ANT 3514 – Intro to Bio Anth ANT 3514 – Intro to Bio Anth LabLab

Megan HosfordMegan Hosfordmhosford@anthro.ufl.edumhosford@anthro.ufl.edu

B329 and B301B329 and B301

MWR (2:00-3:15)MWR (2:00-3:15)

ANT 3415C Lab Policies

Rules for Turlington B304NO food or drinks allowed in the room.NO cell phones or pagers during lab session – these must be turned off.Handle and treat all teaching materials in the room with utmost care and respect. Bone and fossil casts are breakable (and expensive)! COURSE WEBSITEwww.clas.ufl.edu/users/krigbaum/3514

AttendanceLab sessions are MANDITORY. Attendance will be taken at the beginning of each session. If you plan on missing a lab, you must notify your TA at the beginning of the week and you must have a legitimate reason. The TA will place you into another appropriate session for that week. There will be no lab make-up opportunities except under the following situations: (1) serious sickness/injury with official doctor/infirmary letter to Prof. Krigbaum; (2) military or athletic excuses with official documents; (3) other emergencies (talk to your TA or the Prof. Krigbaum for approval).  GradingThere will be 6 lab sessions (20 points each) and 3 lab quizzes (2 in-class and 1 take-home, 10 points each). The three lab quizzes will be given BEFORE exams. Lab homework is due at the beginning of next week’s lab. Lab questions will be drawn from reading materials as well as those based on materials provided during lab hours and lecture. You may turn in the answers of a lab you missed, but answers for in-lab questions will NOT be credited.

Lab 1Lab 1Principles of Principles of

EvolutionEvolutionPart 1: Natural Part 1: Natural

SelectionSelection

EvolutionEvolution The change in gene frequency over time.The change in gene frequency over time.

Natural Selection –The mechanism that determines:1.which characteristics (physical or behavioral) are

best suited to the environment 2.will persist in succeeding generations, given a

stable environment3. advantageous characters become numerous in

future populations at the expense of less favorable characteristics

Measuring ‘fitness’Measuring ‘fitness’►Natural selection acts on genetic Natural selection acts on genetic

variation so that the genes for ‘fit’ variation so that the genes for ‘fit’ phenotypes increase in a population.phenotypes increase in a population.

Who is the most fit?

1. A professional athlete (7-digit income) who is in good health, single, and has no children.

2. A single parent (minimum wage income) who is in fair health and struggling to raise 2 children.

3. A foster parent (modest income) who is in good health and parenting an adopted child.

Lamarkian vs. Darwinian Evolution Lamarkian vs. Darwinian Evolution (LOOK AT QU 1-3)(LOOK AT QU 1-3)

Lamark (~1800)Lamark (~1800)► Variation exists b/c of environment, in response to a Variation exists b/c of environment, in response to a

specific demandspecific demand► An individual’s efforts affected its An individual’s efforts affected its physicalphysical structure structure

inheritedinherited► Individual levelIndividual level► Goal – orientedGoal – oriented► DirectionalityDirectionality

Darwin (1859)•Variation naturally exists•Offspring inherent characteristics from parents•Depending on environment, some characteristics more beneficial than others•Population level•Not goal – oriented•No directionality

Darwin’s WarDarwin’s War► Randomized gene poolRandomized gene pool► Each person maintains a population of 10 individualsEach person maintains a population of 10 individuals► In this environment, higher-ranking cards are being In this environment, higher-ranking cards are being

selected for, aces represent the suite of characteristics selected for, aces represent the suite of characteristics best suited for this current environmentbest suited for this current environment

► Play war, randomly select competition – keep ‘fit’ Play war, randomly select competition – keep ‘fit’ cards, replace ‘unfit’ onescards, replace ‘unfit’ ones

► At the end of 10 rounds (generations), see how final At the end of 10 rounds (generations), see how final population is different from your original populationpopulation is different from your original population

► Record population demography prior to each round Record population demography prior to each round (Round 1 is your original hand)(Round 1 is your original hand)

► Hand in data sheet, I will email class population resultsHand in data sheet, I will email class population results

Lab 1, Part 2: Lab 1, Part 2: Cell Biology and Cell Biology and

GeneticsGenetics

DNA StructureDNA Structure

Deoxyribonucleic acidDeoxyribonucleic acidMain component of chromosomesMain component of chromosomesDouble-stranded moleculeDouble-stranded moleculeContains genetic codesContains genetic codes

Synthesizes proteinSynthesizes proteinMade of two chains of nuclieotides—Made of two chains of nuclieotides—

sugar, phosphate, base (A,T,C,G)sugar, phosphate, base (A,T,C,G)

LOOK AT QUESTION 7LOOK AT QUESTION 7

TerminologyTerminology

GeneGene

ChromosomeChromosome

autosome & sex chromosomeautosome & sex chromosome

AlleleAllele

Diploid & haploidDiploid & haploid

Cell DivisionCell Division

Mitosis-Mitosis- somatic cell DNA replicationsomatic cell DNA replication

simple cell division (1 into 2)simple cell division (1 into 2)

exact replication of the original DNAexact replication of the original DNA

Cell DivisionCell Division

Meiosis-Meiosis- sex cell DNA replication in ovary & sex cell DNA replication in ovary &

testistestis

2 divisions (1 into 4)2 divisions (1 into 4)

random assortmentrandom assortment

recombination (cross-over)recombination (cross-over)

gametegamete

Mendelian GeneticsMendelian Genetics

Gregor Mendel (1822-1884)Gregor Mendel (1822-1884)

Dominance vs. RecessivenessDominance vs. Recessiveness

Homozygous vs. HeterozygousHomozygous vs. Heterozygous

Medelian traitsMedelian traits

Principle of SegregationPrinciple of Segregation

Principle of Independent Assortment Principle of Independent Assortment (LOOK AT QUESTION 11)(LOOK AT QUESTION 11)

Principle of Segregation: Genes (alleles) occur in pairs (because chromosomes occur in pairs). During gamete production, the members of each gene pair separate, so that each gamete contains one member of each pair. During fertilization, the full number of chromosomes is restored, and members of gene or allele pairs are reunited.

