Explain Natural Selection Quick Check
Natural selection causes changes in
populations.
populations.
phenotypes.
phenotypes.
genotypes.
genotypes.
individuals.
Natural selection causes changes in phenotypes within populations. This means that certain traits or characteristics become more or less common in a population over time due to environmental pressures and the survival and reproduction of individuals with certain traits. Through the process of natural selection, certain genotypes (genetic makeup) that result in advantageous phenotypes may become more prevalent in a population, while those that result in disadvantageous phenotypes may become less prevalent or even disappear entirely. However, it is important to note that natural selection acts on individuals rather than the population as a whole.
Natural selection is a fundamental concept in evolutionary biology that helps explain how populations change over time. It is essentially a process where certain traits or characteristics of organisms become more or less common in a population due to their impact on survival and reproduction.
1. Changes in populations: Natural selection causes changes in populations over generations. It acts on the variation that exists within a population and can lead to the appearance of new traits or the reduction or elimination of existing traits.
2. Phenotypes: Natural selection influences the distribution of phenotypes within a population. Phenotypes refer to the observable physical and functional characteristics of an organism, such as its size, color, behavior, etc. Through natural selection, certain phenotypes may become more advantageous for survival and reproduction, leading to their increased prevalence in a population.
3. Genotypes: Natural selection ultimately acts on the genetic variation within a population, which is reflected in the different genotypes individuals possess. Genotypes represent the specific genetic makeup of an organism, including the combination of alleles (alternative forms of genes) they carry. Certain genotypes may confer advantages in terms of survival and reproduction, and thus become more frequent in subsequent generations due to natural selection.
4. Individuals: Although natural selection operates on the genetic variation within populations, it is important to note that it acts on individuals. Individuals with traits that enhance their chances of survival and reproduction are more likely to pass on their genes to future generations. Through repeated iterations of this process, the characteristics that improve the fitness (ability to survive and reproduce) of individuals become more prevalent within populations over time.
The concept of natural selection is a fundamental principle of evolution. It explains how species change over time and adapt to their environments. It is the process by which certain traits or characteristics become more or less common in a population over generations.
In order to understand natural selection, you need to consider the following points:
1. Changes in populations: Natural selection causes changes in populations over time. This occurs because different individuals within a population have variations in their traits. These variations can be genetic or non-genetic.
2. Phenotypes: Phenotype refers to the observable physical traits of an individual, such as its size, color, behavior, or any other characteristic. Natural selection acts on phenotypes, meaning it favors certain phenotypes over others in specific environmental conditions. For example, if a population of deer lives in an area with tall grass, those deer with longer legs may have an advantage in survival because they can better navigate through the grass and escape predators.
3. Genotypes: Genotype refers to the combination of genes an individual possesses. These genes determine the traits expressed in an organism. Natural selection indirectly acts on genotypes by selecting for or against certain phenotypes. For example, if certain genes are responsible for the longer legs in deer, individuals with those genes are more likely to have the advantageous phenotype of longer legs.
4. Individuals: Natural selection acts on individuals within a population. When certain phenotypes provide individuals with a greater chance of survival and reproduction, those individuals are more likely to pass on their genes to the next generation. Over time, this leads to a higher frequency of the advantageous traits in the population, as they become more common.
To summarize, natural selection causes changes in populations by acting on phenotypes, which are influenced by genotypes. It acts on individuals by favoring certain traits that provide better survival and reproductive success.