The Berkeley Evolution Site
The Berkeley site offers resources that can assist students and teachers to understand and teach about evolution. The resources are organized into various learning paths that can be used in a variety of ways like "What does T. rex look like?"
Charles Darwin's theory of natural selection explains that over time creatures that are more adaptable to changing environments thrive, and those that are not extinct. This process of evolution is the basis of science.
What is Evolution?
The term "evolution" can have many nonscientific meanings, including "progress" or "descent with modification." It is an academic term that is used to describe the process of change of characteristics over time in organisms or species. In biological terms this change is caused by natural selection and genetic drift.
Evolution is a fundamental tenet in the field of biology today. It is an established theory that has stood the tests of time and thousands of scientific studies. It does not address spiritual beliefs or God's presence like other theories of science, such as the Copernican or germ theory of diseases.
Early evolutionists, such as Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather), believed that certain physical traits were predetermined to change, in a step-like manner, as time passes. They referred to this as the "Ladder of Nature" or the scala naturae. Charles Lyell first used this term in 1833 in his Principles of Geology.
In the early 1800s, Darwin formulated his theory of evolution and published it in his book On the Origin of Species. It claims that different species of organisms share the same ancestry, which can be proven through fossils and other evidence. This is the modern view on evolution, which is supported in many scientific fields that include molecular biology.
While scientists don't know exactly how organisms developed but they are certain that the evolution of life on earth is the result of natural selection and genetic drift. People with advantages are more likely than others to live and reproduce. They transmit their genes to the next generation. Over time the gene pool slowly changes and evolves into new species.
Some scientists use the term"evolution" in reference to large-scale changes, such the development of a species from an ancestral one. Certain scientists, including population geneticists, define evolution in a broad sense, using the term "net change" to refer to the change in the frequency of alleles across generations. Both definitions are correct and acceptable, but certain scientists argue that allele frequency definitions do not include important aspects of evolutionary process.
Origins of Life
The most important step in evolution is the emergence of life. This occurs when living systems begin to develop at the micro level - within cells, for instance.
The origins of life are an important issue in many disciplines that include biology and chemistry. The question of how living organisms began is a major topic in science because it is an important challenge to the theory of evolution. It is often called "the mystery of life" or "abiogenesis."
Traditionally, the idea that life can arise from nonliving things is known as spontaneous generation or "spontaneous evolution." This was a common belief before Louis Pasteur's research showed that it was impossible for the development of life to be a result of an entirely natural process.
Many scientists still believe that it is possible to transition from nonliving substances to living. The conditions needed for the creation of life are difficult to reproduce in a lab. Researchers interested in the origins and evolution of life are also eager to understand the physical properties of the early Earth as well as other planets.
In addition, the development of life is an intricate sequence of chemical reactions that cannot be predicted from the fundamental physical laws on their own. These include the reading of long, information-rich molecules (DNA or RNA) into proteins that perform some function, and the replication of these intricate molecules to generate new DNA or sequences of RNA. These chemical reactions are often compared with the chicken-and-egg dilemma of how life came into existence in the first place. The development of DNA/RNA as well as protein-based cell machinery is essential for the onset of life, however, without the development of life, the chemical reaction that is the basis for it isn't working.
Abiogenesis research requires collaboration between scientists from different fields. This includes prebiotic chemists, planet scientists, astrobiologists, geologists and geophysicists.
Evolutionary Changes
The term "evolution" is used to describe the general changes in genetic traits over time. These changes can be the result of the adaptation to environmental pressures as discussed in Darwinism.
This latter mechanism increases the number of genes that offer an advantage for survival in an animal, resulting in an overall change in the appearance of the group. The specific mechanisms behind these evolutionary changes include mutation, reshuffling of genes during sexual reproduction, and also gene flow between populations.
Natural selection is the process that allows beneficial mutations to become more common. All organisms undergo mutations and reshuffles of their genes. As noted above, individuals with the beneficial trait have a higher reproductive rate than those that do not. This difference in the number of offspring born over many generations can cause a gradual change in the average number of beneficial characteristics in a group.
This can be seen in the evolution of various beak designs on finches that are found in the Galapagos Islands. They have developed these beaks in order that they can access food more easily in their new environment. These changes in form and shape can aid in the creation of new organisms.
The majority of changes are caused by a single mutation, although sometimes multiple occur simultaneously. Most of these changes are neutral or even harmful to the organism but a small percentage can have a positive impact on the longevity and reproduction of the species, thus increasing the frequency of these changes in the population over time. This is the way of natural selection, and it is able to, over time, produce the cumulative changes that eventually result in an entirely new species.
Some people confuse the notion of evolution with the idea that the traits inherited from parents can be altered through conscious choice or by use and abuse, which is known as soft inheritance. This is a misinterpretation of the nature of evolution and of the actual biological processes that cause it. A more accurate description of evolution is that it is a two-step process that involves the distinct, and often competing, forces of natural selection and mutation.
Origins of Humans
Humans of today (Homo Sapiens) evolved from primates, which is a group of mammal species that includes chimpanzees as well as gorillas. The earliest human fossils indicate that our ancestors were bipeds - walkers with two legs. Genetic and biological similarities suggest that we share a close relationship with chimpanzees. In fact, our closest relatives are chimpanzees of the Pan genus. This includes pygmy as well as bonobos. The last common human ancestor and chimpanzees was between 8 and 6 million years ago.
Humans have developed a range of characteristics over time including bipedalism, the use of fire, and the development of advanced tools. However, it is only in the past 100,000 years or so that the majority of the important traits that distinguish us from other species have emerged. 에볼루션카지노사이트 include a large, complex brain, the ability of humans to create and use tools, and cultural diversity.
The process of evolution occurs when genetic changes allow individuals in a group to better adapt to their environment. This adaptation is driven by natural selection, a process that determines certain traits are more desirable than other traits. The better adjusted are more likely to pass their genes on to the next generation. This is how all species evolve and forms the basis of the theory of evolution.
Scientists refer to it as the "law of Natural Selection." The law says that species that have a common ancestor, tend to develop similar traits over time. This is because the traits make it easier for them to survive and reproduce in their natural environment.
Every living thing has the DNA molecule, which contains the information necessary to direct their growth. The DNA structure is composed of base pairs arranged in a spiral around sugar and phosphate molecules. The sequence of bases found in each strand determines the phenotype - the characteristic appearance and behavior of a person. Variations in a population can be caused by mutations and reshufflings of genetic material (known collectively as alleles).
Fossils from the early human species Homo erectus, as well as Homo neanderthalensis have been discovered in Africa, Asia and Europe. While there are some differences between them, these fossils all support the hypothesis that modern humans first came into existence in Africa. Evidence from fossils and genetics suggest that early humans migrated from Africa into Asia and then Europe.