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215 Cards in this Set
- Front
- Back
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variation
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differences that exist among individuals or populations
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evolution
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change in living organisms over time
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adaptation
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advantageous changes; process of successful interaction between a population and an environment
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cultural anthropology
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variation in cultures of populations in the present or recent past
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archaeology
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study of cultural behaviors in the historic and prehistoric past
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linguistic anthropology
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study of language, which is considered to be a uniquely human trait
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biological anthropology
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concerned w/the biological evolution and variation of the human species, past and present
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Types of time
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ontogenetic (birth, death), intergenerational (parents, grandparents), historical (origins of agri), geological (6 mya = divergence from chimps)
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phylogenetic tree
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branching diagram showing the evolutionary relationships among species
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Aristotle
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-greek philosopher
-384-322 BCE -hierarchical organization of life forms by complexity (~great chain of being) |
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Great Chain of Being
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-Scalae Natura
-greek/roman -linear ranking of organisms -some life forms superior to others -scales persisted until 18/19th c. |
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essentialism
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-organisms have true/ideal form
-living reps of organisms are deviations from ideal |
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James Ussher
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-Archbishop of Ireland
-1581-1656 -date of creation based on biblical story=4004 BCE -earth <6,000 years old |
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John Lightfoot
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-1602-1675
-specified biblical creation date/time |
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Pre-Scientific Revolution
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-world was static
-linear ranking of organisms -earth = 6,000 years old |
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Scientific Revolution
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-began systematic study of the world
-physics, chem, bio, medicine, etc -laid foundations for modern science |
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Nicolaus Copernicus
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-1473-1543
-heliocentric theory=earth revolves around the sun -church declared NC a heretic |
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Galileo Galilei
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-1564-1642
-italian physicist, math, astro, philo -advocated testing new ideas through experimentation -strong proponent of heliocentrism/atomic theory |
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Francis Bacon
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-1561-1626
-"father of the scientific method" -rules for observation/collection of data |
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Fact
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verifiable truth
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Hypothesis
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explanation of observed facts; must be testable
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Testability
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subject to falsification
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theory
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set of hypotheses that have been tested repeatedly and not rejected
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Sir Isaac Newton
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-1642-1727
-Principia Mathematica: Universal Gravitation & Laws of Motion -telescope, color, cooling, speed of sound |
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Carolus Linnaeus
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-swedish naturalist
-first formal classisfication of all living creatures = first taxonomic system |
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taxonomy
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science of describing and classifying organisms
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Linnaean Taxonomy
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-fixity of nature
-placed all species at the same level -clusters of organisms most similar into species and grouped species into genera |
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Georges Cuvier
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-1769-1832
-french anatomist -catastrophism |
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catastrophism
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explained extinctions as due to series of catastrophes during the planet's past
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Jean-Baptiste Lamarck
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-1744-1829
-dynamic relation btwn organism/enviro means organic forms constantly changing |
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Lamarckian Evolution
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1. change in response to enviro
2. inheritance of acquired characteristics 3. passage of traits by law of use/disuse |
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Uniformitarianism
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geological processes that we observe in the world today operated in the same way in the past
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James Hutton
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-1726-1797
-Scottish geologist -developed Uniformitarianism |
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Charles Lyell
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-1797-1875
-scottish geologist -evidence for slowly changing earth -small biological process can produce considerable evolutionary change over time |
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Age of the Earth
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5.4 billion years old
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Thomas Malthus
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-1766-1834
-population grows faster than resources -organisms die before reaching maturity/reproducing |
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Charles Darwin
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-1809-1882
-Origin of Species -Evolution by Natural Selection |
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Alfred Russel Wallace
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-1823-1913
-Evolution by Natural Selection |
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Historical Timeline of Evolutionary Thought
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Erasmus Darwin
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-1731-1802
-Darwin's grandfather -physician, as was Darwin's father |
