Anthropology Mid-Term

mutationism vs. Darwinism Mutationism: Hugo de Vries (1901) evolution via the accumulation of favorable mutations Darwinism: Charles Darwin (1859+) evolution by means of natural selection

"mutationism" vs. "Darwinism"??? 1901-1930s

a unit of inheritance....

*Gene* =

Three botanists .... Hugo DeVries (Netherlands) Carl Correns (Germany) Erich von Tschermark (Austria) .... independently rediscovered Mendel's work. They promote understanding of Mendelian laws of inheritance among scientists

1900

-Cultural anthropology -Linguistic anthropology -Archaeology -Biological anthropology (a.k.a. Physical anthropology)

4 subfields of Anthropology:

-a record of human expression

Anthropology can be considered a humanity because:

-human behavior is complex -generalizations may be hard to test -obtaining a high degree of certainty may be more difficult

Anthropology can be considered a social science because:

the study of humans

Anthropology definition:

a science a social science a humanity

Anthropology is:

holistic and comparative

Anthropology is:

temporal depth geographic breadth conceptual power

Anthropology:

T. Dobzansky et al.—population genetics J. Huxley—theoretical biology -theoretical biology -*Evolution: the Modern Synthesis (1942)* E Mayr—systematics G G Simpson—paleontology L. Stebbins—botany

Applications of synthetic theory 1930-1950+

Testing Observation Measurement

Applying the scientific method involves....

Prehistoric archaeology Historic archaeology Paleoecology Cultural resource management (CRM)

Archaeology (Anthropology): (Material remains)

Paleoanthropology Primatology Human variation Genetics Osteology Paleopathology Forensic anthropology

Biological Anthropology: (human biology in time and space)

an explanation for the origin of organisms

Biological application of Evolution:

CRISPR "Clustered Regularly Interspaced Short Palindromic Repeats" a technique for editing the genome of any species "....can target and excise any gene...even edit out a single base pair within a gene....editing the genome is now easier and cheaper...." a particular gene, known as Crispr, that seemed to help flesh-eating bacteria fight off invasive viruses...its ability to direct its protein, Cas9, to precisely snip out a piece of DNA at any point within the genome and then neatly stitch the ends back together. Crispr relied on two separate kinds of RNA: a guide, which targeted the Cas9 protein to a particular location, and a tracer, which enabled the protein to cut the DNA. The tool Doudna ultimately created with her collaborators paired Crispr's programmable guide RNA with a shortened tracer RNA. Used in combination, the system allowed researchers to target and excise any gene they wanted — or even edit out a single base pair within a gene.

CRISPR

introduced a hierarchical system to organize information about the diversity of living species Linnaeus was the first person to place humans in a system of biological classification; the first person to provide an objective description of humans comparable to that of any other species. put humans with primates (Anthropomorpha) in the first edition of Systema Naturae (1735-1758 10 editions); 1753 Species Plantarum introduced binomial nomenclature;

Carolus Linnaeus

The unity of science is demonstrated by examining the same phenomenon at different levels of analysis 1902, 1903 Walter Sutton—Mendel's genes reside on the *chromosomes* found in the nucleus of the cell *Mendel's Laws* of Segregation & Independent Assortment can be seen by following what happens to the *chromosomes* visible during the active phase of the cell cycle (when sex cells are dividing and producing mature gametes) -Sutton studied spermatogenesis in a Kansas grasshopper (Brachystola magna) at Columbia University ....chromosomes obey Mendel's rules—the first clear argument for the chromosome theory of heredity Sutton regarded chromosomes as units in inheritance, although he did point out that several alleles must reside in one chromosome and therefore be inherited as a unit. -A scientifically-derived model of inheritance that fits the evidence.... enables other scientists to extend the meaning derived from new observations -"Walter Sutton...observed that in the process of cell division, called meiosis, that produces sperm and egg cells, each sperm or egg receives only one chromosome of each type. .......The *segregation pattern of chromosomes* during meiosis matched the *segregation patterns of Mendel's genes."* *Living organisms are composed of cells* (the cell is the structural & functional unit of all living things) 1838 by Schleiden (botanist) & Schwann (zoologist) "The cell theory is to biology as atomic theory is to physics." Chromosomes are threadlike structures in the nucleus of the cell Every organism has a species-typical number of chromosomes 14 chromosomes (7 pairs) in Mendel's garden pea plant 46 chromosomes (23 pairs) in humans A *karyotype* is a visual image of all the chromosomes in a cell of that organism Chromosomes are arranged as homologous pairs By the time the chromosomes become visible in the nucleus of the cell, the DNA has replicated and each chromosome is double-stranded What Mendel proposed is what Sutton saw as he watched grasshopper sex cells divide -Sutton worked on grasshopper chromosomes Meiosis The production of gametes (mature sex cells) from immature sex cells -Double-stranded chromosomes line up as homologous pairs -*First division*, homologous pairs separate -*Second division*, double-stranded chromosomes become single-stranded chromosomes gametes -Gametes (eggs, sperm) have the *haploid* number of chromosomes which are single-stranded -Pairing is restored when sperm fertilizes egg; the fertilized egg has the *diploid* number of chromosomes During *meiosis* chromosomes become visible and line up as pairs. As chromosome pairs *separate*, anything riding on these chromosomes will also separate *Mendel's Law of Segregation can be seen in action*

