The Berkeley Evolution Site
The Berkeley site contains resources that can help students and teachers understand and teach evolution. The resources are organized into various learning paths that can be used in a variety of ways, such as "What does T. rex look like?"
Charles Darwin's theory on natural selection explains how creatures who are better able to adapt to changes in their environment survive over time and those that don't disappear. Science is about this process of biological evolutionary change.
What is Evolution?
The term "evolution" could be used to refer to a variety of nonscientific meanings. For example it could mean "progress" and "descent with modifications." It is a scientific term that refers to the process of change of characteristics in a species or species. The reason for this change is biological terms on natural drift and selection.
Evolution is one of the fundamental tenets of modern biology. It is an established theory that has stood up to the test of time and thousands of scientific studies. Evolution doesn't deal with the existence of God or religious beliefs, unlike many other theories of science, such as the Copernican or germ theory of disease.
Early evolutionists, such as Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather) believed that certain physical characteristics were predetermined to change, in a step-wise manner, as time passes. They referred to this as the "Ladder of Nature" or the 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 have the same ancestry, which can be traced through fossils and other evidence. This is the current view of evolution, which is supported in many disciplines which include molecular biology.
Scientists do not know how organisms evolved however they are certain that natural selection and genetic drift are responsible for the evolution of life. People with desirable traits are more likely to survive and reproduce, and they transmit their genes to the next generation. In time, this results in an accumulation of changes to 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 formation of one species from an ancestral one. Some scientists, like population geneticists, define the term "evolution" in a broader sense by talking about the net variation in the frequency of alleles over generations. Both definitions are correct and acceptable, however some scientists believe that allele-frequency definitions do not include important aspects of evolution.
Origins of Life
The most important step in evolution is the development of life. The emergence of life happens when living systems start to develop at a micro level, like within cells.
The origins of life are an important topic in many areas that include biology and the field of chemistry. The question of how living organisms began has a special place in science since it poses an enormous challenge to the theory of evolution. It is often described as "the mystery of life," or "abiogenesis."
Traditionally, the idea that life could emerge from nonliving things is called spontaneous generation or "spontaneous evolution." This was a common belief before Louis Pasteur's research showed that it was impossible for the emergence of life to occur by a purely natural process.
Many scientists believe it is possible to move from living to nonliving substances. The conditions needed to make life are not easy to reproduce in a lab. Researchers investigating the beginnings of life are also keen to understand 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 replication of complex molecules, such as DNA or RNA, to create proteins that perform a particular function. These chemical reactions can be compared to a chicken-and egg problem: the emergence and development of DNA/RNA, a protein-based cell machinery, is required to begin the process of becoming a living organism. However, without life, the chemistry needed to create it appears to be working.
Research in the field of abiogenesis requires cooperation among scientists from a variety of disciplines. This includes prebiotic scientists, astrobiologists, and planetary scientists.
Evolutionary Changes
The word evolution is usually used today to describe the accumulated changes in the genetic characteristics of a population over time. These changes may result from the response to environmental pressures as discussed in the entry on Darwinism (see the entry on Charles Darwin for background), or from natural selection.
This is a method that increases the frequency of genes that offer an advantage in survival over other species and causes gradual changes in the appearance of a group. These changes in evolutionary patterns are caused by mutations, reshuffling genes in the process of sexual reproduction, and also by gene flow.
While reshuffling and mutation of genes occur in all living organisms The process through which beneficial mutations are more frequent is called natural selection. This happens because, as we've mentioned earlier those who have the beneficial trait tend to have a higher reproductive rate than those with it. Over the course of many generations, this difference in the numbers of offspring born could result in an inclination towards a shift in the average number of beneficial traits within a group of.
An excellent example is the growing beak size on various species of finches on the Galapagos Islands, which have developed different beak shapes that allow them to easily access food in their new habitat. These changes in the form and shape of organisms could also aid in the creation of new species.
Most of the changes that take place are the result of one mutation, however occasionally several will happen at the same time. Most of these changes are not harmful or even harmful to the organism, however a small portion of them could have an advantageous impact on the survival of the organism and its reproduction, thereby increasing their frequency in the population over time. This is the process of natural selection and it is able to be a time-consuming process that produces the gradual changes that eventually result in a new species.
Many people confuse the concept of evolution with the notion that traits inherited can be altered through conscious choice, or through use and abuse, a concept called soft inheritance. 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, independent process, which involves the forces of natural selection as well as mutation.
Origins of Humans
Modern humans (Homo Sapiens) evolved from primates, which is a group of mammal species which includes gorillas and chimpanzees. The earliest human fossils prove that our ancestors were bipeds, walkers with two legs. Genetic and biological similarities suggest that we are closely related to chimpanzees. In fact we are the closest with chimpanzees in the Pan genus which includes pygmy chimpanzees and bonobos. The last common ancestor of modern humans and chimpanzees was born between 8 and 6 million years ago.
Humans have evolved a variety of traits over time, including bipedalism, the use of fire, and the development of advanced tools. It is only within the last 100,000 years that we have developed the majority of our essential traits. They include language, a large brain, the capacity to construct and use complex tools, as well as the diversity of our culture.
Evolution happens when genetic changes allow individuals of a population to better adapt to their surroundings. Natural selection is the mechanism that drives this change. Certain characteristics are more desirable than others. The ones who are better adjusted are more likely to pass on their genes to the next generation. This is how all species evolve and is the basis of the theory of evolution.
Scientists call it the "law of natural selection." The law states that species that share an ancestor will tend to acquire similar traits in the course of time. This is because these traits allow them to survive and reproduce in their natural environment.
All organisms possess a DNA molecule that contains the information needed to guide their growth. The DNA molecule is composed of base pairs that are spirally arranged around phosphate molecules and sugar molecules. 에볼루션 무료체험 of bases found in each strand determines the phenotype, the characteristic appearance and behavior of an individual. Variations in mutations and reshufflings of the genetic material (known as alleles) during sexual reproduction can cause variation in a population.
Fossils from the earliest human species Homo erectus and Homo neanderthalensis have been found in Africa, Asia and Europe. Although there are some differences the fossils all support the hypothesis that modern humans first appeared in Africa. The genetic and fossil evidence suggests that early humans left Africa and moved to Asia and Europe.