Blog # 9 Define the different forms of community interaction: competition, commensalism, mutualism, predation, parasitism Give an example and a picture for each

Competition is a contest between individuals, groups, animals, etc. for territory, a niche, or a location of resources. It arises whenever two or more parties strive for a goal which cannot be shared. Competition occurs naturally between living organisms which co-exist in the same environment. For example, animals compete over water supplies, food, and mates, etc. Humans compete for water, food, and mates, though when these needs are met deep rivalries often arise over the pursuit of wealth, prestige, and fame. Business is often associated with competition as most companies are in competition with at least one other firm over the same group of customers. Commensalism describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. Mutualism is any relationship between individuals of different species where both individuals derive a benefit. An example of mutual symbiosis is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish protects it from the stinging tentacles. Predation describes a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked). Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption. A parasitic relationship is one in which one member of the association benefits while the other is harmed. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving. Biotrophic parasitism is an extremely successful mode of life. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa. An example of a biotrophic relationship would be a tick feeding on the blood of its host.

 

Blog 8 Your choice talk about something you learned or ask a question about something that is confusing you

Blog 7 Compare and contrast two biomes describe them in detail include pictures of plants and animals you are liklely to see

One biome is the freshwater biome. Freshwater is defined as having a low salt concentration — usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (i.e., ocean). These ponds and lakes range in size from just a few square meters to thousands of square kilometers.

 Another biome is the desert biome. Deserts cover about one fifth of the Earth's surface and occur where rainfall is less than 50 cm/year. Although most deserts, such as the Sahara of North Africa and the deserts of the southwestern U.S., Mexico, and Australia, occur at low latitudes, another kind of desert, cold deserts, occur in the basin and range area of Utah and Nevada and in parts of western Asia. Most deserts have a considerable amount of specialized vegetation, as well as specialized vertebrate and invertebrate animals. Soils often have abundant nutrients because they need only water to become very productive and have little or no organic matter. Disturbances are common in the form of occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding. There are relatively few large mammals in deserts because most are not capable of storing sufficient water and withstanding the heat. Deserts often provide little shelter from the sun for large animals. The dominant animals of warm deserts are nonmammalian vertebrates, such as reptiles. Mammals are usually small, like the kangaroo mice of North American deserts. The difference between freshwater and desert biome is that the desert hardly has any water while the freshwater biome is covered with water. 

Blog #6 Which level of a food pyramid is the most important? Support your answer

I think the most important level of the food pyramid is the fruit and vegetable group. Vegetables contain many vitamins and minerals; however, different vegetables contain different spreads, so it is important to eat a wide variety of types. Fruits are low in calories and fat and are a source of natural sugars, fiber and vitamins. The fruit food group is sometimes combined with the vegetable food group. I think these are the most important because even if u eat more than what you need to eat it is still fine. Unlike some of the other groups eating more fruits and vegetable is good for you.

Blog #5 There have been 5 major extinction events throughout history, are humans impacting the 6th? Why or why not?

I think humans are imacting the 6th. Humans have been hunting animals, polluting the air, and causing other harmful things to our planet. For the first time since the dinosaurs disappeared, humans are driving animals and plants to extinction faster than new species can evolve, one of the world's experts on biodiversity has warned. Conservation experts have already signalled that the world is in the grip of the "sixth great extinction" of species, driven by the destruction of natural habitats, hunting, the spread of alien predators and disease, and climate change. Speaking in advance of two reports next week on the state of wildlife in Britain and Europe, Simon Stuart, chair of the Species Survival Commission for the International Union for the Conservation of Nature – the body which officially declares species threatened and extinct – said that point had now "almost certainly" been crossed.

Blog # 4 Describe the three types of selection: directional, stabilizing and disruptive and give an example of each in your own words

Stabilizing selection favors the norm, the common, average traits in a population. Look at the Siberian Husky, a dog bred for working in the snow. Stabilizing selection has chosen a norm for the the size of the Siberian Husky. Directional selection favors those individuals who have extreme variations in traits within a population. For example people pick hounds that were the fastest in their group, from their offspring the breeders again selected the dogs that ran the fastest. By continuing this selection for those dogs, they gradually produced a dog who could run up to 64km/h (40mph). Disruptive selection, like directional selection, favors the extremes traits in a population. Disruptive selection differs in that sudden changes in the environment creates a sudden forces favoring that extreme. Think about the changes in the environment when that meteor crashed into Earth 65mya. If a plague started by the high death rate also hit these stressed animals, they would have been sorely pushed to survive. Evidence shows that they did not. So disruptive selection occurs quickly, selecting for those extreme traits that help organisms survive in the new environmental conditions.

Blog #3 Explain what microevolution is? What are the three ways that variation occurs?

Microevolution is a change in gene frequency within a population over time. This change is due to four different processes: mutation, selection (natural and artificial), gene flow and genetic drift.
Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance. Microevolution can be contrasted with macroevolution, which is the occurrence of large-scale changes in gene frequencies in a population over a geological time period (i.e. consisting of extended microevolution). The difference is largely one of approach. Microevolution is reductionist, but macroevolution is holistic. Each approach offers different insights into the evolution process. Macroevolution can be seen as the sum of long periods of microevolution, and thus the two are qualitatively identical while being quantitatively different. Mutations alter the order of bases in the nucleotides of DNA. Mutations are likely to be rare and most mutations are probably harmful, but in some instances the new alleles can be favored by natural selection. Independent assortment (recombination of chromosomes that occurs during sexual reproduction) and the Crossing over that happens during meiosis.