Archaebacteria. (1) Describe the evolution of the group based on current researc

Question

Archaebacteria. (1) Describe the evolution of the group based on current researched findings. (2) Highlight the closest relatives within Protista, Fungi, Plantae, and Animalia. (3) Summarize the typical roles of the group within the community, ecosystem, and biome level. Use examples! (4) Predict effects of major global change within the group as it relates to other groups/ levels of life, with a focus on energetic relationships. (5) Explain the fundemental biotic relationship between various members of the group and humans; include both positive and negative interactions. (6) List direct manipulations of members of the group for human use. (7) Summarize how the group aides our overall understanding of biology (examples of what the group teach us about fundamental biology concepts).

Explanation / Answer

1)

Archaea are a domain of single-celled microorganisms. They have no cell nucleus or any other organelles inside their cells. In the past Archaea were classified as an unusual group of bacteria and named archaebacteria, but since the Archaea have an independent evolutionary history and manifest numerous differences in their biochemistry from other forms of life, they are now classified as a separate domain in the three-domain system. In this system the three primary branches of evolutionary descent are the Archaea, Eukarya and Bacteria. Archaea are further divided into four recognized phyla, although other phyla may exist. Of these groups the Crenarchaeota and the Euryarchaeota are most intensively studied. Classifying the archaea is somewhat challenging, since the vast majority have never been studied, and have chiefly been detected by analysis of their nucleic acids in samples from the environment.

Archaea replicate asexually in a process known as binary fission. Archaea achieve a swimming motility via one or more tail-like flagellae. Many archaeans are extremophiles, achieving wide environmental tolerance of temperature, salinity, and even radioactive environments. Archaea are thought to be significant in global geochemical cycling, since they comprise an estimated 20 percent of the world's biomass; however, very little is known about the domain, especially marine and deep-sea benthic varieties

Very early probable prokaryotic cell fossils have been dated at approximately 3.5 billion years before present day, making them some of the most primitive and ancient life forms on Earth; however, prokaryotes generally lack distinctive morphologies, thus fossil shapes cannot be used to identify them as archaea. Instead, chemical fossils of unique lipids hold greater information, since such compounds do not occur in other organisms. Some research indicates archaean or eukaryotic lipid remains are present in shales as old as 2.7 billion years. Such lipids have been identified in Precambrian formations, the earliest of which are present in the Isua greenstone belt of western Greenland. This locale boasts the Earth's oldest sediments, circa 3.8 billion years of age

2) Phylogenetic relationships among plants, animals, and fungi were examined by using sequences from 25 proteins. Four insertions/deletions were found that are shared by two of the three taxonomic groups in question, and all four are uniquely shared by animals and fungi relative to plants, protists, and bacteria. These include a 12-amino acid insertion in translation elongation factor 1 alpha and three small gaps in enolase. Maximum-parsimony trees were constructed from published data for four of the most broadly sequenced of the 25 proteins, actin, alpha-tubulin, beta-tubulin, and elongation factor 1 alpha, with the latter supplemented by three new outgroup sequences. All four proteins place animals and fungi together as a monophyletic group to the exclusion of plants and a broad diversity of protists. In all cases, bootstrap analyses show no support for either an animal-plant or fungal-plant clade. This congruence among multiple lines of evidence strongly suggests, in contrast to traditional and current classification, that animals and fungi are sister groups while plants constitute an independent evolutionary lineage.

3) The scope of ecology contains a wide array of interacting levels of organization spanning micro-level (e.g., cells) to planetary scale (e.g., biosphere)phenomena. Ecosystems, for example, contain abioticresources and interacting life forms (i.e., individual organisms that aggregate into populations which aggregate into distinct ecological communities). Ecosystems are dynamic, they do not always follow a linear successional path, but they are always changing, sometimes rapidly and sometimes so slowly that it can take thousands of years for ecological processes to bring about certain successional stages of a forest. An ecosystem's area can vary greatly, from tiny to vast. A single tree is of little consequence to the classification of a forest ecosystem, but critically relevant to organisms living in and on it. Several generations of an aphid population can exist over the lifespan of a single leaf. Each of those aphids, in turn, support diverse bacterial communities. The nature of connections in ecological communities cannot be explained by knowing the details of each species in isolation, because the emergent pattern is neither revealed nor predicted until the ecosystem is studied as an integrated whole. Some ecological principles, however, do exhibit collective properties where the sum of the components explain the properties of the whole, such as birth rates of a population being equal to the sum of individual births over a designated time frame.

