Phenotypes can be caused by genes, environmental factors, or a combination of both. Phenotypic variation, then, is the variability in phenotypes that exists in a population. For example, people come in all shapes and sizes: height, weight, and body shape are phenotypes that vary.
What are possible causes of phenotypic variations?
Phenotypic variations may be caused by differences in long-term programming of gene function rather than variation in gene sequences per se, and studies of the basis for inter-individual phenotypic diversity should consider epigenetic variations in addition to genetic sequence polymorphisms.
What factors affect a phenotype?
An organism’s phenotype results from two basic factors: the expression of an organism’s genetic code, or its genotype, and the influence of environmental factors. Both factors may interact, further affecting phenotype.
What are the three main sources of phenotypic variation?
Overall, the main sources of genetic variation are the formation of new alleles, the altering of gene number or position, rapid reproduction, and sexual reproduction.
What are the two types of phenotypic variation?
The phenotypic variation in populations is the result of genetic variation and two nongenetic sources of variation, namely, environmentally induced variation (EIV) and stochastic developmental variation (SDV).
What is phenotypic change?
Phenotypic plasticity refers to some of the changes in an organism’s behavior, morphology and physiology in response to a unique environment.
What causes increased phenotypic and genetic variation?
Because natural selection acts directly only on phenotypes, more genetic variation within a population usually enables more phenotypic variation. Some new alleles increase an organism’s ability to survive and reproduce, which then ensures the survival of the allele in the population.
What are other factors besides genotype that affect phenotype?
Various factors, including genetic makeup, exposure to harmful substances, other environmental influences, and age, can affect expressivity. Both penetrance and expressivity can vary: People with the gene may or may not have the trait and, in people with the trait, how the trait is expressed can vary.
How can a change in genotype affect phenotype?
An organism’s genotype is the set of genes that it carries. … However, since an organism’s genotype generally affects its phenotype, the phenotypes that make up the population are also likely to change. For example, differences in the genotypes can produce different phenotypes.
How does genotype affect phenotype?
Genotype & Phenotype. Definitions: phenotype is the constellation of observable traits; genotype is the genetic endowment of the individual. Phenotype = genotype + development (in a given environment). … In a narrow “genetic” sense, the genotype defines the phenotype.
What maintains phenotypic variation?
Two types of factors are recognized as contributing to the phenotypic variation in a population, genetic and environmental.
What environmental factors can cause phenotypic variation in plants and animals?
Environment Can Impact Phenotype
Environmental factors such as diet, temperature, oxygen levels, humidity, light cycles, and the presence of mutagens can all impact which of an animal’s genes are expressed, which ultimately affects the animal’s phenotype.
What causes phenotypic plasticity?
Rather, phenotypic plasticity is a developmental process, and the reaction norms that we usually measure in the adult stage, or at reproductive maturity, are in fact the result of a positive feedback between environments and genes throughout the ontogeny of an organism (Schmalhausen, 1949; Smith-Gill, 1983; Pigliucci …