The Berkeley Evolution Site

The Berkeley site offers resources that can assist students and teachers to understand and teach about evolution. The resources are organized into optional learning paths such as "What did T. rex taste like?"

Charles Darwin's theory of natural selection describes how species who are better able to adapt biologically to changing environment survive over time and those that don't become extinct. Science is about this process of evolution.

What is Evolution?

The term "evolution" can have many nonscientific meanings. For instance it could mean "progress" and "descent with modifications." Scientifically it refers to a changing the characteristics of living things (or species) over time. The reason for this change is biological terms on natural selection and drift.

Evolution is a central tenet of modern biology. It is a well-supported theory that has stood the tests of time and thousands of scientific tests. Evolution does not deal with the existence of God or religious beliefs 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 evolve in a gradual manner over time. This was called the "Ladder of Nature" or 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 claims that different species of organisms share a common ancestry, which can be proven through fossils and other evidence. This is the modern view on evolution, and is supported in a wide range of scientific fields which include molecular biology.

While scientists do not know exactly how organisms developed, they are confident that the evolution of life on earth is a result of natural selection and genetic drift. People with advantages are more likely to survive and reproduce. They transmit their genes to the next generation. Over time this leads to gradual changes in the gene pool which gradually lead to new species and types.

Some scientists use the term evolution in reference to large-scale changes, such the evolution of a species from an ancestral one. Certain scientists, including population geneticists, define the term "evolution" in a more broad sense by referring to the net change in allele frequency over generations. Both definitions are acceptable and precise, although some scientists argue that the definition of allele frequency is lacking essential aspects of the evolution process.

Origins of Life

One of the most crucial steps in evolution is the emergence of life. The emergence of life happens when living systems begin to develop at a micro scale, for instance within individual cells.

The origins of life are an important subject in many areas, including biology and the field of chemistry. The question of how living things got their start is a major topic in science due to it being a major challenge to 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 objects was referred to as "spontaneous generation" or "spontaneous evolutionary". It was a common belief prior to Louis Pasteur's tests proved that the creation of living organisms was not achievable through the natural process.

Many scientists still believe that it is possible to go from nonliving materials to living. However, the conditions needed are extremely difficult to reproduce in labs. Researchers studying the origins of life are also interested in understanding the physical properties of the early Earth and other planets.

The life-cycle of a living organism is dependent on a number of complex chemical reactions, which cannot be predicted by basic physical laws. These include the reading and replication of complex molecules, like DNA or RNA, in order to make proteins that perform a specific function. These chemical reactions are often compared with the chicken-and-egg dilemma of how life came into existence: The appearance of DNA/RNA and protein-based cell machinery is essential for the beginning of life, however, without the appearance of life, the chemical process that allows it isn't working.

Abiogenesis research requires collaboration between researchers from different disciplines. This includes prebiotic chemists planet scientists, astrobiologists geophysicists, geologists, and geophysicists.

Evolutionary Changes

The term "evolution" is used to describe the cumulative changes in genetic characteristics 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 from natural selection.

This latter mechanism increases the number of genes that offer an advantage for survival in a species, resulting in an overall change in the appearance of a group. These evolutionary changes are triggered 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 is 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 numbers of offspring born could result in a gradual shift in the number of beneficial traits in a population.

A good example of this is the growth of beak size on various species of finches found on the Galapagos Islands, which have developed beaks with different shapes to enable them to more easily access food in their new habitat. These changes in shape and form can aid in the creation of new organisms.

The majority of the changes that occur are the result of one mutation, however occasionally several will happen at the same time. The majority of these changes could be neutral or even harmful, but a small number can have a beneficial impact on the survival of the species and reproduce with increasing frequency as time passes. Natural selection is a process that can produce the accumulating change over time that eventually leads 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 altered by conscious choice or abuse. This is a misinterpretation of the biological processes that lead up to evolution. It is more precise to say that evolution is a two-step, separate process, which involves the forces of natural selection as well as mutation.

Origins of Humans

Humans today (Homo sapiens) evolved from primates - a species of mammals that also includes chimpanzees and gorillas and bonobos. The earliest human fossils prove that our ancestors were bipeds, walkers on two legs. Genetic and biological similarities show that we have an intimate relationship with the chimpanzees. In actual fact we are the most closely connected to chimpanzees belonging to the Pan genus that includes pygmy and bonobos and pygmy chimpanzees. The last common ancestor of humans and chimpanzees was between 8 and 6 million years old.

In the course of time humans have developed a variety of characteristics, including bipedalism and the use of fire. They also invented advanced tools. 무료에볼루션 's only within the last 100,000 years that we have developed the majority of our important traits. These include language, large brain, the capacity to create and utilize sophisticated tools, and a the ability to adapt to cultural differences.

Evolution happens when genetic changes allow individuals in a group to better adapt to their environment. Natural selection is the process that drives this adaptation. Certain traits are preferred over others. Those with the better adaptations are more likely to pass on their genes to the next generation. This is how all species evolve and is the foundation for the theory of evolution.

Scientists refer to it as the "law of Natural Selection." The law states that species that have a common ancestor are more likely to develop similar characteristics over time. This is because those traits allow them to live and reproduce in their natural environment.

All organisms possess an molecule called DNA that holds the information needed to guide their growth. 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, or the individual's characteristic appearance and behavior. Variations in a population can be caused by mutations and reshufflings of genetic material (known collectively as alleles).

Fossils from the first human species, Homo erectus, as well as Homo neanderthalensis have been found in Africa, Asia and Europe. These fossils, despite some variations in their appearance, all support the hypothesis that modern humans' ancestors originated in Africa. The fossil and genetic evidence suggests that early humans left Africa and migrated to Asia and Europe.