Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Biological Dynamics of Forest Fragments Project wikipedia , lookup
Unified neutral theory of biodiversity wikipedia , lookup
Habitat conservation wikipedia , lookup
Theoretical ecology wikipedia , lookup
Ecological fitting wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Biogeography wikipedia , lookup
Occupancy–abundance relationship wikipedia , lookup
Name: ANSWER KEY SN: Biology 413 (Zoogeography) Mid-term Exam Winter Term 2 - 2014 Directions: 1. Write your name and student number on each page of the exam. 2. All answers should be written in the space provided. If you need extra space, write on the back of the last page and clearly label your answers. 3. The exam is designed to be completed in 50 minutes. Plan accordingly. 4. The exam questions are organized into two parts and consist of 6 pages. 5. PART I consists of 5 short-answer questions. 6. PART II consists of one two-part question and one long-answer (essay-form) question. Marks PART I: 14 points PART II: 22 points TOTAL: 36 points PART I Answer the following questions 1 – 5, using 1-2 sentences or less (point-form is OK) in the space provided. These questions should take no more than 5 minutes each. Question 1 [2 points]: Describe one contribution made by the following individuals to the development of Biogeography: a) Carl von Linnaeus: Father of binomial nomenclature and taxonomy. Believed in immutability of species. Suggested that world's biodiversity originated by dispersal from Mt. Ararat, Turkey where Noah’s Ark was thought to have landed after biblical flood (first incidence of idea that taxa have centres of origin). b) Alexander von Humboldt: Extended Buffon's Law to plants and terrestrial animals. Promoted idea that plant distribution is determined by climate. Coined the term “floristic belts”. Noted complementarity of South American and west African coastlines. c) Phillip Sclater: Made connection between low dispersal ability and ability to reconstruct origin of a region's biota from current composition. Developed first major classification scheme for earth’s biota based on distribution and composition of birds (described over 1,000 species – mostly passerines). Proposed six biogeographic regions, each with distinct centres of origin for regional faunas (still used today). d) Alfred R. Wallace: Compiled observations on distributions, diversity, extinction, disjunctions, and climate effects on distribution into: “The Malay Archipelago”, “The Geographical Distribution of Animals”, “Island Life”. Refined Sclater's regions so concordance in distributions of taxa reflects reality of divisions and processes generating them. Recognized Wallace’s Line separating fauna of SE Asian origin from those of Australian origin. Independently developed ideas on natural selection and the origin of species. Question 2 [2 points]: Answer the following questions based on Figure 2.1: a) What is the name of the latitudinal belt receiving the most direct sunlight? Tropic of Capricorn, 23.5° S Latitude b) What day of the year is it? (in words, or give the approx. date)? December 21 (Winter Solstice)_________________ _ Figure 2.1. Earth tilted on its axis with the angle of incoming sunlight shown. Latitudes indicated with dotted lines (Equator 1labeled). Name: ANSWER KEY SN: Question 3 [2 points]: Explain why we often see the driest deserts on the western side of continents at the Horse Latitudes. Over land, Horse Latitude belts (30° N and S latitude) represent the world’s deserts and Mediterranean climates. In summer, land is warmer than ocean water, and cool westerly winds over oceans absorb water as the air warms and expands while passing over warmer land. In winter, land is cooler than the ocean and moisture-laden westerly winds can bring precipitation to these regions, but this is minimal. The world’s driest deserts occur where very cold currents/winds encounter warm land (e.g., Atacama desert in South America, western Australia, Namib Desert in Africa). Question 4 [4 points]: We discussed in class that community assemblage depends, in part, on energetics and productivity. a) What are the two basic characteristics that affect energy use in organisms? [1 point] Tropic level and body size (or metabolic rate)___________________________________________ b) Which organisms tend to be numerically rare in communities and why? [3 points] Tertiary consumers (top predators). These organisms tend to be large bodied, with high metabolic rates and thus high energetic demands, but at the highest trophic level, they have the least amount of energy available to them, as 90% of energy is lost as heat with energy transfer to higher trophic levels Question 5 [4 points]: Species distributions are dynamic in space and time, but in all cases, ranges can be described by five basic parameters: r, b, d, i, e. a) Use an equation to show how these five parameters are related to one another, and define each parameter using a few words. [2 points] r = b + i – d – e where r is the per capita rate of population growth, b is per capita birth rate, d is per capita death rate, i is per capita immigration rate and e is per capita emigration rate b) Figure 5.1 shows “source” and “sink” habitats that are linked by dispersal. If r > 0 in the sink habitat, what can we infer about parameters b, d and i in the sink habitat? [2 points] In a sink habitat, b < d; however, because r > 0, i must be large to sink compensate for low birth rates/high death rates, or the combined rates of i + b > d source r>0 Figure 5.1. Source and sink habitats. 