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Charles Darwin Life
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-interest in nature
-dropped out of med school in Edinborough -sent to become a priest in Cambridge -1832 begins 5 year voyage on the Beagle |
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Darwin's observations on Beagle voyage
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-observable variation in living species
-variation matched enviro -organisms seem to be adapted/suited to enviro -classification via branching diagrams |
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Natural Selection
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mechanism for evolutionary change favoring the survival and reproduction of some organisms over others because of their biological characteristics
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Key Aspects of Natural Selection
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1. Variation
2. Variation is heritable 3. Fitness -- variation leads difference in # of offspring 4. Successful individuals leave more surviving offspring |
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Alfred Russel Wallace
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-1823-1913
-English natural historian -misfortunes at sea -noticed variation across islands just as Darwin did -sent his theory of "survival of the fittest" to Darwin |
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Wallace's Line
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-suggested that Bali was once connected to the Asiatic continental shelf
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Origin of Species by Means of Natural Selection
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-1858: Darwin/Wallace theory presented jointly
-1859 Darwin published OofS |
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Darwin's Supporting Evidence
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-geographical distribution of species
-artificial selection by humans -vestigial organs -ontogeny and development -homology of structure |
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Geographic distribution of species
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-species are related to those in nearby habitats
-NOT related to species occupying similar habitats |
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Artificial selection by humans
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-selective breeding demonstrated the process of speciation by natural selection
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vestigial organs
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-species have organs/traits that are no longer useful
-these are remnants from past ancestors |
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ontogeny and development
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-more closely related species have similar development paths
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homology
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a state of similarity in structure and anatomical position, but not necessarily in function between different organisms indicating a common ancestry
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Unexplained elements of Darwins' theory
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-transitional forms
-"organs of extreme perfection" -social insects: non-reproductive workers -mechanism of inheritance & maintain variation |
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Gregor Mendel
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-1822-1864
-Austrian monk -plant breeding experiments -discovered genetic info inherited in discrete units |
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Mendelian Genetics
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-units of heredity (allele)
-dominant traits mask recessive traits |
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Genotype
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genetic endowment of an individual
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Phenotype
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actual observable trait
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"Founders of Theoretical Population Genetics"
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-Ronald Fisher, J.B.S. Haldane, Sewall Wright
-reconciled Mendelian Genetics and Darwinism -helped lead to modern synthesis |
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Modern Synthesis
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-1920s-1940s
-Evolution = change in Gene Frequency in Population over Time |
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James Watson
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-1928-
-American, eventually worked in Cambridge -helped discover the structure of DNA w/Crick |
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Francis Crick
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-1916-2004
-British -met Watson in Cambridge -interested in how genetic might be stored in molecular form |
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Maurice Wilkins & Rosalind Franklin
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-working at Randall Lab at King's College in London
-Franklin using x-ray diffraction to examine DNA structure -Wilkins gave image to his friend Crick, w/out Franklin's knowledge |
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Structure of DNA
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-Nature, 1953
-Watson & Crick proposed double helix model of DNA molecule |
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DNA
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-deoxyribonucleic acid
-genetic code -provides info for building, operating, and repairing organisms -replicates itself -critical in protein synthesis -located in nucleus, mitochondria |
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chromosome
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long strand of DNA
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gene
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section of DNA that has identifiable fxn, e.g. codes a protein
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# chromosomes (human, fruit fly)
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-human=23 diploid pairs (46 total)
-fruit fly=4 diploid pairs (8 total) |
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locus
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specific position of a gene or DNA sequence on a chromosome
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genetic map
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ordered list of loci for a particular genome
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allele (molecular genetics)
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alternative forms of a gene at a locus
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molecular structure of DNA
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-double stranded "ladder"
-chem bases: A<-->T (U in RNA), C<-->G |
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DNA replication
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-DNA molecule splits
-new bases/backbone builds off each strand -results in two identical DNA strands |
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Protein Production
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1. DNA splits
2. mRNA formed 3. mRNA transports info to ribosome 4. tRNA facilitates synthesis of amino acid chains 5. amino acid chains form full proteins |
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Introns vs. Exons
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-different sections of initial mRNA
-introns=noncoding; spliced out -exons=protein coding; spliced together |
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regulatory genes