Cell:

*Gene*—*discrete*, stable *unit of inheritance* *Allele*—there can be more than one form of a gene *Pairing*—*organisms* carry two alleles "for each trait"; *gametes* (eggs, sperm) carry just one allele *Dominant* allele vs. *recessive* allele—an allele is not always expressed yet continues to exist *Phenotype* vs. *genotype*—visible in the organism vs. present but not observable *Homozygous* vs. *heterozygous*—alleles of the same gene are identical vs. alleles of the same gene are different -William Bateson...need a new term to describe the study of heredity...used "genetics" in a 1905 1909 Danish botanist Wilhelm Johannsen...suggested that the Mendelian factors of inheritance be called genes. Thomas Hunt Morgan.... genes, strung on chromosomes, are the units of heredity.... 1933 Nobel Prize in Physiology or Medicine for helping establish the chromosome theory of inheritance.

Concepts derived from Mendel's work:

-Acquired by learning (extra-genetic) -Shared by a group -Transmitted from one generation to the next -Cumulative -> cultural evolution

Cultural Anthropology:

Ethnography Ethnology Cross-cultural comparisons Holocultural analysis Human Relations Area Files Culture change Applied anthropology Medical anthropology

Cultural Anthropology:

-mental infrastructure A system of shared meanings that guide *perception and action* water vs. "holy water"

Culture is:

behavior

Culture is:

-did not have a useful theory of inheritance -conceptualized inheritance as the result of *blending* -could not explain the source of *variation* in a species -Gregor Mendel's model of inheritance (1866) did explain a source of variation...*but Darwin never knew about it*

Darwin was interested in *inheritance* but he:

Different from the ancestor e.g. primates have forward-facing eyes and stereoscopic vision (something not found in most vertebrates)

Derived trait:

Sept 2003 US National Human Genome Research Institute (NHGRI) A follow up of the Human Genome Project Interpret the human genome -circa 20,000 genes (transcribe, translate into protein) -98.5% other...regulatory, etc. Coding DNA...transcribed into mRNA and translated into proteins.... For >50% of genes the functions are unknown

ENCODE Project Encyclopedia of DNA Elements

Change in series A -> B -> C -> D -> E but not A <- -> B

Evolution =

any directional change in series (e.g. cultural evolution, stellar evolution)

Evolution definition:

the study of *genes*

Genetics =

the study of inheritance with *genes* as the basic unit

Genetics =

-Population -Organism (An organism can be a human or a pea plant) -Cell -Molecule

Genetics—levels of analysis

T. Dobzansky—population genetics *discrete inheritance* also explains traits of complex inheritance *(polygenic traits)* Mendelian traits vs. polygenic traits?

Genetics—levels of analysis: Population: Putting it all together... The emergence of synthetic theory *(neo-Darwinism)* 1930-1950+

Hand pollinated 29,000 individual plants over a period of 7 years. Carefully observed and counted how traits were passed through successive generations. "....genes inherited from both parents remain distinct entities - even if the characteristics of parents appear to blend in their children."

