Historic Development of the Theories of Evolution Essay Example

living organisms. According to Aristotle, all living beings can be organized in a hierarchical manner, ranging from the least sophisticated and uncomplicated to the most advanced and intricate. At the pinnacle of this hierarchy lies God or deity. In essence, Aristotle's "The Great Chain of Being" posits that all living entities are arranged within an unchanging and stable system that progresses from lower levels to higher ones.

Aristotle disagrees with the idea of increasing an object's position in the hierarchy because he believes that each species was independently created. This goes against the traditional belief in development, where beings undergo change and progress over time. According to "The Great Chain of Being," it was believed that species cannot change. Although Aristotle's contribution to evolutionary theories is more contextual than substantive, he was one of the first philosophers/scientists to propose a concept explaining the relationships between evolving species. Despite not supporting the idea of evolutionary change, his classification of species had significant influence in his society and context. In fact, Aristotle's conviction in fixed species became widely accepted in Western philosophy for many centuries after his death, eventually becoming known as the Doctrine of Fixed Species.

Aristotle's rejection of evolution in the study of nature and biology led to a shift towards the evolutionary position, contrasting with his non-evolutionary perspective on the natural universe. This resulted in Aristotle's theory, known as "The Great Chain of Being," being purely based on philosophical ideas without tangible evidence or empirical data to support it, thus not being considered as "science."

Evolutionary Theory

The concept of development has been present since ancient times in Greece, referring to alterations in living beings and species over

an extended period. This form of development, called biological evolution, has been a subject of discussion and different theories among ancient Greeks and has transformed into the currently accepted theory of evolution by natural selection.

Throughout history, there have been different perspectives on biological development that share common principles. These principles include the belief in a common ancestor and the concept that all living beings have evolved and changed over time. Variations within groups of organisms indicate evolution, while similarities suggest a shared ancestry.

Aristotle's theory of "The Great Chain of Being"

presents an explanation of evolutionary theories by highlighting significant figures such as Aristotle, Lamarck, Wallace, Darwin, and others. Jean-Baptiste Lamarck was a French naturalist from 1744 to 1829 who was one of the first scientists to propose an evolutionary theory supported by observable evidence. Through studying animal species and examining fossil records, Lamarck concluded that life does not remain static as believed by Aristotle but instead undergoes transformations throughout time.

Lamarck introduced the concept of life's ability to change and evolve, which contradicted the widely accepted Doctrine of Fixed Species. This was a significant milestone in the evolution theory's progress. Lamarck was the first to propose a mechanism for gradual species changes over time. He put forth two key concepts regarding evolution:

1. The passing down of acquired traits through the use and disuse of body parts.
2. Organisms becoming more complex as time elapses. These ideas formed the basis of Lamarck's theory and were supported by his observations of various animal species.

According to Lamarck, environmental changes influenced an organism's development by determining whether

certain organs were utilized or not, leading to their growth or reduction respectively.

Lamarck believed that acquired traits in organisms were hereditary and could be passed down to offspring. He used the example of the camelopard's extended a neck to explain his theory of development. According to Lamarck, a camelopard could develop a longer neck throughout its life by constantly straining to reach higher branches. This longer neck then became an acquired trait that could be inherited by future generations.

Lamarck's theory suggested that nature-induced changes gradually led to the development of more complex forms in living beings. This addition to the theory of evolution presented a contrasting mechanism to Aristotle's viewpoint. Lamarckism emerged as an initial evolutionary theory, backed by "observable evidence," and laid the foundation for future innovative ideas. English naturalists Charles Darwin (1809-1882) and Alfred Wallace (1823-1913) also made significant contributions.

Both Darwin and Wallace played important roles in the development of the theory of evolution by proposing natural selection. Independently, they noted that species were constantly changing and identified natural selection as the main reason for this process. Darwin's visit to the Galapagos Islands and Wallace's voyage to the Moluccas Islands provided further evidence supporting their hypothesis. They collaborated in presenting their findings at a seminar in London, which is now acknowledged as the theory of natural selection. Additionally, Gregor Mendel, an Austrian monk and scientist who lived from 1822 to 1884, made significant contributions to advancements in genetics and inheritance.

Mendel's work on genetics and inheritance made a crucial contribution to the history of evolutionary theories. It played a significant role in the acceptance of Darwin and Wallace's theory of evolution, which had previously

lacked an understanding of how traits are inherited and why different versions exist within living beings. Through his experiments with garden pea plants, Mendel provided the genetic mechanism that supported this theory. His experiments led to the establishment of two fundamental laws in genetics and inheritance that greatly enhanced our understanding of how traits are passed down.

