Biology

All types of organisms that are present here on Earth are descendants of their ancestors that lived more than 150 million years ago.  Plants and animals today all came from single-celled organisms that lived more than 3 billion years ago. Evolution is the study of how organisms live through adaptation (Smith, 1993). These adaptations allow organisms to change physically and physiologically over generations in order to live (Krukonis,  Barr, 2008). This biological evolution is the change in the genes of specific species from generation to generation.  A gene is a basic unit of heredity in organisms. Evolution occurs when the frequency of genes are altered in a specific time period. Microevolution is the result of evolution in short time frames with small gene alterations. While in macroevolution, evolution occurs in long time frames with prominent gene alterations. Frequency of genes can also be affected by environmental changes (The History of life looking at the patterns).

Evolutionary changes basic mechanisms are natural selection, genetic drift, mutations, recombination and gene flow. Organisms provide offspring that are similar but not identical. Nature selects characteristics that allow organisms to survive. These changes may be physiological or physical. Genetic variations for survival over several generations can bring about new entirely different species. Small populations with a small number of offspring tend to experience genetic drift. The change in the gene frequency occurs because of random sampling. The genes of the offspring are a random sample of the parents genes. This process causes the genetic variation within species. With the process of natural selection and genetic drift, some genes are altered by the process of mutation. Mutations can cause bad and good mutations. Mutations occur to increase survival in organisms. Good mutations are passed on to the next generations. On the other hand, bad mutations can cause death to organisms. In sexual reproduction, the process of recombination occurs to give a mixture of the parents traits to their offspring. Recombination provides offspring to inherit half of the genes per parent. Interspecies reproduction brings in new genes into a new population, thereby causing gene flow. New genes from another population provide new genetic information into a new gene pool, causing hybrids.

Lamarck hypothesized that species continuously change from one species to another. Because of his out of the box observations, he was attacked by other naturalists. Lamarck was opposing the norm with his theory of the natural process. British naturalists on the other hand, believed in nature as the work of God. The thought of disproving the miracle of life overpowered Lamarck. He was rejected by the scientific community until he died in 1829 (ONeil, 2010). The Origin of Species by Charles Darwin caused varied reactions from different parts of the society. One part of the society in particular that reacted to Darwins theory of evolution is the Christian Church. They immediately observed the insinuation of his theory to the beliefs of creation. Religious leaders form creationism to reject the modern evolutionary theory of Darwin. Creationism literally believed that God created life out of nothing within six days (creationism, 2010). American Protestant fundamentalists also objected in Darwins theory of evolution. Charles Hodge, an American Calvinist created a book called What is Darwinism. His book said that the perfect human body couldnt have been from the process of natural selection. He also argued that believing in the natural selection means rejecting God. Such arguments can still be seen in contemporary articles.

Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck was a French naturalist and soldier. He was also an early evolutionary scientist and a founder of the field of invertebrate paleontology. He was the first to hypothesize that evolution is a gradual process rather than a saltatory theory of evolution (Early concepts of evolution jean baptiste lamarck). Lamarck proposed that life evolves spontaneously from nonliving matter. This type of evolution is defined by Lamarck as the gradual evolution of single-celled organism into complex organisms. He proposed that traits are inherited through use and disuse. However, he did not focus much on this in his theory (Jean-baptiste lamarck biography ). Although he was not much accepted by the scientific community and was mocked, his theory of inheritance of traits was popular in his time. Lamarcks theory initiated the interest on the study of evolution.

Change in the populations gene pool is evolution. Gene pool is defined as the set of genes in a population. Each individual that form a population have their own set of genes that mutate over time. It is the population that evolves when individuals are selected. Genetic variation is essential in evolution. Gene mutation is the source of genetic variation. These mutated genes form alternate forms that are called alleles. Enough alleles make individuals in a population unique.

Genetic mutation is a mechanism that increases genetic variation. Mistakes are made when DNA is copied. These mistakes change a gene causing mutation. Genetic mutation changes a letter of the genetic code, making alleles. Phenotypic manifestations of genetic mutations are often times harmful. However, there are also genetic mutations that can be beneficial and crucial for survival. The rate of evolution is affected by genetic mutations.

Godfrey Hardy and Wilhelm Weinberg concluded that based on mathematical modeling, frequency of genotypes and alleles are constant from one generation to another. Along with other geneticists, evolution will not occur if these conditions in a population are experienced mutation is absent, natural selection is absent, population is huge, all individuals in the population mate, mating is random, all mating produces the same number of offspring and no migration in and out of the population. If such conditions are present, there is a genetic equilibrium which means that evolution is on hold. The Hardy-Weinberg equation is the Mendelian genetics for populations.

DNA or deoxyribonucleic acid is the blueprint of life. RNA or ribonucleic acids, on the other hand, form proteins that make up an organism. Transcription occurs when RNA molecule is formed from a DNA molecule. RNA is formed by copying one of the strands of DNA. The mRNA transfers information to proteins. These proteins contain 20 amino acids and its transformation from codons is called the genetic code. Together with the protein-coding RNA are the non-protein-coding RNA. These types of RNA aid in the formation of proteins. One subtype of this RNA is the ribosomal RNA. Ribosomes are composed of ribosomal RNA. These ribosomes are the main producer of proteins. Ribosomes are present in all organisms because they all need proteins to survive. Such proteins can help evolutionary biologists understand important relationships between organisms and species. Another use of proteins in evolution is the tracing of lineages between species and organisms.

Biological evolution is the study of the origin of life. This branch of science helps us understand the beginning of life. The process of evolution is believed to be caused by the important adaptations of the ancestors. It is through this adaptation that our ancestors are able to survive the harsh conditions millions of years ago. There are believed to be five mechanisms of evolution that affect evolution. These are natural selection, genetic drift, mutations, recombination and gene flow. Evolution, as with many other branches of science, clashes with the religious sector of the society. Religious leaders start to clash with the ideas of evolution. Evolutionary biology challenges the fact that all organisms are not made with miraculous ways.  This seems to disprove that God is the creator of living things. Lamarcks natural process was attacked by his colleagues because of his idea that we all came from single-celled organisms. Even at the publishing of Darwins origin of species, evolutionary biologists are thought as atheists. This is the reason why religious leaders created creationism. Until now, there are still arguments about religion and evolution. A change in the gene pool is evolution. Evolution only occurs in a population. Individual traits in a population have genes that mutate and thereby causing genetic variation. Enough genetic mutations in a population make individuals unique, except twins. Genetic mutations may be good or bad. Mutations occur with the intent of survival for the organism. Good mutations tend to stay in the trait of an individual. On the other hand, bad mutations are fixed by alterations in the specific genes. Proteins that are made up of rRNA are important for evolutionary biologists. All living organisms contain proteins. These proteins are key in understanding relationships and lineages between different organisms and species. There is still much to learn about evolution. There will always be a thin line between science and religion. Evolution is one example of this.