15 Great Documentaries About Evolution Site
에볼루션 블랙잭 Site
The Berkeley site offers resources that can help students and teachers to understand and teach about evolution. The resources are organized into different learning paths like "What does T. rex look like?"
Charles Darwin's theory on natural selection describes how species that are better equipped to adapt biologically to changing environment survive over time and those that do not disappear. Science is all about this process of evolution.
What is Evolution?
The term "evolution" can have many nonscientific meanings, including "progress" or "descent with modification." Scientifically, it refers to a change in the characteristics of living organisms (or species) over time. In biological terms this change is due to natural selection and genetic drift.
Evolution is an important concept in the field of biology today. It is an established theory that has stood the tests of time and thousands of scientific studies. Unlike many other scientific theories such as the Copernican theory or the germ theory of disease, evolution does not address issues of religion or God's existence.
Early evolutionists such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical characteristics were predetermined to change in a gradual manner over time. This was known as 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.
In the early 1800s, Darwin formulated his theory of evolution and published it in his book On the Origin of Species. It claims that different species of organisms share the same ancestry, which can be traced through fossils and other evidence. This is the current perspective on evolution, and is supported in many disciplines which include molecular biology.
Although scientists aren't able to determine the exact mechanism by which organisms evolved, they are confident that the evolution of life on earth is a result of natural selection and genetic drift. People with desirable traits are more likely to survive and reproduce, and they transmit their genes to the next generation. As time passes the gene pool gradually changes and develops into new species.
Some scientists also employ the term"evolution" to refer to large-scale evolutionary changes like the creation of a new species from an ancestral species. Other scientists, like population geneticists, define it more broadly, referring to a net change in the frequency of alleles across generations. Both definitions are valid and palatable, but some scientists argue that allele-frequency definitions miss important aspects of the evolution.
Origins of Life
The most important step in evolution is the emergence of life. This occurs when living systems begin to develop at the micro level - within cells, for instance.
The origins of life are an important issue in many disciplines, including biology and chemical. The question of how living things got their start is a major topic in science because it is a major challenge to the theory of evolution. It is often called "the mystery of life," or "abiogenesis."
The notion that life could be born from non-living objects was referred to as "spontaneous generation" or "spontaneous evolutionary". This was a popular belief prior to Louis Pasteur's experiments proved that the creation of living organisms was not achievable through the natural process.
Many scientists believe it is possible to go from living to nonliving substances. However, the conditions required are extremely difficult to replicate in labs. Researchers interested in the evolution and origins of life are also eager to know the physical properties of the early Earth as well as other planets.
Additionally, the evolution of life is dependent on a sequence of very complex chemical reactions that can't be predicted from basic physical laws on their own. This includes the conversion of long information-rich molecules (DNA or RNA) into proteins that carry out some function and the replication of these complex molecules to produce new DNA or sequences of RNA. These chemical reactions are comparable to the chicken-and-egg issue: the emergence and development of DNA/RNA, the protein-based cell machinery, is necessary to begin the process of becoming a living organism. But without life, the chemistry that is required to enable it does appear to work.
Research in the area of abiogenesis requires collaboration between scientists from a variety of fields. This includes prebiotic chemists, planet scientists, astrobiologists geophysicists, geologists, and geophysicists.
Evolutionary Changes
The term "evolution" is typically used today to refer to the accumulated changes in the genetic characteristics of populations over time. These changes could result from adaptation to environmental pressures as discussed in the entry on Darwinism (see the entry on Charles Darwin for background) or may result from natural selection.
This process increases the number of genes that provide the advantage of survival for an animal, resulting in an overall change in the appearance of the group. These changes in evolutionary patterns are caused by mutations, reshuffling genes during sexual reproduction and the flow of genes.
While mutation and reshuffling of genes occur in all living things and the process by which beneficial mutations are more prevalent is known as natural selection. As mentioned above, those with the beneficial characteristic have a higher reproduction rate than those who do not. This difference in the number of offspring born over a number of generations could result in a gradual change in the number of advantageous characteristics in 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 habitat. These changes in shape and form could also help create new organisms.
The majority of changes are caused by one mutation, however sometimes multiple occur at the same time. Most of these changes are not harmful or even harmful to the organism, however, a small proportion of them can have a positive impact on survival and reproduction, thus increasing their frequency in the population over time. Natural selection is a process that could result in the accumulation of changes over time that lead to the creation of a new species.
Some people confuse the notion of evolution with the notion that the traits inherited from parents can be altered by conscious choice or by use and abuse, which is known as soft inheritance. This is a misunderstood understanding of the nature of evolution, and of the actual biological processes that lead to it. It is more accurate to say that the process of evolution is a two-step independent process, that is influenced by the forces of natural selection and mutation.
Origins of Humans
Humans today (Homo sapiens) evolved from primates - a species of mammals that includes chimpanzees and gorillas and bonobos. The earliest human fossils indicate that our ancestors were bipeds, walkers on two legs. Genetic and biological similarities show that we have the same ancestry with chimpanzees. In fact, our closest relatives are the chimpanzees of the Pan genus. This includes pygmy and bonobos. The last common ancestor between humans and chimpanzees was 8 to 6 million years old.
As time has passed, humans have developed a variety of traits, including bipedalism and the use of fire. They also created advanced tools. It is only within the last 100,000 years that we have developed the majority of our essential characteristics. These include a big brain that is sophisticated human ability to build and use tools, and the diversity of our culture.
Evolution happens when genetic changes allow individuals of a population to better adapt to their environment. Natural selection is the mechanism that triggers this adaptation. Certain traits are preferred over others. Those with the better adaptations 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 call it the "law of natural selection." The law states that species that have a common ancestor are more likely to develop similar traits over time. It is because these traits allow them to live and reproduce in their environment.
Every organism has a DNA molecule that contains the information needed to guide their growth. The DNA molecule is made up 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 unique appearance and behavior. 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. Although there are some differences the fossils all support the idea that modern humans first appeared in Africa. Genetic and fossil evidence also suggest that early humans moved out of Africa into Asia and then Europe.