The Berkeley Evolution Site
The Berkeley site contains resources that can help students and teachers understand and teach evolution. The resources are organized into different learning paths for example "What does T. rex look like?"
Charles Darwin's theory on natural selection explains how creatures that are better equipped to adapt to changes in their environments survive longer and those that don't disappear. Science is about this process of evolution.
What is Evolution?
The term "evolution" could be used to refer to a variety of nonscientific meanings. For instance, it can mean "progress" and "descent with modifications." It is a scientific term that refers to the process of changing characteristics in a species or species. In terms of biology this change is based on natural selection and genetic drift.
Evolution is an important principle in the field of biology today. It is an established theory that has stood the test of time and thousands of scientific experiments. Evolution does not deal with God's presence or spiritual beliefs, unlike many other scientific theories 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-wise way, 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 revealed his theory of evolution in his book On the Origin of Species published in the early 1800s. It claims that different species of organisms share a common ancestry, which can be proven through fossils and other lines of evidence. This is the current view of evolution, and is supported by numerous lines of research in science which includes molecular genetics.
Scientists do not know the evolution of organisms but they are sure that natural selection and genetic drift is the reason for the evolution of life. Individuals with advantageous characteristics are more likely than others to survive and reproduce. These individuals pass on their genes to the next generation. Over time the gene pool slowly changes and evolves into new species.
Some scientists also use the term evolution to refer to large-scale evolutionary changes like the creation of an entirely new species from an ancestral species. Others, like population geneticists, define it more broadly by referring to an overall change in allele frequencies over generations. Both definitions are acceptable and accurate however, some scientists claim that the definition of allele frequency is lacking important features of the evolutionary process.
Origins of Life
The emergence of life is an essential step in evolution. This happens when living systems begin to develop at the micro level, within cells, for instance.
The origins of life is a topic in many disciplines, including biology, chemistry, and geology. The nature of life is a topic of interest in science, as it challenges the theory of evolution. It is sometimes referred to as "the mystery" of life or "abiogenesis."
The idea that life could be born from non-living things was called "spontaneous generation" or "spontaneous evolutionary". This was a common belief prior to Louis Pasteur's experiments proved that the emergence of living organisms was not possible through an organic process.
Many scientists still think it is possible to move from nonliving substances to living ones. However, the conditions that are required are extremely difficult to replicate in labs. Researchers studying the nature of life are also interested in understanding the physical properties of the early Earth and other planets.
The development of life is dependent on a number of complex chemical reactions, which cannot be predicted by simple physical laws. These include the reading and the replication of complex molecules, like DNA or RNA, to produce proteins that perform a particular function. These chemical reactions are often compared to the chicken-and-egg problem of how life first appeared with the appearance of DNA/RNA and protein-based cell machinery is crucial for the beginning of life, however, without the development of life the chemical process that allows it does not appear to work.
Abiogenesis research requires collaboration among scientists from various disciplines. This includes prebiotic scientists, astrobiologists, and planetary scientists.
Evolutionary Changes
The term "evolution" today is used to describe gradual changes in genetic traits over time. These changes may result from adaptation to environmental pressures, as discussed in the entry on Darwinism (see the entry on Charles Darwin for background), or from natural selection.
The latter is a mechanism that increases the frequency of those genes which confer an advantage in survival over others which results in an ongoing change in the overall appearance of a particular population. The specific mechanisms that cause these changes in evolutionary process include mutation or reshuffling genes during sexual reproduction, as well as gene flow between populations.
While reshuffling and mutation of genes occur in all living things and the process by which beneficial mutations are more frequent is known as natural selection. As noted above, individuals with the beneficial trait have a higher reproduction rate than those who don't. This differential in the number of offspring produced over a number of generations could result in a gradual change in the average number advantageous traits within the group.
This is evident in the evolution of various beak shapes for finches from the Galapagos Islands. They have created these beaks to ensure they can get food more easily in their new environment. These changes in the form and shape of living organisms may also help create new species.
The majority of changes are caused by a single mutation, however sometimes multiple occur at the same time. Most of these changes may be neutral or even harmful however, a small percentage could have a positive impact on survival and reproduce and increase their frequency as time passes. This is the process of natural selection, and it is able to be a time-consuming process that produces the accumulating changes that eventually lead to 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 use and abuse, which is known as soft inheritance. This is a misunderstanding of the biological processes that lead up to evolution. It is more accurate to say that the process of evolution is a two-step independent process, which involves the forces of natural selection as well as mutation.
에볼루션 게이밍 of Humans
Humans today (Homo sapiens) evolved from primates - a group of mammals that includes chimpanzees, gorillas, and bonobos. Our ancestral ancestors were walking on two legs, as shown by the first fossils. Genetic and biological similarities suggest that we are closely related to chimpanzees. In fact we are the most closely connected to chimpanzees belonging to the Pan Genus which includes bonobos and pygmy-chimpanzees. The last common human ancestor as well as chimpanzees was between 8 and 6 million years ago.
Humans have evolved a wide range of traits over time including bipedalism, the use of fire and advanced tools. It's only within the last 100,000 years that we have developed the majority of our essential traits. These include a large brain that is sophisticated, the ability of humans to construct and use tools, and cultural variety.
에볼루션 무료체험 of evolution occurs when genetic changes allow members of a population to better adapt to their environment. This adaptation is driven by natural selection, which is a process by which certain traits are preferred over others. The more adapted are more likely to pass their genes on to the next generation. This is how all species evolve and forms the foundation of the theory of evolution.
Scientists refer to this as the "law of natural selection." The law states species that share an ancestor will tend to develop similar traits over time. It is because these traits help them to live and reproduce in their environment.
All organisms have a DNA molecule, which contains the information needed to direct their growth and development. The structure of DNA is composed of base pairs 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. Different mutations and reshufflings of the genetic material (known as alleles) during reproduction causes variation in a population.
Fossils from the first human species, Homo erectus, as well as Homo neanderthalensis have been discovered in Africa, Asia and Europe. Although there are some differences the fossils all support the notion that modern humans first came into existence in Africa. The evidence from fossils and genetics suggests that the first humans left Africa and migrated to Asia and Europe.