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The History Of Evolution Site In 10 Milestones
The Berkeley Evolution Site

Students and teachers who explore the Berkeley site will find a wealth of resources to help them understand and teach evolution. The materials are organized in different learning paths, such as "What does T. rex look like?"

Charles Darwin's theory of natural selection explains that over time creatures that are better able to adapt biologically to changing environments thrive, and those that don't become extinct. Science is about this process of evolution.


What is Evolution?

The word evolution has many nonscientific meanings, including "progress" or "descent with modification." Scientifically, it refers to a process of changing the characteristics of organisms (or species) over time. The reason for this change is biological terms on natural drift and selection.

Evolution is one of the fundamental tenets of modern biology. It is a well-supported theory that has withstood the test of time and thousands of scientific experiments. In contrast to other theories in science, 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 such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical traits were predetermined to evolve in a gradual manner over time. They referred to this as the "Ladder of Nature" or the scala naturae. Charles Lyell first used this term in 1833 in his Principles of Geology.

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 determined through fossils and other lines of evidence. This is the current view on evolution, which is supported in a wide range of areas of science which include molecular biology.

While scientists do not know exactly how organisms developed but they are certain 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.

Certain scientists use the term evolution in reference to large-scale changes, such the formation of one species from an ancestral one. Other scientists, like population geneticists, define the term "evolution" more broadly, referring to an overall variation in the frequency of alleles over generations. Both definitions are correct and acceptable, however some scientists argue that allele-frequency definitions do not include important aspects of evolutionary process.

click the next web page of Life

The emergence of life is a key step in evolution. This happens when living systems begin to develop at the micro level - within individual cells, for instance.

The origin of life is a topic in many disciplines that include biology, chemistry and geology. The origin of life is an area of interest in science, as it is a challenge to the theory of evolution. It is often referred to "the mystery" of life or "abiogenesis."

The idea that life could emerge from non-living objects was referred to as "spontaneous generation" or "spontaneous evolutionary". It was a popular belief before Louis Pasteur's tests proved that the development of living organisms was not achievable through a natural process.

Many scientists still think it is possible to move from nonliving to living substances. However, the conditions needed are extremely difficult to reproduce in labs. This is why researchers investigating the beginnings of life are also interested in determining the physical properties of early Earth and other planets.

The growth of life is also dependent on a series of complex chemical reactions which are not predicted by simple physical laws. These include the transformation of long information-rich molecules (DNA or RNA) into proteins that perform functions, and the replication of these complex molecules to produce new DNA or sequences of RNA. These chemical reactions are often compared to the chicken-and-egg issue of how life began with the emergence of DNA/RNA and protein-based cell machinery is crucial for the beginning of life, but without the development of life the chemistry that makes it possible does not appear to work.

Research in the field of abiogenesis requires collaboration among scientists from various fields. This includes prebiotic chemists planet scientists, astrobiologists geophysicists and geologists.

Evolutionary Changes

Today, the word evolution is used to describe general changes in genetic traits over time. These changes can 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 latter mechanism increases the number of genes that confer an advantage for survival in a species, resulting in an overall change in the appearance of a group. These evolutionary changes are caused by mutations, reshuffling genes in the process of sexual reproduction, and also by gene flow.

Natural selection is the process that allows beneficial mutations to become more common. All organisms undergo mutations and reshuffles of their genes. This happens because, as mentioned above, those individuals with the beneficial trait tend to have a higher reproductive rate than those with it. Over the course of many generations, this difference in the number of offspring born could result in gradual changes in the average number of advantageous traits in a population.

This is evident in the evolution of different beak shapes for finches from the Galapagos Islands. They have created these beaks to ensure that they can eat more easily in their new habitat. These changes in the shape and form of organisms can also be a catalyst for the creation of new species.

The majority of changes are caused by a single mutation, however sometimes multiple occur simultaneously. The majority of these changes are not harmful or even detrimental 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. This is the process of natural selection and it is able to, over time, produce the accumulating changes that ultimately lead to an entirely new species.

Some people think that evolution is a form of soft inheritance, which is the idea that inherited traits can be changed through deliberate choice or misuse. This is a misunderstanding of the nature of evolution, and of the actual biological processes that lead to it. A more accurate description of evolution is that it is a two-step process which involves the separate, and often competing, forces of mutation and natural selection.

Origins of Humans

Humans of today (Homo sapiens) evolved from primates - a species of mammals that also includes chimpanzees and gorillas and bonobos. The earliest human fossils indicate that our ancestors were bipeds. They were walkers with two legs. Biological and genetic similarities indicate that we have a close relationship with the chimpanzees. In actual fact we are the closest related to the chimpanzees within the Pan Genus, which includes bonobos and pygmy-chimpanzees. The last common human ancestor as well as chimpanzees lived between 8 and 6 million years ago.

Over time humans have developed a range of characteristics, such as bipedalism as well as the use of fire. They also created advanced tools. It is only within the last 100,000 years that we've developed the majority of our important traits. They include language, a large brain, the capacity to construct and use complex tools, and cultural diversity.

Evolution occurs when genetic changes allow individuals in a group to better adapt to their surroundings. Natural selection is the mechanism that drives this change. 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 way all species evolve, and the foundation for the theory of evolution.

Scientists call this the "law of natural selection." The law states that species that share an ancestor will tend to develop similar characteristics over time. This is because those traits make it easier for them to survive and reproduce in their natural environment.

Every organism has an molecule called DNA that holds the information needed to guide their growth. The DNA molecule is made up of base pairs that are arranged in a spiral around sugar molecules and phosphate molecules. The sequence of bases within each strand determines the phenotype which is the person's distinctive appearance and behavior. Variations in a population can be caused by reshufflings and mutations of 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 variations in their appearance, all support the hypothesis of modern humans' origins in Africa. The fossil evidence and genetic evidence suggest that early humans moved out of Africa into Asia and then Europe.