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Midterm

BIOL 1001 Midterm 1 Learning Objectives

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Department
Biology
Course
BIOL 1001
Professor
All Professors
Semester
Fall

Description
Define the theory of evolution. [Knowledge] The general term for evolution is any process of change. Biological evolution is descent with modification. Characteristics of a population change over time. Individuals with certain heritable traits produce more offspring than those without those traits. Describe how evolution explains (or is responsible for) the unity and diversity of life on Earth. [Comprehension] Evolution is responsible for the unity and diversity of life and implies that all organisms come from a common ancestor. Life on Earth has changed over time. Different species share common ancestors. Explain how evolution ‘works’ making reference to populations, individuals, and reproduction. [Comprehension] Evolution is caused by random genetic mutations and natural selection. Individuals don’t evolve rather populations do. If a mutation affects a population, then the offsprings will inherit those derived traits. Similarly, spp with an advantage in a particular environment are more likely to reproduce and thereby changing the population through natural selection. Describe characteristics of model organisms ideal for evolutionary studies (be sure that you can explain why these are ideal characteristics). [Knowledge, Comprehension] Model organisms that are ideal for evolutionary study are organisms with short life span, they breed quickly (we can see if the inherited trait is passed on), they mature quickly (reach reproduction stage very quickly after their born and therefore they can produce offsprings quickly), small (easy to have in a lab), easy to maintain (managing all the model organisms will not be difficult) and with fairly easy ethics approval. Define key terms (phylogenetics): systematics, morphology, phylogeny, taxonomy, classification,taxonomic hierarchy, taxon, lineage, monophyletic taxa, common ancestor, paraphyletic taxa, polyphyletic taxa, principle/assumption of parsimony, mosaic evolution, ancestral characters, and derived characters (section 19.5). [Knowledge] Phylogenetics: the study of evolutionary relatedness among groups of org. looking at genetic sequences and morphology Systematics: the branch of biology that studies the diversity of life and its evolutionary relationships. Morphology: the study of the form and structure of organisms and their specific structural features Phylogeny: the evolutionary history of a group of organisms. Taxonomy: the science of the classification of organisms into an ordered system that indicates natural relationship. Classification: an arrangement of organisms into hierarchical groups that reflect their relatedness Taxonomic hierarchy: a system of classification based on arranging organisms into ever more inclusive categories. Taxon (taxa): a sname designating a group of organisms included within a category in the Linnaean taxonomic hierarchy. Lineage: group composed of species, taxa, or individuals related by descent from a common ancestor Monophyletic taxa: a group of organisms that includes a single ancestral species and all of its descendants. Polyphyletic: a group of organisms that belong to different evolutionary lineages and do not share a recent common ancestor Paraphyletic: a group of organism that include an ancestral species and some, but not all of its descendents. Common ancestor: an ancestral organism shared by 2 or more descendant organisms. Principle of parsimony: a principle of systematic biology that states that a particular trait is unlikely to evolve independently in separate evolutionary lineages. Assumption of parsimony: assumption that the simplest explanation should be the most accurate. Mosaic evolution: the tendency of characteristics to undergo different rates of evolutionary change within the same lineage Ancestral characters: a trait that was present in a distant common ancestor Derived characters: a new version of a trait found in the most recent common ancestor of a group  Using the Linnaean system of classification, list from most inclusive, to least inclusive, the terms: phyla, family, genus, species, and domain. [Knowledge, Comprehension] Domain, phyla, family, genus, species Relate the above terms, and their degree of inclusion, to the relative number of organisms (individuals and types of organisms) found within each, explaining how, with respect to the relative numbers of individuals at each level, a mailing address is analogous to the Linnaean taxonomic system. [Comprehension, Analysis, Application] Domain includes all species (a large number) and therefore it is the most inclusive. As you go down the list, you become more specific and there are fewer species being represented. Thus, it becomes less inclusive as you go down the linnean system of classification. A mailing address is similar in that you start with you specific and you become more broader. Describe what is represented by a phylogenetic tree. [Comprehension] A phylogenetic tree represents the evolutionary relationships of groups of organisms. Read a phylogenetic tree. [I.e., given a phylogenetic tree, determine: where speciation events occurred (nodes), common ancestors between specific lineages, orientation of time scale, unique vs. shared histories, and provide one limitation of interpreting a phylogenetic tree.] [Comprehension, Analysis, Application] Section 19.5  Explain why systematists would look at characters that are genetically independent. [Comprehension] It’s necessary because different organismal characters have the same genetic basis. Define and differentiate between the following terms with respect to the information they provide regarding shared ancestry and their use in constructing phylogenies: homology (homologous), analogy (analogous), and homoplasy (homoplasious) [Knowledge, Comprehension, Analysis]. Homology: traint that came from a common ancestor Analogy: traits with the same function in distantly related species Homoplasy: similarity in species due to convergent evolution; cladistic term for analogous  Given the relationship between several groups of organisms, identify structures (e.g., forelimbs and wings of tetrapods) as homologous or homoplasious (analogous). [Analysis] Wings of tetrapods is analogous to wings of birds (therefore analogous). Not too sure what this question is asking Differentiate between ancestral and derived characters and their use in determining evolutionary relationships. [Knowledge, Analysis] Ancestral characters are old forms of traits while derived characters are new forms of traits. Derived characters provide useful information about evolutionary relationships because once a derived character becomes established; it’s usually present in all of that species’ descendants. Describe how outgroup analysis (or comparison) is used to identify ancestral or derived characters. [Comprehension] Outgroup analysis involves comparing the group under study with more distantly related species not otherwise included in analysis. This can help determine if a character is derived or ancestral (so if the outgroup comparison contains the character, than it means it’s ancestral however if it doesn’t, then it’s derived). Identify a phylogenetic tree or description of a group of organisms as monophyletic, paraphyletic or polyphyletic. [Analysis, Application] (19.6) Section 19.6b  Define cladistics and briefly describe how it produces phylogenetic hypotheses. [Knowledge, Comprehension] (19.6b) Cladistics produced phylogentic hypothesis and classifications that reflect only the branching patterns of evolution. Cladists group together species that share derived characters. Describe how the principle/assumption of parsimony is used to construct phylogenetic trees.[Comprehension] (look at 19.6b, as well) Phylogenetic trees take on the most simplest explanation by looking at homologous traits. Analagous traits are more rare and therefore not considered in creating phylogenetic trees.   Describe briefly how a traditional evolutionary systematist determines evolutionary relationships compared to a cladis. [Comprehension] Systematists want to classifications to mirror phylogenetic history (evolutionary history) while a cladist will make groupings based on shared dertived characters (they ignore morphological divergence). Define key terms (history of evolutionary thought): biogeography, comparative, vestigial traits, Scala Naturae/ladder of life, catastrophism, uniformitarianism, gradualism, inheritance of acquired characteristics. [Knowledge] Biogeography: study of geographic distributions of plants and animals Comparative morphology: analysis of the structure of living and extinct organisms. Ladder of life: species had a purpose in the Great chain of being Catastrophism: sudden changes in the world occurred and resulted in mass extinction. (Cuvier went on to saying that God repopulated the Earth) Gradualism: slow processes over long geologic time periods Uniform: present is key to past and vice versa (relatively same rate in terms of geologic processes) Inheritance of acquired characteristics: changes that an organism acquires in its lifetime are inherited by its offspring. Explain why Lamarck’s hypotheses/principles of use and disuse, and inheritance of acquired characteristics leading to evolutionary change, are not supported. [Comprehension] His hypotheses are not supported because evolution is not based on how often a structure is used or not used but rather the genetics. In other words, an organism’s behaviour has no effect on its inheritable traits.  List Lamarck’s four major contributions to evolutionary thought and explain why three of these were integral to Darwin’s evolution by natural selection. [Knowledge] 1) He proposed that all species change thru time 2) He recognized that changes are passed from generation to the next 3) He suggested that organisms change in response to their environments 4) He hypothesized the existence of specific mechanisms that caused evolutionary changes. The first 3 were important in Darwin’s evolution by natural selection because traits that are more advantageous to a particular environment will more likely be passed on to subsequent generations. If that’s the case, populations will change thru time as they adapt to their environments. Explain why gradualism and uniformitarianism were integral to Darwin’s evolution by natural selection. [Comprehension] o (Another way of looking at
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