Gregor Mendel

One of the people to read (1900) & publicize Mendel's 1866 genetics paper Observed new varieties of evening primrose (Oenothera lamarcklana) Coined the word "mutation" Developed a theory of evolution that incorporated genetics The Mutation Theory (1901)

Hugo de Vries 1848-1935

Every person on this earth shares 99.99% of the same genetic code with all other people....The biological difference between individuals is a fraction of the 3 billion base pairs *"...we all are essentially identical twins...even more than I thought"* (Craig Venter, Celera)

Human genome

Descriptive linguistics Sociolinguistics Language change Historical linguistics Language origins- (glottogenesis)

Linguistic Anthropology: (Language is unique to humans)

*Law of Segregation* = paired hereditary units segregate during production of gametes *Law of Independent Assortment* = paired units for distinctive traits assort independent of each other These "laws" presume that the unit of inheritance is discrete and stable as it is passed from parent to offspring. Mendel could not directly perceive the "factors" but the results he observed were consistent with the existence of such discrete hereditary factors (now called "genes"). -Mendel looked at the inheritance of two traits at once with a dihybrid cross (e.g. seed shape & seed color) -Dihybrid cross—look at the inheritance of two traits at the same time...start with plants that only produce "round, yellow" and "wrinkled, green" seeds. Observe what is visible in the F1 generation. Observe what is visible in the F2 generation. -Dihybrid cross—in the parental generation there are only "round, yellow" and "wrinkled, green" seeds. In the F2 generation, there is an enormous variety of shape and color combinations (a variety of phenotypes and genotypes).

Mendel's "Laws":

Mendelian trait -one gene locus controls the expression of the trait Polygenic trait -multiple gene loci control the expression of the trait

Mendelian trait vs. Polygenic trait

-1953 Nature article by Watson & Crick proposed structure of DNA -1957 Crick DNARNAprotein; codons; genetic code -1962 Noble Prize to Watson, Crick and Wilkins -Chromosomes are composed of very long molecules of DNA -DNA is a long series of *nucleotides* *Nucleotide* = base, sugar, phosphate -*Bases* form the rungs of a "ladder" *Sugar/phosphate* molecules form the "rails" -Double helix -*Nucleotides* are the constituents units of the DNA molecule -*Bases* form the rungs of a "ladder" -*Sugar/phosphate* molecules form the "rails" -The DNA molecule is a "ladder" is twisted into a double helix -DNA is an unusual molecule because: 1. DNA molecules replicate and continuously produce new molecules of DNA 2. *The code for producing all the proteins of an organism can be found in the DNA of that organism* -a portion of the long DNA molecule unwinds -one strand is used to produce a molecule of *mRNA (transcription)* -*mRNA* travels from the nucleus to the cytoplasm of the cell -ribosome "reads" the *mRNA* base sequence -Ribosomes translate information on *mRNA* into a *chain of amino acids (translation)* -Proteins are long chains of amino acids....folding produces the finished protein -DNA replication *Molecular level of analysis* -1957 Francis Crick proposed that the principle function of DNA was to code for protein -Information flows in one direction (Transcription -> Translation) -In the nucleus of the cell, *RNA* leaves the nucleus of the cell -The sequence of bases on mRNA is translated into a sequence of amino acids...the primary structure of a protein -Genetic Code mRNA codons and the amino acids they code for -*The amino acid sequence found in a protein such as hemoglobin can be compared across species* -66th amino acid before there is a difference in the amino acid sequence of human and rhesus....112 amino acids (only 1 difference)...11 amino acid differences between a human and a horse The hemoglobin molecule is made up of *four polypeptide chains*...the sequence of amino acids in the beta chain -66th amino acid before there is a difference in the amino acid sequence of human and rhesus....112 amino acids (only 1 difference)

Molecule:

*Sources of variation* explained by genetics -New combinations genes in offspring -*Independent assortment* -*Crossing over* during meiosis...exchanges genetic material as homologous chromosomes line up during meiosis -*Mutation* (change in DNA) introduces new genetic material (increases variation in a population)

