10 Evolution Site Strategies All The Experts Recommend
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 such as "What did T. rex taste like?"
Charles Darwin's theory of natural selection states that in time, creatures more adaptable to changing environments survive and those that don't become extinct. This process of biological evolution is the main focus of science.
What is Evolution?
The word evolution has many nonscientific meanings, such as "progress" or "descent with modification." It is an academic term that is used to describe the process of change of characteristics in a species or species. In visit of biology the change is based on natural selection and genetic drift.
Evolution is a fundamental principle in the field of biology today. It is an established theory that has stood up to the test of time and a multitude of scientific experiments. Unlike many other scientific theories, such as the Copernican theory or the germ theory of disease, evolution is not a discussion of spiritual belief 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 gradual way, over time. This was called the "Ladder of Nature" or scala Naturae. Charles Lyell used the term to describe this idea in his Principles of Geology, first published in 1833.
Darwin revealed his theory of evolution in his book On the Origin of Species which was written in the early 1800s. It asserts that all species of organisms share a common ancestry which can be traced by fossils and other evidence. This is the modern view on evolution, which is supported in a wide range of areas of science, including molecular biology.
Scientists don't know how organisms have evolved however they are certain that natural selection and genetic drift are responsible for the evolution of life. People with desirable traits are more likely to survive and reproduce. These individuals transmit their genes to the next generation. Over time the gene pool slowly changes and develops into new species.
Some scientists employ the term"evolution" to refer to large-scale changes, like the development of one species from an ancestral one. Certain scientists, such as population geneticists, define the term "evolution" in a broader sense by talking about the 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 crucial aspects of the evolutionary process.
Origins of Life
The development of life is a crucial step in the process of evolution. This happens when living systems begin to develop at a micro-level - within individual cells, for instance.
The origins of life is an issue in a variety of disciplines that include biology, chemistry, and geology. The nature of life is an area of great interest in science because it is a challenge to the theory of evolution. It is often called "the mystery of life," or "abiogenesis."
The notion that life could arise from non-living matter was known as "spontaneous generation" or "spontaneous evolutionary". It was a popular belief before Louis Pasteur's experiments proved that the development of living organisms was not achievable through a natural process.
Many scientists still think it is possible to go from nonliving substances to living ones. The conditions needed to create life are difficult to replicate in a laboratory. This is why scientists investigating the origins of life are also keen to understand the physical properties of early Earth and other planets.
The growth of life is dependent on a number of complex chemical reactions, that are not predicted by the basic physical laws. These include the reading and re-reading of complex molecules, like DNA or RNA, to produce proteins that perform a specific function. These chemical reactions are often compared to the chicken-and-egg dilemma of how life first appeared in the first place. The appearance of DNA/RNA and protein-based cell machinery is essential for the beginning of life, but without the development of life, the chemistry that makes it possible isn't working.
Abiogenesis research requires collaboration between researchers from different disciplines. This includes prebiotic scientists, astrobiologists and planetary scientists.
Evolutionary Changes
The term "evolution" is used to describe general changes in genetic traits over time. These changes can be the result of the adaptation to environmental pressures as discussed in Darwinism.
This latter mechanism increases the number of genes that provide the advantage of survival for a species, resulting in an overall change in the appearance of a group. These evolutionary changes are caused by mutations, reshuffling of genes in the process of sexual reproduction, and also by gene flow.
Natural selection is the process that makes beneficial mutations more common. All organisms undergo changes and reshuffles in their genes. This happens because, as we've mentioned earlier those who have the beneficial trait tend to have a higher reproductive rate than those without it. This differential in the number of offspring that are produced over a long period of time can result in a gradual change in the average number advantageous traits within the group.
This is evident in the evolution of different beak shapes for finches from the Galapagos Islands. They have developed these beaks in order they can get food more easily in their new environment. These changes in shape and form can aid in the creation of new organisms.
Most of the changes that take place are the result of a single mutation, but occasionally, multiple mutations occur at once. The majority of these changes are neither harmful nor even harmful to the organism, however, a small proportion of them can have an advantageous impact on the longevity and reproduction of the species, thus increasing the frequency of these changes in the population over time. 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 inherited characteristics can be altered through conscious choice or by use and abuse, which is called soft inheritance. 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 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 and gorillas and bonobos. Our predecessors walked on two legs, as shown by the first fossils. Genetic and biological similarities suggest that we are closely related to chimpanzees. In fact we are the most closely with chimpanzees in the Pan genus, which includes bonobos and pygmy-chimpanzees. The last common ancestor shared between modern humans and chimpanzees was between 8 and 6 million years old.
As time has passed humans have developed a range of traits, including bipedalism and the use fire. They also developed advanced tools. But it's only in the last 100,000 years or so that the majority of the essential characteristics that differentiate us from other species have emerged. They include language, a large brain, the capacity to construct and use complex tools, and the diversity of our culture.
Evolution occurs when genetic changes allow members of a population to better adapt to their surroundings. Natural selection is the process that triggers this adaptation. Certain characteristics are more desirable than others. The more adjusted are more likely to pass their genes on to the next generation. This is how all species evolve and is the basis for the theory of evolution.
Scientists call this the "law of natural selection." The law states species that have an ancestor in common will tend to develop similar traits as time passes. This is because those characteristics make it easier for them to live and reproduce in their environments.
All organisms have a DNA molecule, which provides the information necessary to direct their growth and development. The DNA molecule consists of base pairs that are spirally arranged around phosphate molecules 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 earliest human species Homo erectus, and Homo neanderthalensis have been found in Africa, Asia and Europe. These fossils, despite differences in their appearance, all support the theory that modern humans' ancestors originated in Africa. Evidence from fossils and genetics suggest that early humans moved out of Africa into Asia and then Europe.