The text examines the laws of inheritance proposed by Mendel, including the laws of dominance and segregation, as well as the law of independent assortment. These laws elucidate how advantageous traits can be inherited and transmitted to subsequent generations. By integrating Mendel's theory with Darwin and Wallace's theory of evolution, we gain an understanding of the developmental process and the gradual evolution of organisms. Darwin and Wallace posited that populations within a species residing in distinct environments may undergo diverse evolutionary alterations. They hypothesized that natural selection serves as the mechanism through which organisms adapt to shifting environments.

According to Darwin and Wallace, individuals in populations possess variations in structure or behavior that can be advantageous in a changing environment. These variations, called adaptations, assist organisms in surviving the changing environment. As a result, organisms with beneficial adaptations have a greater likelihood of survival and reproduction, thereby passing these adaptations onto future generations. This evolutionary theory suggests that over time, populations of similar species may gradually become more distinct due to ongoing differential reproduction.

Natural selection is the process by which an environmental change or agent impacts a population, leading to differential reproduction. This means that certain inherited traits are more advantageous for producing viable offspring compared to other traits. Over many generations, this results in the proportion of the advantageous

traits increasing relative to other species. The mechanism of natural selection is rooted in two key concepts: survival of the fittest through advantageous variations, and differential reproduction.

The contributions and theories put forward by Darwin and Wallace have been the most significant and influential in the history of evolutionary theories. Even today, their theory from the 1800s continues to hold scientific relevance and is of utmost importance in the field of biology and biological development.

The widely accepted theory to account for development is now the theory of natural choice. Many following scientists have continued their work on development based on the proposal of Darwin and Wallace. They have conducted research using new engineerings that reveal more evolutionary links and further solidify the theory of natural choice. Stephen Jay Gould and Niles Eldridge were American evolutionary life scientists and paleontologists. Gould lived between 1941 and 2002, while Eldridge was born in 1943 and is still alive today. In 1972, these two proposed a theory known as punctuated equilibrium. This theory is a polish and extension to the current evolutionary theory of natural choice proposed by Darwin and Wallace. The theory of punctuated equilibrium suggests that development occurs in relatively short explosions of rapid alteration, followed by extended long periods of stability within populations.

This theory differs from the theory presented by Darwin and Wallace of development being a gradual alteration from one species to another. The theory presented by Gould and Eldridge is supported by fossil grounds and the dodo record. Many fossil species show small or no alteration over long periods of the geological clip, but shorter periods occur where new species appear and quickly replace the

hereditary species. Therefore, this supports the idea that development occurs in short explosions instead of a gradual pace, as suggested by Darwin and Wallace. The main problem with the evidence for punctuated equilibrium is the incomplete dodo record.

An incomplete dodo record makes it difficult to achieve a significant, scientific understanding of the rate of evolutionary change, as there is a possibility of losing links within the dodo record that could provide more evidence. The theory of punctuated equilibrium by Gould and Eldridge is therefore a theory that does not challenge the theory of evolution by natural selection but instead questions the pace at which evolutionary change occurs. Punctuated equilibrium suggests that evolution happens in short bursts, followed by long periods of stability, while Darwin and Wallace believed that evolution occurred gradually over long periods of time. Gould and Eldridge contribute to the evolutionary theory and thus play an important role in the historical development of evolution.

Using new evidence and research, the authors have made a valuable contribution by proposing a theory that modifies old knowledge. This suggests that theories can be updated based on advancements in technology and newly discovered evidence, resulting in different and novel findings.

Gould; Eldridge's Theory of Punctuated Equilibrium Timeline Showing the Historical Development of Evolutionary Theories
During the mid-1700s to early 1800s, Lamarck, a French scientist, was deeply influenced by the French Revolution. These societal and cultural impacts shaped both his life and his theory of evolution.

The Gallic revolution had a significant impact on France, causing societal and political turmoil and leading to major transformations. It affected various aspects of life, including religion and the economy. Furthermore, this revolution influenced Lamarck's approach

as a scientist, which can be seen in his decision to rename the Royal Garden where he conducted his research with a name unrelated to the French monarchy. Additionally, Lamarck faced social and cultural pressures that shaped his work, such as the prevailing belief in the Doctrine of Fixed Species. During this time period, most people did not believe in evolution or change. As a result, Lamarck presented his evolutionary theory based on observable evidence to the general public.

Jean-Baptiste Lamarck's theory challenged the prevailing belief that species were created independently and remained unchanged over time, making it the first widely acknowledged theory in this regard. The response to Lamarck's work was influenced by society's lack of knowledge and the impact of the French Revolution.