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act as switches to turn protein-coding genes on or off
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mitosis
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-process of cell replication by duplication; produces two identical cells
-interphase, prophase, metaphase, anaphase, telophase |
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meiosis
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-creation of sex cells by replication of chromosomes followed by two cell divisions
-contains half of an individuals chromosomes |
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reproduction
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-biological process by which new individual organisms are produced from their parents
-asexual and sexual |
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ovum & sperm
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-ovum=female gamete
-sperm=male gamete |
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fertilization
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-fusion of gametes
-each haploid gamete contributes 23 chromosomes to create a diploid embryo |
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mtDNA
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-mitochondrial DNA
-small ring of DNA found in the mitochondria -inherited solely from the mother |
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genome
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total DNA sequence of an organism
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microevolution
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changes in frequencies of alleles from one generation to the next; freq. of alleles, geno, pheno for entire populations
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macroevolution
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long-term patterns of genetic change over thousands and millions of generations; origin of new species
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breeding population
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group of organisms that tend to choose mates from the group
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genotype frequency
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measure of the relative proportions of different genotypes within a population
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allele frequency
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measure of the relative proportions of alleles within a population
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dominant allele
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masks the effect of another allele at given locus
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recessive allele
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masked by the effect of another allele at a given locus
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codominant allele
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one allele variant is not dominant over the other
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homozygote
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both alleles at a given locus are identical
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heterozygote
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two alleles at a given locus are different
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Reginald Punnett
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-1875-1967
-British geneticist -wrote first textbook on genetics -created Punnett Square |
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Hardy-Weinberg Principle
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-relates allele freq. in a population to expected genotype frequencies in the next generation
-p^2 + 2pq + q^2 = 1 -assumes nonrandom mating and no evolution -German scientist and British Mathematician developed idea separately |
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Populations not in H-W Equilibrium
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-H-W equilibrium predicts that allele/genotype frequencies will be stable
-if allele frequencies change, then the assumptions are violated and evolution is observed |
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Forces of Evolution
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-Mutation
-Natural Selection -Genetic Drift -Gene Flow |
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Mutation
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mechanism for evolutionary change resulting from a random change in the genetic code
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Mutations: Cause & Effect
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-cause: radiation, heat, ingested substance. must be in sex cells to matter
-effects: harmful, advantageous, or neutral -do not lead to major changes in allele frequencies; but only force that creates new variation |
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Types of Mutation
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-single DNA base (Sickle cell)
-large sections of DNA -entire chromosome (Down's syndrome) |
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Genetic Drift
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random change in allele frequency from one generation to the next
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Estimated Rate of Mutation
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btwn .1 and 10 mutations/million genes each generation
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Influence of Genetic Drift
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-larger effect in small populations, e.g. Dunkers in the U.S. (MN blood type)
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Founder Effect
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type of genetic drift caused by the formation of a new population by a small number of individuals
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Gene Flow
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movement of alleles from one population to another
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migration
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movement of individuals from one place to another
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Effects of Gene flow
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-promotes genetic similarity by mixing gene pools -introduce new variation by spreading mutations through gene flow
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Determinants of Gene Flow (Humans)
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-geographic distance -sociocultural groups -ethnic differences -religious differences -social class
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Natural Selection
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mechanism for evolutionary change favoring the survival and reproduction of some organisms over others because of their biological characteristic
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Fitness
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organism's probability of survival and reproduction
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Tay-Sachs disease
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-recessive homozygote -lipid buildup disorder -children die in first year -fitness=0
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interaction of evolutionary forces
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mutation introduces new genetic variants and genetic drift, gene flow, and natural selection change the frequency of the mutant allele
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Dwarfism
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-bone-growth disorder -single DNA base substitution -heterozygotes have disease; homozygotes die -natural selection acts against dominant homozygote
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Balancing Selection
