Galápagos marine iguanas

Definition

Galápagos marine iguanas are a unique species of iguana found only in the Galápagos Islands, known for their ability to forage in the ocean for algae. These reptiles have adapted to their marine environment through various key innovations, such as their specialized diet and swimming capabilities, which illustrate the processes of adaptive radiation that occur in isolated ecosystems.

5 Must Know Facts For Your Next Test

1. Galápagos marine iguanas can dive up to 10 meters deep to feed on algae and can hold their breath for about 30 minutes.
2. They are the only marine lizards in the world, showcasing a unique adaptation to a marine lifestyle.
3. The coloration of marine iguanas can vary significantly based on the environment, with darker individuals absorbing more sunlight on cold days.
4. Their ability to swim and forage in saltwater is complemented by specialized nasal glands that help excrete excess salt from their bodies.
5. Marine iguanas exhibit sexual dimorphism, with males being larger than females and often displaying brighter colors during mating season to attract partners.

Review Questions

• How do Galápagos marine iguanas demonstrate adaptive radiation in response to their environment?
  • Galápagos marine iguanas show adaptive radiation through their unique adaptations that enable them to thrive in a marine environment. They have developed physical traits such as flattened tails for swimming and specialized limbs for clinging onto rocks while feeding. These adaptations allow them to exploit a different ecological niche compared to their terrestrial relatives, showcasing how species can diverge from a common ancestor based on environmental pressures.
• Discuss the impact of isolation on the evolution of Galápagos marine iguanas and their ecological role in the Galápagos Islands.
  • Isolation has significantly impacted the evolution of Galápagos marine iguanas by allowing them to develop distinct traits not found in other iguana species. This isolation has led to the emergence of an endemic species that plays a crucial ecological role in controlling algal growth along the shores. Their feeding habits help maintain the balance of the ecosystem, illustrating how isolated environments can foster unique evolutionary pathways while supporting biodiversity.
• Evaluate the evolutionary significance of Galápagos marine iguanas and how they exemplify key concepts in evolutionary biology.
  • Galápagos marine iguanas exemplify key concepts in evolutionary biology by illustrating how natural selection and adaptive radiation work in isolated ecosystems. Their adaptations for a marine lifestyle provide clear evidence of evolutionary changes driven by environmental challenges. Furthermore, studying these iguanas offers insights into evolutionary processes and highlights the importance of conservation efforts, as their specialized nature makes them vulnerable to changes in their habitat due to human activity and climate change.

Related terms

Adaptive radiation: The rapid evolution of diversely adapted species from a common ancestor, often following the colonization of new habitats.

Endemic species: Species that are native to and found only within a specific geographic area, such as the Galápagos Islands.

Natural selection: The process by which individuals with favorable traits are more likely to survive and reproduce, leading to evolutionary change over time.