The Berkeley Evolution Site
The Berkeley site has resources that can help students and teachers to understand and teach about evolution. The resources are arranged into different learning paths like "What did T. rex taste like?"
Charles Darwin's theory on natural selection explains how creatures who are better able to adapt biologically to changing environments over time, and those that don't become extinct. Science is about this process of biological evolution.
What is Evolution?
The term "evolution" has a variety of nonscientific meanings, such as "progress" or "descent with modification." It is a scientific term that is used to describe the process of change of characteristics over time in organisms or species. This change is based in biological terms on natural selection and drift.
Evolution is a central tenet of modern biology. It is a concept that has been tested and confirmed through thousands of scientific tests. In contrast to other theories in science such as the Copernican theory or the germ theory of disease, evolution is not a discussion of religion or the existence of God.
Early evolutionists, like 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 referred to as 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.
Darwin published his theory of evolution in his book On the Origin of Species which was written in the early 1800s. It asserts that different species of organisms share an ancestry that can be traced through fossils and other evidence. This is the current view of evolution, which is supported by many lines of scientific research, including molecular genetics.
While scientists don't know exactly how organisms evolved however they are sure that the evolution of life on earth is the result of natural selection and genetic drift. People with desirable traits are more likely to live and reproduce, and they pass their genes on to the next generation. Over time the gene pool slowly changes and develops into new species.
Certain scientists also use the term"evolution" to refer to large-scale changes in evolutionary processes such as the creation of an entirely new species from an ancestral species. Certain scientists, including population geneticists, define the term "evolution" in a broader sense by referring to the net change in the frequency of alleles across generations. Both definitions are correct and acceptable, however some scientists believe that allele-frequency definitions miss important aspects of the evolution.
Origins of Life
The birth of life is a crucial stage in evolution. discover here happens when living systems begin to evolve at the micro level - within cells, for example.
The origins of life are an important topic in many fields, including biology and chemical. The origin of life is an area of great interest in science, as it challenges the theory of evolution. It is sometimes referred to as "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 common belief before Louis Pasteur's research showed that it was impossible for the development of life to be a result of an entirely natural process.
Many scientists still believe that it is possible to transition from nonliving substances to living. The conditions needed to create life are difficult to reproduce in a lab. Researchers interested in the origins and evolution of life are also keen to know the physical properties of the early Earth as well as other planets.
The life-cycle of a living organism is also dependent on a series of complex chemical reactions which cannot be predicted by the basic physical laws. These include the reading and the replication of complex molecules, such as DNA or RNA, to create proteins that serve a specific function. These chemical reactions are comparable to a chicken-and egg problem that is the emergence and growth of DNA/RNA, protein-based cell machinery, is essential for the onset life. However, without life, the chemistry that is required to make it possible does appear to work.
Abiogenesis research requires collaboration between researchers from different disciplines. 에볼루션바카라사이트 includes prebiotic scientists, astrobiologists, and planetary scientists.
Evolutionary Changes
The term "evolution" is commonly used today to describe the accumulated changes in the genetic traits of populations over time. These changes may result from adaptation to environmental pressures as explained in the article on Darwinism (see the entry on Charles Darwin for background) or natural selection.
This is a process that increases the frequency of those genes in a species which confer a survival advantage over others which results in an ongoing change in the overall appearance of a particular population. The specific mechanisms that cause these evolutionary changes include mutation or reshuffling genes during sexual reproduction, and gene flow between populations.
Natural selection is the process that allows beneficial mutations to become more common. All organisms undergo changes and reshuffles in their genes. As previously mentioned, those who possess the desirable trait have a higher reproduction rate than those who don't. This difference in the number of offspring born over many generations can result in a gradual change in the average number advantageous traits within a group.
This is evident in the evolution of various beak shapes on finches from the Galapagos Islands. They have developed these beaks so that they can access food more easily in their new environment. These changes in shape and form can aid in the creation of new organisms.
The majority of the changes that occur are caused by one mutation, but sometimes, several changes occur at once. The majority of these changes are neither harmful nor 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 the frequency of these changes in the population over time. This is the mechanism of natural selection and it can, over time, produce the accumulating changes that ultimately lead to an entirely new species.
Some people confuse the notion of evolution with the idea that the traits inherited from parents can be changed through conscious choice, or through use and abuse, a notion known as soft inheritance. This is a misunderstanding of the biological processes that lead up to the process of evolution. It is more precise to say that evolution is a two-step, separate process that involves the forces of natural selection and mutation.
Origins of Humans
Modern humans (Homo sapiens) evolved from primates, a group of mammals that also includes chimpanzees, gorillas, and bonobos. Our predecessors walked on two legs, as demonstrated by the first fossils. Genetic and biological similarities suggest that we are closely related to Chimpanzees. In reality, our closest relatives are the chimpanzees of the Pan genus. This includes pygmy, as well as bonobos. The last common ancestor of modern humans and chimpanzees was born between 8 and 6 million years ago.
Humans have developed a range of traits over time such as bipedalism, use of fire and advanced tools. However, it is only in the last 100,000 years or so that most of the characteristics that differentiate us from other species have emerged. They include a huge, complex brain, the ability of humans to create and use tools, and cultural diversity.
Evolution occurs when genetic changes allow members of the group to better adapt to the environment. Natural selection is the mechanism that triggers this adaptation. Certain characteristics are more desirable than 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 basis of the theory of evolution.
Scientists call this the "law of natural selection." The law states that species which share an ancestor will tend to develop similar characteristics in the course of time. This is because these characteristics make it easier for them to live and reproduce in their natural environment.
Every organism has the DNA molecule, which contains the information necessary to direct their growth. The DNA molecule consists of base pairs that are arranged in a spiral around sugar molecules and phosphate molecules. The sequence of bases within each string determines the phenotype or the characteristic appearance and behavior of an individual. Different mutations and reshufflings of the genetic material (known as alleles) during sexual reproduction cause variations in a population.
Fossils of the earliest human species, Homo erectus and Homo neanderthalensis have been discovered in Africa, Asia, and Europe. While there are some differences between them, these fossils all support the idea that modern humans first appeared in Africa. Genetic and fossil evidence also suggest that early humans came from Africa into Asia and then Europe.