WHY ECOLOGY MATTERS PART 1

Question 1

Why have penguins not been able to reach the arctic?

Answer 1

• The tropical waters in which they live have imposed a barrier that has prevented them from reaching the arctic

Question 2

Barrier

Answer 2

• prevents the dispersal of organisms/species

- prevents an individual from moving from their place of birth to a place where they can reproduce and exploit

Question 3

What were the 6 broad regions that were defined by Alfred Wallace?

Answer 3

Nearctic, Palearctic, Neotropical, Ethiopian, Oriental, Australian

-He proposed that the isolations of these land massed provided geographical barriers that caused for diverging evolution of populations and the origin of many species

Question 4

What Assurance do we have that any organism can live in a different area?

Answer 4

• Transplant studies: Introducing organisms to a new environment and ecological setting and see if they are able to survive and reproduce
• If the organisms are able to survive and reproduce then it is indicative that these organisms were previously restricted by the inability of dispersal
• Many of the crops that are fundamental to our economy and health have been introduced by transplant experiments

Question 5

The European Starling

Answer 5

In the ’80s, around 80 individuals of the European starling were introduced to New York City

• A few months later, 80 more were introduced
• it took around 10 years for the starling to become permanently established in this region. the speediness of this process was due to the migration and reproduction of juvenile birds
• considered a pest because it is bold and aggressive and competes with native species for resources

Question 6

Cane Toad

Answer 6

• known to be a pest of scarab beetles, which were attacking the sugarcane crop
• introduced in Australia and the Caribbean and quickly saw that it became a pest itself
• it possesses a toxin that can have damaging effects on native birds and fish
• invaded streams and local residents proposed that they could drain the shallow waters, however, those bring complex consequences that are to be avoided
• the message left by this intorudction is that we need to investigate the potential effects of introducing a species and seeing whether the benefits outweigh the costs

Question 7

Rainbow Trout

Answer 7

• native to the west coast of Canada and have spread through North America
• prized game fish for fishers but have been known to displace brook trout, which are also prized game fish in the Americas

Question 8

How can we ensure that a successful transplant will happen?

Answer 8

• Introducing more individuals increases the likelihood of the success of the transplant experiment
• Especially, since having a small population increases the likelihood of chance events occurring such as genetic drift that will cause random changes in the frequencies of alleles within that population

Question 9

The exception to having more individuals increases the likelihood of success

Answer 9

• The sambar deer were successfully introduced to New Zealand with 2 individuals
• Himalayan (???) was successfully introduced with 5 individuals

Question 10

Steps in Invasion Process

Answer 10

1. Transport
2. Establishment
3. Spread
4. Impact

Question 11

Why might transplant experiments?

Answer 11

1. The biological environment will not be suitable for the organism thus disabling it from surviving in the environment
2. There may be physical or chemical factors that cause the abnormal development of the organism or prevent them from reproducing

Question 12

Common mussel

Answer 12

• Found in abundance in large bodies of water
• not commonly found in small bodies of water due to the presence of their prey, crabs and starfish
• in order to ensure that they can survive in these protected waters, they can be placed in cages to protect them from their predators

Question 13

The effects of geography on climate

Answer 13

• Geographical ranges and expansions are extremely affected by climate change
• CO2 emissions and greenhouse gases affect the distributions and geographical ranges of these species

Question 14

Before we can ask ourself is species ranges are affected mostly by climate, we must ask ourselves

Answer 14

1. Are the species absent in that region because its dispersal has been limited?
2. Are the species absent in that area because it has not recognized the habitat as suitable yet
3. Are there species interactions that have prevented them from reaching other environments?
4. Is there a physical and chemical factor that limits their ranges?
   Before we can make any conclusions about if climatic variables have the most prominent effect on the ranges of species, we must ask ourselves the following questions.

Question 15

Vanderwal and The Australian Birds

Answer 15

Vanderwal studied previous distribution in the Australian bird in the past 60 years and concluded that they are moving toward the poles at a faster rate than they did in the past. This is conducive to the principle that global warming is causing our species to shift toward the poles in order to maintain their current temperature

Question 16

Stream fishes

Answer 16

• Moving upward of the streams toward the poles in order to maintain their current living temperatures
• not moving fast enough so either they need to start moving faster or they will die out

Question 17

Mangrove

Answer 17

• shrubs that live in saltwater and in warm areas
• starting to move polewards and thus are not expanding poleward
• has great consequences for the larvae in that community that are dependent on the resources that it provides