Question

1. Which of the following is true regarding the Pleistocene Overkill Hypothesis that likely occurred in North America about 10-12,000 years ago?

A. Fauna that migrated across the Bering land bridge with the Clovis hunters did not die because they had evolved to ‘know’ what these people were like (Ecological Naiveté).

B. Migrating Eurasian species outcompeted native flora and fauna leading to their extinction.

C. The guns carried by the Clovis hunters were unlike anything ever seen by Mastadons and other large Pleistocene megafauna.

D. Large organisms died out because invading humans carried with them an unusual parasite that they were not resistant to (evolution of increased competitive ability)

E. Rapid climate change killed off the large organisms, but smaller organisms were able to cope with the changes.

2. Moose are well adapted to cold climates. Their long legs confer them an advantage when escaping predictors in deep snow and their dark fur absorbs incoming solar radiation which keeps them warm. However, moose are experiencing increased stressors which are causing their population to decline in Minnesota. What stressor(s) did we discuss that negatively affect moose populations (also remember the article from The Atlantic)? Select all that apply.

Rising temperatures

Habitat loss

Loss of beaver ponds due to trapping of beavers

Winter Ticks

Changes in wildfire activity

Increases in wolf predation on adult moose

Reduced snow cover

3. A small South American frog produces a toxin that repels the snakes that feed on it. This frog then becomes invasive in the United States and populations of the frog no longer produce a toxin (because its main predator is absent). Now the frog produces 200 times as many eggs. This is best considered an example of_______.

A. the Evolution of Increased Competitive Ability (EICA)  

B. the Linnaean Shortfall  

C. Ecological Differentiation  

D. Adaptive Ecological Vulnerability

4. Which of the following scenarios would have the greatest influence on the growth of Lyme Disease within a forest.

A. The evolution of resistance to the spirochete that carries Lyme disease among small mammals.

B. An increase in predators of small mammals (owls, hawks, etc.) that leads to a reduction of their population.   

C. An increase in white-tailed deer populations due to a lack of hunting pressure   

D. in increase in small mammal populations due to either a bumper crop of food for them or a dramatic reduction of their predators.

Answer 1

1. According to Pleistocene overkill hypothesis "humans were responsible for the Late Pleistocene extinction of megafauna in northern Eurasia and North and South America"
It was hypothesised that humans of the hunter-gatherer era hunted a large amount of species to extinction 10,000-12,000 years ago. They had hunt the large animals and allowed them to get extinct.
Hence, option D is the correct answer.

2. Because of habitat loss, moose are not getting the sufficient place for their feeding. So slowly, their population is getting declined in number.
Hence, second option is the correct answer.

3. According to the Evolution of Increased Competitive Ability (EICA) , lack of predation make the invasive species to reallocate it's resources of defense for some other useful purpose.
Here from the given it is evident that the invasive frog start producing 200 times as many eggs because of lack of predation.

Hence, option A is the correct answer.

4. Lyme disease is a tick-borne illness caused by the bacterium Borrelia burgdorferi. Deer ticks can carry the bacteria that cause Lyme disease.
The disease-causing agent is a tick-borne spirochete bacterium of the genus Borrelia, and disease vectors are ticks of the genera Ixodes.
When there is the evolution of resistance to the spirochete that carries Lyme disease among small mammals, it would have the greatest influence on the growth of Lyme Disease within a forest.

Hence, option A is the correct answer.