Penguins (Aves Sphenisciformes) are flightless birds that predominantly inhabit the icy regions of the Southern Hemisphere, although some species live in warmer climates. Systematically, they encompass 18 species. The most well-known species are the emperor, king, Adélie, Humboldt, Galápagos and little penguin. Through evolution, they have developed various adaptations to survive in extreme conditions. Genome sequencing of certain penguin species has identified numerous genes responsible for these special adaptations. Fossil evidence suggests that the ancestors of penguins were much larger than the present-day species. Their reproductive strategies include complex mating rituals and shared parental care for eggs and offspring, with both parents actively participating in incubation and feeding of the young. The lives of modern penguins are affected by climate change, habitat destruction, and environmental pollution, which has led to most contemporary species being endangered.