Exam Questions Flashcards
Q1. How would you describe early views of the Earth (including its age), the organization of species, ideas about fossils and extinction prior to the 1700s?
▪ early views about the Earth were made by the church
▪ the age of the Earth was estimated to be created in 4004 BC. James Ussher came to the conclusion of the exact date when the Earth was created by using the biblical stories to trace back the timeline of the creation of the Earth
▪ church claimed that organisms were created by God
▪ they believed that organisms were static and never changed
▪ this theory was known was the fixity of species: once created organisms never change
▪ another claim made by the church was that living things were independently created by God and arranged in a hierarchy. This theory is called The Great Chain of Being created by Aristotle
▪ this hierarchy were groupings based on physical similarities: God was at the top and stone at the bottom
▪ fossils considered as remains of dead organisms and not extinct beings with no living representative
Q2. How and why did these views change?
▪ what changed is that Europeans started to travel the world to learn more about God’s creations and realized its unique biodiversity
▪ people discovered the world was not flat
▪ the Scientific Revolution happened
▪ heliocentrism: Copernicus (1514) claimed that the planets revolved around the sun instead of the Earth
▪ universe of motion: Galileo (1600s) came up with the idea that the universe was dynamic and changing
▪ 17th century discoveries and inventions: telescope
▪ laws of physics, motion and gravity, anatomical sciences, scientific instruments
Q3. The ideas for Darwin and Wallace’s theory of evolution were put in motion by so many natural
historians coming before them. Describe the contributions of some of these early scientists and
how they influenced the work of Darwin and Wallace.
▪ John Ray:
▪ father of natural history
▪ species - reproductive isolation
James Hutton (1726-1797)
▪ geologist
▪ created deep time
▪ claimed that rock formation, tectonics, and erosion are processes that take time
Erasmus Darwin (1731-1802)
▪ claimed that life started in the ocean
▪ all species come from a common ancestor
▪ proposed ideas: deep time, competition for resources, influence of environment
Comte de Buffon (1707-1788)
▪ common ancestry shared by humans and apes
▪ natural history: dynamic science
▪ “organic particles”: environment acts directly on organisms
▪ deep time
▪ revision of species definition: fertility
▪ accommodation: physical and cultural differences between humans result of differing environments
▪ organisms would change do to adaptation
Thomas Malthus (1766-1834)
▪ competition for resources
▪ pop size increases exponentially while food supply increases arithmetically
▪ resource availability keeps pop growth in check
Q4. Describe the significant contributions of Jean Baptiste de Lamarck.
▪ came up with the term biology and entomology
▪ invertebrate
▪ first to explain process of evolutions
▪ Inheritance of Acquired Characteristics (Use/Disuse)
▪ right about adaptive change wrong about how traits were inherited (no genetic bases)
Q5. Describe the fundamental aspects of Darwinian evolution.
▪ Heritable traits
▪ Variation
▪ Fitness is relative
▪ Time
Fundamentals of Natural Selection
organisms with the most favorable traits survive and reproduce
▪ trait must be inherited if natural selection is to act on it
▪ cannot occur without pop variation in inherited characteristics
▪ can only act on traits that affect reproduction
Fundamentals of Natural Selection
▪ Fitness: a relative measure that changes as the environment changes.
▪ Reproductive success: the number of offspring an individual produces and rears to reproductive age.
▪ Selective pressures: forces in the environment that influence reproductive success in individuals.
Q6. How did Darwin and Mendel’s ideas about heredity differ?
▪ Charles Darwin and blended inheritance
▪ Mendel’s experiments on pea plants
▪ offspring are not blended
▪ offspring follow predictable pattern in expression of traits (“factors”/genes); one inherited from each parent
▪ dominant and recessive alleles
▪ experiments successfully showed how heredity occurs in very simple/discrete/mendelian traits
discrete traits
controlled by alleles at single locus
ex. albinism, left chin, hypodontia of lateral incisors, ABO blood group system
dominant trait conditions
occurs if one of the allele is inherited
ex. achondroplasia (dwarfism), Marfan syndrome, Huntington disease
recessive trait conditions
individual has to inherit it by both parents (if they inherent one of the alleles then they will be a carrier)
ex. cystic fibrosis, Tay-Sachs disease, Sickle-cell anemia
Q7. Identify and describe the three forms of selection discussed in lecture.
