The experiments highlighted in the previous video are testing acclimation, not adaptation. How might scientists research the ability of coral to adapt to sea temperature changes? In either a well-developed paragraph, or a flowchart/diagram, design and describe an experiment that could test such a hypothesis.
The correct answer and explanation is:
Experiment Design to Test Coral Adaptation to Sea Temperature Changes
Hypothesis: Corals can adapt genetically to increased sea temperatures over multiple generations through natural selection.
Experiment Design:
- Selection of Coral Species: Choose a fast-growing coral species with a relatively short generation time (e.g., Acropora species).
- Controlled Environment Setup: Establish multiple tanks that simulate natural reef conditions. Divide the tanks into two groups:
- Control Group: Maintained at current average sea temperatures.
- Experimental Group: Gradually increase the temperature over a pre-determined range to simulate future ocean warming.
- Initial Sampling: Collect baseline data on genetic diversity, health, and temperature tolerance of corals in both groups.
- Reproductive Cycles: Allow corals to reproduce naturally within the tanks for several generations (e.g., 5–10 generations).
- Monitoring and Selection:
- Monitor coral health, growth rates, and survival.
- Collect genetic samples to identify any changes in gene frequencies associated with thermal tolerance.
- Cross-Testing: After several generations, expose both control and experimental group corals to acute temperature stress and compare survival rates.
- Analysis:
- Determine if genetic adaptations occurred in the experimental group.
- Compare changes in gene expression, epigenetic markers, or alleles linked to thermal tolerance.
Explanation
This experiment tests whether corals can adapt genetically to increased sea temperatures rather than just acclimate. Adaptation involves changes in heritable traits through natural selection, while acclimation refers to short-term physiological adjustments within a single generation.
The use of multiple generations is essential to detect adaptation. By exposing corals to elevated temperatures over generations, selective pressures favor individuals with genetic traits conferring higher thermal tolerance. Over time, these traits may become more common, indicating adaptation. Cross-testing with acute temperature stress allows researchers to evaluate whether these traits provide functional survival advantages.
Genetic analysis provides insights into the molecular basis of adaptation. Scientists can identify specific genes or alleles linked to heat tolerance, helping to distinguish between genetic adaptation and reversible epigenetic changes. These findings could be applied to conservation efforts, such as identifying heat-tolerant populations or developing assisted evolution strategies.
Maintaining a control group is crucial to distinguish natural genetic drift or other factors from thermal adaptation. Monitoring both groups ensures that observed changes result from experimental conditions, not random variation. The multi-generational approach, while time-consuming, is critical for studying adaptation since it reflects natural evolutionary processes.
This experiment could also reveal the limits of coral adaptability, helping predict their survival under future climate scenarios. Understanding these mechanisms enables better-targeted conservation strategies to protect coral reefs in a warming world.