During the DNA replication process, the parent and the daughter DNA look similar but they won’t be identical. DNA is susceptible to high variations.Complete answer:
-Any difference between organisms in genetic or phenotypic attributes is known as variation in ecology.
-Variation can occur between individuals in any measurable characteristic like size, shape, color, metabolic activity, etc.,
-Variation can be of two types. Interspecific variation and intra-specific variation.
Intraspecific variation: Intraspecific variation means variation within the species and between individuals. One relatable example of intraspecific variation is tall and short stature in humans.
Inter-specific variation: Inter-specific variation means variation between different species of the same genus. For inter-specific variation, we can consider the difference between Homo sapiens and our close cousins, Homo neanderthalensis, an extinct species of archaic humans who had shorter limbs and a broader torso. Inter-specific variation gets even more complex when we compare humans and other primates, though advanced, they are not known to have such extensive verbal communication or complex thought processes.
-Variation can be due to genetic factors (spontaneous mutations in genes encoding proteins) or can be due to the external environment too.
-Considering the trait of height in humans, short stature can be due to the genes from the parents or due to malnutrition during a young age. Thus, variation can be classified into genetic variation and environmental variation.
-Though environmental sources of variation are extensive and numerous (like food availability, temperature, exposure to UV rays, radiation exposure, water, and humidity), sources of genetic variation can be zeroed down to mutation, meiotic recombination, and gene flow.
-But in reality, most variations are a combination of both genetic and environmental effects and thus a trait in an individual can be amplified or compensated by the two forces of genetic and environmental variation.Note:
The environmental conditions keep on varying from time to time. These environmental changes will make survival difficult for the living species. But the variations will make the living organisms adapt to the changing environmental conditions. The thermophilous bacteria is an example of variants that have adapted itself to survive at very hot climatic conditions.