▪ natural selection
▪ artificial selection
▪ sexual selection
natural selection
organisms that are better adapted to their environment are more likely to survive and contribute genetic material to future generations
artificial selection
humans selectively breed for desirable traits; some are beneficial, others are not
▪ pros: increase change in pop
▪ cons: breeding problems and can’t survive on their own
sexual selection
selection for features/behaviors associated with mating
ex. male peacock tail attracts females
Q8. What are some factors that produce and redistribute variation in a population? How do these factors
work?
▪ mutation
▪ gene flow
▪ genetic drift
mutation
▪ change in order of chemical bases
▪ can also occur in response to environmental conditions or replication error
▪ source of new variation in a pop
▪ must occur in a gamete to be evolutionarily significant
▪ can pos or neg affect organism
▪ only way to produce new genes
gene flow
▪ transmission, sharing or exchange of genes between pops though interbreeding
▪ important way variation is redistributed among pops
▪ individuals mate in new population, but don’t necessarily stay there
genetic drift
▪ random, occurs in small pops
▪ alleles become more/less prevalent (ex. Founder Effect)
Founder Effect
▪ occurs when a small group separates from a diverse population
▪ restricted representation of alleles in founding group due to genetic bottleneck
▪ if breeding is restricted, subsequent generations have low genetic variability–susceptible to extinction
▪ rare alleles can become more common
▪ occurs after colonization of new areas (ex. porphyria)
genetic bottleneck
reduction in diversity in a founding pop
▪ greatly reduced genetic diversity is bad for the pop bc if the environment changes, they don’t have enough diversity to deal with that change (could lead to mass extinction)
Q9. What are some characteristics of animals at different levels of the taxonomy of living organisms discussed thus far (Kingdom → Mammalia)?
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Kingdom: Animalia
▪ cells that contain a nucleus and other cell organelles
▪ can move
▪ dependent on other organisms as a food source
Phylum: Chordata
▪ rod-like spine
▪ nerve cord
▪ muscles
Subphylum Vertebrata
▪ segmented bony spinal column
▪ developed brain with a sense of smell
▪ heads and tails
Class: Mammalia
▪ hair
▪ longer ontogeny
▪ regulated body temp
Q10. How are phylogenetic systematics and cladistics similar? In what ways do they differ?
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Similarities
▪ branching diagrams
▪ patterns of relatedness; constructing classifications to reflect close evolutionary relationships
▪ character analysis (visible traits)
▪ homologous characters (shared from recent common ancestor)
Differences
▪ time (Evolutionary systematics)
▪ ancestor-descendant relationships (Evolutionary systematics) vs fossil and living species analyzed together (Cladistics)
Q11. Why do researchers use homologous characteristics to construct hypotheses of evolutionary relationships?
▪ to understand what led to the development of that trait
▪ observable part/attribute of an organism
▪ primitive/ancestral: inherited from an ancient ancestor
▪ derived: changed from the ancestral condition
Q12. What is the Biological Species Concept and what are some problems with its application?
species is a group of interbreeding or potentially interbreeding organisms that produce fertile offspring and that are reproductively isolated from all other such groups (not defined similar to appearance)
Problems with BSC
▪ Demonstrating capacity to successfully interbreed
▪ Asexually reproducing species?
▪ Hybrids?
▪ The fossil record
Q13. Discuss some ways that human populations become variable.
▪ gene flow
▪ non-random mating
▪ adaptation to local environmental conditions
Gene flow
▪ Interchange of genes between populations
▪ Adds variability to a population
Non-random mating
▪ Endogamy: mating within a distinct group (e.g., cultural, religious, community)
▪ Causes populations to be more similar
Adaptation to local environmental conditions
▪ causes populations to be more similar
▪ latitudinal gradient in skin colour (melanin) relative to the Equator due to exposure to sun
▪ variation due to climate, lifestyle, diet
Q14. How can skin colour be beneficial in one environment and problematic in another. Discuss with reference to vitamin D deficiency and folate degradation.
