5 Reasons Evolution Site Is A Good Thing
The Berkeley Evolution Site
Teachers and students who browse the Berkeley site will find resources to assist them in understanding and teaching evolution. The materials are organized in optional learning paths like "What does T. rex look like?"
Charles Darwin's theory of natural selection explains that over time creatures that are more able to adapt to changing environments survive and those that are not extinct. This process of evolution is the basis of science.
What is Evolution?
The word evolution has many nonscientific meanings, such as "progress" or "descent with modification." Scientifically it refers to a process of changing the characteristics of living organisms (or species) over time. This change is based in biological terms on natural selection and drift.
Evolution is the central tenet of modern biology. It is a concept that has been tested and verified through thousands of scientific tests. Contrary to other theories of science like 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 traits were predetermined to change in a step-like manner, as time passes. This was known 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.
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 have a common ancestry, which can be traced through fossils and other lines of evidence. This is the modern view of evolution that is supported by numerous lines of research in science, including molecular genetics.
While scientists don't know exactly how organisms developed, 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 live and reproduce, and they transmit their genes to the next generation. Over time the gene pool slowly changes and develops into new species.
Some scientists use the term evolution in reference to large-scale changes, like the development of a species from an ancestral one. Certain scientists, including population geneticists, define the term "evolution" in a broad sense, referring to the net change in the frequency of alleles across generations. Both definitions are valid and acceptable, however some scientists believe that allele-frequency definitions miss important aspects of the evolutionary process.
Origins of Life
A key step in evolution is the appearance of life. The emergence of life occurs when living systems begin to develop at a microscopic level, like within individual cells.
The origin of life is an issue in a variety of disciplines such as geology, chemistry, biology and chemistry. The nature of life is a topic that is of immense interest to scientists, as it challenges the theory of evolution. It is often referred to "the mystery" of life or "abiogenesis."
The notion that life could be born from non-living matter was known as "spontaneous generation" or "spontaneous evolutionary". This was a popular belief prior to Louis Pasteur's tests proved that the development of living organisms was not achievable through a natural process.
Many scientists still believe that it is possible to go from nonliving materials to living. However, the conditions that are required are extremely difficult to reproduce in the laboratory. Researchers who are interested in the origins and development of life are also keen to learn about the physical characteristics of the early Earth as well as other planets.
The growth of life is dependent on a number of complex chemical reactions which are not predicted by the basic physical laws. These include the reading and the replication of complex molecules, like DNA or RNA, in order to make proteins that perform a specific function. These chemical reactions can be compared with the chicken-and-egg issue that is the emergence and growth 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 create it is working.
Research in the field of abiogenesis requires collaboration between scientists from a variety of disciplines. This includes prebiotic scientists, astrobiologists and planet 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 be the result of the adaptation to environmental pressures as explained in Darwinism.
The latter is a mechanism that increases the frequency of genes that confer an advantage in survival over others which results in a gradual change in the overall appearance of a particular population. These evolutionary changes are triggered by mutations, reshuffling genes during sexual reproduction and gene flow.
While reshuffling and mutation of genes are common in all organisms and the process by which beneficial mutations are more frequent is called natural selection. As mentioned above, those who possess the desirable trait have a higher reproduction rate than those who don't. Over the course of many generations, this difference in the number of offspring produced can result in an inclination towards a shift in the amount of desirable characteristics in a particular population.
This is evident in the evolution of different beak shapes for 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 can also aid in the creation of new species.
The majority of the changes that take place are caused by a single mutation, but occasionally several will happen simultaneously. Most of these changes can be harmful or neutral however, a few can have a beneficial impact on survival and reproduction with increasing frequency over time. This is the process of natural selection, and it can be a time-consuming process that produces the cumulative changes that ultimately lead to a new species.
Some people confuse the notion of evolution with the idea that traits inherited can be changed through conscious choice or use and abuse, which is known as soft inheritance. This is a misunderstanding of the nature of evolution and of the actual biological processes that lead to it. visit is that evolution is a two-step procedure that involves the distinct, and often competing, forces of mutation and natural selection.
Origins of Humans
Modern humans (Homo Sapiens) evolved from primates, which is a group of mammal species which includes gorillas and chimpanzees. The earliest human fossils show that our ancestors were bipeds, walkers on two legs. Biological and genetic similarities indicate that we have an intimate relationship with Chimpanzees. In fact, our closest relatives are the chimpanzees belonging to the Pan genus. This includes pygmy, as well as bonobos. The last common ancestor between humans and chimpanzees was between 8 and 6 million years old.
As time has passed humans have developed a number of characteristics, including bipedalism and the use of fire. They also created advanced tools. It is only in the last 100,000 years or so that the majority of the traits that distinguish us from other species have developed. They include language, a large brain, the capacity to create and utilize complex tools, and the diversity of our culture.
Evolution is when genetic changes allow members of an organization to better adapt to the environment. Natural selection is the mechanism that drives this adaptation. Certain characteristics are more desirable than others. People with better adaptations are more likely to pass their genes to the next generation. This is the process that evolves all species and is the foundation of the theory of evolution.
Scientists refer to this as the "law of natural selection." The law says that species that have a common ancestor are more likely to develop similar characteristics over time. This is because the traits make it easier for them to live and reproduce in their environment.
All organisms have DNA molecules, which is the source of information that helps guide their growth and development. The DNA molecule consists of base pairs that are spirally arranged around sugar molecules and phosphate molecules. The sequence of bases within each strand determines phenotype, or the individual's characteristic appearance and behavior. Different mutations and reshuffling of the genetic material (known as alleles) during reproduction causes variation in a population.
Fossils of the first human species, Homo erectus and Homo neanderthalensis were discovered in Africa, Asia, and Europe. These fossils, despite some differences in their appearance, all support the hypothesis that modern humans' ancestors originated in Africa. Genetic and fossil evidence also suggest that early humans migrated from Africa into Asia and then Europe.