In opposition to mutations, modifications are included in the band width of the genome

Genome

In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

 of an individual creature. Modifications are dependent on the plentifulness of the substrate, light, warmths, stress, training, and so on.

A modification is a change in the physical appearance of an organism

Organism

In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...

 (phenotype) caused by environmental factors. Modifications are not inheritable as they do not affect the genes.

Occurrence

Modifications often occur in domesticated animals: Decrease of the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

 weight by 20 to 30 percent, decline of the cerebral cleavage

Cleavage (embryo)

In embryology, cleavage is the division of cells in the early embryo. The zygotes of many species undergo rapid cell cycles with no significant growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a...

 especially in the projection areas of the sense organs, changes in the hormone

Hormone

A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

 status and in the behaviour.

Modificability

In heredity the genes of the parents are passed on to their offspring unchanged. That is why the organisms which carry the same genotype

Genotype

The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...

 should be identical in every feature. However, this is not the case. Due to environmental conditions they can vary from each other up to a certain point. There are two types of modifications: the continuous modification and the switching modification.

To illustrate the modificability you can take a look at our cultivated plants. The harvest of those plants do not only depend on the quality of the seeds but also greatly on environmental factors like the condition of the soil, the nutrient content of the soil, the fertilization, the humidity

Humidity

Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...

 and temperature

Temperature

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

 as well as the interference of other plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s.

Example: Dandelion

If you take a lowland dandelion and plant half of it in the lowland and the other half in the mountains the result will be a dandelion with big leaves in the lowland and one with small leaves in the mountains. The reason is that in the lowland the environmental conditions are different from those in the mountains.