Anthropology 101: Human Biological Evolution Lecture 1: Intro & Scientific Method Dr. Leanna Wolfe [email protected] Office AHS Drop In Hours: 5:00-6:30 PM AHS 303
May 17, 2015
Anthropology 101: Human Biological Evolution
Lecture 1: Intro & Scientific Method
Dr. Leanna [email protected]
Office AHSDrop In Hours:5:00-6:30 PM AHS 303
Anthropology = the study of humankindFour subfields of Anthropology
Applied Anthropology
Biological Anthropology
Archeology
Linguistic Anthropology
Cultural Anthropology
The Subfields of Biological Anthropology
Anthropology: Study of Humans+ How Evolution Works
Charles Darwin Peppered Moths in Industrial England
How Does Evolution Works in Other Primates?
MacaquesRing-tailed Lemur
What is the History of the Human Lineage?
A. afarensis A. africanus A. aethiopicus
H. erectus H. sapiens
How did Evolution shape hominin adaptations?
• Bipedality
• Tool use
• Behavior• Culture
How does Evolution shape minds, bodies, & behavior in modern humans?
Introduce yourself to your neighbor.
What do you think/how do you feel about studying anthropology? Do you believe in Natural Selection?
Course Requirements
How to do well in this class• Do the reading ahead of class• Come to class on time• Ask questions• Pay attention• Be curious• Do the assignments on time• Take notes during lecture• Access lecture notes online• Form a study group
• Two Midterm Exams with short in-class Essays
• Two Take-Home Essays• In-class activities• Final Exam (no essays)• Zoo Project (Class Trip on
Saturday June 28)• Schedule of Assignments &
Exams on Syllabus• Extra Credit Options
Class Website
• To access go to http://drleannawolfe.com/physicalanthro.html
• Essay Topics• Link to Power Points• Link to Zoo Project• Links to Assigned Articles• Links to Class Lectures• Links to Extra Credit• Exam Review Information
Important Dates and Enrollment Changes
• Last day to drop a class without receiving a “W” June 18
• Last day to drop the class receiving a “W” July 9
• Only 3 attempts allowed per class
• If you miss class during the 1st week, I will drop you• If you miss 2 classes at all, I can drop you.
3 in a row, I will drop you. Unless you speak with me and make arrangements
• But, its your responsibility to drop if you aren’t attending!!
Plagiarism Cheating
• Turning in work done by another person
• Copying the words of another person
• Presenting the ideas of another person as your own without proper citation
• Copying and pasting text from a website
• Looking at another person’s test, homework etc when asked to work independently
• Use of study aids when asked to work from your own memory
• Sharing your work with another student
To understand why we are the way we are, we need to know
• How the scientific method operates
• Science is essential to our lives• You need to understand how it
operates• You need to be able to evaluate
science in the media• Measure things as a way of
testing hypotheses
What is Science?
• Process of explaining natural phenomena through observation and experimentation
Measure observed phenomena
Test hypotheses
Follow the Scientific Method
J.J. "Mad Scientist". common.wikimedia.org 02/25/08. 03/31/06 http://commons.wikimedia.org/wiki/Image:Mad_scientist.svg
What is a hypothesis?
• provisional explanations requiring verification or falsification through testing
proposes a causal relationship between two variables
Predict how X will affect Y
• (X) Independent variable(s) – things that are– Water, sunlight, soil
• (Y) Dependent variable(s) – things that are affected
– Height of plant– Thickness of roots– Number of leaves
The Scientific Method• Question• Read• Hypothesis• Methods• Collect data
Rigorous & replicable Quantitative Statistics Falsifiable
• Relate back to your hypothesis
Repeat!
The process of science generates a theory
• broad statement of scientific relationships• underlying principles• substantially verified through the testing of hypotheses• A broad explanatory statement of scientific fact
• It guides the formation of hypotheses to explain things observed in the world
• It has been supported by repeated and varied testing of related hypotheses
• Hypothesis - narrow focus explaining the relationship between a few specific phenomena
A theory
IS• A theory is backed by lots of evidence• A theory is a statement of scientific fact• A theory is open to evaluation and testing• A theory has the potential to be falsified/revised
IS NOT• A theory is NOT a hunch or a guess• A theory is not an absolute• A theory is not unknowable or immeasurable
Any proposition that is stated as absolute or doesn’t allow for
the possibility of falsification is not a scientific hypothesis.