Natural selection acts on existing *variation* in a population

An organism...with visible traits: -Pisum savitum (garden pea plant) -Gregor Mendel -1856-1863 experiments on 29,000 Pisum savitum -Published 1866 Proceedings of the Natural History Society of Brunn -*Discrete inheritance* (not blending) -1900 Re-discovery by Hugo de Vries, Carl Correns, Eric von Tschermarck -Hand pollinated 29,000 individual plants over a period of 7 years. Carefully observed and counted how traits were passed through successive generations. "....genes inherited from both parents remain distinct entities - even if the characteristics of parents appear to blend in their children." https://www.genome.gov/25520157/online-education-kit-1859-darwin-published-on-the-origin-of-species-proposing-continual-evolution-of-species/ -Mendel picked 7 traits to observe. Each trait that he decided to observe was a trait of simple inheritance (one gene locus controlled the expression of the trait). Each trait existed in two alternate forms. -Started with plants that only produced one version of the trait (all yellow seeds or all green seeds). Then hand pollinate to produce hybrid offspring and observe which version of the trait the offspring of hybrid cross-pollination inherits. Then cross hybrid with hybrid to see what happens in the F2 generation. -In the F2 generation, the trait missing in the F1 generation re-appears. The results of many hybrid experiments showed a 3 to 1 ratio of the "dominant" allele (e.g. yellow seeds) to the "recessive" allele (green seeds) in the F2 generation. Mendel developed a hypothesis to explain these results. Then tested and confirmed this hypothesis with more experiments. -Hypothesis *"Hereditary factors" are paired in organisms...These particles segregate during the production of eggs and sperm...Pairing is restored when sperm and egg fuse to form a fertilized egg* *Observable traits are produced by invisible "hereditary factors" that are paired in organisms but which segregate during the production of gametes* -Organisms have pairs of "hereditary factors"; gametes have singular units of inheritance

Organism:

Same as the ancestor e.g. primates have 5 fingers just like most other terrestrial vertebrates

Primitive trait:

-procedure -accumulation

Science definition: -a ______________ for arriving at conclusions -an established __________________ derived from the above procedure

-procedure Observation, data collection via explicit techniques Generalization, tentative explanation (hypothesis) Testing (verification) Rejecting or tentatively accepting the hypothesis *All "conclusions" are subject to continuing challenge...conclusions can be "falsified" (Karl Popper) (There is risk in prediction)*

Science is a ______________

The *unity* of science is demonstrated by examining the same phenomenon at different levels of analysis: organism cell molecule Science is *generative*...a scientifically-derived model of inheritance that fits the evidence enables other scientists to extend the meaning derived from new observations

Scientific Knowledge:

-1500-1700 -concepts -instruments -forms of communication

Scientific Revolution: Huff, Toby E. 2011 *Intellectual Curiosity and the Scientific Revolution.* Cambridge University Press. In _______-_______-a dramatic change in the understanding of the natural world occurred in Europe -New ____________ -> modern astronomy, physics, anatomy, physiology -New ______________ telescope, microscope, barometer, air pump -New ___________________ scientific society, scientific journal "infectious curiosity" accumulation of "intellectual capital"

-generative -coordinated (mostly) -> unity of science

Scientific knowledge is:

an important concept in biology that has helped us to organize and understand the variety of life on earth Millions of species have been identified...each marked by unique traits, reproductive isolation and a distinctive ecological niche Millions of species have been identified...each marked by unique traits, reproductive isolation and ecological niche

Species

*Genetics* -Discrete particles (genes) can produce continuous *variation* -Mutation, independent assortment, crossing over during meiosis continuously add *variation* *Darwinism* -Natural selection acts on variation to produce directional change in a species...evolution by means of natural selection

Synthetic theory of evolution

neo-Darwinism

Synthetic theory of evolution =

population geneticists: R.A. Fisher -The Genetical Theory of Natural Selection (1930) -Evolution = change in allele frequency from one generation to the next JSB Haldane Sewall Wright Th. Dobzhansky -worked with Drosophia (fruit flies) -Discrete particles can produce continuous evolution -Genetics of polygenic traits

Synthetic theory of evolution= synthesis of Darwinism & genetics

Trait ^ Protein ^ Gene Francis Crick 1956; Nature paper 1970

The Central Dogma:

