Biology 101 Exam 4 Study Guide
Biology 101 Exam 4 Study Guide BY 101
Jacksonville State University
Popular in Introductory Biology I
Popular in Biology
This 3 page Study Guide was uploaded by Kimberly Burke on Friday January 22, 2016. The Study Guide belongs to BY 101 at Jacksonville State University taught by Dr. Tolley-Jordan (TJ) in Fall 2014. Since its upload, it has received 44 views. For similar materials see Introductory Biology I in Biology at Jacksonville State University.
Reviews for Biology 101 Exam 4 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/22/16
Bio Exam 4 • Evolution-change in alleles through time; change in shape through time; not goal oriented o Darwin-naturalist, noticed shape difference o Most fundamental basis of biology b/c idea of natural selection o Aristotle – everything still here we just haven’t found it yet – fixed view of species o Species change through time due to natural selection of specific heritable traits § Organisms once had same climate, adapt as climate changes o Before Mendel – science was all observation o Animals on the Galapagos Islands found no where else in the world § Different beaks on finches b/c different foods o Alfred Russell Wallace – findings from East Indies – persuaded Darwin to publish o Generalizations from the Origin of Species § Fossil Record should yield intermediate links between great groups of organisms • Archaeopteryx – transitional fossil between reptiles & birds § The age of the Earth has to be much older than a few thousand years • Radioactive dating – find out how old things are o Radioisotopes – form of an element with an unstable nucleus; decays into atoms of another element o Half life – time it takes for half of a radioisotope’s atoms to decay into a daughter element o Africa slammed into Alabama 380 mil years ago § Heredity – he knew that another mechanism besides phenotype blending had to be responsible for his hypothesis of natural selection to work • Evidence from plate tectonics – San Andreas Fault • Ring of Fire – highly volcanic o Acclamation – short period of time o Adaptation – multiple generation s o Viruses (not living) but still evolve • Population – # of individuals in the same species in the same plce at the same time o Individuals acclimate while populations evolve o For population to persist it must adapt to environmental challenges o Adaptation is the long term genetic response of a population to environmental stress that increases the survival & reproductive success of the population o Genetic variation – backbone of natural selection o Abiotic factors – external – volcano, drought o Biotic factors – internal – diseases o Humans: global distribution, no predators, modify landscape, same constraints as other animals § Live in the tropics, warm & wet areas o Measurement on population size requires: sex ratios, generation time, ucture, survivorship, reproductive potential/costs o Density dependent – govern population size; overcrowding leads to intra specific competition § Resource distribution – food not evenly distributed § Behavioral shifts – war, disease, hunger o Allelic frequency - % of Dominant allele & recessive allele in a population § Force that cause changes to a population through time are shown genetically § Processes that lead to drastic shifts in allelic frequencies • Gene flow – immigration/emigration into a population; have to successfully mate • Nonrandom mating – individuals w/ certain genotypes sometimes mate w/ 1 another more commonly than would be expected on a random basis; inbreeding; creates rare traits • Genetic drift – in SMALL populations frequency of alleles change drastically by chance alone o Bottleneck effect – majority of population does not survive o Don’t mate outside of population o Founder effect – individuals from main populations go to a new location • Speciation – accumulated traits will cause individuals to differ from their ancestors o New species will evolve; not equal among groups o MACROEVOLUTION – emergence of evolutionary novelties among diverse lineages § Humans & octopi have similar eyes § Big forces/events in population; caused by isolation; long periods of times o Extinction – total loss; extirpation – loss of patches, movement § 9% of all species are extinct; 5 mass extinctions in the distant past o Speciation is greater than extinction & wil l become more rapid o Cladogenesis – branching evolution – new species arises from parent population § BIOLOGICAL DIVERSITY o Create a mountain – split species o Allopatric speciation –gene flow could not occur; long time barriers § Geographic isolation – makes new species – large scale § Ecological isolation – same area – small scale § Peripheral populations- geographic isolation of a small population on the edge of the range of the main population; natural barrier § Barrier to movement – splits ancestral population into 2 distinct populations w/out gene flow § Founder effect – colonization of remote area by one of a few individuals § Peripheral isolation – population on the periphery of a species range becomes geographically isolated § Colonization – over generations; founder effect –new species adapt & diversify • New habitats / few species allows rapid diversification o Resources are sufficient • New habitat-niche-quick speciation • Adaptive radiation – new species adapting rapidly o Mendelian Genetics preserve genetic variation from 1 generation to the next § Laws of segregation & independent assortment o Population genetics – gene frequencies – sum of all individuals w/ genotype of interest/total population o Traits of a stable population § No mutation, no emigration/immigration, random mating, population size is very large, no selection of specific traits § Populations meeting all requirements are in equilibrium § If the trait of interest adheres to mendelian genetics – determine the allele/gene frequencies § Perfectly stable populations in nature do not exist o Hardy-Weinberg Equilibrium – genetics defining stable populations § Based on the fact that a gene has 2 alleles & the frequencies of these alleles in the entire population have 2 2 2 to equal 1 (p+q) =1 / p +2pq+q =1 • P =frequency of population homozygous for the dominant allele • 2pq=frequency of population that is heterozygous 2 • q =frequency of population homozygous for the recessive allele § Populations in equilibrium are not evolving § Allelic frequencies should stay the same through successive generations of a population if they are stable & not changing (not evolving) § Evolving = shifting away from equilibrium • Agents of Evolutionary change o Microevolution – changes in allele frequencies on a population scale o Mutation, gene flow (immigration/emigration), non random mating, genetic drift o Opposite of Hardy-Weinberg o Must have mutations for different alleles to form § Mutations need to be “selected” ; take time to apply § Selection – true agent of evolutionary change • Artificial selection – breeder selects desired characteristics • Natural selection – environmental conditions determine which individuals in a population produce the most offspring o 3 conditions required: variation in traits, differences in # of offspring, variation much be genetically inherited o Selection to avoid predators, to match climatic conditions, for pesticide resistance o Sexual selection o Differential success in reproduction among individuals that vary in their heritable traits (must have genetic variation) o Increases the adaptation of organisms to their environment o Adapt to environmental changes • Works by survival of the fittest phenotype; dominant > alternative; dominalected • Reproductive Barriers o Sympatric speciation – new species evolves fro single ancestor while inhabiting same region § Behavioral isolation – species differ in mating rituals & other behaviors § Temporal isolation – species in same area, same habitat, r eproduce in different seasons or different times o Mechanical isolation – structural differences between species prevent mating § Can have geographical, ecological, & timing overlap o Prezygotic - no gamete function; gametes of one species function poorly wit h gametes of another § Plants wont accept pollen from another plant; gametes don’t fuse o Postzygotic – hybrid invariability or infertility – hybrid embryos do not develop properly – hybrid adults do not survive in nature or are sterile § Plants make hybrids; some caused by humans • Evolving: mutation, small population, nonrandom mating, gene flow • Not Evolving: no mutation, large population, random mating, no gene flow
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'