BIOL1020 Final Review PDF

**[BIOL\*1020 textbook notes by chapter.]** [11.1 What is Evolution?] - A biological population is a group of individuals of the same species that is somewhat independent of the other groups, often isolated from them by geography. - Biological evolution is a change in the characterist...

**[BIOL\*1020 textbook notes by chapter.]** [11.1 What is Evolution?] - A biological population is a group of individuals of the same species that is somewhat independent of the other groups, often isolated from them by geography. - Biological evolution is a change in the characteristics of a biological population that occurs over the course of generations. - Changes that take place for short amounts of time are not evolutionary. - Natural selection is the process by which populations adapt to their changing environment - Microevolution is small changes that occur within a biological population - The accumulation of microevolutionary changes that results in the origin of a new species is called macroevolution - The Theory of Evolution - All species present on Earth today are descendants of a single common ancestor, and all species represent the product of millions of years of accumulated microevolutionary changes. - Scientific theory : a statement that provides the current best explanation of how the universe works, supported by numerous lines of evidence and withstood repeated experimental tests. - The Theory of Common Decent : a controversial topic among non-biologists. Often referred to as Darwinism [11.2 Charles Darwin and the Theory of Evolution] - The theory of evolution us sometimes called "Darwinism" because Darwin is credited with bringing it into the mainstream of modern science. - Jean Baptiste Lamarck : stated that organisms adapted to their environments, proposed that species strive for perfection. - Galápagos islands : tortoise different on each island, - Wallace had a manuscript containing an almost identical mechanism for evolutionary change to Darwin's theory of natural selection - Most Europeans believed that God created the organisms and they had not changed significantly. Called the static model hypothesis - Transformation hypothesis : organisms were created and changes have occurred by microevolution in these species but brand new species have not arisen - Separate type hypothesis : different types of organisms arose separately and since have diversified into numerous species [11.3 Examining evidence for Common Descent] - Linnaean Classification: gave all species of organisms two-part names in Latin that contained information about a species' traits - Linnaean Classification : from broadest to narrowest groupings: Kingdom. Phylum, class, order, family, genus, species - Anatomical Homology : - Convergent evolution : similar structures in unrelated organisms with similar lifestyles. - Vestigial traits: nonfictional or greatly reduced features left over from common ancestor - Developmental homologies : similarities among the developmental process of species - Molecular homology : closer related species have closer related genes - Molecular clock : rate of change in certain DNA sequences due to the accumulation of mutations that affect the DNA sequence but no the protein sequence. - Biogeography : - The Fossil Record : the chronological appearance of other groups of fossils supports the theory of evolution. - Radiometric dating : by determining the ration of radioactive element to daughter product in a rock sample and knowing the half-life of the radioactive element scientists can estimate the number of years that have passed since the rock formed. [11.4 Are alternatives to the Theory of Evolution equally Valid?] - Biological classification : the most logical and useful system groups organisms hierarchically - Anatomical homology : organisms that look quite different have surprisingly similar structures - Vestigial traits : some species display traits that are nonfunctional but have a functional equivalent in other species - Biogeography : the distribution of organisms on Earth corresponds in part to the relationship implied by biological classification - Homology in development : early embryos of different species often look similar - Homology of DNA : the DNA sequences of species that are closely related in a taxonomic grouping are more similar than those from more distantly related groups. - The fossil record.: the remains of extinct organisms show progression from more ancient forms to more modern forms - The most compelling evidence for the single origin of all life is the universality of both DNA and the relationship between DNA and proteins - Consilience : there is agreement among observations derived from different sources. **[Chapter 12 Natural Selection]** [12.1 Return of a killer] - Antibiotics revolutionized tuberculosis treatment in the 1940s [12.2 Natural selection causes evolution] - Darwin proposed that through the process of natural selection the physical or behavioral traits of organisms that lead to increased survival or reproduction become common within their population. - Darwin's observations : - Individuals within populations vary - Some of the variation among individuals can be passed onto their offspring - Populations of organisms reduce more offspring than will survive - Survival and reproduction are not random - Adaptations : traits that