4) Ecology and evolution are considered sister disciplines of the life sciences. Natural selection, life history, development,adaptation, populations, and inheritance are examples of concepts that thread equally into ecological and evolutionary theory. Morphological, behavioural and genetic traits, for example, can be mapped onto evolutionary trees to study the historical development of a species in relation to their functions and roles in different ecological circumstances. In this framework, the analytical tools of ecologists and evolutionists overlap as they organize, classify and investigate life through common systematic principals, such as phylogenetics or the Linnaean system of taxonomy. The two disciplines often appear together, such as in the title of the journal Trends in Ecology and Evolution.[108] There is no sharp boundary separating ecology from evolution and they differ more in their areas of applied focus. Both disciplines discover and explain emergent and unique properties and processes operating across different spatial or temporal scales of organization.While the boundary between ecology and evolution is not always clear, ecologists study the abiotic and biotic factors that influence evolutionary processes, and evolution can be rapid, occurring on ecological timescales as short as one generation.

Cognitive ecology integrates theory and observations from evolutionary ecology andneurobiology, primarily cognitive science, in order to understand the effect that animal interaction with their habitat has on their cognitive systems and how those systems restrict behavior within an ecological and evolutionary framework. "Until recently, however, cognitive scientists have not paid sufficient attention to the fundamental fact that cognitive traits evolved under particular natural settings. With consideration of the selection pressure on cognition, cognitive ecology can contribute intellectual coherence to the multidisciplinary study of cognition."As a study involving the 'coupling' or interactions between organism and environment, cognitive ecology is closely related to enactivism, a field based upon the view that "...we must see the organism and environment as bound together in reciprocal specification and selection...".

5) The ecological complexities human beings are facing through the technological transformation of the planetary biome has brought on the Anthropocene. The unique set of circumstances has generated the need for a new unifying science called coupled human and natural systems that builds upon, but moves beyond the field of human ecology. Ecosystems tie into human societies through the critical and all encompassing life-supporting functions they sustain. In recognition of these functions and the incapability of traditional economic valuation methods to see the value in ecosystems, there has been a surge of interest in social-natural capital, which provides the means to put a value on the stock and use of information and materials stemming from ecosystem goods and services. Ecosystems produce, regulate, maintain, and supply services of critical necessity and beneficial to human health (cognitive and physiological), economies, and they even provide an information or reference function as a living library giving opportunities for science and cognitive development in children engaged in the complexity of the natural world. Ecosystems relate importantly to human ecology as they are the ultimate base foundation of global economics as every commodity and the capacity for exchange ultimately stems from the ecosystems on Earth.

Ecology is an employed science of restoration, repairing disturbed sites through human intervention, in natural resource management, and in environmental impact assessments. Edward O. Wilson predicted in 1992 that the 21st century "will be the era of restoration in ecology". Ecological science has boomed in the industrial investment of restoring ecosystems and their processes in abandoned sites after disturbance. Natural resource managers, in forestry, for example, employ ecologists to develop, adapt, and implement ecosystem based methods into the planning, operation, and restoration phases of land-use. Ecological science is used in the methods of sustainable harvesting, disease and fire outbreak management, in fisheries stock management, for integrating land-use with protected areas and communities, and conservation in complex geo-political landscapes.

7) There are two fundamental concepts in biology: cell theory, and evolution.

Cell theory refers to the fact that all living things are made of cells. The way that cells grow and divide explains how large organisms grow and develop. The way that cells differentiate explains how tissues and organs form to perform different functions. The way that cells split their genetic material (chromosomes) explains how organisms display their characteristics.

Evolution refers to the fact that all living things *change* over time. Specifically, populations (such as species) slowly change in their inherited characteristics from generation to generation. This explains everything from commonalities and differences between species, why there are so many species and where they come from. Why species have the same DNA system. Why we find fossils where we do, or why certain animals live in some regions and not others (e.g. why there are no kangaroos in Africa, or elephants in Australia), etc.

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