Similarly, Mendel's contribution to evolutionary theories is just as significant as other scientific figures. His research on inheritance and genetics provided a way to identify evolutionary relationships. Without his work on inheritance and his laws regarding trait transmission, the theory of evolution may not have progressed to its current stage.

The relevance and credibility of others' work were provided by his work and contribution, and it is through his experimental work that we can understand how living things change over time and evolve. Aristotle introduced the theory of "The Great Chain of Being" and proposed that species cannot change and are "fixed". Aristotle lived in ancient Greece during the 300s BC. During this time, Greece was highly advanced and heavily influenced by the culture of Ancient Rome. This era was a period of abundant scientific and philosophical development, with prominent figures like Plato and Aristotle presenting innovative doctrines and ideas.

Aristotle's work on "The

Great Chain of Being'' and his philosophical and scientific work in general, were heavily influenced by his context within ancient Greece. Ancient Greece placed a great deal of importance on faith, which played a fundamental role in the development of ideas, literature, philosophy, and scientific thought. Aristotle's concepts regarding relationships between species and "The Great Chain of Being'' were also strongly influenced by religion. Religion had a significant impact on his work, as his "The Great Chain of Being'' incorporates a hierarchical link from the lowest and simplest to the highest and most complex, with the apex representing deity or God.

Aristotle presents the idea that each living being is positioned within a hierarchical scale, with each being created individually. His concept of creation and the existence of God is evident in his work discussing the relationships among living beings, which were heavily influenced by ancient Greek society and culture. Additionally, Aristotle's philosophy was influenced by other philosophers, including his teacher, Plato.

Aristotle

Influence of society and culture:

• The historical development of evolutionary theories is greatly influenced by society, culture, and context.
• The societal and cultural environment at the time when evolutionary theories were proposed impacts the response and content of those theories.

During ancient times, theories were heavily influenced by religion and traditional culture. In contrast, in the post-modern era, opinions are more openly expressed, and theories are more widely accepted if they are backed by tangible evidence. The shape and form of ideas and scientific work are determined by one's context, society, and culture.

Assess how each scientist and their theory were influenced by society and culture, as well as the available cognition during their time period. Stephen Jay

Gould and Niles Eldridge were born in the mid to late 1900s, a time when there was a wealth of knowledge regarding evolutionary theory thanks to the contributions of Darwin, Wallace, Mendel, Lamarck, and Aristotle. Additionally, Gould and Eldridge had access to more recent technologies and scientific methods. A significant aspect supporting the theory of punctuated equilibrium is the fossil evidence and the study of the fossil record. During the mid to late 1900s, paleontology experienced a substantial increase in its effectiveness and overall understanding.

The dodos' information and examination were conducted at a more detailed and crucial level. This supports Gould and Eldridge's theory, as the engineering advancements during that time period aligned with their theory. Additionally, the existing exposure of society to the evolutionary ideas of Darwin, Wallace, Lamarck, and others gave Gould and Eldridge a solid starting point for their own theory. Their theory of punctuated equilibrium was an expansion of the already widely accepted theory of natural selection. They did not dispute the Darwin-Wallace theory but instead questioned the rate of evolution.

Based on new information available at the time, they suggested a theory about the rate of development.

Gregor Mendel

Born and lived in Austria during the 1800s, Mendel's work went largely unnoticed until many years after its publication. In 1866, Mendel shared his findings on hereditary traits, but it wasn't until 1900 that his work was rediscovered and acknowledged for its significance. This delay in recognition can be attributed to the limited knowledge about genetics, inheritance, and cellular life, including chromosomes and mitosis, during that time. Consequently, Mendel's research was seen as groundbreaking compared to previous studies, which led to scientists misunderstanding

its importance.

The prevailing belief was that traits in offspring were a result of blending during heredity. However, Mendel proposed that the laws of dominance and segregation were responsible for the traits in offspring. Mendel's research was groundbreaking and unlike anything that society had seen before, so it was largely ignored and his theories were dismissed.

Charles Darwin; Alfred Wallace

During the 1800s, Darwin and Wallace were primarily influenced by various social and cultural changes that impacted the development of their theory of evolution. These influences included the Age of Enlightenment, the industrial revolution, and the emergence of Great Britain as a global power. The Age of Enlightenment, which occurred in the 18th century, emphasized reason and evidence. This was a favorable time for the proposal of the Darwin-Wallace theory, as it was based on scientific evidence and observable facts, aligning with the shift towards reason and science in the Age of Enlightenment.

