Choose either (A) climate change or, (B) human hunting practices as the key driv
ID: 106907 • Letter: C
Question
Choose either (A) climate change or, (B) human hunting practices as the key driver of extinctions and follow the six steps listed below to create a general, directional and measurable hypothesis for your chosen key driver of extinctions.
Approximately 88 large vertebrate taxa disappeared from the Sahul (the Pleistocene- era continent that combined Australia with New Guinea and Tasmania) during the Pleistocene, and it is thought that the majority of losses have taken place sometime within the last 400,000 years (Wroe et al. 2012) and many extinctions seem to occur around 60,000-40,000 years ago. Some researchers believe that these extinctions were the result of climate change (i.e. that climate conditions changed too rapidly or too intensely that large animals were unable to cope with the extreme conditions). An alternative view posits that the arrival of humans into Australia around 46,000 years ago (+/- 6000 years) caused rapid ecosystem change coupled with over hunting resulting in the extinction of many large animals (McGlone 2012; Rule et al. 2012).
Here's the six step and example answer. Please follow the structure of example step by step.
1. Identify what the problem is. Do not use the terms "I think" to start the hypothesis.
2. Make an educated guess as to what direction of the relationship or difference is.
3. Identify the major variables.
4. Start by stating the general hypothesis in a simple declarative statement.
5. Now that you have written the general hypothesis, write the directional hypothesis.
6. With the directional hypothesis behind you, finish with the measureable hypothesis.
*****Example*********
A worker on a fish-farm notices that his trout seem to have more fish lice in the summer, when the water levels are low, and wants to find out why. His research leads him to believe that the amount of oxygen is the reason - fish that are oxygen stressed tend to be more susceptible to disease and parasites.
He proposes a general hypothesis.“Water levels affect the amount of lice suffered by rainbow trout.”
This is a good general hypothesis, but it gives no guide to how to design the research or experiment. The hypothesis must be refined to give a little direction.
He later writes a directional hypothesis which states: "Rainbow trout suffer more lice when water levels are low.”
Now there is some directionality, but the hypothesis is not really testable, so the final stage is to design an experiment around which research can be designed, a testable hypothesis.
The researcher finally writes a measurable hypothesis in the correct If… then…because format.
The measurable hypothesis states:“If water levels are low then Rainbow trout will suffer more lice because there is less oxygen in the water.”
This is a testable hypothesis – the researcher has established variables, and by measuring the amount of oxygen in the water, eliminating other controlled variables, such as temperature, he/she can see if there is a correlation against the number of lice on the fish.
Explanation / Answer
88 large vertebrate taxa disappeared from the Sahul (the Pleistocene- era continent that combined Australia with New Guinea and Tasmania) during the Pleistocene, and it is thought that the majority of losses have taken place sometime within the last 400,000 years.The vast majority of extinctions across geological time are wholly attributable to climate-related factors
Human involvement in the disappearance of some species remains possible but unproven. Mounting evidence points to the loss of most species before the peopling of Sahul and a significant role for climate change in the disappearance of the continent’s megafauna.
The argument for a primary human role in the extinction of megafauna has been based on the presumption that the arrival of humans on Sahul was synchronous with the disappearance of all now-extinct megafauna .
A link between the two seemed obvious to advocates of a human-driven process , and a role for climate change was subsequently discounted. The case for a human role was buttressed by claims that was a time of relatively stable climatic conditions . As such, human activities were therefore the only credible explanation for the extinctions
Sahul—mainland Australia, Tasmania, and New Guinea—comprised up to 11 million km2 at glacial maxima. Although dominated by an expansive desert core , environments ranged from periglacial in Tasmania to tropical in New Guinea .
general hypothesis:CLIMATE CHANGE affects on the environment over the continent on small,medium and large species.
Directional hypothesis:As progressive drying of gacial and the potential impacts of climatic flux on plants and animals, including humans, has been limited by the relatively coarse resolution of the fossil
Measurable hypothesis: Advances in our knowledge of paleoclimates are steadily improving our understanding of the complexities of the extinction processes. Mounting evidence increasingly points to climate change as the primary driver of Pleistocene faunal extinctions. Many species of megafauna did not persist into the late Pleistocene, but were completed before humans arrived. Importantly, a role for humans in the disappearance of any surviving taxa, although possible, is yet to be demonstrated. Extinct species that persisted until or beyon, finally disappeared within the context of a rapidly deteriorating climate.