banner

Now that you have done the experiments, you can draw a conclusion based on the evidence you collected. Take a look at your data an dthen answer the questions below.

According to the results of this experiment, does leptin have any effect on mate choice behavior in New Mexico spadefoot toads?

The results are not conclusive.
Yes
No

What conclusion can you draw from this experiment?

Injecting leptin can sometimes cause New Mexico spadefoot toads to choose to hybridize with Plains spadefoot toads.

What needs to be changed about this experiment to confirm that the results are accurate? In other words, how can we make sure that this wasn't just a fluke?

Include more toads in the experiment.
Remove the control group.
Inject the control group with a different hormone.

And that is how you do science. You find a question that needs answering, design an experiment that will give you enough evidence to answer it, interpret your results, and then release your new-found understanding to the world.

More experiments still need to be done to fully understand how leptin affects mate choice. The behavioral experiment only gives us part of the picture. We now know that leptin can cause toads to choose to hybridize even if their tadpoles get no benefit from it. Now Nick aims to answer two more questions. Where in the brain does leptin go? How do leptin levels change during egg development? This requires a different kind of experiment than what you have seen here. In behavioral experiments you can easily see the effects of leptin. But when you are researching it on a molecular level you have to get creative to really "see" what the hormone is doing. Nick will do molecular research procedures like a northern blot and ELISA to answer these questions. We will not explore these in detail here, but the linked videos and the following diagrams give a quick explanation of how they work.

So why do we do this research? It may not seem like anyone should care about toad behavior. But many experiments that may seem pointless or obscure turn out to be very useful! Years ago, scientists found a pheromone that silkworm moths to attract mates. Silkworms are an invasive species; they lay their eggs on trees, and their larvae create a large white "nest" as they eat the leaves. It turns out that these pheromones can be used to lure the moths into traps to reduce their population without using poisons that pollute the environment.

Context-dependent behavior is important to understand because we can learn about the signals that cause animals (including humans) to show abnormal behavior. When we understand more about context-dependent behavior, we can use that information to understand human behavioral disorders. It would then be possible to find ways to treat them more effectively. So-called "psychological" disorders are just as physical as any other illness, but because so little is understood about the brain, we don't yet know how to cure them.

You could say that the brain is the real final frontier. There are many years of work ahead if we want to really understand why and how we behave and think in the way we do, but researchers all over the world are working every day to bring us ever closer to this goal.