Say "Yes" To These 5 Evolution Site Tips
The Berkeley Evolution Site
The Berkeley site contains resources that can help students and teachers to understand and teach about evolution. The resources are organized into a variety of learning paths like "What did T. rex taste like?"
Charles Darwin's theory of natural selection explains that over time creatures that are better able to adapt biologically to changing environments survive and those that do not become extinct. Science is all about this process of evolutionary change.
What is Evolution?
The word evolution can be used to refer to a variety of nonscientific meanings. For example it could mean "progress" and "descent with modifications." Scientifically it is a term used to describe a change in the characteristics of living things (or species) over time. In biological terms, this change is based on natural selection and genetic drift.
Evolution is a fundamental concept in modern biology. It is an accepted theory that has stood up to the tests of time and thousands of scientific experiments. Evolution doesn't deal with spiritual beliefs or God's presence like other scientific theories such as the Copernican or germ theory of diseases.
Early evolutionists, such as Erasmus Darwin (Charles’s grandfather) and Jean-Baptiste Lamarck believed that certain physical characteristics were predetermined to evolve in a step-like fashion over time. This was known 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 an ancestry that can be traced using fossils and other evidence. This is the modern view of evolution, which is supported by a variety of research lines in science that include molecular genetics.
Scientists don't know how organisms evolved however they are certain that natural selection and genetic drift are the primary reason for the development of life. Individuals with advantageous traits are more likely to survive and reproduce, and they pass their genes on to the next generation. As time passes the gene pool gradually changes and develops into new species.
Some scientists also employ the term evolution to refer to large-scale evolutionary changes, such as the formation of a new species from an ancestral species. Certain scientists, such as population geneticists define evolution in a broad sense, using the term "net change" to refer to the change in allele frequency over generations. Both definitions are correct and acceptable, however certain scientists argue that allele frequency definitions miss important aspects of the evolutionary process.
Origins of Life
The most important step in evolution is the appearance of life. This occurs when living systems begin to develop at a micro-level - within individual cells, for example.
The origins of life are an important subject in many fields that include biology and the field of chemistry. The question of how living organisms began has a special place in science due to it being an important challenge to the theory of evolution. It is often called "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 common belief prior to Louis Pasteur's tests proved that the creation of living organisms was not possible through the natural process.
Many scientists believe it is possible to transition from nonliving to living substances. However, the conditions needed are extremely difficult to replicate in labs. This is why researchers investigating the origins of life are also interested in understanding the physical properties of the early Earth and other planets.
In addition, the development of life is an intricate sequence of chemical reactions that cannot be predicted based on basic physical laws on their own. These include the reading and re-reading of complex molecules, such as DNA or RNA, to produce proteins that perform a specific function. These chemical reactions can be compared with a chicken-and egg problem which is the development and emergence of DNA/RNA, protein-based cell machinery, is necessary for the onset life. Although, without life, the chemistry needed to enable it is working.
Research in the field of abiogenesis requires cooperation among scientists from many different fields. This includes prebiotic chemists the astrobiologists, the planet scientists geophysicists, geologists, and geophysicists.
Evolutionary Changes
Today, the word evolution is used to describe general changes in genetic traits over time. These changes may be the result of adaptation to environmental pressures as explained in Darwinism.
This mechanism also increases the frequency of genes that provide an advantage for survival in an animal, resulting in an overall change in the appearance of a group. The specific mechanisms responsible for these changes in evolutionary process include mutation and reshuffling of genes in sexual reproduction, and also gene flow between populations.
Natural selection is the process that makes beneficial mutations more common. All organisms undergo mutations and reshuffles of genes. As noted above, individuals who have the advantageous trait have a higher reproductive rate than those that do not. This differential in the number of offspring produced over many generations can cause a gradual change in the average number advantageous traits in the group.
This can be seen in the evolution of different beak designs on finches that are found in the Galapagos Islands. They have developed these beaks so that they can access food more easily in their new habitat. These changes in shape and form could aid in the creation of new organisms.
The majority of changes are caused by one mutation, but sometimes several 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 survival of the organism and its reproduction, thereby increasing their frequency in the population over time. This is the process of natural selection and it is able to eventually result in the cumulative changes that eventually result in the creation of a new species.
Some people confuse the idea of evolution with the notion that the traits inherited from parents can be changed through conscious choice or use and abuse, a notion called soft inheritance. This is a misinterpretation of the nature of evolution and of the actual biological processes that cause it. It is more accurate to say that the process of evolution is a two-step, independent process, which involves the forces of natural selection and mutation.
Origins of Humans
Modern humans (Homo sapiens) evolved from primates, a group of mammals that includes chimpanzees and gorillas and bonobos. Our ancestors walked on two legs, as evidenced by the earliest fossils. Genetic and biological similarities suggest that we are closely related to chimpanzees. In actual fact we are the most closely with chimpanzees in the Pan genus which includes pygmy chimpanzees and bonobos. The last common ancestor between humans and chimpanzees was between 8 and 6 million years old.
As time has passed, humans have developed a number of characteristics, such as bipedalism and the use of fire. They also developed advanced tools. It is only in the last 100,000 years or so that most of the essential characteristics that differentiate us from other species have been developed. These include a large brain that is complex, the ability of humans to construct and use tools, and cultural diversity.
Evolution happens when genetic changes allow individuals in a group to better adapt to their environment. Natural selection is the mechanism that triggers this adaptation. Certain characteristics are more desirable than others. People with better adaptations are more likely to pass on their genes to the next generation. This is the way all species evolve and is the basis for the theory of evolution.
Evolution KR call this the "law of natural selection." The law states that species that have an ancestor in common will tend to acquire similar traits as time passes. It is because these traits allow them to reproduce and survive within their environment.
Every organism has the DNA molecule, which contains the information necessary to direct their growth. The structure of DNA is made of base pairs which are arranged in a spiral, around sugar and phosphate molecules. The sequence of bases within each strand determines the phenotype - the distinctive appearance and behavior of a person. Variations in a population are 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 discovered in Africa, Asia and Europe. These fossils, despite a few differences in their appearance all support the idea of modern humans' origins in Africa. The evidence from fossils and genetics suggests that early humans left Africa and migrated to Asia and Europe.