The Berkeley Evolution Site
The Berkeley site has resources that can help students and teachers understand and teach evolution. The resources are arranged into different learning paths like "What did T. rex taste like?"
Charles Darwin's theory of natural selection explains how creatures who are better able to adapt biologically to changing environments over time, and those who do not become extinct. Science is about the process of biological evolution.
What is Evolution?
The term "evolution" could be used to refer to a variety of nonscientific meanings. For example it could refer to "progress" and "descent with modifications." Scientifically it refers to a changing the characteristics of living things (or species) over time. The reason for this change is biological terms on natural drift and selection.
Evolution is a central tenet of modern biology. It is an accepted theory that has stood up to the tests of time and thousands of scientific experiments. Contrary to other theories of science such as the Copernican theory or the germ theory of disease, the evolution theory is not a discussion of spiritual belief or the existence of God.
Early evolutionists such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical traits were predetermined to evolve in a step-like fashion over time. This was known 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 asserts that different species of organisms share a common ancestry, which can be proven through fossils and other evidence. This is the modern view of evolution, which is supported by a variety of research lines in science that include molecular genetics.
Although scientists aren't able to determine the exact mechanism by which organisms evolved but they are certain that the evolution of life on earth is a result of natural selection and genetic drift. People with advantages are more likely to survive and reproduce. These individuals then pass their genes on to the next generation. In time this leads to gradual changes in the gene pool, which eventually result in new species and forms.
에볼루션 블랙잭 employ the term"evolution" to describe large-scale evolutionary changes, such as the formation of the new species from an ancestral species. Certain scientists, including population geneticists define evolution in a broader sense by talking about the net change in the frequency of alleles across generations. Both definitions are acceptable and accurate however, some scientists claim that the allele-frequency definition omits essential aspects of the evolution process.
Origins of Life
The development of life is a key stage in evolution. This happens when living systems begin to develop at a micro-level - within individual cells, for example.
The origins of life are an important topic in many areas that include biology and the field of chemistry. The question of how living things got their start is of particular importance in science because it is an enormous challenge to the theory of evolution. It is sometimes referred to as "the mystery" of life or "abiogenesis."
Traditionally, the belief that life can emerge from nonliving things is called spontaneous generation, or "spontaneous evolution." This was a popular view before Louis Pasteur's experiments showed that it was impossible for the creation of life to occur by an entirely natural process.
Many scientists still believe it is possible to make the transition from nonliving materials to living. The conditions necessary for the creation of life are difficult to replicate in a laboratory. This is why scientists studying the beginnings of life are also keen to understand the physical properties of the early Earth and other planets.
The growth of life is dependent on a number of complex chemical reactions, which cannot be predicted by basic physical laws. These include the reading and the replication of complex molecules, such as DNA or RNA, to produce proteins that perform a particular function. These chemical reactions are often compared with the chicken-and-egg issue of how life first appeared: The emergence of DNA/RNA and protein-based cell machinery is essential for the beginning of life, but without the development of life the chemical process that allows it is not working.
Research in the field of abiogenesis requires collaboration among scientists from a variety of fields. 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 could be the result of the adaptation to environmental pressures as discussed in Darwinism.
This is a process that increases the frequency of those genes that confer an advantage in survival over others, resulting in an ongoing change in the appearance of a group. 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 mutations and reshuffles of genes. As noted above, individuals who possess the desirable trait have a higher reproductive rate than those who do not. Over the course of several generations, this variation in the number of offspring produced can result in a gradual shift in the number of advantageous traits in a population.
This can be seen in the evolution of various beak shapes for finches from the Galapagos Islands. They have created these beaks to ensure that they can access food more quickly in their new home. These changes in the shape and appearance of organisms can also help create new species.
에볼루션 블랙잭 of changes are caused by a single mutation, but sometimes several occur at the same time. Most of these changes are neutral or even harmful to the organism, however a small portion of them could be beneficial to the survival of the organism and its reproduction, thereby increasing their frequency in the population over time. Natural selection is a mechanism that could result in the accumulation of changes over time that lead to the creation of a new species.
Some people think that evolution is a form of soft inheritance that is the belief that inherited traits can be altered by conscious choice or by abuse. This is a misinterpretation of the biological processes that lead 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 and mutation.
Origins of Humans
Humans of today (Homo Sapiens) evolved from primates, which is a group of mammal species that includes chimpanzees and gorillas. Our ancestors walked on two legs, as evidenced by the oldest fossils. Genetic and biological similarities suggest that we are closely related to chimpanzees. In fact we are the most closely related to the chimpanzees within the Pan Genus which includes bonobos and pygmy-chimpanzees. The last common ancestor of modern humans and chimpanzees was between 8 and 6 million years ago.
Over time humans have developed a variety of traits, including bipedalism and the use of fire. They also developed advanced tools. It is only within the last 100,000 years that we have developed the majority of our important traits. These include language, a large brain, the capacity to create and utilize complex tools, and the diversity of our culture.
The process of evolution is when genetic changes allow members of the group to better adapt to the environment. Natural selection is the process that triggers this adaptation. Certain traits are preferred over others. The ones with the best adaptations are more likely to pass on their genes to the next generation. This is how all species evolve, and the foundation for the theory of evolution.
Scientists refer to it as the "law of natural selection." The law states that species that have a common ancestor are likely to acquire similar traits as time passes. This is because these traits help them to survive and reproduce within their environment.
All organisms possess an molecule called DNA that holds the information needed to guide their growth. The structure of DNA is made of base pairs that are arranged in a spiral around phosphate and sugar molecules. The sequence of bases within each strand determines phenotype, or the individual's characteristic appearance and behavior. The variations in a population are caused by mutations and reshufflings in genetic material (known collectively as alleles).
Fossils from the first human species, Homo erectus, and Homo neanderthalensis have been discovered in Africa, Asia and Europe. Although there are some differences, these fossils all support the notion that modern humans first came into existence in Africa. The fossil evidence and genetic evidence suggest that early humans moved out of Africa into Asia and then Europe.