increase and individual's relative fitness in a particular environment - The large bill can be explained because birds with this attribute are able to crack open large, tough seeds- the only food available during severe droughts - Darwin saw that variations with less desirable traits often were lost within the population - Artificial selection : when traits are specifically breed for. i.e. dog breeders - Natural selection in the lab : environments are manipulated to see how they influence the selections of a species - Natural selection in wild populations : Traits evolve due to necessity, bad traits die off and leave the gene pool [12.3 Natural Selection since Darwin] - Modern synthesis : the union between genetics and evolution - Directional selection : causes the population traits to move in a particular direction, leads to a change in a population over time - Stabilizing selection : extreme variants in a population are selected against, and the traits of the population stay the same. - Diversifying selection : causes the evolution of a population consisting of two or more variants. [12.4 Natural Selection and Human Health] - Tuberculosis fits Darwin's observations - Organisms in the population vary : even with drug treatment some patients do not get better due to having different mutations of TB - Variation among organisms can be passed on to offspring : the traits that cause frug resistance are coded for in a bacterium's DNA and when it divided to reproduce that DNA is passed on. - More organisms are produced than survive : antibiotic treatment eliminates most of the bacteria in the infected individual's body - An organisms survival is not random : bacterial cells with traits that make them more resistant to the antibiotic are more likely to survive than that are less resistant. **[Chapter 13 Speciation and Macroevolution]** [13.1 What is a Species?] - Linnaeus developed a classification scheme that grouped organisms according to shared traits using two part names, genus then family name - Genus : a broader group - Modern biologists added subspecies names to some species - Species : a group of individuals that can interbreed and produce fertile offspring - Gene pool : the sum total of the alleles found in all the individuals of a species - Gene flow : the spread of an allele throughout a species' gene pool - Prefertilization barriers : prevent fertilisation from occurring - Spatial isolation : individuals from different species do not come in contact with each other - Behavioral : ritual behaviors that prepare partners for mating are different in different species - Mechanical : sex organs are incompatible - Temporal : timing of readiness to reproduce - Gamete incompatibility : proteins on egg that allow sperm binding do not bind with sperm from another species - Postfertilization barriers : Feralization occurs, but hybrid cannot reproduce - Hybrid invaiability : Zygote cannot complete development because genetic instructions are incomplete - Hybrid sterility : hybrid organism cannot produce offspring because chromosome number is odd. - Speciation is the evolution of one or more species from an ancestral form - Three steps are necessary for a new species to arise - 1\. Isolation of the gene pools of subgroups of the species - 2\. Evolutionary changes in the gene pool of one or both isolated populations - 3\. The evolution of reproductive isolation between these populations, prevent any future gene flow - Adaptive radiation is the establishment of a new population far from an original population may lead to the evolution of several new species - Allopatric : populations that are isolated from each other by distance or a barrier - Sympatric : separation between the gene pools of two populations even if the populations are living near each other - In plants, isolation of gene pools can occur instantaneously without any barriers between populations. A simple hybrid between two plant species is typically infertile because it cannot make gamete. However, some hybrid plants can become fertile is a mistake during mitosis produces a cell containing duplicated chromosomes. The process of chromosome duplication is called polyploidy, and it results in a cell that contains two copies of each chromosome from each parent species - Polyploidy occurs in some animal groups, such as insects and frogs - Gradualism: Darwin assumed that speciation occurred over millions of years as tiny changes gradually accumulated. - Other biologists have argued that most speciation events are sudden, result in dramatic changes in gorm withing the course of a few thousand years, and are followed by many thousands or millions of years of little change, known as punctuated equilibrium [13.2 Are Human Races Biological?] - Biological race describes races as populations of a single species that have diverged from each other because of isolation of their gene pools, also referred to as the genealogical species concept - Paleontologist : scientists who study fossils. - The ancestors of humans are known only through the fossil record. - Biological species : Species consists of organisms that can interbreed and produce fertile offspring and are reproductively isolated from other species - Benefits of using this concept : useful in identifying boundaries between populations of similar organisms. Relatively easy to evaluate for sexually reproducing