Class Notes (807,463)
Canada (492,648)
Anthropology (1,560)
ANTA01H3 (412)

Introduction lecture

13 Pages
Unlock Document

University of Toronto Scarborough
Genevieve Dewar

Lecture Anthropology: Concepts: Evolution & Human Origins What is Evolution? How does it work? Five traits: 1. Adapt to environment 2. Natural selection 3. Sexual selection(desirable traits) 4. Variation already exists in a population 5. Survival of the fittest What is Species?  A group of creatures which breed together and produce viable and fertile offspring  May be quite similar in appearance (Dogs) &( Deer)  May all live in one part of the world (Polar bear)  Share behavioural traits  Distinguish between members of own species & others Darwin (1859):  The origin of species(profound book in science) Pre-Enlightened Period:  According to genesis-Adam & Eve creation story  Everything made in 6 days  Animals  Men  Never really any change History of origins:  Origin of the earth & therefore humans based on his interpretation of the bible  In 1650 AD  OCT.23 4004 AD  Later addition 9am Geology Contributes:  Catastrophists  George curie  If only 600 yrs. ,then global & violent catastrophes to explain canyons ,mountains Uniformitarianism:  “To learn about the earth study the earth”(Buffon)  Process we use today to explain life  Hutton(1788AD):slow working, uniform & natural processequals 100.000 yrs  Lyell(1875): “The present is key to present”  Reverend Chalmers: Ussher was wrong-not a bible Corolus Linnaeus:  Categorising the works plants &animals  7 basic layers or lax on levels  Binomial system  Homo sapiens(wise men)  Said first we are part the animal system Archaeology:  Stone tools  Thunderstones Or Pre-metal stone age Conclusion of the Enlightenment period:  Fossils  Extinct animals  Strata & stratigraphy Lamarck-First mechanism: 1. Adaption to the environment 2. Progression towards perfection(No final Result) 3. Inheritance of acquired characteristics(no getting traits)  Exam Question Darwin & Wallace:  Natural selection: Variation already exists between individuals of the same species, allows form of adaptation to change in the environment  Survival of the fittest& Sexual Selection: Those individuals that are by chance best adapted to an environment will have higher reproductive success  Increase the frequency of the trait within the species/population  Variation is random and there is no direction  Good trait increase in frequency Grant & Grant (2002):  Study of the finches:  Beaks on animals  The ones that had the beaks favorable to environment survived  Ex. Population grew for the larger beaked birds(useful for seeds) Darwin’s Finches:  Change occurs adaption to change for local environment  Changes works on the variation of traits already present  No direction Natural Selection: 1. Favourable variations promote survival of the individuals in whom they appear a. Traits are inherited by their offspring’s b. Favourable variations 2. Unfavorable variations don’t promote survival a. May cause individuals to die at an early age b. May reduce fertility of bearers, who have few offspring’s c. Either way, unfavorable variations tend to be removed from the population 3. For any species, natural forces act to favour the expansion of some traits and favor the removal of other traits form future generations Process of Evolution:  Mutation  Act on individual  Gene flow  Act on population  Genetic drift  Act on population Gregor Mendel (1822-1884):  Breeding experiments with pea plants  Traits in offspring are not passed solely by either parent  Traits are passed in small, independent package from parent  We call these packages “genes” Mendel’s Breeding program:  Crossbred  F1 generation  F2 generation  (Punette Square) G g G GG Gg GG Gg G  Each observed derives from a package of information(gene) acquired by the individual at conception  For each trait an individual possesses two genes one from each parent  Homozygous: For a given trait ,individual receives the same gene from parents.(Green & Green);Two matching genes  Heterozygous: Individual receives two different gene forms from parents.(Green & yellow)  Alleles: The whole set off different forms for a given gene  Mendel’s peas had alternate genes or allele for green seeds and for yellow seeds  Sometimes the yellow allele was expressed:(appeared in the plant)  Sometime the green allele was expressed  Dominant genes: Always expressed in the individual who carries them such as green peas  Recessive genes: Overpowered by a dominant gene, if one is present, and not expressed. Such as yellow peas  Recessive genes are expressed only if they are homozygous (if no dominant gene is present)  Recessive genes are likely to be passed to offspring as are dominant genes-even though their presence may be unknown to the observer Simple traits:  Thumb dominance  Darwin’s tubercle  Hair whorl  Tongue curling  Ear wax colour The expression of genetic Dominance:  Genotype: all the genes in an individual  Phenotype: the visible individual  The expression of genetic dominance +  Physical changes caused by events in the individuals life  The phenotype is what we actually SEE  The genotype represents our real genetic structure, or DNA  Genome: the entire range of alleles in species; the gene pool Most physical traits represent complex association of several different genes:  Gene complexes: often include genes on completely different chromosomes  Co-dominant: Blend together rather than dominating or submitting(Hair colour\ DNA & Genes:  DNA: double helix  Group of three bases = Codon  Genes are a sequence of codons like sentences on a DNA string Chromosomes:  Are paired  One comes from each parent  Matching locations on paired chromosomes are alleles of a single gene  46 chromosomes in all-23 each parent  22 paired autosomes;2 sex chromosomes Sex chromosomes:  Combination of sex chromosomes influence physical sex characteristics of individual:  X:Largest chromosome  Y:Smallest chromosome  XX: Female  XY: Male What causes new traits?:  Changes in genes  Changes in chromosome  New complexes or combination between genes Source of variation: Process of Evolution:  Genetic Mutation  Genetic Flow  Genetic Drift Genetic Flow:  Demes: Separate breeding populations(due to social or environmental purposes)  If two demes start to interbreed, then new genetic material is introduced or flows into both gene pools  Gene flow acts to homogenize population, preventing speciation Genetic Drift  Fission: Individual Demes  Founder effect  In a small population, there may be only a few individuals who possess a particular gene  Gene can be lost if individuals doesn’t reproduce  In a small population, everyone is closely related, inbred  Mutations spread quickly through the population  Easy for a mutated form to become “norm” Theories of speciation:  Gradualism: all populations are changing all the time, gradually changing into new forms and forming new species  Punctuated equilibrium: popu
More Less

Related notes for ANTA01H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.