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selection for the heterozygote and against the homozygote (e.g. sickle cell and malaria)
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Simple vs. Complex Genetic Traits
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-simple: single locus, discreet units of interitance, finite number of pheno. -complex: continuous distributions (e.g. height) w/complex modes of inheritance
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Modes of Inheritance
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simple, polygenic, pleiotropy
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polygenic trait
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complex genetic trait affected by two or more loci
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peitropy
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single allele affects more than one trait
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genetic variation
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variation caused by genetic factors
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environmental variation
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variation due to differences in environmental factors
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total variation
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combination of genetic and environmental variation
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heritability
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proportion of total variation of a trait due to genetic variation; common measure in studies of complex traits; genetic variation/total variation; .5<high heritability
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types of selection
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stabilizing selection, directional selection, disruptive selection
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stabilizing selection
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form of selection against extreme values in a continuous trait (e.g. human birth weight); see increase in intermediate values
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directional selection
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selection against one extreme in a continuous trait and/or selection for the other extreme; change in one direction over time (e.g. human brain size)
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disruptive selection
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extreme values are selected over intermediate trait values; can contribute to speciation (e.g. cactus spine numbers)
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Nonrandom mating
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e.g. inbreeding, assortive mating; no change in allele frequency, but a change in genotype frequency
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inbreeding
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nonrandom mating that occurs with mating between biologically related individuals; results in increased homozygosity
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assortive mating
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nonrandom mating based on phenotypic similarity or dissimilarity
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positive assortive mating
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seek mates with traits similar to yourself
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negative assortive mating
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seek mates with traits dissimilar to yourself
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sexual selection
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acts on traits that afect differential reproduction among individuals of the same sex; secondary sexual characteristics (e.g. body size, strength, tooth weaponry, coloration)
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Types of sexual selection
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1. competition over access to mates (males) 2. choice of mates (females)
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sexual dimorphism
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differences in size between the sexes; associated w/male competition and dominance (e.g. Gorillas)
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sexual monomorphism
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males/females similar in size and strength; associated with equality in relationships (e.g. Gabons)
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priority of access
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males that have outcompeted other males by attaining higher rank or status often gain priority of access to important resources (food, mates)
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Male vs. Female Reproductive Approaches
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females physiologically limited # of offspring/reproduction is more costly; females certain of parentage; females provide parental care; more time investment
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Female Mate Choice
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selection of one or more mates by females
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Optimal Mate Choice for Females
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males that: acquire food, protect, contribute to infant care, have good genes, not related
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Sir Francis Galton
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1822-1911; Englishman and Prolific Scholar; interested in variation among human populations, coined term 'eugenics'
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Eugenics
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study of alll agencies under human control which can imporve or impair the racial quality of future generations; bio-social movement with philosophy for the improvement of human heredity
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Henry Godard
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1866-1957; American psych and eugenicist; IQ testing advocate and institutionalizing those with low Iqs
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Eugenics Implemented
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attempt to improve human gene pool through: institutions, sterilization, euthanasia, mass extermination
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Misconceptions about Natural selection
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bigger is not always better, newer is not always better, natural selection doesn't always work, no invetable direction, not perfect, all structures are not adaptive
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orthogenesis
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the idea that evolution will continue in a given direction because of a vaguely defined non-physical "force"
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Theistic Evolution
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belief that God operates through the natural process of evolution
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Scopes Monkey Trial
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Tenn. vs. John Scopes; 1925. ACLU backed a teacher to violate anti-evolution law
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John T. Scope
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high school teacher; friend at local ACLU asked him to pursposely violate Butler Act (anti-evolution teaching)
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Clarence Darrow
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represented John Scopes in trial; leading member of the ACLU
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William Jennings Bryan
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represented State of Tenn.; well known orator and strong opponent of Darwinism/evolution