2 Name: ANSWER KEY SN: PART II Answer the following Questions 6-7. Use sentences for Questions 6-b and 7 in the space provided. Question 6 [10 points]: Figure 6.1 and 6.2 show the relationship proposed by Santiago Claramunt and colleagues to support their hypothesis for an “intermediate dispersal model”. Figure 6.1 Relationship between wing-aspect ratio and dispersal ability A geographic barrier: strong B C intermediate weak distribution: Figure 6.2 Relationship between dispersal ability (x-axis) and speciation rates (y-axis). In Figure 6.2 above, using the lines under A, B and C, use one word to describe the relative strength of a geographic barrier. [2 points] 3 Name: ANSWER KEY SN: a) Provide an explanation for the proposed “intermediate dispersal model”, based on what you have learned about mechanisms of speciation and dispersal. Use Figures 6.1 and 6.2 to support your answer. [8 points] Figure 6.1 shows a positive relationship between a bird’s dispersal ability and its wing-aspect ratio. Thus, birds with higher wing-aspect ratios should be better at colonizing areas beyond geographic barriers compared to birds with low wing-aspect ratios. In Figure 6.2, we see a hump-shaped relationship between dispersal ability and speciation rate. For birds with low dispersal capacity (A), the strength of a given geographic barrier should be large. As such, the geographic range of this species should be spatially restricted. Because the species is a poor disperser, the likelihood of establishing populations outside the range is low, offering little or no opportunity for allopatry and consequently, low speciation rates (we assume sympatric speciation is unlikely). For birds with high dispersal capacity (C), a given geographic barrier will not be effective in preventing dispersal. Species with high dispersal capacity would be expected to exhibit a larger geographic distribution with high gene flow, preventing any divergence of populations in allopatry. In contrast, an intermediate dispersal ability (B) allows some individuals to overcome geographic barriers, resulting in the establishment of allopatric (isolated) populations (as depicted in the figure). However, dispersal (gene flow) is not high enough to prevent divergence in allopatry, resulting in relatively high speciation rates. Once allopatric populations are established, they will likely diverge as the result of either differing ecological selection pressures or genetic drift until reproductive isolation is attained. __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 4 Name: ANSWER KEY SN: Question 7 [12 points]: In class, we discussed numerous potential determinants of species distributions in the context of the fundamental and realized niche. In the space provided, describe the fundamental and realized niche [4 points] and provide four possible determinants of species distributions as they relate to the fundamental/realized niche concept, using an example to support your answers [8 points]. The fundamental niche is the total range of abiotic environmental conditions in which a taxon can survive and reproduce. From Hutchinson, the n-dimensional hypervolume (or multidimensional space) that describes the range of abiotic environmental conditions in which a taxon can survive and reproduce (each abiotic factor is a single dimension). The realized niche is a subset of the fundamental niche comprising the actual environmental conditions in which a taxon survives and reproduces in nature, including biotic factors (e.g., competition, predation, mutualism, parasitism). (4 points) There are many possible determinants of distributions, including abiotic interactions (e.g., climate/soil related factors), biotic interactions (i.e., direct/diffuse competition, predation, parasitism, mutualism), metapopulation dynamics, disturbance and historical factors/dispersal barriers. Full credit given for describing four different factors supported by a logical example (2 points per example for 8 points total). ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ __________________________________________________________________________________ 5