The Berkeley Evolution Site
The Berkeley site has resources that can assist students and teachers learn about and teach evolution. 에볼루션사이트 are organized into optional learning paths, such as "What does T. rex look like?"
Charles Darwin's theory of natural selection states that in time, creatures more adaptable to changing environments do better than those that do not become extinct. Science is about this process of evolutionary change.
What is Evolution?
The word evolution can have a variety of meanings that are not scientific. For instance, it can mean "progress" and "descent with modifications." Scientifically it is a term used to describe a changing the characteristics of living organisms (or species) over time. This change is based in biological terms on natural selection and drift.
Evolution is a fundamental tenet in modern biology. It is a theory that has been tested and verified through thousands of scientific tests. Evolution does not deal with spiritual beliefs or God's presence like other scientific theories such as the Copernican or germ theory of disease.
Early evolutionists, such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical traits were predetermined to evolve in a gradual 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.
In the early 1800s, Darwin formulated his theory of evolution and published it in his book On the Origin of Species. It asserts that different species of organisms share the same ancestry, which can be traced through fossils and other lines of evidence. This is the current view on evolution, which is supported in many scientific fields, including molecular biology.
Scientists aren't sure the evolution of organisms however they are certain that natural selection and genetic drift are responsible for the development of life. Individuals with advantageous traits are more likely to survive and reproduce, and these individuals pass their genes on to the next generation. Over time, the gene pool gradually changes and develops into new species.
Some scientists use the term"evolution" to refer to large-scale changes, such the development of one species from an ancestral one. Other scientists, like population geneticists, define it more broadly by referring a net variation in the frequency of alleles over generations. Both definitions are accurate and acceptable, but some scientists argue that allele-frequency definitions do not include important aspects of evolution.
Origins of Life
The development of life is a key step in evolution. This happens when living systems begin to evolve at the micro level - within individual cells, for example.
The origin of life is an important topic in many fields, including biology and chemistry. The nature of life is a topic of interest in science, as it is a challenge to the theory of evolution. It is sometimes referred to as "the mystery" of life or "abiogenesis."
Traditionally, the idea that life can arise from nonliving things is called spontaneous generation, or "spontaneous evolution." This was a popular belief prior to Louis Pasteur's experiments showed that it was impossible for the creation of life to occur by a purely natural process.
Many scientists still think it is possible to go from living to nonliving substances. The conditions needed for the creation of life are difficult to reproduce in a lab. Researchers studying the origins of life are also interested in understanding the physical properties of the early Earth and other planets.
Furthermore, the growth of life is dependent on the sequence of extremely complex chemical reactions that cannot be predicted from basic physical laws on their own. These include the reading and re-reading of complex molecules, such as DNA or RNA, in order to make proteins that serve a specific function. These chemical reactions can be compared to the chicken-and-egg problem that is the emergence and growth of DNA/RNA, protein-based cell machinery, is required for the beginning of life. However without life, the chemistry that is required to enable it appears to be working.
Abiogenesis research requires collaboration with scientists from various disciplines. This includes prebiotic chemists planet scientists, astrobiologists geophysicists and geologists.
Evolutionary Changes
The term "evolution" is typically used today to describe the accumulated changes in the genetic traits of populations over time. These changes could result from the response to environmental pressures as explained in the article on Darwinism (see the entry on Charles Darwin for background), or from natural selection.
This is a process that increases the frequency of genes that confer a survival advantage over others, resulting in a gradual change in the appearance of a particular population. These evolutionary changes are triggered by mutations, reshuffling genes during sexual reproduction and gene flow.
Natural selection is the process that allows beneficial mutations to become more common. All organisms undergo changes and reshuffles of their genes. This is because, as mentioned above, those individuals with the beneficial trait tend to have a higher reproductive rate than those who do not have it. Over many generations, this difference in the numbers of offspring born could result in an inclination towards a shift in the average number of advantageous traits within a group of.
This is evident in the evolution of different beak shapes on finches from the Galapagos Islands. They have developed these beaks so that they can eat more easily in their new environment. These changes in shape and form can aid in the creation of new organisms.
The majority of changes are caused by one mutation, however sometimes multiple occur simultaneously. Most of these changes may be negative or even harmful, but a small number could have a positive impact on the survival of the species and reproduce with increasing frequency as time passes. Natural selection is a process that causes the accumulating change over time that eventually leads to the creation of a new species.
Many people confuse the concept of evolution with the idea that the traits inherited from parents can be altered through conscious choice, or through use and abuse, which is 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 independent process, that is influenced by the forces of natural selection and mutation.
Origins of Humans
Modern humans (Homo sapiens) evolved from primates - a species of mammals that includes chimpanzees, gorillas, and bonobos. The earliest human fossils indicate that our ancestors were bipeds - walkers with two legs. Genetic and biological similarities show that we have the same ancestry with chimpanzees. In actual fact, our closest relatives are chimpanzees from the Pan genus. This includes pygmy as well as bonobos. The last common human ancestor as well as chimpanzees was born between 8 and 6 million years ago.
In the course of time, humans have developed a number of characteristics, including bipedalism and the use of fire. They also created advanced tools. But it's only in the past 100,000 years or so that most of the traits that distinguish us from other species have emerged. These include language, large brain, the ability to build and use complex tools, as well as the ability to adapt to cultural differences.
Evolution happens when genetic changes allow individuals of a population to better adapt to their surroundings. Natural selection is the process that drives this adaptation. 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 the process that evolves all species and forms the foundation of the theory of evolution.
Scientists call this the "law of natural selection." The law states that species that have a common ancestor are more likely to develop similar characteristics over time. This is because those traits allow them to survive and reproduce in their natural environment.
Every living thing has a DNA molecule that contains the information necessary to direct their growth. The DNA molecule consists of base pairs that are spirally arranged around phosphate molecules and sugar 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 reshufflings and mutations of genetic material (known collectively as alleles).
Fossils of the first human species, Homo erectus and Homo neanderthalensis, have been found in Africa, Asia, and Europe. These fossils, despite a few differences in their appearance all support the idea of modern humans' origins in Africa. The fossil and genetic evidence suggests that the first humans left Africa and moved to Asia and Europe.