Comparing Lamarck's Theory Of Natural Selection

Lamarck recognized that the match of organisms to their environments can be explained by gradual

Evolution has been a very debatable topic since the theory of evolution first evolved. By definition, evolution is “the process by which different kinds of living organism are believed to have developed from earlier forms during the history of the earth”, but there are many different types of “evolution” such as coevolution, divergent, parallel and convergent – all with different theories. Jean Baptiste Lamarck was a French naturalist who invented the theory of inheritance of acquired characteristics (aka. “soft inheritance”). This evolutionary theory described how the natural environment affected the way an animal used their body parts. The features used regularly or for survival are passed onto the creatures offspring, and the parts that weren’t used, weren’t. On the other hand, another English naturalist Charles Darwin established a theory of “natural selection”. A process in which creatures that survived in their environment would pass their genes through the generations, compared to the weaker species with a lower survival rate, who reproduce less offspring or none.

Evolution is a theory that is supported with evidence that characteristics of living organisms change over generations. A species can change over time and may even split into two new species through a process called Speciation. Each new species adapts to its new environment through adaptability. This is the ability of an organism to change its physical and chemical nature to adjust to its surroundings. For example, adaptive radiation is a form of evolution that Charles Darwin had discovered.

Lamarck believed that a population of individuals all of the same kind (identical characteristics in all members). Individuals capable of transformation. Whereas Darwin thought that a population of interbreeding individuals with similar characteristics, though variation is common among all of them at all times. Individuals fixed and unchanging. Population capable of transformation. For example Lamarck also thought that if a giraffe

Darwin’s theory of evolution proposed a mechanism for decent with modification. His studies resulted in the proposal of two forms of selection, including sexual selection and natural selection. (3) The concept of sexual selection was developed by Darwin to account for many adaptations that appear incompatible with natural selection (3). Natural selection is a major component of evolution however it is still not fully understood. (2)

Darwin’s “descent of modification” phrase highlights his view of unity and diversity of life. Unity occurs as species descend from the common ancestors. Diversity occurs as the species are modified and evolve as they branch away from their ancestors. The mean by which this occurs is called “natural selection”. Darwin rationalized that certain individuals would be more likely to survive and reproduce than others. As generations went on, higher portions of the population would have traits that increased their survivability as long as the environment was stable. Darwin noted observations from nature to form his theory of natural selection. The observations were that there are traits in populations that varied from individual to individual and

Both Wallace and Darwin explored the proposals that had been set forth by the likes of Lamarck, Lyell, and Thomas Malthus. In 1858 the Linnaean Society of London published the contributions of both Wallace and Darwin, which although had significant differences shared the framework of proposing decent with modification based on natural selection. The principle of natural selection provides the rationale of how changes occur in a species over time. It represents the sum total of all environmental factors exerting pressure on a species. The pressure either benefits an organism that has a favorable variation; triggering a natural advantage to the survival value of that organism/species, or either the pressure exposes weaknesses in an organism/species that has unfavorable variations. Unfavorable

Many scientists believe variations are caused by environmental factors, such as food availability, weather and more; and that species evolve when environmental conditions change to increase the species survival. Darwin censures this idea; he believed that the main cause of variation is due to reproduction (Chapter I). Darwin suggested that parents pass down specific characteristics to their offspring, and those variations are continued on in the following generations. The problem with Darwin’s theory of reproduction is that Darwin did not comprehend how or why some characteristics are perennial and how others are not. Darwin’s inferences on variations also conflict with the idea that God created species independently, which was widely understood by many people in a time where religion was prominent (Chapter II).

This stated that evolutionary changes within organisms were caused by environmental factors, and would then modify their behavior. According to Lamarck, the changes in traits could be hereditarily passed from one generation to the next, creating a constant change over time for the species. Stating the prospect of natural selection, Lamarck’s theories paralleled Darwin’s; only Lamarck came up with his theories way before Darwin ("Jean-Baptiste Lamarck (1744-1829)”).

The theory of evolution states that organisms change over time.The changes the organism's have help them better adapt to their environment. These changes will help them survive and have more offspring in their environment. Charles Darwin came up with theory of evolution. The theory of evolution is supported by five things, or evidence.

Lamarck used two main principles already accepted to prove his evolutionary theory. The first was use and disuse, the idea that parts of the body that are used extensively become larger and stronger. The other was inheritance of acquired characteristics, which stated that an organism could pass these modifications to its offspring.

Biological evolution is the name for the changes in gene frequency in a population of a species from generation to generation. Evolution offers explanation to why species genetically change over years and the diversity of life on Earth. Although it is generally accepted by the scientific community, Charles Darwin’s theory of evolution has been studied and debated for several decades. In 1859, Darwin published On The Origin of Species, which introduced the idea of evolutionary thought which he supported with evidence of one type of evolutionary mechanism, natural selection. Some of the main mechanisms of evolution are natural selection, mutation, and genetic drift. The idea that all life on Earth shares a common ancestor has been around for

Jean-Baptiste Lamarck (1755-1829) is one of the best-known early evolutionists, holding a belief that evolution was a continuous development and strived toward greater complexity and perfection. Through which, his theory of evolution was that living organisms evolved in a unceasingly up ward direction, from dead matter, through simple to more complex forms and towards human “perfection” (Nesci.edu, 2015). From his theories of Inheritance of Acquired Characteristics; where organisms adapt to their environments and those changes were passed onto their off springs (Corbis, 2001), to his theories of Use and Disuse, where organisms that are not used progressively disappear (Evolution.berkeley.edu, 2015). Lamarck was the first biologist to publish

Future followers of Lamarck tried to modify Lamarckism in order to make it acceptable, based on the idea of adaptation and an intimate direct and causal relationship between structure, function and environment. Prominent Neo-Lamarckians like Mc Dougall, Giard (1846-1908), Cope (1840-1897), and T.H. Morgan believed that only those characters, which are incorporated into the germplasm, are inherited to the next generation and result in origin of new species. Under Neo-Lamarckism following assumptions were proposed:

Many knowledge claims in human and natural science are based on theories. Jean Lamarck proposed the theory of evolution in 1801. The theory of evolution proposed by Lamarck was based on the idea that organisms had to change their behavior to survive. For instance, if a giraffe stretched it neck for a long period of time to reach the leaves as the top of the tree, then a “nervous fluid” would flow in the neck and make it longer. Thus, its