The Berkeley Evolution Site

The Berkeley site contains resources that can help students and teachers understand and teach evolution. The materials are arranged in various learning paths that can be used in a variety of ways for example "What does T. rex look like?"

Charles Darwin's theory of natural selection states that over time creatures that are more adaptable to changing environments do better than those that do not become extinct. Science is concerned with the process of biological evolution.

What is Evolution?

The term "evolution" can be used to refer to a variety of nonscientific meanings. For example it could refer to "progress" and "descent with modifications." Scientifically it is a term used to describe a changes in the traits of living organisms (or species) over time. This change is based in biological terms on natural selection and drift.

Evolution is a fundamental principle in the field of biology today. It is a theory that has been tested and proven through thousands of scientific tests. Evolution does not deal with spiritual beliefs or God's presence like other theories of science, such as the Copernican or germ theory of disease.

Early evolutionists, such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical characteristics were predetermined to change in a stepped-like manner over time. They referred to this 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.

Darwin revealed his theory of evolution in his book On the Origin of Species which was written in the early 1800s. It asserts that all species of organisms share an ancestry that can be traced by fossils and other evidence. This is the modern view on evolution, and is supported by a variety of scientific fields that include molecular biology.

Scientists aren't sure the evolution of organisms but they are sure that natural selection and genetic drift is the primary reason for the evolution of life. People with desirable traits are more likely to live and reproduce. These individuals then pass their genes on to the next generation. As time passes this leads to an accumulation of changes in the gene pool which gradually result in new species and forms.

Some scientists use the term"evolution" in reference to large-scale change, such as the evolution of one species from an ancestral one. Certain scientists, including population geneticists, define evolution in a broad sense, referring to the net variation in the frequency of alleles over generations. Both definitions are acceptable and precise however, some scientists claim that the allele-frequency definition is missing crucial aspects of the evolutionary process.

Origins of Life

The birth of life is an essential step in evolution. This happens when living systems begin to evolve at the micro level - within cells, for instance.

The origins of life are an important issue in a variety of fields such as biology and chemistry. The nature of life is a topic of interest in science, as it is a challenge to the theory of evolution. It is sometimes referred to as "the mystery" of life or "abiogenesis."

Traditionally, the belief that life can emerge from nonliving things is known as spontaneous generation, or "spontaneous evolution." This was a common belief before Louis Pasteur's research showed that it was impossible for the creation of life to happen through the natural process.

Many scientists still think it is possible to transition from nonliving substances to living ones. However, the conditions that are required are extremely difficult to reproduce in a laboratory. This is why researchers studying the beginnings of life are also keen to understand the physical properties of early Earth and other planets.

In addition, the development of life depends on an intricate sequence of chemical reactions that cannot be predicted from the fundamental physical laws alone. These include the reading and re-reading of complex molecules, such as DNA or RNA, in order to make proteins that perform a specific function. These chemical reactions can be compared with the chicken-and-egg problem that is the emergence and growth of DNA/RNA, protein-based cell machinery, is necessary for the onset life. Although without life, the chemistry required to make it possible appears to be working.

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

Evolutionary Changes

Today, the word evolution is used to describe the gradual 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 is a process that increases the frequency of genes which 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 caused by mutations, reshuffling genes during sexual reproduction, and the flow of genes.

While reshuffling and mutation of genes are common in all organisms and the process by which beneficial mutations are more frequent is known as natural selection. As noted above, individuals who have the advantageous trait have a higher reproduction rate than those that do not. This difference in the number of offspring that are produced over a long period of time can cause a gradual change in the average number advantageous traits in a group.

One good example is the increase in the size of the beaks on different species of finches in the Galapagos Islands, which have evolved different shaped beaks to enable them to more easily access food in their new habitat. These changes in form and shape can also aid in the creation of new species.

The majority of changes are caused by one mutation, but sometimes several occur at once. The majority of these changes could be harmful or neutral however, a small percentage could have a positive impact on survival and reproduction with increasing frequency as time passes. Natural selection is a process that can produce the accumulating changes over time that lead to the creation of a new species.

Some people confuse the notion 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 misunderstanding of the nature of evolution, and of the actual biological processes that cause it. A more accurate description is that evolution is a two-step procedure which involves the separate and often antagonistic forces of mutation and natural selection.

Origins of Humans


Humans of today (Homo sapiens) evolved from primates - a group of mammals that also includes chimpanzees and gorillas and bonobos. Our predecessors walked on two legs, as shown by the first fossils. Genetic and biological similarities suggest that we are closely related to chimpanzees. In fact our closest relatives are chimpanzees belonging to the Pan genus. This includes pygmy, as well as bonobos. The last common ancestor between modern humans and chimpanzees was 8 to 6 million years old.

In the course of time, humans have developed a variety of traits, including bipedalism and the use of fire. They also developed advanced tools. It is only within the last 100,000 years that we have developed the majority of our essential characteristics. They include language, a large brain, the capacity to build and use sophisticated tools, and a cultural diversity.

Evolution happens when genetic changes allow members of a population to better adapt to their environment. This adaptation is triggered by natural selection, a process whereby certain traits are favored over others. The ones with the best adaptations are more likely to pass their genes to the next generation. This is the process that evolves all species and is the basis of the theory of evolution.

에볼루션 call this the "law of natural selection." The law states that species that have a common ancestor, tend to develop similar traits over time. It is because these traits allow them to survive and reproduce within their environment.

Every living thing has a DNA molecule, which contains the information needed to direct their growth and development. The DNA molecule is composed of base pairs arranged spirally around sugar molecules and phosphate molecules. The sequence of bases within each strand determines the phenotype, the distinctive appearance and behavior of an individual. Variations in a population are caused by mutations and reshufflings in genetic material (known collectively as alleles).

Fossils of the first human species, Homo erectus and Homo neanderthalensis, have been found in Africa, Asia, and Europe. These fossils, despite differences in their appearance all support the idea that modern humans' ancestors originated in Africa. The fossil and genetic evidence suggests that early humans left Africa and moved to Asia and Europe.