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Creationism
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Origin stories from Judeo-Christian-Islamic tradition; Genesis account of the creation of earth and life forms
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Creation Science
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modern version of creationism; Arkansas law required to teach but it was overturned after ACLU challenge
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Intelligent design
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idea that the biolocial world was created by an intelligent entity and did not arise from natural processes; claim that some characteristics too complex to come from natural selection; e.g. Dover and Kansas
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Biological Species Concept
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groups of interbreeding natural populations that are reproductively isolated from other such groups
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Problems with the BSC
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1.Applying to fossil record
2.Many named species don't conform to this definition (e.g. baboons) |
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Speciation
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formation of a new species from a parent species; populations that have become reproductively isolated and genetically divergent from the parent species
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Reproductive Isolation
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reduced or eliminated gene flow between populations (e.g. geographic isolation)
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Genetic Divergence
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evolutionary forces (mutation, genetic drift, and natural selection) act on isolated populations created genetically distinct
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Anagenesis
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-transformation of one species into another
-"straight line" evolution: A-->B |
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Chronospecies
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labels given to different points in the evolutionary lineage of a single species over time
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Cladogenesis
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-branching evolution
-formation of one or more new species that branch from an original species -A --> A & B |
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Allopatric speciation
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one species branching into two as a result of geographic and reproductive isolation (e.g. chimps and bonobos)
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Sympatric speciation
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formation of new species in the absence of geographic isolation; often results from different behaviors
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Adaptive radiation
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formation of many new species following the availability of new environments or the development of a new adaptation (e.g. Madagascar)
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Gradualism (theory & mechanism)
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-view that macroevolution is a slow, gradual process
-small changes accumulate in each gen. -mechanism: natural selection on small mutations in large populations |
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Punctuated Equilibrium (theory & mechanism)
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-macroevolution as long periods of stasis and short periods of rapid evolutionary change
-mechanism: advantageous mutation spreads rapidly in small populations through inbreeding and genetic drift |
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Extinction
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-species entirely dying out
-more than 99% of all species ever existed became extinct -rapid ecological change; mass extinction |
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Levels of Taxonomic Classification
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Kingdom, Phylum, Class, Order, Family, Genus, Species (KPCOFGS=King Phillip Cooked On Four Grills Simultaneously)
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Methods of Taxonomic Classification
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-phenotypes (before molecular genetics)/morphology (physical structure)
-genetic distance |
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Human Classification
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-K: Animalia
-P: Chordata (vertebrates) -C: Mammalia (mammals) -O: Primates -F: Hominidea (Homoniods) -G: Homo -S: sapiens |
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Hominin Species
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-multiple species overlapped w/Homo sapiens:
-Homo erectus, H. neanderthalansis, Homo floresiensis |
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Homo sapiens
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-characterized by craniofacial features associated w/large brain and bidpedalism
-latin for "wise man"/"knowing man" |
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Limitations of Linneaus' Classification
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-no info about evolutionary relationships
-dimension of time is absent |
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Darwin's "Tree of Life"
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-addressed limits of Linneaus'
-tree diagram w/branches and twigs connecting species -expressed evolutionary relationships and time |
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Speciation & Classification
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-speciation explains hierarchy of organisms
-group of species that share a common ancestor can be arranged in a family tree |
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Phylogeny
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evolutionary history of a group of organism
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Phylogenetic Tree
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branching diagram showing the evolutionary relationships among species
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Reading Phylogenetic Trees
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-root=common ancestor of every organism
-branch=speciation events -leaf=organism -node=common ancestor of all branches out of it -evolutionary time/change represented along the length of the tree |
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homoplasy
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-similarity independent of evolution (e.g. wings of birds and insects)
-not an indicator of common ancestry |
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Types of homoplasy
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-parallel evolution: independent evolution of similar traits in closely related species
-convergent evolution: " " in distinct evolutionary lines |
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Classification of evolutionary relationships
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-homologous traits (due to a common ancestor)
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Types of homologous structures
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-primitive: trait that has not changed since ancestral state
-derived: trait that has changed from an ancestral state |
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Distinguishing Derived and Primitive Traits
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-development
-fossil record -outgroups |
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Derived vs. Primitive: Development
