1 14 2014 What is Anthropological Genetics A synthetic discipline that applies the methods theories of genetics to evolutionary questions posed by anthropologists Questions concern processes of human evolution human diaspora causes patterns of human variation bio cultural interaction in complex diseases Anthropological Genetics vs Human Genetics Emphasis on smaller reproductively isolated non western populations Tests the conclusions reached using western populations Offers alternate settings to test hypotheses 3 History of Anthropological Genetics Roots in evolutionary biology Genetics Molecular Biology Bioinformatics laboratory methodologies Synthesized in the late 1960s and early 1970s Participants in a Symposium on Anthropological Genetics 1970 In 1970 MH Crawford organized the first symposium on Anthropological Genetics in Santa Fe New Mexico at the School of American Research Twelve researchers from US France and UK participated Methods and Theories of Anthropological Genetics Paradigm A widely accepted model pattern or theoretical framework Major Trends Continue the focus on scientific method Focus on evolution Bio cultural perspective Social responsibility Ecology the study of interactions among species and the environment Anthropological ecology human ecology behavioral geography cultural ecology Recent Trends in Culture Research 1 2 4 5 6 7 8 Future Goals To understand the extent of and basis for biobehavioral variation at the population community family sex age and individual levels Predict the limits of our adaptability based on our culture and our existing biological 1 variation Social responsibility Ecology the study of interactions among species and the environment Anthropological ecology human ecology behavioral geography cultural ecology 1 14 2014 Recent Trends in Culture Research Future Goals To understand the extent of and basis for biobehavioral variation at the population community family sex age and individual levels Predict the limits of our adaptability based on our culture and our existing biological variation AAAG http www anthgen org New species of mouse lemur 2005 The Evolution and Classification of Species The Birth and Death of Species Misconceptions about Evolution Classification of Species What is a Species The biological species concept defines species in terms of reproductive capability If organisms from two populations are capable of breeding naturally and can produce fertile offspring then they are classified in the same species The concept of semispecies has been suggested for populations that are only partially isolated from each other reproductively 13 The Mule o The Horse left and the Donkey middle are capable of breeding and producing offspring called mules right o o Mules are sterile o o Horse and Donkey are different species 14 Species Change naming species Researchers often modify the species concept to deal with complications in Anangenesis is one mode of evolutionary change where a single species exists at any given point in time but evolves over a period of time This is straight line evolution Cladogenesis is the other mode of species change It involves the formation of one or more new species speciation that branch from an original species Tree of Life http tolweb org tree The fossil record shows many examples of new species arising through cladogenesis 7 8 9 10 11 12 15 16 17 18 Speciation Species naming is complicated by evolutionary relationships which are not always clear among fossil forms Populations become new species when genetic differences are great enough to prevent successful inbreeding and when they become reproductively isolated from 2 Tree of Life http tolweb org tree The fossil record shows many examples of new species arising through cladogenesis 1 14 2014 17 18 Speciation Species naming is complicated by evolutionary relationships which are not always clear among fossil forms Populations become new species when genetic differences are great enough to prevent successful inbreeding and when they become reproductively isolated from the original parent species Reproductive Isolation is genetic change that can lead to an inability to produce This is the result of reduced or eliminated gene flow between populations Geographic isolation is the most common means of reducing gene flow between 19 Reproductive Isolation 1st Step to Speciation fertile offspring populations 20 Genetic Divergence 2nd Step to Speciation Isolation Mutation genetic drift and natural selection will produce genetic divergence Continued debate persists over the role of various evolutionary force in producing genetic divergence Recently the view is that new species often form from small populations and are affected extensively by mutation and genetic drift 21 The Birth and Death of Species Speciation minimally results in two species the original parent species and the new offspring species Certain circumstances produce many new species that can come in a short period of time 22 Adaptive Radiation The formation of many new species following the availability of new environments or the development of a new adaptation 23 The Birth and Death of Species Tempo and Mode of Macroevolution Punctuated Equilibrium Gradualism 3 23 The Birth and Death of Species Tempo and Mode of Macroevolution 1 14 2014 Punctuated Equilibrium Gradualism 24 Extinctions and Mass Extinctions Extinction This may be due to rapid ecological change If we do not have the appropriate genetic variation to deal with the change or it is too rapid Likely the fate of all species Mass Extinction is the extinction of a large number of species at the same time 25 Misconceptions about Evolution The Nature of Selection Survival of the Fittest Misconception Bigger is Better implies that natural selection will always lead to larger structures is not accurate Body size Brain size continued 26 Misconceptions about Evolution The Nature of Selection Misconception Newer is Better implies that traits more recent in origin are superior because they are newer is not accurate Five fingers vs bipedalism Which came first continued 27 Misconceptions about Evolution The Nature of Selection Misconception Natural Selection Always Works implies that natural selection always provides opportunity for some members of a species to survive is not accurate Natural selection can only operate on existing variation continued 28 Misconceptions about Evolution The nature of selection There is an inevitable direction in