Principle of Independent Assortment: The distribution of one pair of alleles into gametes does not influence the distribution of another pair. The genes controlling different traits are inherited independently of one another.

LOOK AT QUESTION 8LOOK AT QUESTION 8

Lab 1, Part 3:Lab 1, Part 3:Forces of EvolutionForces of Evolution

EvolutionEvolution – – change in gene frequency over timechange in gene frequency over time acts on a populationacts on a population

Forces of Evolution - factors that produce and redistribute variation:

1. Natural Selection 2. Gene Flow3. Genetic Drift4. Mutation (Recombination)

(LOOK AT QUESTION 13)

Gene FlowGene Flow

The exchange of genes between The exchange of genes between populationspopulations

- - migrations (group or individual-level)migrations (group or individual-level)

Inherent mechanism within human and non-human species

- Social taboos against incest

- Fundamental basis for sex-specific patterns of philopatry & migration

Genetic Drift Genetic Drift (LOOK AT QUESTION 15)(LOOK AT QUESTION 15)

Changes in allele frequencies due to:Changes in allele frequencies due to:►Random factorsRandom factors►Small population sizeSmall population size

• Founder effect – prevents gene flow genetic bottleneck

- colonization

- disasters

Examples:

- Cheetahs – decreased reproductive potential

- Taiwanese macaques – geographic isolation

MutationMutation

►Changes of alleles, A aChanges of alleles, A a►Mutation rates are usually low in big pop’Mutation rates are usually low in big pop’►Natural selection determines the Natural selection determines the

frequency of the mutated allelefrequency of the mutated allele►Basic creative force in evolution—the Basic creative force in evolution—the

ONLY way to produce new genetic ONLY way to produce new genetic variationvariation

►LOOK AT QUESTION 14LOOK AT QUESTION 14

Types of SelectionTypes of Selection

► 1. Stabilizing:1. Stabilizing:

when environment is stable, maintains when environment is stable, maintains genotypic and phenotypic status quogenotypic and phenotypic status quo

► 2. Directional:2. Directional:

responses to environmental change and responses to environmental change and productive shifts in composition of a productive shifts in composition of a population’s gene pool and collective population’s gene pool and collective phenotypes phenotypes

LOOK AT QUESTION 9 and 16!LOOK AT QUESTION 9 and 16!

Hardy-Weinberg TheoremHardy-Weinberg Theorem

► Predicts the distribution of genotypes in Predicts the distribution of genotypes in subsequent generations of a populationsubsequent generations of a population

► pp22+2pq+q+2pq+q22=1, where=1, where pp22 : % homozygous dominant : % homozygous dominant 2pq : % heterozygous2pq : % heterozygous qq22 : % homozygous recessive : % homozygous recessive

LOOK AT QUESTION 17LOOK AT QUESTION 17

Hardy-Weinberg TheoremHardy-Weinberg Theorem

Assumptions:Assumptions:► A large populationA large population► Random matingRandom mating► Equal numbers of males and femalesEqual numbers of males and females► Absence of natural selectionAbsence of natural selection► No mutation, genetic drift or gene flowNo mutation, genetic drift or gene flow► No migration in or outNo migration in or out

What will happen if H-W Theorem holds?What will happen if H-W Theorem holds?

Species ConceptsSpecies Concepts► Biological Species ConceptBiological Species Concept – – a group of a group of

individuals capable of producing fertile offspringindividuals capable of producing fertile offspring Based on gene flow and reproductive isolationBased on gene flow and reproductive isolation Limitations?Limitations?

• Ecological Species Concept – a group of organisms exploiting a single niche

- Stresses the role of natural selection

- Limitations?

No easy answer – not necessarily mutually exclusive!

Doesn’t allow for hybrids (e.g. baboons)

Does a niche define a species, or does a species define a niche?

Reproductive behavior can’t be traced through the fossil record

READ QUESTION 18 AND READ QUESTION 18 AND LISTEN CAREFULLY LISTEN CAREFULLY

ABOUT THE NEXT THREE ABOUT THE NEXT THREE SLIDESSLIDES

SpeciationSpeciation

►The process by which a new species The process by which a new species evolves from a prior speciesevolves from a prior species

►The most basic process in The most basic process in macroevolutionmacroevolution

SpeciationSpeciation

► AnagenesisAnagenesis: : one species evolves into one species evolves into anotheranother

A BA B

► CladogenesisCladogenesis: : ancestral species evolves ancestral species evolves into branches of descendent speciesinto branches of descendent species

B B

A A’A A’

Models of SpeciationModels of Speciation

► GradualismGradualism: : New species evolves by gradual changes New species evolves by gradual changes

from the original onefrom the original one

► Punctuating equilibrium:Punctuating equilibrium:

Not unidirectional Not unidirectional