-Anatomy -Taxonomy -Natural history -*Paleontology* -*catastrophism* -*Transmutation* -Zoological Philosophy (1809) -Tree of Life -Inheritance of acquired characteristics

The Evolution of Evolution: Pre-Darwin: -_____________ (Andreas Vesalius 1514-1564) De Humanis Corporis Fabrica (1543) -___________ (Carolus Linnaeus 1707-1778) Systema Naturae (1753) -______________ (Comte de Buffon 1707-1788) Histoire Naturelle (1749) -*_________________ (Georges Cuvier 1769-1832) An Essay on the Theory of the Earth (1813)* -*__________________* -*_______________ (Jean Baptiste Lamarck 1744-1829) Zoological Philosophy (1809)* -___________________ -___________________ -___________________

-1809-1882 -Poor student -Careful observer of nature -Voyage on Beagle (1831-1836) -Lyell's book + biogeography (especially Galapagos Islands) -*"transmutation of species"* (evolution) -1838 read Malthus "Essay" -Sketched outline of evolution via natural selection -Did not publish his idea until 1859 -On the Origin of Species (1859) *evolution via natural selection* -The Descent of Man and Selection in Relation to Sex (1871) *sexual selection* -The Expression of Emotions in Man and Animals (1872) *behavior evolves*

The Evolution of Evolution: DARWIN:

Thomas Malthus An Essay on the Principle of Population An Essay on the Principle of Population, as it Affects the Future Improvement of Society with Remarks on the Speculations of Mr. Godwin, M. Condorcet, and Other Writers. LONDON, PRINTED FOR J. JOHNSON, IN ST. PAUL'S CHURCH-YARD, 1798. -populations tend to increase faster than the supply of food....there is competition for limited resources... death from war, famine, disease with only some survivors

The Evolution of Evolution: DARWIN:

Wrote essay "On the tendency of varieties to depart indefinitely from the original type" Letter to Darwin (1858) 1858 Linnaean Society meeting (joint paper presented)

The Evolution of Evolution: DARWIN: Alfred Russel Wallace (1823 - 1913)

Principles of Geology -(1830) *"uniformitarianism"* Implies -a constantly changing earth -an ancient earth

The Evolution of Evolution: DARWIN: Charles Lyell (1797-1875)

a natural process is responsible for the origin and diversity of organisms... a natural process (not a human-like designer), is responsible for the "good-fit" seen between an organism and its environment

The Evolution of Evolution: DARWIN: Darwin provided a naturalistic explanation for design and complexity

Biogeography Domesticated animals Comparative anatomy Comparative embryology Vestigial organs Fossils

The Evolution of Evolution: DARWIN: Darwin's Evidence:

Heaven forfend me from Lamarck nonsense of a "tendency to progression" "adaptations from the slow willing of animals" &c,—but *the conclusions* I am led to *are not widely different from his*—*though the means of change are* wholly so—

The Evolution of Evolution: DARWIN: Darwin's letter to Joseph Hooker 1844

Fact 1 Fact 2 -> Inference 1 Fact 3 Fact 4 -> Inference 2 -> Inference 3 Fact 5

The Evolution of Evolution: DARWIN: Darwin's model of evolution by means of natural selection (Ernst Myer's diagram)

