Gene Pools Are the Total Collection of Alleles in a Population
- Consider for a moment that a gene pool as a vast library containing all the genetic information of a population.
- Each individual in this population is like a book, carrying a unique combination of alleles, different versions of a gene.
Definition
Gene pool
The total collection of all alleles present in a population.
SNPs are often used in genetic studies to track inheritance patterns and identify genes associated with diseases.
Multiple Alleles in Gene Pools
- While an individual can inherit only two alleles for a gene (one from each parent), a population can have many more alleles for the same gene.
- This diversity is crucial for evolution and adaptation.
Apples Use Multiple Alleles to Avoid Inbreeding
- The S-gene in apple trees prevents self-pollination, ensuring genetic diversity.
- There are over 30 alleles of the S-gene in the apple gene pool.
- Each tree inherits two alleles and rejects pollen carrying the same S-allele as its own.
Example Cross
- A Jazz apple (S₂S₃) will reject pollen from another Jazz tree or a Golden Delicious (S₂S₃) because they share S-alleles.
- A Gala apple (S₅S₉) can successfully cross-pollinate with Jazz or Golden Delicious because its alleles are different.
An apple tree with the genotype $S_2S_3$ will reject pollen carrying either $S_2$ or $S_3$, ensuring cross-pollination with genetically diverse trees.
AnalogyThink of a gene pool as a toolbox. Each allele is a different tool, and the more tools available, the better equipped the population is to adapt to challenges.
