1- The Mojave Desert of the western United States is characterized by a hot, dry

Question

1- The Mojave Desert of the western United States is characterized by a hot, dry climate. Scientists predict that temperatures in this region will increase by an average of 4.7° F over the next 30 years. Birds found here (like ground-dwelling roadrunners) are endotherms and have many adaptations to reduce the amount of heat absorbed into the body while active in the daytime.

If temperatures increase in this area as predicted, how might the plumage (the feathers covering the body) of these roadrunners change under the influence of natural selection?

The plumage will likely become thicker and increase the amount of heat trapped by the body.
The plumage will likely become lighter and increase heat reflected away from the body.
The plumage will likely become longer and increase heat absorption into the body.
The plumage will likely become darker and increase heat absorbed from the environment.

2- Western spadefoot toads breed and deposit their fertilized eggs in small, often short-lived ponds. The tadpoles grow in the ponds for a period of time before undergoing a metamorphosis into an adult frog. One unusual characteristic of spadefoot tadpoles is the ability to change body form during development. Normally most tadpoles are herbivorous and feed on plant material. However, when conditions in the ponds suggest they are beginning to dry up (e.g., an increase in water temperature or concentration of organic waste), a small percentage of individuals in the population undergo a dramatic change in body form and habit and begin to eat their competitors. This ability is considered to be advantageous as it both reduces the number of competitors in the pond and speeds up the rate of development of the transformed tadpoles.

If global climate change continues (as predicted) to increase the average temperature of habitats around the world, how would populations of spadefoot toads likely evolve in response to an increase in pond temperatures?

Spadefoot toads would likely evolve to increase the period of tadpole development.
Spadefoot toads would likely evolve to have a higher percentage of tadpoles be herbivorous.
Spadefoot toads would likely evolve to lay fewer eggs to try and offset the increase in the mortality rate.
Spadefoot toads would likely evolve to have a higher percentage of toads become carnivorous.

Explanation / Answer

1. If the temperature of area increases,

The plumage will get lighter to reflect heat from the body. The light color of plumage will reflect away, gradually lowering the amount of heat absorbed.

If the plumage will become thicker, it will trap the heat which will become unfit for survival.

If the plumage becomes longer to absorb heat, this will gradually increase body temperature of the endothermal bird.

If the plumage becomes darker to absorb heat from surrounding, gradually increasing body temperature. And we are discussing adaptaions to reduce heat.

So option 2 will be correct.

2. If the global temperature increases,

the spadefoot toads would likely evolve to have ahigher percentage of toads become carnivorous. Because the carnivorous have an elevated rate of development. This speed in rate of development also reduces the competition.

Hence, 4th option will be correct.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.