species - Disadvantages : Cannot be applied to organisms who reproduce asexually or to fossils. May not be meaningful when two populations of the same species are separated by large geographical distances - Genealogical species : Species consist of organisms that can interbreed, are all descendants of a common ancestor, and represent independent evolutionary lineages - Benefits : Each species has its own unique evolutionary history. Can be used with asexually reproducing species - Disadvantages : difficult to apply in practice. Requires detailed knowledge of gene pools of populations within a biological species. Cannot be applied to fossil organisms - Morphological species : Species consist of organisms that share a unique set of physical characteristics that is not found in other groups of organisms - Benefits : Easy to use in practice on both living and fossil organisms. Only a few key features are needed for identification - Disadvantages : Does not necessarily reflect evolutionary independence from groups - Allele frequency : when a trait becomes more common in a population due to evolution - The study of the effect of evolutionary change on allele frequencies is known as populations genetics - No alleles are found in all members of a race. - Populations within a race are often as different as populations compared across races. [13.3 why Human Groups Differ] - Convergent evolution : traits that are shared by unrelated populations because they share similar environmental conditions. Occurs when natural selection for similar environmental factors causes unrelated organisms to resemble each other. - Genetic drift is a change in allele frequency that occurs due to chance - Founder/bottleneck effect : a small sample of a large population establishes a new population or survives a disaster - Chance events in small populations : the carrier of a rare allele does not reproduce - Sexual selection : when a trait influences the likelihood of mating (bigger tailed peacocks draw more attention from female peacocks) - Assertive mating : when individuals prefer to mate with others with similar traits to them (tall women tend to marry tall men) **[Chapter 14 Biodiversity and Classification]** [14.1 Biological Classification] - Biodiversity : the variety withing and among living species - Systematists : scientists who specialize in describing and categorizing a particular group of organisms - Biological classification : organization of biodiversity into discrete and logical categories - Kingdoms : categorize organisms according to cell type and method of obtaining energy - All organisms have basic similarities in their DNA sequences and the closer species are related the more similar their DNA sequences are. [14.2 the Diversity of Life ] - Prokaryote : do not contain a nucleus, (bacteria and archaea) - Eukaryotes : contains nucleus - Most prokaryotes are unicellular and are often called microorganisms or microbes - Kingdom plantae : Multicellular, make own food, largely stationary - Kingdom animalia : Multicellular, rely on other organisms for food, mobile for at least port of life cycle - Kingdom fungi : Multicellular, rely on other organisms for food, reproduce by spores, body made up of thing filaments called hyphae - Kingdom Protista : Mostly single-celled forms, wide diversity of lifestyles, including plant-like, fungus-like, and animal-like - Kingdom bacteria L Prokaryotic, mostly single0celled forms, although some form colonies or filaments - Kingdom archaea : Prokaryotic, mostly single-celled forms, although some form colonies or filaments - Endosymbiotic theory : the mitochondria and chloroplasts found in eukaryotic cells descended form bacteria that took up residence inside larger primitive eukaryotes.' - Symbiosis : when organisms live together - Vertebrates : animals with backbones, account for 4% of total species in animalia kingdom - Invertebrates : animals without backbones , account for 96% of animalia [14.3 Learning about Species] - Developing evolutionary classifications : based on the principle that the descendants of a common ancestor are likely to share any biological trait that first appeared in that ancestor. - Phylogeny : the evolutionary relationship of species - Cladistics analysis : the examination of the variation in traits relative to a closely related species to determine phylogeny **[Chapter 15 Population ecology ]** [15.1 Population Growth] - Ecology : the study of the interactions among organisms as well as the relationships between organisms and their environments. - Population : al of the individuals of a species withing a given area - Mark-recapture method : researches capture many individuals withing a defined area, mark them, and release them back into the environment. Later the researchers capture another group of individuals in the same area and calculate the proportions of the previously marked individuals in this group. - Population size estimate = (marked induvials released)(size of second sample)/(marked animals recaputred) - Clumped distribution : high densities of individuals in certain resource-rich areas and low densities everywhere else - Uniform distribution : equal distances among individuals, normally seen withing territorial species - Random distribution : there is no compelling factor to bring individuals together or push them apart - Human population