How does the number of genes in humans compare with that in other species?

Sourav PanNovember 8, 2024

Answered

The number of genes in humans is comparable to that in other species, but there are notable differences across various organisms. Here’s a summary based on recent findings:

Gene Count in Humans

• The current estimate for the number of protein-coding genes in the human genome is approximately 20,000 to 25,000. This figure is significantly lower than earlier estimates that suggested up to 100,000 genes due to advancements in genomic sequencing and annotation techniques.

Comparison with Other Species

• Daphnia pulex (Water Flea): This freshwater crustacean holds the record for the most genes among animals, with about 31,000 genes. Its high gene count is attributed to a faster rate of gene duplication compared to other species.
• Other Model Organisms:
  • Saccharomyces cerevisiae (Baker’s Yeast): Approximately 6,000 genes.
  • Caenorhabditis elegans (Nematode): About 18,000 genes.
  • Drosophila melanogaster (Fruit Fly): Roughly 13,000 genes.

Evolutionary Perspective

• The variation in gene numbers among species often reflects evolutionary adaptations and complexity. For instance, more complex organisms tend to have larger gene families due to processes like gene duplication and divergence. This phenomenon allows for functional specialization of proteins and contributes to the diversity of life forms.

Similarities with Closely Related Species

• Humans share a high degree of genetic similarity with other primates. For example, humans and chimpanzees share about 98.8% of their DNA, indicating that many genes are conserved across these species despite differences in gene expression and regulation that contribute to distinct traits