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The Berkeley site has resources that can assist students and teachers to understand and teach about evolution. The resources are organized into optional learning paths for example "What does T. rex look like?"
Charles Darwin's theory on natural selection describes how species who are better equipped to adapt to changes in their environments survive longer and those who do not disappear. This process of evolution is the basis of science.
What is Evolution?
The word evolution can be used to refer to a variety of nonscientific meanings. For instance 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 selection and drift.
Evolution is a key tenet in modern biology. It is an established theory that has withstood the tests of time and thousands of scientific studies. Evolution does not deal with spiritual beliefs or God's presence in the same way as other theories of science, such as the Copernican or germ theory of diseases.
Early evolutionists, such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical characteristics were predetermined to change in a step-like fashion over time. They called this the "Ladder of Nature" or the scala naturae. Charles Lyell first used this term in 1833 in his Principles of Geology.
Darwin published his theory of evolution in his book On the Origin of Species published in the early 1800s. It states that all species of organisms share a common ancestry which can be traced using fossils and other evidence. This is the current view on evolution, which is supported in a wide range of areas of science, including molecular biology.
While scientists don't know the exact mechanism by which organisms evolved, they are confident that the evolution of life on earth is the result of natural selection and genetic drift. Individuals with advantageous characteristics are more likely to survive and reproduce. They transmit their genes on to the next generation. Over time, the gene pool gradually changes and evolves into new species.
Some scientists employ the term"evolution" in reference to large-scale change, such as the development of an animal from an ancestral one. Other scientists, such as population geneticists, define the term "evolution" more broadly by referring a net variation in the frequency of alleles over generations. Both definitions are acceptable and precise however some scientists believe that the allele-frequency definition is missing essential aspects of the evolution process.
Origins of Life
The most important step in evolution is the emergence of life. This happens when living systems begin to develop at the micro level, within cells, for example.
The origins of life are an important topic in many areas such as biology and the field of chemistry. The origin of life is an area that is of immense interest to scientists, as it is a challenge to the theory of evolution. It is sometimes referred to "the mystery" of life or "abiogenesis."
The notion that life could be born from non-living things was called "spontaneous generation" or "spontaneous evolutionary". It was a common belief prior to Louis Pasteur's tests proved that the development of living organisms was not achievable through the natural process.
Many scientists still believe it is possible to make the transition from nonliving materials to living. However, the conditions that are required are extremely difficult to replicate in a laboratory. 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 development of life is dependent on a number of complex chemical reactions which are not predicted by the basic physical laws. This includes the conversion of long information-rich molecules (DNA or RNA) into proteins that perform a function and the replication of these complex molecules to create new DNA or RNA sequences. These chemical reactions are often compared with the chicken-and-egg dilemma of how life first appeared with the emergence of DNA/RNA and protein-based cell machinery is crucial to the birth of life, however, without the development of life the chemical process that allows it is not working.
Abiogenesis research requires collaboration among scientists from various disciplines. This includes prebiotic chemists, astrobiologists, planetary scientists geophysicists and geologists.
Evolutionary Changes
The term "evolution" is commonly used to describe the cumulative changes in genetic characteristics of an entire population over time. These changes could result from the response to environmental pressures as described in the entry on Darwinism (see the entry on Charles Darwin for background), or from natural selection.
Related Homepag is a process that increases the frequency of genes in a species that offer an advantage in survival over other species, resulting in an ongoing change in the appearance of a population. The specific mechanisms responsible for these evolutionary changes include mutation or reshuffling genes during sexual reproduction, and also gene flow between populations.
While mutation and reshuffling of genes are common in all organisms The process through which beneficial mutations are more prevalent is called natural selection. This is because, as noted above those with the advantageous trait are likely to have a higher reproduction rate than those who do not have it. Over the course of many generations, this differential in the number of offspring produced can result in gradual changes in the amount of desirable traits within a group of.
One good example is the growing the size of the beaks on different species of finches in the Galapagos Islands, which have evolved different shaped beaks to enable them to more easily access food in their new habitat. These changes in shape and form could also aid in the creation of new species.
The majority of changes are caused by one mutation, however sometimes multiple occur at the same time. The majority of these changes could be harmful or neutral however, a few can have a beneficial impact on survival and reproduction, increasing their frequency over time. This is the mechanism of natural selection and it can be a time-consuming process that produces the cumulative changes that eventually result in an entirely new species.
Many people confuse evolution with the idea of soft inheritance, which is the idea that inherited traits can be altered by conscious choice or by abuse. This is a misinterpretation of the biological processes that lead to the process of evolution. A more precise description is that evolution involves a two-step process, which involves the separate and often antagonistic forces of mutation and natural selection.
Origins of Humans
Humans of today (Homo Sapiens) evolved from primates, which is a group of mammal species that includes chimpanzees and gorillas. Our ancestral ancestors were walking on two legs, as shown by the earliest fossils. Genetic and biological similarities show that we share the same ancestry with the chimpanzees. In actual fact, our closest relatives are the chimpanzees of the Pan genus. This includes pygmy as well as bonobos. The last common ancestor between modern humans and chimpanzees dated between 8 and 6 million years old.
Humans have evolved a variety of characteristics over time such as bipedalism, use of fire and advanced tools. However, it is only in the past 100,000 years or so that most of the important traits that distinguish us from other species have emerged. These include a big brain that is complex human ability to create and use tools, and the diversity of our culture.
The process of evolution occurs when genetic changes enable members of an organization to better adapt to their environment. This adaptation is triggered by natural selection, a process whereby certain traits are favored over others. The ones who are better adapted are more likely to pass on their genes to the next generation. This is the way all species evolve and is the foundation for the theory of evolution.
Scientists refer to this as the "law of natural selection." The law states species that have a common ancestor are likely to develop similar characteristics over time. It is because these traits help them to live and reproduce in their environment.
All organisms have a DNA molecule, which provides the information necessary to direct their growth and development. The DNA molecule is composed of base pairs that are arranged in a spiral around sugar molecules and phosphate molecules. The sequence of bases within each strand determines the phenotype - the distinctive appearance and behavior of a person. A variety of changes and reshuffling of genetic material (known as alleles) during sexual reproduction cause variation in a population.
Fossils of the first human species, Homo erectus and Homo neanderthalensis have been discovered in Africa, Asia, and Europe. These fossils, despite a few variations in their appearance, all support the idea of modern humans' origins in Africa. The genetic and fossil evidence suggests that early humans left Africa and moved to Asia and Europe.