The Berkeley Evolution Site
Students and teachers who explore the Berkeley site will find a wealth of resources to assist them in understanding and teaching evolution. The materials are arranged in different learning paths for example "What does T. rex look like?"
Charles Darwin's theory on natural selection describes how species that are better equipped to adapt biologically to changing environment survive over time and those who do not disappear. Science is about the process of biological evolution.
What is Evolution?
에볼루션 사이트 " can have many nonscientific meanings, including "progress" or "descent with modification." It is scientifically based and is used to describe the process of change of traits over time in organisms or species. The reason for this change is biological terms on natural selection and drift.
Evolution is a fundamental principle in the field of biology today. It is an established theory that has withstood the test of time and thousands of scientific tests. In contrast to other theories in science, such as the Copernican theory or the germ theory of disease, the evolution theory does not address issues of religious belief or God's existence.
Early evolutionists like Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical characteristics were predetermined to change in a stepped-like manner over time. This was called the "Ladder of Nature" or scala naturae. Charles Lyell used the term to describe this concept in his Principles of Geology, first published in 1833.
Darwin revealed his theory of evolution in his book On the Origin of Species which was written in the early 1800s. It asserts that different species of organisms share a common ancestry, which can be proven through fossils and other evidence. This is the current perspective of evolution, which is supported in a wide range of disciplines, including molecular biology.
While scientists don't know exactly how organisms evolved however they are sure that the evolution of life on earth is the result of natural selection and genetic drift. Individuals with advantageous characteristics are more likely to live and reproduce. They pass on their genes on to the next generation. As time passes this leads to a gradual accumulation of changes in the gene pool, which eventually lead to new species and forms.
Some scientists use the term"evolution" in reference to large-scale changes, like the development of an animal from an ancestral one. Some scientists, like population geneticists, define evolution in a broad sense, using the term "net change" to refer to the change in the frequency of alleles across generations. Both definitions are correct and acceptable, but some scientists believe that allele-frequency definitions omit important features of evolution.
Origins of Life
The emergence of life is an essential step in the process of evolution. This happens when living systems begin to evolve at the micro level, within individual cells, for example.
The origins of life are an important topic in many areas, including biology and chemistry. The origin of life is a topic of great interest in science because it challenges the theory of evolution. It is sometimes referred to "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". It was a common belief prior to Louis Pasteur's experiments proved that the development of living organisms was not possible by the natural process.
Many scientists still believe it is possible to go from nonliving substances to living. However, the conditions that are required are extremely difficult to replicate in labs. This is why scientists studying the origins of life are also interested in determining the physical properties of early Earth and other planets.
Furthermore, the growth of life is dependent on a sequence of very complex chemical reactions that can't be predicted from basic physical laws on their own. These include the reading and the replication of complex molecules, like DNA or RNA, to create proteins that serve a specific function. These chemical reactions are often compared to the chicken-and-egg problem of how life first appeared: The development of DNA/RNA as well as protein-based cell machinery is crucial to the birth of life, but without the appearance of life the chemistry that makes it possible isn't working.
Research in the field of abiogenesis requires cooperation among scientists from many different disciplines. This includes prebiotic scientists, astrobiologists and planet scientists.
Evolutionary Changes
The word evolution is usually used to describe the accumulated changes in the genetic characteristics of populations over time. These changes could result from the response to environmental pressures as discussed in the entry on Darwinism (see the entry on Charles Darwin for background) or natural selection.
This latter mechanism increases the number of genes that offer the advantage of survival for the species, leading to an overall change in the appearance of a group. These changes in evolutionary patterns are caused by mutations, reshuffling of genes during sexual reproduction and the flow of genes.
Natural selection is the process that makes beneficial mutations more frequent. All organisms undergo mutations and reshuffles of genes. This is because, as we've mentioned earlier those who have the advantageous trait are likely to have a higher reproductive rate than those without it. Over the course of many generations, this differential in the numbers of offspring born could result in an inclination towards a shift in the number of advantageous traits in a population.
This is evident in the evolution of different beak shapes for finches from the Galapagos Islands. They have created these beaks to ensure that they can eat more easily in their new environment. These changes in shape and form could also help create new organisms.
The majority of changes are caused by a single mutation, although sometimes multiple occur simultaneously. The majority of these changes could be neutral or even harmful however, a small percentage may have a positive effect on survival and reproduction and increase their frequency over time. Natural selection is a process that causes the accumulating change over time that leads to the creation of a 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 through use and abuse, a concept known as soft inheritance. This is a misunderstood understanding of the nature of evolution and of the actual biological processes that lead to it. It is more accurate to say that evolution is a two-step, separate 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 that includes gorillas and chimpanzees. The earliest human fossils show that our ancestors were bipeds, walking on two legs. Genetic and biological similarities suggest that we have an intimate relationship with chimpanzees. In actual fact we are the most closely with chimpanzees in the Pan genus which includes bonobos and pygmy-chimpanzees. The last common human ancestor and chimpanzees was born between 8 and 6 million years ago.
Humans have evolved a variety of traits throughout time, including bipedalism, the use of fire, and the development of advanced tools. But it's only in the past 100,000 years or so that the majority of the essential characteristics that differentiate us from other species have been developed. These include a large, complex brain human ability to construct and use tools, as well as the diversity of our culture.
The process of evolution occurs when genetic changes allow individuals in a group 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 ones who are better adaptable are more likely to pass on their genes to the next generation. This is the way all species evolve and is the basis of the theory of evolution.
Scientists refer to it as the "law of Natural Selection." The law states that species which share a common ancestor tend to develop similar characteristics over time. It is because these traits allow them to survive and reproduce within their environment.
All organisms possess a DNA molecule that contains the information needed to control their growth. The DNA molecule is made up of base pairs that are spirally arranged around phosphate molecules and sugar molecules. The sequence of bases within each strand determines phenotype which is the person's distinctive appearance and behavior. A variety of mutations and reshufflings of the genetic material (known as alleles) during reproduction causes variations in a population.
Fossils from the earliest human species, Homo erectus and Homo neanderthalensis were discovered in Africa, Asia, and Europe. Although there are some differences they all support the idea that modern humans first appeared in Africa. The evidence from fossils and genetics suggests that early humans left Africa and migrated to Asia and Europe.