-*Evolution* explains the origin of species... -*Natural selection* drives evolutionary change across generations -"I have been now ever since my return engaged in a very presumptuous work & which I know no one individual who wd not say a very foolish one.— I was so struck with distribution of Galapagos organisms &c &c & with the character of the American fossil mammifers, &c &c that I determined to collect blindly every sort of fact, which cd bear any way on what are species.— I have read heaps of agricultural & horticultural books, & have never ceased collecting facts— At last gleams of light have come, & I am almost convinced (quite contrary to opinion I started with) that *species are not* (it is like confessing a murder) *immutable.* Heaven forfend me from Lamarck nonsense of a "tendency to progression" "adaptations from the slow willing of animals" &c,—but *the conclusions* I am led to are not widely different from his—though *the means of change* are wholly so— *I think I have found out* (here's presumption!) *the simple way by which species become exquisitely adapted to various ends.* — You will now groan, & think to yourself 'on what a man have I been wasting my time in writing to.'— I shd, five years ago, have thought so.— " 1844 letter to Joseph Hooker -*"As more individuals are produced than can possibly survive, there must in every case be a struggle for existence,* either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life... Excessive reproduction & competition for limited resources exists in all species -...Can it, then, be though improbable, *seeing that variations useful to man have undoubtedly occurred,* that *other variations useful in some way to each being* in the great and complex battle of life, *should sometimes occur* in the course of thousands of generations? Individuals vary in heritable traits. These variants in heritable traits are sometimes useful, sometimes harmful - If such do occur, can we doubt (remembering that more individuals are born than can possibly survive) that *individuals having any advantage,* however slight, over others, would *have the best chance of surviving and of procreating their kind?* On the other hand, we may feel sure that any variation in the least degree injurious would be rigidly destroyed. Individuals with *advantageous variants* get to *reproduce* and pass those traits to the next generation Individuals with *disadvantageous variants* do not pass traits to the next generation (they die without reproducing) *This preservation of favorable variation and the rejection of injurious variations, I call Natural Selection."* (Charles Darwin, 1859, On the Origin of Species) -"As more individuals are produced than can possibly survive, there must in every case be a *struggle for existence*, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life...Can it, then, be though improbable, seeing that variations useful to man have undoubtedly occurred, that *other variations useful in some way* to each being in the great and complex battle of life, *should sometimes occur in the course of thousands of generations?* If such do occur, can we doubt (remembering that more individuals are born than can possibly survive) that *individuals having any advantage,* however slight, over others, *would have the best chance of surviving and of procreating their kind?* On the other hand, we may fee sure that any variation in the least degree injurious would be rigidly destroyed. This preservation of favorable variation and the rejection of injurious variations, I call *Natural Selection."* (Darwin, 1859, On the Origin of Species) -*Natural law*...a natural process is responsible for the origin and diversity of organisms

The Evolution of Evolution: DARWIN: On the Origin of Species (1859)

The natural world shows divine order...the existence of design suggests a designer... "...the necessity, in each particular case, of *an intelligent designing mind* for the contriving and determining of the forms which organized bodies bear".

The Evolution of Evolution: DARWIN: William Paley Natural Theology (1802)

evolution in an age of genetic information -based on Fact 5 in Ernst Mayr diagram (Heritability of much of the individual variation) (source: Animal breeders)

The Evolution of Evolution: Post-Darwin:

A multi-year effort to *find all the genes that code for all the* traits found in humans Establish *the sequence of nucleotides* that make up each chromosome of a typical human and establish *which of these function as "genes"* (and code for proteins) Sponsored by the Department of Energy and the National Institutes of Health Now mapped genomes of about 800 species (2011)—cat, dog, pufferfish, sloth, tree shrew, chimpanzee Genes are specific sequences of bases that encode instructions on how to make proteins. Genes comprise only about 2% of the human genome; the remainder consists of noncoding regions 3.2 billion base pairs about 20,500 genes (1.5% of the genome....98.5% of genome is "noncoding") 99.9% of base pairs are identical in all humans....

The Human Genome Project (1990-2003)

genome

The __________ is an organism's complete set of DNA

80

The genomes of about _____ mammalian species have been sequenced

-Organism *(Mendel)* Gene = invisible particles ("hereditary factors") control the expression of traits; each particle is discrete and stable as it is passed from parent to offspring -Cell *(Sutton)* *genes ride on chromosomes* Gene = unit on a chromosome that codes for a protein (cf. gene locus = location on a chromosome) -Molecule *(Watson & Crick)* Gene = sequence of nucleotides that code for a protein (or a portion of a DNA molecule) The "central dogma" (gene protein trait)

What is a gene?

saiga antelopes of Kazakhstan....Mongolia's western Khovd province...." ancient animal that once roamed the grasslands of the world with the woolly mammoth and the saber-toothed tiger" Energy out vs. Energy in: Energy out: -Homeothermy (fur) -Reproduction -Internal gestation -Lactation -Extended parental care -Emotional bond -Play by immatures -Mastication (chew food) -...heterodonty Energy in: -Heterodonty -Mastication *Mammals have 4 kinds of teeth* incisors, canines, pre-molars, molars (mammals have *heterodonty*) All contemporary mammals are descended from small, nocturnal, insect-eating mammals that emerged from reptilian ancestors more than 170 Mya The descendants of these first mammals include > 20 orders of contemporary mammals Primates are an order of mammals (which emerged about 60 Mya)

What is a mammal?

