The Berkeley Evolution Site

Students and teachers who explore the Berkeley site will find a wealth of resources to aid in understanding and teaching evolution. The materials are organized in optional learning paths for example "What does T. rex look like?"

Charles Darwin's theory of natural selection explains how in time, creatures more adaptable to changing environments survive and those that don't become extinct. Science is all about this process of evolution.

What is Evolution?

The term "evolution" has a variety of nonscientific meanings, including "progress" or "descent with modification." Scientifically it is a term used to describe a changing the characteristics of organisms (or species) over time. In terms of biology, this change is caused by natural selection and genetic drift.

Evolution is one of the fundamental tenets of modern biology. It is a theory that has been verified by thousands of scientific tests. Evolution does not deal with God's presence or spiritual beliefs, unlike many other scientific theories such as the Copernican or germ theory of disease.

Early evolutionists, such as Jean-Baptiste Lamarck and Erasmus Darwin (Charles's grandfather) believed that certain physical traits were predetermined to change in a step-wise manner, as time passes. This was referred to 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 states that all species of organisms have a common ancestry which can be traced through fossils and other evidence. This is the current perspective on evolution, and is supported in many areas of science which include molecular biology.

Scientists aren't sure the evolution of organisms, but they are confident that natural selection and genetic drift is the reason for the development of life. People with traits that are advantageous are more likely to survive and reproduce, and these individuals transmit their genes to the next generation. Over time, the gene pool gradually changes and develops into new species.

Certain scientists use the term evolution in reference to large-scale changes, such the formation of a species from an ancestral one. Other scientists, such as population geneticists, define the term "evolution" more broadly by referring to an overall variation in the frequency of alleles over generations. Both definitions are accurate and acceptable, however some scientists argue that allele-frequency definitions omit important features of evolution.

Origins of Life

The most important step in evolution is the appearance of life. This occurs when living systems begin to evolve at the micro level - within individual cells, for example.

The origins of life is an issue in a variety of disciplines, including biology, chemistry and geology. The origin of life is an area that is of immense interest to scientists, as it challenges the theory of evolution. It is often referred to as "the mystery of life," or "abiogenesis."

Traditionally, the notion that life could emerge from nonliving objects is known as spontaneous generation, or "spontaneous evolution." This was a popular view before Louis Pasteur's experiments proved that it was impossible for the emergence of life to happen through an entirely natural process.

Many scientists still think it is possible to transition from living to nonliving substances. The conditions needed to make life are not easy to replicate in a laboratory. 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.

The development of life is dependent on a variety of complex chemical reactions which are not predicted by basic physical laws. These include the reading and re-reading of complex molecules, such as DNA or RNA, to create proteins that serve a specific function. These chemical reactions are often compared with the chicken-and-egg issue of how life began: The development of DNA/RNA as well as proteins-based cell machinery is vital for the beginning of life, however, without the appearance of life the chemical reaction that is the basis for it is not working.

Research in the area of abiogenesis requires collaboration among scientists from many different disciplines. This includes prebiotic chemists, planet scientists, astrobiologists geophysicists, geologists, and geophysicists.

Evolutionary Changes

Today, the word 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 explained in Darwinism.

The latter is a mechanism that increases the frequency of genes that confer an advantage in survival over other species, resulting in an ongoing change in the overall appearance of a group. The specific mechanisms responsible for these changes in evolutionary process include mutation, reshuffling of genes during sexual reproduction, and gene flow between populations.

Natural selection is the process that makes beneficial mutations more frequent. All organisms undergo changes and reshuffles of genes. As previously mentioned, those who have the advantageous trait have a higher reproductive rate than those who do not. This differential in the number of offspring that are produced over a long period of time can result in a gradual shift in the average number of beneficial traits in a group.

A good example of this is the growing beak size on various species of finches found on the Galapagos Islands, which have evolved different shaped beaks to allow them to more easily access food in their new habitat. These changes in shape and form could also aid in the creation of new species.


The majority of the changes that take place are the result of one mutation, however sometimes, several changes occur simultaneously. Most of these changes may be harmful or neutral, but a small number can have a beneficial impact on the survival of the species and reproduce with increasing frequency over time. This is the process of natural selection and it can be a time-consuming process that produces the gradual changes that eventually lead to the creation of a new species.

Many people confuse the concept of evolution with the notion that traits inherited can be altered by conscious choice or use and abuse, which is known as soft inheritance. This is a misinterpretation of the biological processes that lead to the process of evolution. It is more accurate to say that the process of evolution is a two-step, separate process that involves the forces of natural selection as well as mutation.

Origins of Humans

Modern humans (Homo Sapiens) evolved from primates, which is a group of mammal species that includes chimpanzees as well as gorillas. The earliest human fossils prove that our ancestors were bipeds. They were walkers with two legs. Genetic and biological similarities show that we share a close relationship with chimpanzees. In reality we are the closest with chimpanzees in the Pan Genus that includes pygmy and bonobos and pygmy chimpanzees. The last common human ancestor as well as chimpanzees was born between 8 and 6 million years ago.

Over time, humans have developed a variety of characteristics, such as bipedalism as well as the use of fire. They also created advanced tools. But it's only in the last 100,000 years or so that most of the essential characteristics that differentiate us from other species have developed. These include language, a large brain, the capacity to construct and use complex tools, and the diversity of our culture.

The process of evolution occurs when genetic changes allow individuals in a group to better adapt to their surroundings. Natural selection is the mechanism that drives this adaptation. Certain traits are preferred over others. People with better adaptations are more likely to pass their genes to the next generation. This is how all species evolve, and the basis for the theory of evolution.

Scientists refer to it as the "law of natural selection." The law states that species which share a common ancestor tend to develop similar traits over time. This is because these traits help them to survive and reproduce within their environment.

Every living thing has a DNA molecule that contains the information necessary to direct their growth. The structure of DNA is made of base pairs arranged in a spiral around sugar and phosphate molecules. The sequence of bases in each string determines the phenotype or the distinctive appearance and behavior of a person. 에볼루션 Links to an external site. in a population are caused by reshufflings and mutations of genetic material (known collectively as alleles).

Fossils of the earliest human species, Homo erectus and Homo neanderthalensis were discovered in Africa, Asia, and Europe. While there are some differences between them the fossils all support the idea that modern humans first came into existence in Africa. The fossil evidence and genetic evidence suggest that early humans migrated from Africa into Asia and then Europe.