Natural Selection: Changes in Population

1. The diagram shows light and dark colored beetles that live on a tree.

 Which result is most likely to occur to the beetle population due to predation over time?

• The number of light colored beetles in the population will increase.

• There will be more dark-colored beetles than light-colored beetles.

• The number of light-colored beetles will decrease

• The dark-colored beetles will move to a different type of tree.

1. A new predator of rabbits has been introduced within the ecosystem. The new predator runs

            faster  than the native predator. Which statement best describes what will most likely occur in the rabbit

population due to the introduction of the predator?

• 1. Slower rabbits will develop stronger legs and pass the traits to their offspring.

• 1. Slower rabbits will develop stronger legs and pass the traits to their offspring.

• 1. Rabbits will mutate and produce offspring with a different species that has faster runners.

• 1. Faster rabbits will survive and reproduce, increasing the average speed of the rabbit population.

 Farmers spray pesticides on their plants to protect the plants from being eaten by insects.      

           Some individual insects have a genetic mutation that makes them resistant to the toxins in the      

            pesticides. Which statement best describes how only a few resistant individuals resulted in the pesticide     

            becoming ineffective?

  

• The resistant insects change the toxin on the plants, making it safer for others.

• The resistant insects grow larger and eat less of the plants.

• The resistant insects eat the contaminated surface and leave the rest for others.

• The resistant insects are able to survive to reproduce to create a population that is also resistant. 

The quiver tree grows in the desert areas in southern Africa. In recent decades average temperatures have been rising in southern Africa. Scientists predict that this warming trend will continue. Quiver trees in the hottest parts of the range that are near to the equator are dying, but quiver trees at high elevations or in parts of the range that are further from the equator are growing and reproducing.

Which of these best explains what is happening to the quiver tree population in southern Africa?

3. 
   

• 1. Individual quiver trees are unable to adjust to the rising temperatures and only those in cooler parts of the range will survive.

• 1. The quiver trees species is unable to survive the rising temperatures throughout its range. The species is likely to undergo rapid extinction.

• 1. Individual quiver trees can quickly adapt to rising temperatures. Individual trees will change their method of seed dispersal in cooler parts of the range.

• 1. The quiver trees species will survive by producing offspring suited for warmer temperatures.

5. The Mexican long-nosed bat species roosts in Big Bend National Park in West Texas. The bat feeds on nectar and pollen and hovers while it feeds. Additionally, its tongue can extend up to eight centimeters. The other bat species in the park without this adaptation is greatly decreasing in number.

Using at least two sentences, explain why this adaptation of the Mexican long-nosed bats is evidence of natural selection. Be sure to include some or all words from the word bank: reproduce, survive, population, reproductive success, resources, outcompete.