-Organism—a change in a trait that is stable through successive generations -Mutations in cell structure (e.g. trisomy) have serious consequences for the individual but are not important for the evolution of the species. Point mutations increase the variation in a population. Natural selection acts on this variation...favorable traits increase in successive generations -Cell— e.g. too many chromosomes in a gamete such as trisomy of 21st chromosome = Down's syndrome Consequences for individuals but not for populations (evolution takes place in populations) -Mutations in cell structure (e.g. trisomy) have serious consequences for the individual but are not important for the evolution of the species since these individuals do not reproduce. Point mutations increase the variation in a population. Natural selection acts on this variation...favorable traits increase in frequency over successive generations leading to evolutionary change in that population -Molecule constant introduction of *point mutations* increases variation in a *population...* -*Natural selection acts on this variation*... traits favorable in the current environment increase in frequency over successive generations -*Before a cell divides*, it makes an exact copy of each strand of DNA so that new cells will have a complete set of all genes. Sometimes during this process, there is a mistake. These mistakes are called *mutations*.

What is a mutation?

Perissodactyla-odd-toed ungulate (horse, rhino, tapir) ; Artiodactyla even toed ungulate (cow, pig, camel) *Primates* are an order of *mammals*. Primates are a diverse order with 300+ species *Primate way of life = eyes + hands* *(eye-hand coordination)* Bony protection in primates Non-primate mammal (raccoon)- -Good peripheral vision Primates- -Eyes face forward -Bony protection -Cross-over of visual tracts -Stereoscopic vision -Color vision -Reduced snout in anthropoids for reduced emphasis on smell Lemur and monkey are both primates but lemur is more "primitive." Eyes face forward but wide distance between orbits. The monkey has eyes very close together and set in a complete bony socket. Primates have grasping hands & feet (prehensile) with: -nails (not claws) -tactile pads with *touch receptors* -friction ridges Primate have nails instead of claws on all [or most] digits -A claw is an extension of the last bone of the digit. A nail floats on soft tissue and is not attached to any bone. Primates use visually-guided reaching to feed -A nocturnal slow loris harvests (grasps) an insect with its hand and then feeds Visually-guided tool use Primates have mobile appendages & hindlimb dominance Traveling, feeding and resting in trees requires *versatile* limb movement SUMMARY: Primates: EYES Eyes face forward Bony protection Cross-over of visual tracts Stereoscopic vision Color vision FACE Reduced snout for reduced emphasis on smell HANDS & FEET Grasping appendages Nails not claws Friction ridges Touch receptors LIMBS Mobile appendages Hindlimb dominance *Brain* Elaboration of cerebral cortex Increase in total brain size -*Elaboration of the cerebral hemispheres and the neocortex* *Elaboration of the neocortex in primates* -The neocortex is a multi-layered arrangement of neurons that is -found only in mammals -highly expanded in primates -neocortex -> -sensory perception -motor commands -spatial reasoning The size of the olfactory bulbs did not diminish relative to body size, but the occipital and temporal neocortex expanded so greatly that the olfactory bulbs became small by comparison. *Life history* includes slow maturation and long life *Primates reproduce slowly* -One offspring each gestation -Long gestation -Long period of immaturity -Emphasize *vision* (not smell) -*Manipulation* with eye-hand coordination; *touch* receptors on fingertips -Multi-dimensional *locomotion* -Large *brains* -*Slow* maturation and long life -*Sociality ->* complexity in communication & cognition

What is a primate?

Primitive traits Generalized skeleton— (e.g. five fingers, clavicle) Generalized dentition— (4 different kinds of teeth) -Having 4 different kinds of teeth is a primitive trait (incisors, canines, pre-molars & molars) since 4 kinds of teeth are also found in the earliest mammals of 200 Mya Primitive traits dentition skeleton Derived traits eye hand locomotion/posture brain life history sociality

What is a primate?

