- What is evolution?
- RELATED WORDS
- Darwin's Theory of Evolution: Definition & Evidence
- Should Evolution Treat Our Microbes as Part of Us?
What is evolution?
The theory of evolution is based on the idea that all species are related and gradually change over time. Evolution relies on there being genetic variation in a population which affects the physical characteristics phenotype of an organism. Some of these characteristics may give the individual an advantage over other individuals which they can then pass on to their offspring.
What is natural selection? Individuals in a species show variation in physical characteristics. This variation is because of differences in their genes. Individuals with characteristics best suited to their environment are more likely to survive, finding food, avoiding predators and resisting disease. These individuals are more likely to reproduce and pass their genes on to their children. Individuals that are poorly adapted to their environment are less likely to survive and reproduce.
Therefore their genes are less likely to be passed on to the next generation. As a consequence those individuals most suited to their environment survive and, given enough time, the species will gradually evolve. Natural selection in action: the Peppered moth Before the industrial revolution in the mids, the peppered moth was most commonly a pale whitish colour with black spots.
This colouring enabled them to hide from potential predators on trees with pale-coloured bark, such as birch trees. The rarer dark-coloured peppered moths were easily seen against the pale bark of trees and therefore more easily seen by predators.
- Darwin's Theory Of Evolution!
- The Art of Preserving Poultry: A Little Book Full of All the Information You Need.
- Fresh Wounds: Early Narratives of Holocaust Survival?
- Never Alone!
A pale peppered moth on an oak tree. Image credit: Shutterstock.
A pale peppered moth on a dark tree. Related Content:. Evolution of modern humans.
Evolution of the human brain. Are humans still evolving? What is genetic variation? Natural selection was the fundamental concept in his explanation. Natural selection occurs because individuals having more-useful traits, such as more-acute vision or swifter legs, survive better and produce more progeny than individuals with less-favourable traits. Genetics , a science born in the 20th century, reveals in detail how natural selection works and led to the development of the modern theory of evolution.
Beginning in the s, a related scientific discipline , molecular biology , enormously advanced knowledge of biological evolution and made it possible to investigate detailed problems that had seemed completely out of reach only a short time previously—for example, how similar the gene s of humans and chimpanzees might be they differ in about 1—2 percent of the units that make up the genes. This article discusses evolution as it applies generally to living things.
For a discussion of human evolution, see the article human evolution. For a more complete treatment of a discipline that has proved essential to the study of evolution, see the articles genetics, human and heredity.
- Regards Metisses (French Edition)?
- RELATED CONTENT.
- Variation and Heritability.
Specific aspects of evolution are discussed in the articles coloration and mimicry. Applications of evolutionary theory to plant and animal breeding are discussed in the articles plant breeding and animal breeding. A detailed discussion of the life and thought of Charles Darwin is found in the article Darwin, Charles.
Darwin's Theory of Evolution: Definition & Evidence
Darwin and other 19th-century biologists found compelling evidence for biological evolution in the comparative study of living organisms, in their geographic distribution, and in the fossil remains of extinct organisms. The amount of information about evolutionary history stored in the DNA and proteins of living things is virtually unlimited; scientists can reconstruct any detail of the evolutionary history of life by investing sufficient time and laboratory resources. Evolutionists no longer are concerned with obtaining evidence to support the fact of evolution but rather are concerned with what sorts of knowledge can be obtained from different sources of evidence.
The following sections identify the most productive of these sources and illustrate the types of information they have provided.
Should Evolution Treat Our Microbes as Part of Us?
Evolution scientific theory. Written By: Francisco Jose Ayala. See Article History. Read More on This Topic.