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The Berkeley site offers resources that can help students and educators to understand and teach about evolution. The resources are organized into optional learning paths, such as "What did T. rex taste like?"
Charles Darwin's theory of natural selection states that in time, creatures better able to adapt biologically to changing environments do better than those that don't become extinct. This process of evolution is what science is all about.
What is Evolution?
The word evolution can 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 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 the central tenet of modern biology. It is a theory that has been tested and verified through thousands of scientific tests. Contrary to other theories of science, such as the Copernican theory or the germ theory of disease, evolution does not address issues of religion or the existence of God.
Early evolutionists, including Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather) believed that certain physical characteristics were predetermined to change, in a step-wise way, over time. They called this the "Ladder of Nature" or 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 states that all species of organisms share an ancestry that can be traced using fossils and other evidence. This is the current view of evolution, which is supported in a wide range of areas of science which include molecular biology.
While scientists do not 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. People with traits that are advantageous are more likely to survive and reproduce, and they pass their genes on to the next generation. In time this leads to an accumulation of changes in the gene pool, which eventually lead to new species and forms.
Some scientists employ the term"evolution" to refer to large-scale change, such as the evolution of a species from an ancestral one. Others, like population geneticists, define the term "evolution" more broadly by referring to an overall change in the frequency of alleles across generations. Both definitions are accurate and palatable, but certain scientists argue that allele frequency definitions omit important features of evolutionary process.
Origins of Life
The emergence of life is a crucial stage in evolution. This occurs when living systems begin to develop at the micro level, within individual cells, for instance.
The origin of life is an important subject in many disciplines such as biology and chemical. The question of how living things got their start is of particular importance in science due to it being an important challenge to the theory of evolution. Recommended Website is often called "the mystery of life," or "abiogenesis."
Traditionally, the belief that life could emerge from nonliving things is known as spontaneous generation, or "spontaneous evolution." This was a popular view before Louis Pasteur's experiments proved that it was impossible for the creation of life to happen through the natural process.
Many scientists believe that it is possible to transition from nonliving materials to living. The conditions required to make life are not easy to reproduce in a lab. This is why scientists investigating the nature of life are also keen to understand the physical properties of early Earth and other planets.
Additionally, the evolution of life is a sequence of very complex chemical reactions that can't be predicted from basic physical laws on their own. These include the reading and re-reading of complex molecules, like DNA or RNA, to create proteins that perform a specific function. These chemical reactions can be compared with a chicken-and egg problem which is the development and emergence of DNA/RNA, a protein-based cell machinery, is essential to begin the process of becoming a living organism. Although without life, the chemistry needed to make it possible appears to be working.
Abiogenesis research requires collaboration between researchers from different fields. This includes prebiotic chemists astrobiologists, planetary scientists geophysicists and geologists.
Evolutionary Changes
The term "evolution" is commonly used today to describe the accumulated changes in genetic characteristics of an entire population over time. These changes may be the result of adaptation to environmental pressures as discussed in Darwinism.
The latter is a mechanism that increases the frequency of those genes in a species that offer an advantage in survival over others, resulting in an ongoing change in the appearance of a group. The specific mechanisms responsible for these changes in evolutionary process include mutation or reshuffling genes during sexual reproduction, as well as gene flow between populations.
While reshuffling and mutations of genes occur in all living organisms and the process by which beneficial mutations are more prevalent is referred to as natural selection. This is because, as noted above those who have the beneficial trait tend to have a higher fertility rate than those with it. Over the course of several generations, this difference in the numbers of offspring born can result in gradual changes in the amount of desirable traits within a group of.
This can be seen in the evolution of different beak shapes for finches from the Galapagos Islands. They have created these beaks to ensure they can get food more easily in their new environment. These changes in shape and form could also help create new organisms.
The majority of the changes that occur are the result of one mutation, but 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 be beneficial to the longevity and reproduction of the species, thus 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, which is the idea that traits inherited from parents can be changed through conscious choice or by abuse. This is a misunderstanding of the biological processes that lead to the process of evolution. It is more accurate to say that evolution is a two-step, independent process, that is influenced by the forces of natural selection as well as mutation.
Origins of Humans
Modern humans (Homo Sapiens) evolved from primates, a group of mammal species which includes chimpanzees and gorillas. The earliest human fossils show that our ancestors were bipeds, walkers on two legs. Genetic and biological similarities suggest that we are closely related to the chimpanzees. In fact, our closest relatives are chimpanzees belonging to the Pan genus. This includes pygmy, as well as bonobos. The last common ancestor shared between modern humans and chimpanzees was between 8 and 6 million years old.
Humans have developed a range of traits throughout 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 essential characteristics that differentiate us from other species have been developed. These include language, a large brain, the ability to construct and use complex tools, and cultural diversity.
The process of evolution occurs when genetic changes enable members of a group to better adapt to their environment. This adaptation is driven by natural selection, a process that determines certain traits are preferred over others. The more adaptable are more likely to pass on their genes to the next generation. This is how all species evolve and the basis of the theory of evolution.
Scientists refer to it as the "law of natural selection." The law states that species which have an ancestor in common will tend to acquire similar traits as time passes. This is because these traits allow them to live and reproduce in their environments.
All organisms have a DNA molecule, which provides the information necessary to guide their growth and development. The DNA molecule is composed of base pairs arranged spirally around sugar molecules and phosphate molecules. The sequence of bases found in each strand determines the phenotype, the appearance and behavior of an individual. Variations in a population can be caused by mutations and reshufflings of genetic material (known collectively as alleles).
Fossils from the earliest human species, Homo erectus and Homo neanderthalensis have been discovered in Africa, Asia, and Europe. These fossils, despite differences in their appearance all support the theory that modern humans' ancestors originated in Africa. The fossil evidence and genetic evidence suggest that early humans moved from Africa into Asia and then Europe.