, but none is considered evolutionarily “better” than the other species and none of them reflect/represent the “objective” of evolution. Thus, evolution is not like a climb up a ladder of progress, but rather a tree with millions of branches that grow and fall off over time.

Works Cited/Bibliography:

http://evolution.berkeley.edu/evolibrary/article/0_0_0/sneakermales_01 http://evolution.berkeley.edu/evosite/misconceps/index.shtml http://www.bio.ilstu.edu/Armstrong/misconceptions.doc http://www.fossilmuseum.net/Evolution.htm http://www.madsci.org/posts/archives/jun2001/992025301.Ev.r.html http://www.nap.edu/openbook/0309063647/html/81.html http://www.talkorigins.org/faqs/evolphil/teleology.html http://www3.uakron.edu/biology/evolution/html/misconceptions.htm https://kb.osu.edu/dspace/bitstream/1811/2178/1/V22N07_173.pdf

External Source(s): The following website is a great resource for teachers who are teaching their students about the concept of evolution and how it works; it also has great lesson plans including various activities inside and outside of the classroom: http://evolution.berkeley.edu/evosite/evohome.html