The Berkeley Evolution Site
The Berkeley site contains resources that can help students and educators understand and teach evolution. The resources are organized into optional learning paths for example "What does T. rex look like?"
Charles Darwin's theory of natural selection explains how over time creatures that are better able to adapt biologically to changing environments thrive, and those that are not extinct. Science is all about this process of biological evolution.
What is Evolution?
The term "evolution" has a variety of nonscientific meanings. For instance "progress" or "descent with modification." It is an academic term that refers to the process of change of traits over time in organisms or species. In terms of biology the change is caused by natural selection and genetic drift.
Evolution is the central tenet of modern biology. It is a concept that has been proven by a myriad of scientific tests. 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, including Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather), believed that certain physical characteristics were predetermined to change, in a gradual manner, over time. They referred to this as the "Ladder of Nature" or scala naturae. Charles Lyell first used this term in 1833 in his Principles of Geology.
Darwin published his theory of evolution in his book On the Origin of Species, written in the early 1800s. It states that all species of organisms share an ancestry that can be determined through fossils and other lines of evidence. This is the modern view on evolution, which is supported in a wide range of disciplines, including molecular biology.
Scientists don't know how organisms have evolved but they are sure that natural selection and genetic drift is the primary reason for the development of life. People with advantages are more likely to survive and reproduce. These individuals then pass their genes on to the next generation. Over 에볼루션 바카라 무료체험 and evolves into new species.
Some scientists use the term"evolution" to refer to large-scale change, such as the evolution 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 variation in the frequency of alleles over generations. Both definitions are acceptable and precise however, some scientists claim that the allele-frequency definition omits essential aspects of the evolution process.
Origins of Life
One of the most crucial steps in evolution is the appearance of life. This occurs when living systems begin to evolve at the micro level, within individual cells, for instance.
The origins of life are an important subject in a variety of areas, including biology and chemical. The question of how living things started is of particular importance in science because it is an enormous challenge to the theory of evolution. It is often described as "the mystery of life" or "abiogenesis."
Traditionally, the belief that life can emerge from nonliving things is known as spontaneous generation or "spontaneous evolution." This was a popular view before Louis Pasteur's experiments proved that it was impossible for the emergence of life to happen through an entirely natural process.
Many scientists still think it is possible to go from living to nonliving substances. The conditions needed for the creation of life are difficult to replicate in a laboratory. Researchers interested in the evolution and origins of life are also eager to know the physical properties of the early Earth as well as other planets.
The growth of life is dependent on a variety of complex chemical reactions, which are not predicted by the basic physical laws. These include the reading and replication of complex molecules, like DNA or RNA, to create proteins that serve a specific function. These chemical reactions are often compared with the chicken-and-egg issue of how life first appeared: The development of DNA/RNA as well as protein-based cell machinery is crucial to the birth of life, however, without the development of life, the chemical process that allows it does not appear to work.
Research in the field of abiogenesis requires collaboration among scientists from a variety of disciplines. This includes prebiotic chemists, planet scientists, astrobiologists, geologists and geophysicists.
Evolutionary Changes
The term "evolution" is typically used to describe the accumulated changes in the genetic traits of populations over time. These changes may be the result of the adaptation to environmental pressures as described in Darwinism.
This is a process that increases the frequency of those genes in a species that offer an advantage in survival over other species and causes gradual changes in the appearance of a group. The specific mechanisms that cause these evolutionary changes are mutation and reshuffling of genes in sexual reproduction, and gene flow between populations.
While reshuffling and mutation of genes occur in all living things The process through which beneficial mutations become more common is called natural selection. This is because, as mentioned above, those individuals with the advantageous trait are likely to have a higher reproduction rate than those who do not have it. Over the course of many generations, this difference in the number of offspring born can result in a gradual shift in the number of advantageous characteristics in a particular population.
An excellent example is the growing beak size on various species of finches found on the Galapagos Islands, which have evolved different shaped beaks to enable them to more easily access food in their new environment. These changes in the shape and appearance of living organisms may also aid in the creation of new species.
The majority of changes are caused by a single mutation, but sometimes several occur simultaneously. Most of these changes are neither harmful nor even harmful to the organism however a small portion of them could be beneficial to the survival of the organism and its reproduction, thereby increasing the frequency of these changes 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 which is the notion that inherited traits can be changed by deliberate choice or misuse. This is a misunderstanding of the nature of evolution and of the actual biological processes that lead to it. It is more precise to say that evolution is a two-step, separate process that 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 chimpanzees as well as gorillas. Our predecessors walked on two legs, as shown by the earliest fossils. Biological and genetic similarities indicate that we have an intimate relationship with Chimpanzees. In fact we are the most closely with chimpanzees in the Pan Genus that includes pygmy and bonobos and pygmy-chimpanzees. The last common human ancestor and chimpanzees was between 8 and 6 million years ago.
As time has passed humans have developed a number of characteristics, such as bipedalism as well as the use of fire. They also invented advanced tools. It's only within the last 100,000 years that we have developed the majority of our important traits. They include a huge, complex brain and the capacity of humans to create and use tools, as well as the diversity of our culture.
The process of evolution is when genetic changes allow members of a group to better adapt to their environment. This adaptation is triggered by natural selection, which is a process by which certain traits are preferred over others. The better adapted are more likely to pass their genes on to the next generation. This is how all species evolve, and the basis of the theory of evolution.
Scientists call it the "law of natural selection." The law states that species which share a common ancestor tend to develop similar traits over time. It is because these traits allow them to live and reproduce in their environment.
Every organism has a DNA molecule that contains the information necessary to direct their growth. The DNA molecule is composed of base pairs that are arranged in a spiral around phosphate molecules and sugar molecules. The sequence of bases in each strand determines the phenotype - the distinctive appearance and behavior of a person. Variations in a population are caused by reshufflings and mutations of genetic material (known collectively as alleles).
Fossils of the first human species, Homo erectus and Homo neanderthalensis were discovered in Africa, Asia, and Europe. While there are some differences between them the fossils all support the notion that modern humans first came into existence in Africa. The evidence from fossils and genetics suggests that early humans left Africa and moved to Asia and Europe.