The Berkeley Evolution Site
Teachers and students who browse the Berkeley site will find a wealth of resources to help them understand and teach evolution. The resources are organized into different learning paths for example "What does T. rex look like?"
Charles Darwin's theory of natural selection explains how creatures who are better equipped to adapt to changes in their environments survive longer and those that do not become extinct. This process of biological evolution is what science is all about.
What is Evolution?
The term "evolution" can have many nonscientific meanings. For instance "progress" or "descent with modification." Scientifically, it refers to a process of change in the characteristics of living things (or species) over time. The reason for this change is biological terms on natural drift and selection.
Evolution is the central tenet of modern biology. 에볼루션 블랙잭 is an accepted theory that has withstood the test of time and a multitude of scientific experiments. It does not address the existence of God or religious beliefs, unlike many other scientific theories 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 traits were predetermined to change, in a step-like way, over time. This was called the "Ladder of Nature" or scala Naturae. 에볼루션코리아 used the term to describe this idea in his Principles of Geology, first published in 1833.
Darwin published his theory of evolution in his book On the Origin of Species which was written in the early 1800s. It claims that different species of organisms share an ancestry that can be proven through fossils and other lines of evidence. This is the current view on evolution, which is supported by a variety of disciplines which include molecular biology.
Scientists don't know how organisms evolved however they are certain that natural selection and genetic drift are the primary reason for the development of life. People with advantages are more likely to survive and reproduce. They pass on their genes on to the next generation. In time this leads to an accumulation of changes in the gene pool, which eventually lead to new species and forms.
Certain scientists use the term evolution in reference to large-scale changes, such the development of one species from an ancestral one. Some scientists, like population geneticists, define the term "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 correct and acceptable, but certain scientists argue that allele frequency definitions do not include important aspects of evolution.
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 a micro-level - within individual cells, for instance.
The origins of life is an issue in a variety of disciplines that include geology, chemistry, biology and chemistry. The question of how living things started has a special place in science since it poses an enormous challenge to the theory of evolution. It is sometimes referred to "the mystery" of life or "abiogenesis."
Traditionally, the belief that life can arise from nonliving objects is known as spontaneous generation, or "spontaneous evolution." This was a popular belief prior to Louis Pasteur's research showed that it was impossible for the creation of life to occur by the natural process.
Many scientists still believe that it is possible to transition from nonliving substances to life. However, the conditions that are required are extremely difficult to replicate in a laboratory. This is why scientists studying the nature of life are also keen to understand the physical properties of early Earth and other planets.
In addition, the development of life is a sequence of very complex chemical reactions that cannot be predicted from the fundamental physical laws alone. These include the reading and re-reading of complex molecules, such as DNA or RNA, to create proteins that perform a specific function. These chemical reactions are often compared with the chicken-and-egg issue of how life began with the emergence of DNA/RNA and protein-based cell machinery is crucial for the onset of life, but without the appearance of life, the chemical reaction that is the basis for it is not working.
Research in the field of abiogenesis requires collaboration between scientists from many different disciplines. This includes prebiotic scientists, astrobiologists, and planet scientists.
Evolutionary Changes
Today, the word evolution is used to describe gradual changes in genetic traits over time. These changes can be the result of adapting to environmental pressures, as described in Darwinism.
This is a process that increases the frequency of genes that confer a survival advantage over others and causes a gradual change in the overall appearance of a population. These evolutionary changes are caused by mutations, reshuffling of genes during sexual reproduction and gene flow.
While reshuffling and mutation of genes are common in all organisms The process through which beneficial mutations become more common is referred to as natural selection. As previously mentioned, those who have the advantageous trait have a higher reproductive rate than those who don't. Over many generations, this variation in the numbers of offspring born could result in gradual changes in the average amount of desirable 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 allow them to more easily access food in their new home. These changes in shape and form can also aid in the creation of new species.
The majority of changes are caused by one mutation, although sometimes multiple occur at once. Most of these changes can be harmful or neutral, but a small number may have a positive effect on survival and reproduction, increasing their frequency over time. This is the process of natural selection and it can eventually result in the gradual changes that eventually lead to a new species.
Some people confuse the notion of evolution with the idea that the traits inherited from parents can be changed through conscious choice or use and abuse, a notion called soft inheritance. This is a misinterpretation of the nature of evolution and of the actual biological processes that trigger it. It is more accurate 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 group of mammals that includes chimpanzees, gorillas, and bonobos. Our ancestral ancestors were walking on two legs, as demonstrated by the earliest fossils. Genetic and biological similarities suggest that we are closely related to Chimpanzees. In fact we are the closest connected to chimpanzees belonging to the Pan genus that includes pygmy and pygmy chimpanzees and bonobos. The last common ancestor shared between modern humans and chimpanzees dated between 8 and 6 million years old.
Over time, humans have developed a variety of traits, including bipedalism and the use of fire. They also created advanced tools. However, it is only in the last 100,000 years or so that the majority of the characteristics that differentiate us from other species have been developed. These include a large brain that is complex, the ability of humans to construct and use tools, as well as cultural variety.
Evolution occurs when genetic changes enable members of a group to better adapt to their environment. This adaptation is triggered by natural selection, a process whereby certain traits are preferred over others. The ones with the best adaptations are more likely to pass their genes to the next generation. This is how all species evolve, and it is the basis of the theory of evolution.
Scientists refer to it as the "law of Natural Selection." The law states that species which have a common ancestor, tend to develop similar characteristics over time. It is because these traits allow them to live and reproduce in their environment.
Every living thing has DNA molecules, which provides the information necessary to control their growth and development. The DNA structure is composed of base pair which are arranged in a spiral, around sugar and phosphate molecules. The sequence of bases 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 and Homo neanderthalensis have been found in Africa, Asia and Europe. These fossils, despite variations in their appearance, all support the hypothesis that modern humans' ancestors originated in Africa. 에볼루션코리아 fossil and genetic evidence suggests that the first humans left Africa and moved to Asia and Europe.