* Genetic Variation: Every individual inherits a unique combination of genes from their parents. This means there are variations in the DNA sequences of genes, even at the same position within the genome.
* Alleles: Different versions of the same gene are called alleles. For example, a gene for eye color might have an allele for brown eyes and another allele for blue eyes. An individual may inherit two copies of the same allele (homozygous) or two different alleles (heterozygous).
* Mutations: Changes in DNA sequence, called mutations, can occur spontaneously or due to environmental factors. These mutations can create new alleles, leading to further genetic variation within a population.
* Genetic Diversity: The presence of different alleles and mutations within a population is called genetic diversity. This diversity is essential for a species' ability to adapt to changing environments.
Therefore, while individuals share many of the same genes, the specific versions of those genes (alleles) can vary considerably, leading to a wide range of genetic differences within a population.
