Question

As the ocean became saltier, whales and fish independently evolved mechanisms to maintain the concentration of salt in their bodies; this can be explained by A. divergent evolution. B. parallel evolution. C. convergent evolution. D. analogous evolution.

Short answer

C. convergent evolution.

Step-by-step solution

- Understand the Definitions

Review the definitions of the evolutionary terms: divergent evolution, parallel evolution, convergent evolution, and analogous evolution.

- Identify the Key Concept

The key concept in the question is that whales and fish evolved similar mechanisms independently to maintain salt concentration in their bodies.

- Match the Key Concept with Definitions

Compare the key concept to the definitions: Divergent evolution occurs when two species evolve differently from a common ancestor; Parallel evolution happens when two related species evolve similar traits independently. Convergent evolution is when unrelated species develop similar traits independently due to similar environmental pressures; Analogous evolution refers to structures that perform the same function but are not derived from a common ancestral structure.

- Select the Correct Answer

Given that whales and fish developed similar mechanisms independently due to the same environmental pressure (saltier ocean), the correct term is convergent evolution.

Key concepts

evolutionary mechanisms

Evolutionary mechanisms are the processes that drive the changes in species over time. These mechanisms include:

• Natural selection: The process where organisms better adapted to their environment tend to survive and produce more offspring.
• Mutation: Random changes in the DNA sequence that can lead to new traits.
• Genetic drift: Random changes in the frequencies of alleles in a population.
• Gene flow: The transfer of genetic material from one population to another.

In the context of our exercise, these mechanisms help explain how different species can develop similar traits to adapt to environmental changes, like an increase in salt concentration in the ocean.

salt concentration

Salt concentration in the environment, particularly in marine habitats, is a crucial factor that influences the survival and evolution of organisms. Marine species have developed various ways to regulate the salt content in their bodies to avoid dehydration or salt toxicity.

Osmoregulation is the process by which organisms control the concentration of water and salts in their bodies. Whales and fish, despite being different species, have evolved mechanisms for osmoregulation to survive in the increasingly salty waters. This adaptation prevents their cells from shrinking due to loss of water or swelling due to excess salt. These mechanisms are critical for maintaining homeostasis, which keeps their internal environment stable and suitable for their biological functions.

independent evolution

Independent evolution refers to the phenomenon where different species develop similar traits or characteristics separately. This independent development can occur due to similar environmental pressures that necessitate the evolution of specific adaptations.

In our exercise, whales and fish did not share a common ancestor with the same salt concentration mechanisms. Instead, they independently evolved similar solutions to handle the saltier ocean environment. This is a classic example of convergent evolution where unrelated species adapt in comparable ways because they face similar challenges or needs.

marine biology

Marine biology is the study of organisms in the ocean and other saltwater environments. It explores how these organisms interact with their environment, develop, and adapt to changes. Marine biologists study various aspects like genetics, behavior, and physiology of oceanic species.

Understanding how marine organisms deal with salt concentration is a significant topic within marine biology. Researchers investigate the physiological adaptations that allow for osmoregulation and other mechanisms, providing insights into how organisms survive and thrive in their habitats. The study of such adaptive mechanisms helps us understand broader ecological and evolutionary processes, emphasizing the interplay between organismal biology and environmental factors like salt concentration.