growth is exponential - Growth rate : percentage change in population size over a single year. Birth rate -- death rate - Demographic transition : birth rates drop towards lowered death rates [15.2 Limits to Population Growth] - Carrying capacity : the maximum population the can be supported indefinitely in a given environment - Logistic growth : when the birth rate and death rate become equal and the population stabilized at its maximum size. Shown as an S-shaped curve on a simplified graph of population size - Density dependant factors :p population-limiting factors that increase in intensity as ta population increases in size. (limited food supply, increased risk of disease, increase in toxic waste levels) - Density independent factors : i.e. severe droughts that increase the death rate in plant populations regardless of their density or increased temperatures that increase the birth rate in insects. - Net primary productivity (NPP) : the amount of food energy available on the planet [15.3 the Future of the Human Population] - Unlike nearly all other species, human populations are not simply at the mercy of environmental conditions. With out ability to transform the natural world, humans have helped populations circumvent seemingly fixed natural limits. - Population crash : a steep decline in population. - Population cycle : for populations with high birth rates, rapid growth followed by dramatic crashes - Demographic momentum : the lag between when a population approaches carrying capacity and when it actually responds to that environmental limit. - Population pyramid : a summary of the numbers and proportions of individuals of each sex and each age group. - As women become more educated the amount of children they have decreases and they have children later on in life **[Chapter 16 Community and Ecosystem Ecology]** [16.1 The Sixth Extinction ] - Endangered Species Act (ESA) : a law passed in the I.S in 1973 to protect and encourage the population growth of threatened and endangered species. - Endangered organisms are at organisms at high risk of extinction - Extinction : the complete loss of a species or subspecies - Threatened organism : at high risk of becoming endangered - Mass extinction : species losses that are global in cale and affect large numbers of species. Have dramatic impact - Background extinction rate : the rate at which species are lost through the normal evolutionary process. - Marine species extinction rate: 0.0001% - Mammal extinction rate : 0.0002% - The current rate of extinction is 1% - According to the World Conservation Union (IUCN) 42% or amphibians, 6% of mammals, 13% of birds, and 40% of conifers are in danger of extinction. - Causes of extinction : - Habitat degradation : caused by agricultural, industrial, and residential development. Takes away habitable area for species. - Introduced species : nonnative species that are introduced to and environment and compete for resources. Did not coevolve with native species - Overexploitation : when the rate of human use of a species outpaces reproductions. Occurs wen a particular organism is highly prized by humans and used. - Pollution : the release of poisons, excess nutrients, and other wastes into the environment. - Food chain : sunproducersprimary consumerssecondary consumers - Trophic pyramid : the bottom-heavy relationship between the biomass of a population at each level of the chain. - Trophic level : one level on the trophic pyramid. i.e. primary consumers - Eutrophication : when something consumes too much oxygen and doesn't leave enough other species (in water) [16.2 The consequences of Extinction] - Loss of resources : when resources used by humans become increasingly hard to source due to overexploitation - Most species are beneficial to humans because they are part of a biological community, consisting of all the organisms living together in a particular habitat area - Ecological niche : a role or "job" of a species - Mutualism : a relationship where both species benefit - Commensalism : a relationship where one species benefits and the other is unaffected (i.e. egrets and domestic cattle) - Predator : a species that survives by eating another species - Competition: when two species of organisms both require the same resources for. Life. The competition limits the size of the competing populations - Competitive exclusion : the inevitable elimination from a habitat of one or to different species with identical needs for resources - Keystone species : a single species that plays a dramatic roles in determining the composition of their system's food web. - Ecosystem : all of the organisms living in a given area along with their nonbiological environment. - Energy low : in nearly all ecosystems the primary energy source is the sun. Producers turn sun energy into biomass during photosynthesis. Only 10% of that biomass can be turned into energy for the primary consumer, and then only 10% of the primary consumer's biomass turns into energy for the secondary consumer and so on. - Nutrient cycling : When essential mineral nutrients for plan growth pass through a food web, they are generally not lost form the environment but rather brought around in a cycle - Decomposer : typically bacteria and fungi which break down waste produced by consumers - Biophilia : the instinctive desire to commune with nature [16.3 Saving