In addition, when eggs and sperm are produced, genetic material is shuffled and recombined in ways that produce new combinations of genes. Sexual reproduction thus increases genetic variation, which increases the raw material on which natural selection operates. Genetic variation within a species -- also known as genetic diversity -- increases a species' opportunity for change over successive generations.
Learn More The Advantage of Sex. Evolution is not a random process. The genetic variation on which natural selection acts may occur randomly, but natural selection itself is not random at all.
The survival and reproductive success of an individual is directly related to the ways its inherited traits function in the context of its local environment. Whether or not an individual survives and reproduces depends on whether it has genes that produce traits that are well adapted to its environment. Learn More Life's Grand Design. Evolution and "survival of the fittest" are not the same thing.
Evolution refers to the cumulative changes in a population or species through time. Natural selection works by giving individuals who are better adapted to a given set of environmental conditions an advantage over those that are not as well adapted. Survival of the fittest usually makes one think of the biggest, strongest, or smartest individuals being the winners, but in a biological sense, evolutionary fitness refers to the ability to survive and reproduce in a particular environment.
Popular interpretations of "survival of the fittest" typically ignore the importance of both reproduction and cooperation. To survive but not pass on one's genes to the next generation is to be biologically unfit. And many organisms are the "fittest" because they cooperate with other organisms, rather than competing with them.
Learn More Adaptation and Natural Selection. In the process of natural selection, individuals in a population who are well-adapted to a particular set of environmental conditions have an advantage over those who are not so well adapted.
The advantage comes in the form of survival and reproductive success. For example, those individuals who are better able to find and use a food resource will, on average, live longer and produce more offspring than those who are less successful at finding food. Inherited traits that increase individuals' fitness are then passed to their offspring, thus giving the offspring the same advantages.
Individual organisms don't evolve. Populations evolve. This is why members of the same family tend to have similar characteristics. Selective breeding involves selecting parents that have characteristics of interest in the hope that their offspring inherit those desirable characteristics. If you have any other comments or suggestions, please let us know at comment yourgenome.
Can you spare minutes to tell us what you think of this website? Open survey. In: Facts Society and Behaviour. 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. Then, of course, there are those times that really leave us scratching our heads. And why do men have nipples? Evolution is all about creatures gradually adapting to their environment, right?
For instance, some non-adaptive, or even detrimental, gene variants may be on the same DNA strand as a beneficial variant.
By hitching a ride on the same DNA strand as the useful variant, a non-adaptive gene can quickly spread throughout a population. Some of these mutations will be harmful, and will probably be eliminated by natural selection.
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