The Berkeley Evolution Site
The Berkeley site contains resources that can help students and educators understand and teach evolution. The resources are organized into a variety of learning paths, such as "What did T. rex taste like?"
Charles Darwin's theory of natural selection describes how species that are better equipped to adapt to changes in their environment survive over time and those that do not disappear. This process of evolution is the basis of science.
What is Evolution?
The term "evolution" could have a variety of meanings that are not scientific. For example it could refer to "progress" and "descent with modifications." Scientifically it refers to a process of changes in the traits of living things (or species) over time. The reason for this change is biological terms on natural drift and selection.
Evolution is an important principle in the field of biology today. It is a concept that has been tested and verified through 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 spiritual belief or the existence of God.
Early evolutionists, including Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather) believed that certain physical traits were predetermined to change in a step-wise manner, as time passes. This was called the "Ladder of Nature" or scala Naturae. Charles Lyell used the term to describe this idea in his Principles of Geology, first published in 1833.
Darwin presented his theory of evolution in his book On the Origin of Species published in the early 1800s. It states that all species of organisms have an ancestry that can be determined through fossils and other evidence. This is the modern view of evolution, which is supported by many lines of research in science which includes molecular genetics.
Scientists don't know how organisms evolved, but they are confident that natural selection and genetic drift are the reason for the evolution of life. 에볼루션 사이트 with desirable traits are more likely to live and reproduce. These individuals pass on their genes on to the next generation. Over time the gene pool gradually changes and evolves into new species.
Some scientists also employ the term evolution to refer to large-scale evolutionary changes, such as the formation of the new species from an ancestral species. Some scientists, like population geneticists, define the term "evolution" in a broad sense, using the term "net change" to refer to the change in allele frequency over generations. Both definitions are valid and acceptable, however some scientists believe that allele-frequency definitions miss important aspects of the evolution.
Origins of Life
A key step in evolution is the appearance of life. The emergence of life occurs when living systems start to develop at a micro level, like within individual cells.
The origins of life is one of the major topics in various disciplines, including geology, chemistry, biology and chemistry. The question of how living organisms began is of particular importance in science due to it being a major challenge to the theory of evolution. It is often described as "the mystery of life," or "abiogenesis."
The notion that life could be born from non-living matter was known as "spontaneous generation" or "spontaneous evolutionary". This was a popular belief before Louis Pasteur's tests showed that the creation of living organisms was not achievable through an organic process.
Many scientists believe it is possible to go from nonliving to living substances. The conditions necessary to create life are difficult to reproduce in a lab. Researchers interested in the origins and development of life are also keen to know the physical properties of the early Earth as well as other planets.
The growth of life is also dependent on a series of complex chemical reactions that are not predicted by basic physical laws. These include the reading and replication of complex molecules, like DNA or RNA, in order to make proteins that serve a specific function. These chemical reactions are often compared with the chicken-and-egg dilemma of how life began: The development of DNA/RNA as well as proteins-based cell machinery is vital for the onset of life, but without the emergence of life the chemical reaction that is the basis for it is not working.
Abiogenesis research requires collaboration between scientists from different fields. This includes prebiotic scientists, astrobiologists, and planet scientists.
Evolutionary Changes
The term "evolution" is commonly used to describe the cumulative changes in the genetic traits of a population over time. These changes may be the result of the adaptation to environmental pressures as described in Darwinism.
This process increases the frequency of genes that provide an advantage for survival in the species, leading to an overall change in the appearance of a group. These evolutionary changes are triggered by mutations, reshuffling of genes during sexual reproduction, and the flow of genes.
Natural selection is the process that allows beneficial mutations to become more common. All organisms undergo mutations and reshuffles of their genes. As noted above, individuals who have the advantageous trait have a higher reproductive rate than those who don't. Over the course of several generations, this difference in the number of offspring born could result in an inclination towards a shift in the number of advantageous traits in a population.
A good example of this is the increase in beak size on different species of finches in the Galapagos Islands, which have developed beaks with different shapes to enable them to more easily access food in their new habitat. These changes in form and shape can also aid in the creation of new species.
The majority of the changes that occur are caused by one mutation, but occasionally, multiple mutations occur simultaneously. Most of these changes are neutral or even harmful to the organism, but a small percentage can have an advantageous impact on the survival of the organism and its reproduction, thereby increasing their frequency in the population over time. Natural selection is a mechanism that causes the accumulating change over time that eventually leads to a new species.
Many people confuse the concept of evolution with the idea that inherited characteristics can be altered through conscious choice or by use and abuse, a concept called soft inheritance. This is a misunderstanding of the biological processes that lead to evolution. It is more accurate to say that evolution is a two-step, separate process that involves the forces of natural selection as well as mutation.
Origins of Humans
Humans today (Homo sapiens) evolved from primates - a group of mammals that includes gorillas, chimpanzees, and bonobos. The earliest human fossils show that our ancestors were bipeds. They were walkers on two legs. Genetic and biological similarities suggest that we are closely related to chimpanzees. In actual 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 born between 8 and 6 million years ago.
As time has passed humans have developed a number of characteristics, such as bipedalism and the use of fire. They also created advanced tools. But it's only in the last 100,000 years or so that most of the important traits that distinguish us from other species have developed. They include a huge, complex brain, the ability of humans to create and use tools, and the diversity of our culture.
Evolution happens when genetic changes allow individuals in a group to better adapt to their surroundings. Natural selection is the process that drives this change. Certain characteristics are more desirable than others. The more adapted are more likely to pass on their genes 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 that species which have a common ancestor are more likely to develop similar traits over time. This is because these traits help them to survive and reproduce within their environment.
Every living thing has DNA molecules, which provides the information necessary to guide their growth and development. The DNA molecule is composed of base pairs arranged spirally around phosphate molecules and sugar molecules. The sequence of bases within each strand determines phenotype or the individual's unique appearance and behavior. Variations in mutations and reshufflings of the genetic material (known as alleles) during sexual reproduction cause variations in a population.
Fossils from the early human species Homo erectus, as well as Homo neanderthalensis have been found in Africa, Asia and Europe. Although there are some differences, these fossils all support the idea that modern humans first appeared in Africa. The evidence from fossils and genetics suggests that early humans left Africa and moved to Asia and Europe.