▪ Melanin: pigment influencing expression of skin colour
▪ Produced by melanocytes in epidermis
▪ Absorbs UV rays and protects against overexposure
▪ Populations closer to the Equator have same number of melanocytes but the amount and size of melanin vary
▪ Darker skin colour selected for; ↑ selection for melanin production
▪ Benefits of darker skin: protective effect against disruptions in folate metabolism
Vitamin D synthesis
▪ Produced in our skin as a result of exposure to sunlight
▪ Also obtained from diet: oily fish, egg yolk, mushrooms, supplementation
▪ Important for bone mineralization, melanin production, protective against certain disease
▪ Populations close to the Equator have exposure to sun all year round
▪ Less exposure to sun at higher latitudes, colder climates, clothes → lighter skin
▪ Rickets: vitamin D deficiency in children affecting bone mineralization (curved legs)
Q15. How have scientists tried to classify patterns of human variation in the past? Were these attempts successful? Why or why not?
▪ 5 races of humans: ▪ Caucasian ▪ Mongolian ▪ Malayan ▪ Ethiopian ▪ American ▪ what about natives of Australia
Q16. What is taphonomy? What are some factors that influence whether an organism becomes preserved in the fossil record or not?
▪ Study of the process of fossilization
Preservation potential: Biological make up
hard parts, small vs large bones
Preservation potential: Habitat
weathering (temperature, humidity, exposure to solar radiation), wind and water erosion, trampling
How to become a fossil in an ideal world
▪ immediate burial in alkaline soil
▪ water conditions
Relative dating
▪ Older than/younger than
▪ e.g., stratigraphy
▪ Nicholas Steno (1638-1686)
▪ Law of Superposition: rock layers arranged in a time sequence with older rocks lower down and younger rocks higher up
Chronometric dating
▪ Used to determine actual age in years
Potassium-argon (K/Ar) dating
▪ When rocks are formed, they contain potassium but no argon (e.g., through volcanism)
▪ As the rocks begin to cool, argon begins to accumulate
Paleocene
Plesiadapiforms
Eocene
Strepsirhines & haplorhines
first “true” primates
Oligocene
Catarrhines & platyrrhines
Miocene
Apes
Pliocene
Australopiths
How to biped
▪ the foramen magnum in centre of cranium ▪ "S" curve spine ▪ short and broad pelvis ▪ angled femur ▪ arched foot ▪ non-divergent big toe
Early hominins
the australopiths
H. habilis
▪ East and south Africa
▪ made Oldowan tools
▪ basic tools (look like regular rocks)
H. erectus
▪ Africa and Asia
▪ made acheulean tools (hand axes)
▪ tools modified on both sides to make sharp cutting edges
H. neanderthalensis
▪ Belgium ▪ made Mousterian tools ▪ tools for different purposes ▪ tools cutting animal meat or hides ▪ made of bone and wood or combo ▪ complex tools ▪ small portable tools
Modern Humans
▪ Africa ▪ tools made of diff material ▪ fish hooks, needles, blade tools ▪ very specific functions ▪ very complex ▪ took a long time
Modern Humans: Anatomy
▪ Large brain size (1350 cc) ▪ Globular cranial vault ▪ Not so much face (gracile, reduced brow ridges) ▪ Vertical frontal ▪ Orthognathic ▪ Gracile mandible WITH A CHIN! ▪ Smaller teeth ▪ Bipedal
bio cultural organisms
humans are able to have a wide spread of geo distribution as a species bc of degree of adaptive flexibility
Neolithic Revolution
▪ New Stone Age: 11 700 years ago
▪ hunting and gathering → food production (agriculture and domestication)
▪ changed the way humans interacted with their environments and each other
Agriculture/farming
▪ ensures that plants and animals with desirable traits are predictably available to humans as food and for raw materials
▪ cultural process
Domestication
interdependence between humans and specific plants and animals
▪ artificial selection for specific traits which results in genetic change
▪ evolutionary process
Food Production
producing more food than needed for immediate subsistence
Preparation of Food Production
▪ storage is key!