Vertebrates have a vertebral column protecting the spinal cord and a skull protecting the brain. Having nervous tissue centralized as a spinal cord and a brain is part of being a chordate. Internal skeleton -> greater probability of fossilization

What is a vertebrate?

Plants can turn solar energy into carbohydrate (food) via photosynthesis. Animals must consume other living organisms in order to survive (other plants, other animals). Their mobility enables them to obtain food.

What is an animal?

-Having 5 fingers is a primitive trait -Having nails (not claws) is a derived trait

When modern primates are compared to early mammals of 200 Mya....

*Evolution*—ancestors and descendants in a long lineage *Genetics*—studies how traits are passed from parent to offspring over a single generation (or a few generations) The constituent unit of evolution is a single generation or a few generations (the focus of *genetics*)

Why is genetics important for understanding evolution?

Arboreal theory (F. Wood-Jones)-monkeys climbing trees Visual-predation theory (Matt Cartmill)-lemur eating that insect-gross video

Why primate traits?

human

anthropos =

True

iClicker: True or False *Anthropology* is the study of humans. It is holistic and comparative. It invented and depends on the concept of culture for explaining differences in the behavior of people living in distinct groups.

True

iClicker: True or False *Darwinism* is a term used to describe change in successive populations by means of natural selection. *Neo-Darwinism* is a modified version of Darwin's original idea. It includes an understanding of how inheritance works and how variation is generated in populations.

True

iClicker: True or False *Science* is a system for deriving reliable, systematic knowledge about natural phenomena. It emphasizes explicit methods for data collection and analysis that can be replicated by independent observers. It requires that all assertions (hypotheses) are subject to testing and can be falsified.

True

iClicker: True or False At the level of the molecule The molecular structure of DNA was modeled by James Watson and Francis Crick in a 1953 Nature article. They described DNA as composed of long strings of nucleotides with paired nitrogenous bases forming the *rungs* of a ladder and sugar-phosphate sequences forming the *rails* of the ladder. The entire molecule is twisted into a double helix. -James Watson and Francis Crick (with help from work by Maurice Wilkins and Rosalind Franklin).

True

iClicker: True or False Carolus Linnaeus was an 18th century Swedish botanist who brought order to our understanding of species diversity. He organized organisms into a hierarchical sequence of nested categories (which included species, genus, order, class and kingdom). Modern taxonomists still use this hierarchical system of nested categories but have added many more levels.

True

iClicker: True or False Darwin provided a naturalistic explanation for the design and complexity of organisms. By doing so, he brought biology under the umbrella of the scientific revolution.

True

iClicker: True or False For more than 20 years after Darwin first conceived of evolution by means of natural selection, he collected evidence. He presented both his idea and the evidence which supported this idea in an 1859 book entitled On the Origin of Species by Means of Natural Selection .

True

iClicker: True or False Gregor Mendel developed a model of inheritance with *discrete* and *stable* units (now called genes) that are passed from parent to offspring. In the 20th century, Dobzhansky showed that traits of complex inheritance (like skin color) were also the result of discrete and stable genes. *Polygenic traits* are the product of *multiple gene loci* making a contribution to the trait while *Mendelian traits* are those in which only *one gene locus* codes for the trait.

True

iClicker: True or False Reproduction in mammals can be distinguished from that in other classes of vertebrates (such as fish, amphibia, reptiles, and birds). Mammals have a complex reproductive system which includes internal gestation, lactation after birth and extended parental care. No other vertebrate (and no invertebrate) has all of these traits.

True

iClicker: True or False The amino acid sequence of the *hemoglobin* of a *human* and a *rhesus monkey* are very similar. There is only one amino acid difference in the beta chain. In contrast, there are multiple amino acid differences between a rhesus monkey and a *horse*. This shows that rhesus monkeys shared a common ancestor with humans more recently than with horses. Comparing proteins is a way to show degree of evolutionary relationship among living species. Ancient proteins like *cytochrome c* are shared by many species This shows there is a deep evolutionary relationship among diverse organisms...including organisms that seem very distinct from one another Humans and yeast are related but in a very distant way -Cytochrome c...shows a deep evolutionary tree for a diversity of organisms, including orgasms that do not otherwise seem similar

"word" (study of)

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