1. How do biologists define evolution? Charles Darwin was a 19th century naturalist who purposed current theories. Biologists defined evolution as the cumulative genetic changes that occur in a population of organisms over time.
2. What are Darwin’s four premises of evolution by natural selection? Four premises of evolution by Natural Selection-1. High Productive Capacity- Each species produce more offspring than will survive to maturity. 2. Heritable Variation- Individuals vary in traits that may impact survival. 3. Limits on Population Growth, or a Struggle For Existence- Outside pressure on which individuals will survive. 4. Differential Reproductive Success- Best adapted individuals reproduce more successfully than less adapted individuals.
3. What are the three domains of life? To which domain do you belong? Three domains of life- 1. Archaea 2. Bacteria, 3. Eukarya. Humans belong in the domain called Eukarya.
4. What is the effect of each of the following on population size: birth rate, death rate, immigration, and emigration? Birth rate- When the birth rate goes up, the population size goes up. Death rate-Death rate goes up and the population size goes down. Immigration-When immigration goes up, the population size goes up. Emigration-When emigration goes up and the population size goes down. R=(b-d) + (i-e)
5. How do intrinsic rate of increase and carrying capacity produce the J-shaped and S-shaped population growth curves? In the J-shaped curve, there’s an intrinsic rate of growth (Biotic Potential) which produces growth rate under the ideal conditions (Exponential). The carrying capacity for the S-shaped curve is more realistic, can be useful in management, and is rarely stabilized because the curve goes up and down.
6. What are two examples of density-dependent factors that affect population growth? What are two examples of density-independent factors? Disease and Competition are some of the examples of the Density Dependent Factors that affect population growth. Killing frost and severe blizzards are two examples of the Density Independent Factors.
7. What are the three main survivorship curves? Type I- Individuals who survive at an early stage tend to live longer and die of old age. Type II- Individuals whose probability of dying is not related to their age. Type III- Individuals who tend to die at an early age.
8. What is an ecological niche? An ecological niche is the organism’s role. The ecological niche is also potential idealized and is the totality of an organism’s adaptions, it’s use of resources, and the lifestyle which it is fitted.
9. What is the principle of competitive exclusion? Of resource partitioning? The principle of competitive exclusion is when one species excludes another from a portion of the same niche as a result of competition for resources. While the principle for resource partitioning is when coexisting species niche are different from each other.
10. What is symbiosis? What are the three kinds of symbiosis? Symbiosis is an intimate relationship between members of 2 or more species. Mutualism, Commensalism, and Parasitism are known to be the three kinds of symbiosis.
11. Describe how evolution has affected predator-prey relationships. Evolution effects predation because of the consumption from one species to another; which has been resulted in the coevolution of which are both predator and prey strategies. But predators have been known to be evolved greater efficiencies as a way to catch prey, while prey can be evolved in better ways to escape from the predators in our ecosystems. But adaptations related to predator-prey interactions can actually include predator strategies; such as pursuit, ambush, and prey strategies such as plant defenses (Spines, thorns, and thick wax are known to be plant defenses) and animal defenses such as warning coloration and cryptic coloration.
12. What is a keystone species? Why do we consider the wolf a keystone species? Keystone species are a species which is often a predator that exerts profound influence on a community. We consider wolves to be keystone species because the dependence of other species on the keystone species is apparent when the keystone species is removed.
13. What are ecosystem services? Ecosystem Services are important environmental benefits that ecosystems provide such as clean air to breathe, clean water to drink, and fertile soil to grow crops.
14. What is ecological succession? How does primary and secondary succession differ? The ecological succession is a process where a community develops slowly through a series of species. Primary and Secondary Succession are different because primary succession begins in a previously uninhabited environment and no soil is present (Ex: bare rocks, cooled lava fields). The secondary succession is a succession where it begins in an environment following destruction of all or part of the earlier community (such as abandoned farmland).