▪ delayed return
▪ preventing rot, pests, etc.
▪ technological innovation: drying, smoking, pottery/use of vessels, “on the hoof”
Consequences of Algaculture
▪ changes in settlement patterns, new technology, biological consequences
▪ changed human societies directly and indirectly and our environments
▪ agriculturalists were malnourished, had higher infection rates, short, and short life span
Civilization
a stage of human social and cultural development and organization that is complex
Characteristics of a Civilization
- large population centres/urban areas
- form of government/administration
- specialization of labour
- traditions and other shared cultural practices
- monuments, architecture and art forms
- shared communication strategies (ex. writing)
- social stratification/class system
- stability and expansion requires trade, conflict and exploration
Sumerian
- first complex urban civilization in the region of Sumer, 4900–4350 years ago
- encompassed ~12 city-states, ex. Uruk (city), Ubaid (citystate)
- true social stratification with kings chosen by the gods
- warfare
Ziggurat
mud-brick temple-pyramids built on elevated platforms
• control of agriculture
Cuneiform
administrative tool
used to keep track of algacultural practices and recording history
Arithmetic
development of calendar, clocks
• sexagesimal system (based on 60, ex. seconds, minutes, etc.)
Primate Characteristics
▪ extant vs extinct ▪ hair ▪ sweat glands, mammary glands ▪ live young ▪ long ontogeny ▪ heterodont ▪ endothermic ▪ larger brain ▪ capacity for learning and behavioral flexibility
Limbs and Locomotion
▪ tendency towards erect posture (vertical spine position)
▪ flexible, generalized limb structure (move in trees and ground)
▪ engage in a number of locomotor behaviors
▪ prehensile (grasping) hands and feet, sometimes tails
▪ differ from most mammals
▪ pentadactyly
▪ opposable thumb/big toe
▪ nails
▪ highly innervated tactile pads (nerve) at the end of digits – enhanced sense of touch
arboreal
active in the trees
ex. feeding, sleeping, socializing
terrestrial
active on the ground; more common in larger species
brachiation
▪ suspension
▪ elongated arms and hands, curved phalanges, cupped hands, extensive arm musculature
ex. gibbons and siamangs
prehensile tail
grasping tail that acts like a limb
ex. some New World monkeys from central and south America (howler monkeys)
knucklewalking
resting on middle set of phalanges
ex. African apes, gorillas
Dentition and Diet
▪ unspecialized teeth/generalized dentition – omnivorous diet
▪ fruit, leaves, gums, seeds, insects, honey, meat
maturation
▪ more efficient fetal nourishment
▪ longer gestation (pregnancy)
▪ reduced number of offspring, ↑ degree of care (k-selected vs r-selected)
▪ delayed maturation/longer ontogeny and learning period
▪ longer life span
learning
greater dependence on flexible, learned behavior; social groups and permanent association of adult males
behaviour
daytime activity pattern in most species
Pongines: Orangutans (Pongo)
▪ Borneo and Sumatra ▪ suspensory, quadrumanous climbers, fist walking ▪ mostly eat fruit ▪ extremely sexually dimorphic ▪ solitary
Gorillas (Gorilla)
▪ Equatorial Africa ▪ largest of the living primates ▪ primarily terrestrial, knucklewalking ▪ mostly eat fruit and plants ▪ groups consist of one large silverback male, a few adult females, and their offspring
Chimpanzees (Pan troglodytes)
- Equatorial and Western Africa
- smaller than gorillas, less sexually dimorphic
- arboreal; terrestrial: knuckle walk, bipedal
- broad diet: geographic and seasonal variability; hunting!
- variable group size; complex social behavior
- More complex tool use: termite and ant sticks, hammerstones
Bonobos (Pan paniscus)
▪ Democratic Republic of Congo ▪ chimp-like ... sort of ▪ arboreal ▪ sex ▪ social groups –male/female bonded pairs ▪ diet similar to chimps