Why we use the scientific method
• Testable (falsifiable) hypotheses• Replicable methods• Competition and collaboration among scientists
• New theories gain acceptance Explain odd findings that older theories can’t explain Lead to new TESTABLE predictions Lead to new discoveries
• All results and theories open to debate & refinement
Creationism & Intelligent Design
• Biblical explanation for the origin of the universe, species, humans
relies on faith in bible not evidence Not open to testing = absolutes
• Argue that evolution is an unproven theory
• Intelligent Design = creationism No testable predictions regarding the designer or
creator Try to disprove or discredit evidence for evolutio
Can you Understand Evolution and Be Religious?
Geologic Time Scale
• Measures history of Earth – 4.5 billion years• Organizes history of Earth into various units• Eon > Era > Period > Epoch• Important to understand the scale and pace of evolution
Solar System forms
Earth forms
Life appears on Earth
3.5 Billion YA
Mesozoic
CenozoicPhanerozoic Eon
Paleozoic
Animal life diversifies starting in the Paleozoic
Marine invertebrates
Firstvertebrates
Arthropods
Age of Fishes, 1st amphibians
& insects
Age of amphibians, 1st reptiles, 1st great
insect radiation
570 mya 500 430 395 345 280 225 190
Cambrian
Expansion of reptiles,decline of amphibians
Ordovician Silurian Devonian
Carboniferous
Permian
TriassicJurassic & Cretaceous
Paleozoic Era Mesozoic Era
225 190 136 65
1st Mammals (Monotremes) & dinosaurs
Age of dinosaurs1st birds
1st flowering trees (angiosperms)!st Marsupials, Placental mammalsDinosaurs vanish @ 65mya Continent(s) breaking apart
Mammals, birds, insects
flourish
Triassic Period Jurassic PeriodCenozoic EraCretacous
Period
Mesozoic Era
Recognizable fauna of the Mesozoic
Starting in the Mesozoic the earth rearranged itself (200 mya – present)
The Mesozoic: Triassic (225 mya)• Pangea was a single continent• Dinosaurs & small mammals evolve• Pangea HUGE land mass
Hot, arid, seasonal, some coastal areas more humid
Transition fromTriassic to Jurassic
The Mesozoic: Jurassic (190 mya)• 200 mya Pangea starts breaking up
Laurasia & Gondawana• Oceans are barriers to gene flow = new species form• World gets warmer, climate stable when continent splits• Dinosaurs and mammals evolve in this warmer world
The Mesozoic: Cretaceous (136 mya)
• Rise of angiosperms = fruits bearing trees = new foods• Placental mammals evolve• Adaptive Radiation
Gymnosperms
Angiosperms
The Mesozoic: Cretaceous (136 mya)
Continents & Climate @ 94 mya
Life’s great until mass extinction of dinosaurs 65 mya
Primates finally start to enter the scene, 65 mya
65 54 34 23 5
Paleocene Epoch Eocene Miocene
PliocenePleistocene
Oligocene
PlesiadapiformsFirst Primates Evolve
Prosimians thrive1st AnthropoidsEvolve
Monkeys &1st primatesin South America
HominoidsHumans
Hominins
1.8 mya
Cenozoic Era: 65 my - present: 7 Epochs
Holoocene
10 kya
Continental drift is important part of human history because it changed global climates
25C = 77 F10C = 50 F
Temperatures have declined steeply from Eocene to presentHuge fluctuations in last 5 my
The Cenozoic: Paleocene• Paleocene wet & warm
Radiation of mammal taxa with some primate-like traits
Plesiadapiforms – not quite yet primates thrive Europe & North America Primate-like molars Ankles for climbing trees
Purgatorius
Dryomomys
The Cenozoic: Eocene
• Eocene wetter & warmer Tropical forests SA isolated from NA & Europe =
new species First true primates Prosimian-like traits Two families in North America &
Europe Adapidae
– Lemur-like prosimians Omomyidae
– Tarsier-like prosimians• Mass extinction at end of Eocene• First Anthropoids evolve
Smilodectes
The Cenozoic: Oligocene
• Oligocene getting colder & drier more seasonal variation Mostly modern continent positions
South America still separate Cold water currents cooling earth