Species] - It is hard to know exactly which species are closest to extinction, and that means that the most effective way to prevent loss of species is to preserve as many different kinds of habitats as possible - Biodiversity hot spots : natural areas making up less than 2% of Earth's surface but contain up to 505 of all mammal, bird, reptile, amphibian, and plant species. - Ecotourism : encourage travel to natural areas in ways that conserve the environment and improve the well-being of local people - Although preserving a variety of habitats ensures less extinctions already endangered species require a more individualized approach. - Small populations are more vulnerable to extinction - Genetic variability : the sum of all the alleles and their distribution withing the species - Heterozygote advantage : if each allele codes for a functional protein, a heterozygous individual produces two slightly different proteins that preform essentially the same function - Heterozygosity declines in small populations over time. When interbreeding occurs the chance that their offspring will be homozygous for any allele is relatively high. - Small populations also lose genetic variability because of genetic drift. - Extinction vortex : a small population can become trapped in a positive-feedback process that causes it to continue to shrink in size, eventually leading to extinction. **[Chapter 17 Climate and Biomes]** [17.1 Climate determines Habitability] - Climate : the average conditions of a place measured over time - Weather : the current conditions - Solar irradiance : the total solar energy per square meter of land or water surface - Summer solstice : when the sun reaches its maximum - Winter solstice : when the sun reaches its minimum - Local influences on climate : altitude, proximity of a large body of water, a land's surface and vegetation - Local temperature patterns : temperature drops as altitude increases, temperature near oceans, seas, and large lakes are influenced by the thermal properties of water, the amount of light absorbed or reflected by a surface will also influence surrounding air temperature - Local precipitation patterns : affected by the proximity of the land to a large body of water. Wind blowing across warm and accumulates water vapor that condenses and falls when it reaches a cooler landmass. [17.2 Terrestrial biomes and the human footprint] - Biome : a geographic area defined by its primary vegetation - Tundra : Very low average temperature. Very short growing season, permafrost. Nar the poles and at very high altitudes - Desert : Scant rainfall. Dry soils, very sparse vegetation. Plants often covered with spines and adapted to store water. Near 30 north or south of the equator : northern Africa, southwestern US - Tropical : High rainfall, high average temperatures. Tall trees, relatively little understory. Great diversity of species. Around equator. - Temperate (Deciduous) : Sufficient rainfall, moderate with some freezing temperatures. Three distinct layers : deciduous canopy, trees, shrubs, and spring-lowering plants in the understory. Middle latitudes of the Northern Hemisphere : eastern North America, western and central Europe, and eastern China - Boreal : Sufficient rainfall with cold average temperatures. Dominated by evergreen coniferous trees with a very short growing season. Northern latitudes and high altitudes : northern north America norther Europe and Asia, and high mountains in more temperate zones. - Chaparral : Moderate average temperatures, moderate seasonal rainfall, periodic fires. Dominated by spiny evergreen shrubs and maintained by frequent fires. Areas surrounding the mediterranean sea and in patches in southern California, South Africa, and southwest Australia - Savanna L Lower rainfall, above freezing temperatures. Scattered individual trees, maintained by periodic fires of large-animal grazing. Tropical : about half of Africa, as well as large area of India, South America, and Australia. - Prairie and Steppe : Lower rainfall, seasonally cold. Tall(prairie) or short (steppe) grasses, no woody plants. Temperate areas in the middle of large landmasses : central North America, central Asia, parts of Australia, and southern South America. [Aquatic biomes (NOT ON EXAM)] - Freshwater : Less that 0.1% total volume of salts - Lakes and Ponds : Inland, some fry up seasonally. Yearly seasonal turnovers in larger lakes causing mixing of nutrients that would settle to bottom. - Rivers and Streams : Flowing water moving in one direction. Different habitats along the wat, from the fast-flowing, oxygen-rich regions at the headwaters to the sluggish, sediment-filled waters near the mouth. - Wetlands : Standing water with emergent plants. High species diversity due to high-nutrient levels at water-land interface - Marine (Saltwater) - Oceans : Contains multiple habitats, including (clockwise from top) intertidal zones, where. Organisms are exposed to fluctuating water levels; deep abyssal zones where no light penetrates; and open ocean - Coral Reefs : Tropical areas in relatively shallow water. Reefs are made up of minerals deposited by coral animals and provide habitat for a diverse array of species. - Estuaries : Where freshwater rivers flow into intertidal areas; mix of salt- and freshwater; Highly productive due to nutrients from rivers and warmer temperatures.