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development: derived characters often appear early on in development and disappear late (e.g. tail)
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Derived vs. Primitive: Fossil Record
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-fossil record helps compare to ancestors of living species
-e.g. first mammals had 5 digits |
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Outgroup
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group that is more distantly related to the species being classified aids in determining whether ancestral state of a trait is primitive/derived
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Shared vs. Unique traits
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-e.g. absence of tail is shared derived trait b/c found in other primates
-e.g. bipedalism is a unique derived trait b/c not found in other primates |
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Types of Biological Classification
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-evolutionary systematics
-cladistics |
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Evolutionary Systematics
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-overall similarity of all homologous traits
-most number of homologous traits grouped together -not necc. based on actual evolutionary relationships |
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Cladistics
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-stresses evolutionary relationships based on shared derived homologous traits
-primitive traits and unique derived traits not considered |
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Parsimony
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-economy in explanation, least complex path
-preferred phylogenetic tree is most parsimonious/requires least evolutionary change |
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Molecular phylogenies
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-compare sequences of DNA to determine primitive, derived, and shared derived molecular patterns
-helps establish evolutionary relationships/validity of species/subspecies |
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Genetic distance
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-measure of overall genetic similarity:
1. ID homologous DNA 2. Sequence DNA 3. # of bases at which sequence differs |
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Molecular Clock
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-mutations may build up in any given stretch of DNA at a reliable rate
-based on observed regularities in rate of genetic change -used to measure time elapsed since two species shared a common ancestors |
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Estimated Divergence Date
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(genetic distance)/(rate at which genetic distance accumulates through time)
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Boas & Moving Past Race
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-study of 17,000 ppl of different ethnicities
-did not deny heritability of physical features, but environment also has influence -discredited Morton |
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Samuel George Morton
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-1799-1851
-measured skulls of different races -skulls/brains varied in size -concluded races had different intelligence |
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Biological Race & Genetic Evidence
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-genetic variation is far greater within than between human populations
-no genetic marker that differentiates race -genetic variation in Euro/Asians is a subset of that found in Africans |
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Biology of Skin color
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-skin reflectance can't determine subspecies
-distribution is related to relative intensity of UV light in regions of ancestors -example of continuous variations |
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Human Variation
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-largely structured geographically
-not related to a "race" concept -humans are more alike than unlike |
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Origin of Modern Humans: Fossil Evidence
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-200,000 ya in Africa=first anatomically modern humans
-discovered in 60s/70s by Leaky in Ethiopia |
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Modern Human craniofacial anatomy
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-more well-rounded skull
-small brow ridge -prominent chin |
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Genetic relationships between populations
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-strong relationship to geographic distances b/c:
-gene flow (more flow between closer populations) -sequential founding of populations (history of human expansion) |
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Isolation by Distance Model
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predicts that the genetic distance between populations will increase as the geographic distance between them increases
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Expansions out of Africa
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-1.9 mya=expansion of H. erectus
-650,000 ya=spread of H. heidelbergensis -130,000=origin/expansion of modern humans |
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Multiregional Evolution Model
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-modern humans emerged simultaneously in major regions of the Old World from local archaic humans
-common ancestor is early H. erectus in Africa at least 1 mya -emphasizes the role of migration |
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Out of Africa Model
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-modern human anatomy first appeared in Africa, then spread across the Old World
-modern humans encountered archaic humans living elsewhere in the world |
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African Replacement Model
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-modern humans migrated around the world and replaced preexisting human populations
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Assimilation Model
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transition to modern anatomy in Africa, then these changes spread to other populations through gene flow
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Evidence used to form theories of Human Origins
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-fossil record has been used as support for several theories
-genetic: present day variation and compare genomes of ancient/modern people |
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Most Recent Common Ancestor
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-most recent individual from which a set of organisms are descended
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Mitochondrial Eve
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-found by tracing back mtDNA until all lines converge
-200,000 years ago in E Africa |
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Genetic Data on Human Origins
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-support the Out of Africa model
-small genetic differences between groups (would be large w/multiregional) -most variation in Africa -Mitochondrial Eve |
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Svante Paabo
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-grew up in Stockholm
-biologist; interest in mummies -discovered Neandertals contributed some genes to modern humans |
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Genetic Geneaology
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-trace the path of our ancestors
-Standard Maternal Ancestry Package |
