The Berkeley Evolution Site
Teachers and students who visit the Berkeley site will find a wealth of resources to assist them in understanding and teaching evolution. The materials are organized into a variety of learning paths like "What did T. rex taste like?"
Charles Darwin's theory of natural selection describes how species who are better equipped to adapt biologically to a changing environments over time, and those that don't become extinct. This process of evolution is the basis of science.
What is Evolution?
The term "evolution" can be used to refer to a variety of nonscientific meanings. For example it could mean "progress" and "descent with modifications." Scientifically it is a term used to describe a changes in the traits of organisms (or species) over time. This change is based in biological terms on natural drift and selection.
Evolution is a fundamental principle in the field of biology today. It is an accepted theory that has stood the test of time and a multitude of scientific experiments. Evolution does not deal with spiritual beliefs or God's presence in the same way as other scientific theories such as the Copernican or germ theory of diseases.
Early evolutionists like Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical traits were predetermined to change in a step-like fashion over time. This was known as 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 share an ancestry that can be proven through fossils and other evidence. This is the current perspective on evolution, which is supported in many scientific fields, including molecular biology.
While scientists do not know exactly how organisms developed, they are confident that the evolution of life on earth is a result of natural selection and genetic drift. Individuals with advantageous characteristics are more likely to survive and reproduce. These individuals pass on their genes on to the next generation. Over time the gene pool slowly changes and develops into new species.
Some scientists employ the term"evolution" to refer to large-scale change, such as the development of a species from an ancestral one. Certain scientists, including population geneticists define evolution in a more broad sense by referring to the net change in allele frequency over generations. Both definitions are correct and acceptable, but some scientists argue that allele-frequency definitions omit important features of evolution.
Origins of Life
The emergence of life is a key step in evolution. The emergence of life occurs when living systems begin to develop at a micro level, such as within cells.
The origin of life is an important subject in a variety of disciplines, including biology and chemical. The question of how living things got their start is of particular importance in science because it is an enormous challenge to the theory of evolution. It is sometimes referred to as "the mystery" of life or "abiogenesis."
The idea that life could arise from non-living things was called "spontaneous generation" or "spontaneous evolutionary". It was a popular belief prior to Louis Pasteur's experiments proved that the emergence of living organisms was not achievable through the natural process.
Many scientists believe it is possible to move from living to nonliving substances. However, the conditions needed are extremely difficult to reproduce in a laboratory. This is why scientists investigating the beginnings of life are also interested in understanding the physical properties of early Earth and other planets.
The development of life is dependent on a variety of complex chemical reactions which are not predicted by simple physical laws. 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 are often compared with the chicken-and-egg dilemma of how life began: The development of DNA/RNA as well as protein-based cell machinery is crucial for the beginning of life, however, without the development of life, the chemical reaction that is the basis for it does not appear to work.
Research in the area of abiogenesis requires collaboration among scientists from various disciplines. This includes prebiotic scientists, astrobiologists and planetary scientists.
Evolutionary Changes
The term "evolution" is typically used to describe the accumulated changes in genetic characteristics of populations over time. These changes can be the result of the adaptation to environmental pressures as explained in Darwinism.
This is a process that increases the frequency of those genes that offer a survival advantage over others, resulting in gradual changes in the appearance of a particular population. These changes in evolutionary patterns are caused by mutations, reshuffling of genes during sexual reproduction, and gene flow.
Natural selection is the process that allows beneficial mutations to become more common. All organisms undergo changes and reshuffles in their genes. This is because, as mentioned above those with the advantageous trait are likely to have a higher fertility rate than those without it. This variation in the number of offspring produced over many generations can result in a gradual change in the number of advantageous traits in the group.
An excellent example is the growth of the size of the beaks on different species of finches found on the Galapagos Islands, which have developed beaks with different shapes to enable them to more easily access food in their new environment. These changes in form and shape can also help create new organisms.
The majority of changes are caused by a single mutation, however sometimes multiple occur at once. The majority of these changes are neutral or even detrimental to the organism, however, a small proportion of them can have a positive impact on survival and reproduction, thus increasing their frequency in the population over time. Natural selection is a process that can produce the accumulating change over time that leads to the creation of a new species.
Some people think that evolution is a form of soft inheritance that is the belief that traits inherited from parents can be changed by conscious choice or abuse. This is a misinterpretation of the nature of evolution and of the actual biological processes that cause it. It is more accurate to say that evolution is a two-step independent process, which involves the forces of natural selection and mutation.
Origins of Humans
Modern humans (Homo Sapiens) evolved from primates, a species of mammal species which includes gorillas and chimpanzees. The earliest human fossils indicate that our ancestors were bipeds. 에볼루션코리아 were walkers with two legs. Genetic and biological similarities suggest that we have a close relationship with Chimpanzees. In actual fact our closest relatives are the chimpanzees of the Pan genus. This includes pygmy and bonobos. The last common ancestor of modern humans and chimpanzees was between 8 and 6 million years ago.
Over time humans have developed a variety of characteristics, including bipedalism as well as the use of fire. They also created advanced tools. It is only within the last 100,000 years that we have developed the majority of our key characteristics. These include a large, complex brain human ability to construct and use tools, and the diversity of our culture.
The process of evolution is when genetic changes allow members of an organization to better adapt to their environment. This adaptation is triggered by natural selection, a process whereby certain traits are preferred over other traits. The more adjusted are more likely to pass on their genes to the next generation. This is how all species evolve, and the basis of the theory of evolution.
Scientists refer to this as the "law of natural selection." The law states that species that have an ancestor in common will tend to develop similar characteristics as time passes. This is because these traits make it easier for them to live and reproduce in their natural environment.
All organisms have a DNA molecule that contains the information needed to control their growth and development. The DNA structure is composed of base pair arranged in a spiral around phosphate and sugar molecules. The sequence of bases within each string determines the phenotype or the appearance and behavior of an individual. Different changes and reshuffling of genetic material (known as alleles) during sexual reproduction can cause variations in a population.
Fossils of the first human species, Homo erectus and Homo neanderthalensis have been discovered in Africa, Asia, and Europe. These fossils, despite some variations in their appearance, all support the hypothesis that modern humans' ancestors originated in Africa. Genetic and fossil evidence also suggest that early humans moved from Africa into Asia and then Europe.