Africa & SA tropical forests remain Tropics receding in other areas
Age of the Anthropoid (monkeys) Parapithecidae (Apidium) Proliopithecidae (Aegypotopithecus)
First platyrrhines in South America! First Hominoids (apes) evolve
Aegypotopithecus
The Cenozoic: Miocene
• Miocene warm & moist at beginning Got colder & drier Forests retreating = open woodland habitat Himalayas form = block warm cold air currents Rift valley forms = rain shadow & dry savannah
The Cenozoic: Miocene
• Miocene warm & moist at beginning Golden age of the Hominoids (apes) (early Miocene)
Great diversity of species Fruit diet specialization Some arboreal quadrupeds, some terrestrial
quadrupeds, suspensory adaptations later
• Late Miocene getting drier & colder Ape shift to knuckle-walking adaptations Ape species retreat to remaining tropics Mass extinction of apes at end of Miocene First hominins evolved (late Miocene)
Proconsul
Ardipithecus
Proconsul
• Lived in African rainforest• DF: 2.1.2.3• Terrestrial quadruped• Large (165-220 lbs)• No tail• Sexually dimorphic• Frugivorous
Dryopithecus
• European Radiation
• Brachiator, also terrestrial quadruped on palms
• DF: 2.1.2.3
• Frugivorous & Folivorous Thin enamel, low
rounded cusps on molars
• Small canines
Sivapithecus
• Asian ancestor of Orangutans• Concave face• Flared zygomatic arches• Large (70-150 lbs)• DF: 2.1.2.3• Large canines• Heavy molars - tough foods
Others ate more fruit• Some species terrestrial, others
arboreal Suspensory adaptations
The distribution of primate species shifted during Miocene
5 mya23 mya
• Monkeys are more r-selected than apes
• reproduce faster
• respond quickly to environmental changes
• apes didn’t adapt to changes, stayed in tropical forest niches
The Cenozoic: Age of the Hominins• Pliocene begins frequent temperature fluctuations
Hominins diversify Australopithecines & Paranthropines
• Pleistocene: extreme temperature fluctuations Genus Homo appears 1.8 mya
Primate Evolution: A summary
• Mesozoic: Cretaceous: Placental mammals & Angiosperms • Cenozoic
Paleocene: Plesiadapiforms Eocene: Age of Prosimians Oligocene: Age of Anthropoids + first Hominoids (apes) Miocene: Hominoids expand + first Hominins (7mya) Pliocene: Hominins diversify (5-1.8 mya) Pleistocene: First genus Homo (1.8 mya)
200,000 ya: First Homo sapiens Holocene: 10,000 ya: History
Classifying species into taxa
• Linnaeus – classification based on
physical similarity Genus species, e.g. Homo sapiens
• Nested hierearchies of similarity due
to common descent (Darwin)
VERTEBRATES
Birds Mammals
Sparrow Flamingo Lion Squirrel
Phylogeny
• Phylogeny = evolutionary relationships among groups of species
• When one species splits into 2 Share some ancestral traits Differ in some derived traits
• Differences accumulate within evolutionary lineages over time
Homologous traits: shared phylogenetic history
Similar underlying structures can be modified
for very different functions
Bats fly
Dugongs swim
Moles digAll share the same
Basic limb structure because share common ancestor
Analogous traits: different phylogenetic history
Different structures can be used for similar functions
• Bats and birds fly
• Bat wing is modified from bones of hand
• Bird wings are modified from bones of forelimb
Convergent Evolution: leads to analogous traits
Adaptation to solve similar ecological problems
(Smilodon): (Thylacosmilus):placental mammal marsupial mammal
Both animals adapted to catch large prey with teeth and claws.
Adaptation to solve similar problems
(Smilodon): (Thylacosmilus): placental mammal marsupial mammal
Convergent Evolution: leads to analogous traits
Where do we fit in? Homo sapiens• Kingdom: Animal• Phylum: Chordata• Class: Mammalia• Order: Primates
• Suborder: Anthropoidea• Infraorder: Catarrhini• Superfamily: Hominoidea• Family: Hominidae• Subfamily: Homininae• Tribe: Hominini• Genus: Homo• Species: sapiens