The theory of development, formulated by Darwin and Wallace, was greatly influenced by the industrial revolution. This period of technological advancement had a profound impact on society at the time. Darwin and Wallace's theory of development can be seen as another scientific innovation, arising from the numerous inventions and advancements in technology. Although Darwin's theory was not widely known to the public at first, it received significant support from Wallace, who independently came up with the same theory. Additionally, the ascent of Great Britain as a world power helped spread the Darwin-Wallace theory to other countries.

Therefore, the theory proposed by Darwin and Wallace of natural selection was influenced by a range of societal and cultural factors. Punctuated Equilibrium is another form of evolutionary theory that has

evolved since the time of Darwin and Wallace. In light of new evidence, Gould and Eldridge proposed the theory of punctuated equilibrium, suggesting that evolution occurs in short rapid bursts of change, followed by long periods of stability within populations. This differs from the idea put forward by Darwin and Wallace, which suggests that evolution happens gradually over extended periods of time. The proposal of punctuated equilibrium was supported by analyzing and studying fossil evidence and the fossil record.

The concept of punctuated equilibrium is a modification of the theory proposed by Darwin and Wallace. It suggests that evolution occurs at a different rate than previously thought, occurring in short bursts rather than slowly over long periods of time. Many fossilized remains support this theory, showing millions of years of stability without any evolutionary changes, followed by shorter periods in which new species appear and replace existing ones. Neo-Darwinism refers to the Darwinian evolution based on Mendel's work in genetics. This concept incorporates Mendelian genetics to support and explain the theory of genetic variation leading to the formation of new species proposed by Darwin and Wallace.

Before Mendel's work, Darwin was unable to explain the cause of variations within species or how those variations could be passed down to future generations. Mendel's research in genetics and heredity provided the solution to these problems, and it was during the early 20th century that scientists combined Darwin's and Mendel's work to form the ideas known as Neo-Darwinism. Darwin and Wallace had already identified natural selection as the mechanism for species evolution, believing that species evolved through the gradual accumulation of genetic differences. However, through Neo-Darwinism, other processes have been

recognized as capable of producing new species.

These include: random or chance events, called familial impetus and alterations in the number of sets of chromosomes, known as mutations. Therefore, evolutionary thought evolved into Neo-Darwinism, which explained the initial aspects related to Darwin's theory of natural selection.

Neo-darwinism

State how evolutionary theory has changed/developed since Darwin proposed his theory of natural selection. The "old" methods used to understand the evolutionary relationships between humans and other Primates consisted of techniques that were not based on complex technologies but rather relied on observation and human analysis. The "old" methods used to study these evolutionary relationships were comparative anatomy, comparative embryology, and comparative behavior. Scientists like Darwin employed these methods to examine the evolutionary relationships between humans and other Primates.

Comparative anatomy involves comparing the structures of different living beings to identify similarities and differences. In the past, it was used to determine possible evolutionary relationships between organisms. For instance, in the 1860s, Ernst Haeckel, a German life scientist, classified several primates such as Pongo pygmaeus, gorillas, and Pan troglodytes into one family, while humans were placed in a separate family. Haeckel's decision was based on comparing the anatomical structures of both humans and primates.

Haeckel observed that gorillas and Pan troglodytess were more closely related to each other compared to worlds or Pongo pygmaeuss. This conclusion was based on the similarities in the construction of their hind limb and the enamel on their teeth. Scientists also used comparative embryology and behavioral characteristics to gather information about the evolutionary relationships between humans and primates. Comparative embryology involves studying and comparing the developmental stages of different species. Within this

field, it is evident that there are several distinct similarities between humans and primates, such as the presence of gill slits and suit muscles.

The text suggests that embryos of closely related organisms, such as worlds and Primatess, have similar characteristics and features, indicating a possible shared common ancestor. Another comparison between worlds and Primatess was made based on their behavior. Scientists observed human behavior and compared it to cardinal behavior to find any similarities that may indicate evolutionary relationships between the two species. The information shows that the previous method used for this comparison relied on observations and physical analysis rather than chemical analysis. These previous methods provided physical information about the evolutionary relationships between worlds and Primatess.

Old Technology


Technology

Advancements in technology have enabled scientists to better understand the evolutionary relationships between worlds and other Primatess.

The study of chemicals found in cells, known as biochemistry, enables a more in-depth exploration of the evolutionary connections between organisms and other beings. Amino acid sequencing, DNA-DNA hybridization, and DNA sequencing are new technological advancements that have allowed for a more comprehensive examination of evolutionary relationships. Before these technologies were available, scientists had limited means to investigate and analyze these relationships.