Evolution Site Tips From The Top In The Business
The Berkeley Evolution Site
The Berkeley site offers resources that can assist students and teachers learn about and teach evolution. The resources are organized into a variety of learning paths such as "What did T. rex taste like?"
Charles Darwin's theory on natural selection describes how species who are better equipped to adapt to changes in their environment survive over time and those that do not end up becoming extinct. This process of evolution is what science is all about.
What is Evolution?
The term "evolution" can have many nonscientific meanings, including "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. The reason for this change is biological terms on natural selection and drift.
Evolution is the central tenet of modern biology. It is an accepted theory that has withstood the tests of time and thousands of scientific tests. Evolution doesn't deal with the existence of God or religious beliefs like other theories in science, like the Copernican or germ theory of disease.
Early evolutionists, like Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather) believed that certain physical characteristics were predetermined to change in a step-wise manner, over time. They called this the "Ladder of Nature" or the scala naturae. Charles Lyell first used this term in 1833 in his Principles of Geology.
Darwin presented his theory of evolution in his book On the Origin of Species published in the early 1800s. It states that all species of organisms have common ancestors that can be traced by fossils and other evidence. This is the current view on evolution, and is supported by a variety of areas of science that include molecular biology.
Scientists do not know the evolution of organisms but they are sure that natural selection and genetic drift is responsible for the evolution of life. People with traits that are advantageous are more likely to live and reproduce, and these individuals pass their genes on to the next generation. As time passes, the gene pool gradually changes and develops into new species.
Some scientists also use the term evolution to refer to large-scale evolutionary changes such as the creation of the new species from an ancestral species. Certain scientists, such as population geneticists define evolution in a broad sense, using the term "net change" to refer to the variation in the frequency of alleles over generations. Both definitions are valid and acceptable, however certain scientists argue that allele frequency definitions do not include important aspects of evolutionary process.
Origins of Life
One of the most crucial steps in evolution is the development of life. The beginning of life takes place when living systems start to develop at a micro level, such as within cells.
The origin of life is an important issue in a variety of fields, including biology and chemical. The origin of life is a subject of interest in science because it challenges the theory of evolution. It is often referred to as "the mystery of life" or "abiogenesis."
The idea 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 tests proved that the emergence of living organisms was not possible by the natural process.
Many scientists still believe that it is possible to make the transition from nonliving substances to living. The conditions required for the creation of life are difficult to reproduce in a lab. This is why researchers studying the nature of life are also interested in determining the physical properties of early Earth and other planets.
Furthermore, the growth of life is an intricate sequence of 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, in order to make proteins that serve a specific function. These chemical reactions are often compared with the chicken-and-egg issue of how life first appeared with the emergence of DNA/RNA and protein-based cell machinery is crucial for the onset of life, but without the appearance of life, the chemical process that allows it isn't 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 word evolution is usually used to refer to the accumulated changes in the genetic characteristics of populations over time. These changes may result from the response to environmental pressures as described in the entry on Darwinism (see the entry on Charles Darwin for background) or natural selection.
This is a process that increases the frequency of genes that confer an advantage in survival over other species, resulting in a gradual change in the appearance of a population. These evolutionary changes are triggered by mutations, reshuffling of genes during sexual reproduction, and the flow of genes.
Natural selection is the process that makes beneficial mutations more common. All organisms undergo mutations and reshuffles of genes. This is because, as mentioned above, those individuals with the advantageous trait are likely to have a higher reproductive rate than those who do not have it. Over many generations, this differential in the numbers of offspring born can result in a gradual shift in the average number of beneficial traits within a group of.
This can be seen in the evolution of different beak shapes on finches from the Galapagos Islands. They have developed these beaks so they can get food more easily in their new habitat. These changes in the shape and appearance of living organisms may also aid in the creation of new species.
Most of the changes that occur are caused by one mutation, however sometimes, several changes occur simultaneously. Most of these changes can be negative or even harmful however, a small percentage could have a positive impact on the survival of the species and reproduce with increasing frequency over time. This is the mechanism of natural selection and it could be a time-consuming process that produces the cumulative changes that eventually lead to the creation of a new species.
Many people mistakenly associate evolution with the concept of soft inheritance that is the belief that inherited traits can be changed through conscious choice or by abuse. This is a misinterpretation of the nature of evolution and of the actual biological processes that trigger it. A more precise description is that evolution is a two-step procedure which involves the separate and often conflicting forces of mutation and natural selection.
Origins of Humans
Humans today (Homo sapiens) evolved from primates - a group of mammals that also includes gorillas, chimpanzees, and bonobos. Our ancestral ancestors were walking on two legs, as shown by the earliest fossils. Genetic and biological similarities suggest that we are closely related to Chimpanzees. In actual fact, we are most closely connected to chimpanzees belonging to the Pan Genus, which includes bonobos and pygmy-chimpanzees. Read the Full Article of modern humans and chimpanzees was between 8 and 6 million years ago.
As time has passed humans have developed a range of characteristics, including bipedalism as well as the use of fire. They also developed advanced tools. It is only in the last 100,000 years or so that the majority of the important characteristics that differentiate us from other species have been developed. They include a huge brain that is complex human ability to create and use tools, as well as the diversity of our culture.
Evolution happens when genetic changes allow members of a population to better adapt to their environment. Natural selection is the process that drives this change. Certain characteristics are more desirable than others. The ones who are better adjusted are more likely to pass on their genes to the next generation. This is how all species evolve, and the foundation for 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 as time passes. This is because the traits make it easier for them to survive and reproduce in their environments.
All organisms have a DNA molecule that contains the information needed to guide their growth and development. The DNA structure is composed of base pairs which are arranged in a spiral, around phosphate and sugar molecules. The sequence of bases in each strand determines the phenotype - the characteristic appearance and behavior of an individual. The variations in a population are caused by reshufflings and mutations of genetic material (known collectively as alleles).
Fossils from the early human species Homo erectus, and Homo neanderthalensis have been discovered in Africa, Asia and Europe. Although there are some differences, these fossils all support the hypothesis that modern humans first appeared in Africa. Evidence from fossils and genetics suggest that early humans migrated out of Africa into Asia and then Europe.