The Berkeley Evolution Site
Teachers and students who browse the Berkeley site will find resources to assist them in understanding and teaching evolution. The materials are arranged into different learning paths such as "What did T. rex taste like?"
Charles Darwin's theory on natural selection describes how species who are better equipped to adapt to changes in their environments over time, and those that don't become extinct. Science is concerned with this process of evolution.
What is Evolution?
The word evolution can be used to refer to a variety of nonscientific meanings. For example it could mean "progress" and "descent with modifications." It is a scientific term that is used to describe the process of change of traits over time in organisms or species. This change is based in biological terms on natural selection and drift.
Evolution is one of the fundamental tenets of modern biology. It is a well-supported theory that has withstood the tests of time and thousands of scientific tests. Unlike many other scientific theories such as the Copernican theory or the germ theory of disease, evolution does not address questions of religious belief or the existence of God.
Early evolutionists such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical traits were predetermined to change in a gradual manner over time. They called this the "Ladder of Nature" or 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 have the same ancestry, which can be determined through fossils and other evidence. This is the modern view of evolution that is supported by many lines of scientific research, including molecular genetics.
Scientists aren't sure how organisms have evolved however they are certain that natural selection and genetic drift is the primary reason for the development of life. People with traits that are advantageous are more likely to live and reproduce, and these individuals pass their genes on to the next generation. As time passes, the gene pool gradually changes and evolves into new species.
Certain scientists also use the term"evolution" to describe large-scale evolutionary changes like the creation of an entirely new species from an ancestral species. Certain scientists, including population geneticists, define the term "evolution" in a more broad sense by talking about the net change in the frequency of alleles across generations. Both definitions are valid and acceptable, however certain scientists argue that allele frequency definitions miss important aspects of the evolution.
Origins of Life
The emergence of life is an essential stage in evolution. This happens when living systems begin to develop at the micro level - within cells, for example.
The origins of life is a topic in many disciplines, including geology, chemistry, biology and chemistry. The origin of life is a topic of interest in science, as it challenges the theory of evolution. It is often referred to as "the mystery of life," or "abiogenesis."
The idea that life could emerge from non-living objects was referred to as "spontaneous generation" or "spontaneous evolutionary". This was a common belief prior to Louis Pasteur's experiments proved that the development of living organisms was not possible by an organic process.
Many scientists believe it is possible to go from nonliving substances to living ones. However, the conditions needed are extremely difficult to reproduce in the laboratory. This is why researchers investigating the nature of life are also interested in determining the physical properties of early Earth and other planets.
In addition, the development of life is a sequence of very complex chemical reactions that can't be predicted based on basic physical laws on their own. These include the reading and replication of complex molecules, such as DNA or RNA, in order to make proteins that perform a particular function. These chemical reactions can be compared to the chicken-and-egg issue: the emergence and development of DNA/RNA, the protein-based cell machinery, is necessary to begin the process of becoming a living organism. But without life, the chemistry that is required to enable it does appear to work.
Research in the field of abiogenesis requires cooperation among scientists from a variety of disciplines. This includes prebiotic chemists, the astrobiologists, the planet scientists, geologists and geophysicists.
Evolutionary Changes
The term "evolution" is commonly used today to describe the accumulated changes in the genetic traits of populations over time. These changes may result from the response to environmental pressures as explained in the article on Darwinism (see the entry on Charles Darwin for background), or from natural selection.
This latter mechanism increases the frequency of genes that offer the advantage of survival for the species, leading to an overall change in the appearance of a group. The specific mechanisms that cause these evolutionary changes include mutation or reshuffling genes during sexual reproduction, and also gene flow between populations.
While reshuffling and mutations of genes are common in all living things The process through which beneficial mutations are more frequent is referred to as natural selection. This occurs because, as mentioned above those who have the beneficial trait tend to have a higher fertility rate than those who do not have it. This difference in the number of offspring that are produced over a number of generations could result in a gradual shift in the number of advantageous traits in a group.
An excellent example is the growing the size of the beaks on different species of finches found on the Galapagos Islands, which have developed beaks with different shapes that allow them to easily access food in their new habitat. These changes in shape and form can aid in the creation of new organisms.
The majority of changes are caused by a single mutation, although sometimes multiple occur simultaneously. The majority of these changes are neither harmful nor even harmful to the organism, however, a small proportion of them can have an advantageous impact on the survival of the organism and its reproduction, thereby increasing their frequency in the population over time. This is the way of natural selection and it could eventually result in the accumulating changes that eventually result in the creation of a new species.
Some people confuse the idea of evolution with the notion that traits inherited can be altered by conscious choice or by use and abuse, a concept known as soft inheritance. This is a misunderstanding of the biological processes that lead up to evolution. A more accurate description is that evolution involves a two-step process, involving the independent and often antagonistic forces of natural selection and mutation.
Origins of Humans
Modern humans (Homo sapiens) evolved from primates, a group of mammals that includes chimpanzees and gorillas and bonobos. Our ancestors walked on two legs, as shown by the earliest fossils. Genetic and biological similarities suggest that we are closely related to chimpanzees. In actual fact our closest relatives are the chimpanzees belonging to the Pan genus. This includes pygmy, as well as bonobos. The last common ancestor of modern humans and chimpanzees dated 8 to 6 million years old.
Over time, humans have developed a variety of characteristics, including bipedalism and the use fire. They also created advanced tools. It is only within the last 100,000 years that we've developed the majority of our essential characteristics. These include language, a large brain, the capacity to construct and use sophisticated tools, and a cultural diversity.
The process of evolution is when genetic changes allow members of an organization to better adapt to their environment. This adaptation is driven by natural selection, which is a process by which certain traits are favored over other traits. The better adapted are more likely to pass their genes on to the next generation. This is how all species evolve and is the basis for the theory of evolution.
Scientists refer to it as the "law of Natural Selection." The law says that species that have a common ancestor are more likely to develop similar traits over time. This is because these traits help them to live and reproduce in their environment.
Every organism has a DNA molecule, which contains the information needed to guide their growth and development. 에볼루션 코리아 of DNA is made of base pairs which are arranged in a spiral, around sugar and phosphate molecules. The sequence of bases within each strand determines the phenotype which is the person's distinctive appearance and behavior. 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, and Homo neanderthalensis have been found in Africa, Asia and Europe. Despite some differences they all support the notion that modern humans first appeared in Africa. Genetic and fossil evidence also suggest that early humans moved out of Africa into Asia and then Europe.