5 Reasons Evolution Site Is Actually A Good Thing

The Berkeley Evolution Site

The Berkeley site offers resources that can help students and educators understand and teach evolution. The materials are arranged in optional learning paths like "What does T. rex look like?"

Charles Darwin's theory of natural selection explains how over time, animals that are more able to adapt to changing environments do better than those that do not become extinct. Science is about this process of evolutionary change.

What is Evolution?

The term "evolution" has a variety of nonscientific meanings. For instance "progress" or "descent with modification." Scientifically, it refers to a process of change in the characteristics of organisms (or species) over time. In terms of biology, this change is due to natural selection and genetic drift.

Evolution is a central tenet of modern biology. It is a theory that has been confirmed by thousands of scientific tests. Unlike many other scientific theories like the Copernican theory or the germ theory of disease, the evolution theory does not address issues of religious belief or God's existence.

Early evolutionists, such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical traits were predetermined to evolve in a step-like fashion 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.

Darwin presented his theory of evolution in his book On the Origin of Species, written in the early 1800s. It asserts that all species of organisms have a common ancestry which can be traced by fossils and other evidence. This is the modern view of evolution that is supported by many research lines in science that include molecular genetics.

While scientists do not know exactly how organisms developed however they are sure that the evolution of life on earth is the result of natural selection and genetic drift. People with desirable traits are more likely to live and reproduce. These individuals transmit their genes to the next generation. In time this leads to a gradual accumulation of changes to the gene pool which gradually create new species and types.

Some scientists employ the term"evolution" to refer to large-scale changes, like the evolution of a species from an ancestral one. Other scientists, such as population geneticists, define it more broadly by referring to the net change in the frequency of alleles across generations. Both definitions are accurate and palatable, but some scientists argue that allele-frequency definitions omit important features of evolutionary process.

Origins of Life

One of the most crucial steps in evolution is the development of life. This happens when living systems begin to develop at a micro-level - within individual cells, for example.

The origins of life are a topic in many disciplines, including biology, chemistry and geology. The question of how living things got their start is of particular importance in science because it is 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 emerge from non-living objects was referred to as "spontaneous generation" or "spontaneous evolutionary". This was a popular belief prior to Louis Pasteur's experiments 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 substances to living. However, the conditions needed are extremely difficult to replicate in a laboratory. Researchers who are interested in the origins and development of life are also keen to know the physical properties of the early Earth as well as other planets.

The development of life is also dependent on a series of complex chemical reactions, that are not predicted by basic physical laws. These include the reading and replication of complex molecules, like DNA or RNA, to create proteins that serve a specific function. These chemical reactions are comparable to the chicken-and-egg problem which is the development and emergence of DNA/RNA, the protein-based cell machinery, is essential for the onset life. But, without life, the chemistry required to make it possible does appear to work.

Abiogenesis research requires collaboration with scientists from different disciplines. This includes prebiotic scientists, astrobiologists and planet scientists.

Evolutionary Changes

The term "evolution" is typically used to describe the accumulated changes in the genetic traits of populations over time. These changes could be the result of the adaptation to environmental pressures as described in Darwinism.

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

Natural selection is the process that makes beneficial mutations more frequent.  Full Content  undergo changes and reshuffles of genes. As noted above, individuals who possess the desirable trait have a higher reproduction rate than those who do not. Over the course of many generations, this differential in the number of offspring born can result in an inclination towards a shift in the number of beneficial traits in a population.

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

The majority of the changes that take place are caused by one mutation, however sometimes, several changes occur at the same time. Most of these changes may be neutral or even harmful however, a small percentage could have a positive impact on survival and reproduce and increase their frequency over time. This is the mechanism of natural selection and it can be a time-consuming process that produces the gradual changes that eventually result in a new species.

Some people think that evolution is a form of soft inheritance that is the belief that traits inherited from parents 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. It is more accurate to say that the process of evolution is a two-step independent process, that is influenced by the forces of natural selection and mutation.

Origins of Humans

Humans today (Homo sapiens) evolved from primates - a group of mammals that includes gorillas, chimpanzees, and bonobos. Our ancestors walked on two legs, as evidenced by the earliest fossils. Biological and genetic similarities indicate that we share a close relationship with chimpanzees. In fact we are the closest related to the chimpanzees within the Pan Genus, which includes bonobos and pygmy-chimpanzees. The last common ancestor of modern humans and chimpanzees dated 8 to 6 million years old.

Over time humans have developed a range of characteristics, such as bipedalism and the use of fire.  Full Content  created advanced tools. It is only within the last 100,000 years that we've developed the majority of our essential traits. These include language, large brain, the capacity to build and use complex tools, and the ability to adapt to cultural differences.

The process of evolution is when genetic changes allow members of an organization to better adapt to their environment. Natural selection is the process that triggers this adaptation. Certain traits are preferred over others. The more adapted are more likely to pass their genes on to the next generation. This is the process that evolves all species and forms the basis of the theory of evolution.

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

Every living thing has the DNA molecule, which contains the information necessary to direct their growth. The DNA molecule is composed of base pairs that are spirally arranged around sugar molecules and phosphate molecules. The sequence of bases in each strand determines the phenotype, the characteristic appearance and behavior of a person. A variety of mutations and reshuffling of the genetic material (known as alleles) during reproduction causes variation in a population.

Fossils of the earliest human species, Homo erectus and Homo neanderthalensis have been discovered in Africa, Asia, and Europe. Despite some differences they all support the notion 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.