ANT 001 Final Exam Flashcards
Microevolution
evolution within populations of a single species
Macroevolution
evolution at, or above, species level
Principle of uniformitarianism
same processes that are acting today have been acting throughout Earth’s history
Modern synthesis 1st wave
builds bridges between genetic and evolution
Modern synthesis 2nd wave
builds bridges between micro and macro
What are the three species concepts?
biological, ecological, evolutionary
Biological species concept
species is a group of reproductively isolated organisms (no gene flow)
Ecological species concept
species is a group of organisms bound by selection pressures that are distinct from selection pressures on other groups
Evolutionary species concept
species is a lineage of populations that descend from a common ancestor, distinct from other lineages
Allopatric speciation
speciation that occurs when biological populations of the same species become isolated due to geographical changes (mountain building, emigration)
Parapatric speciation
when a species is spread over a large geographic area, but only reproduces with local species
Sympatric speciation
evolution of a new species from thriving ancestral species while both continue to inhabit the same geographic region
Speciation
formation of new and distinct species in the course of evolution
Linnaean classification
Carolus of taxonomy created by carols Linnaeus
Phylogeny
representation of evolutionary history and relationships between groups of organisms
Molecular “clocks”
measure of evolutionary change over time at the molecular level that allows scientists to predict how long ago two related ancestors diverged from a common ancestor
Ancestral trait
traits inherited from the common ancestor
Derived trait
traits that just appeared (mutation) in the most recent ancestor
Convergent evolution
process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities
Common evolutionary history
ancestral group of organisms that is shared by multiple lineages
Homology
structures that are similar due to a shared ancestry (vertebraes all have spines)
Analogy
structures that do not share an origin but have a similar function (butterfly & bird wings)
Microevolution –> ?
macroevolution, given time
When does speciation occur?
geographic or behavior barriers interrupt gene flow, or when selection favors mechanisms to limit interbreeding
Extant
opposite of extinction, still alive and most recent
Human role in extinction
habitat loss, hunting, disease
Habitat loss
clear-cut logging for timber, land conversion for agriculture and livestock
Hunting
bushmeat, pet trade
Disease
epidemics, emerging infectious diseases
Range restriction for primates
predicted to narrow: current primate distribution –> agricultural expansion –>predicted primate range by the end of the century low
Major ultimate threats to primates
poverty, population expansion, poor governance
Shared derived traits
traits two or more related species have in common but some slightly more distant ancestors represented the phylogeny lack these traits
Outgroup
group of organisms not belonging to the group whose evolutionary relationships are being investigated
Strepsirrhini
moist nose
Haplorrhini
dry nose
Prosimian
primitive primate group that includes lemurs, lorises, and tarsiers
Anthropoids
human-like creatures
Infraorder Platyrrhini
flat-nosed new world monkeys (diurnal, arboreal, prehensile tails, 3 premolars)
Infraorder Catarrhini
down-nosed old world monkeys, apes, humans (medium to large groups, mostly in Africa,
Monophyletic
descended from a common ancestor or ancestral group not shared with any other group
Paraphyletic
descended from a common ancestor or ancestral group but not including all of the descendant groups
Apes
no tail, broader noses, larger brains, y-shaped ridges on molars,
Locomotion
movement or ability to move from one place to another
Locomotion in chest morphology
monkey deep trunk (sitting on branches), hominid wide trunk (hanging from branches)
Phylogenetic
evolutionary development or diversification of a species or a particular feature of an organism
Natural selection favors primates who:
find food, avoid predation, find mates & raise offspring
Environment
community of living organisms + non-living components
Primate socio-ecology
study of how primate social systems are influenced by the environment
Social systems
primate societies (different gender ratios)
Insectivore
feeding on or adapted for feeding on insects
Folivore
animal that feeds on leaves
Frugivore
animal that feeds on fruit
Fruit seeds & Molars
seed specialists need a thick molar enamel
Fruit specialization
low rounded molar (grinding) large piercing incisors (piercing fruit husk) rigid, bony plates (rubbing fruit against)
Gum Specialization
gum: viscous secretion from trees and shrubs, large prominent incisors, gouging
Insect Specialization
sharp teeth for piercing & shearing prey
Leaves Specialization
high cusps (slicing, shearing crests) thin molar enamel (thin enamel creates sharp edges)
Mechanical function of digestion
teeth
Chemical digestion
stomach, small intestine, large intestine, caecum
Metabolic rate
(body weight) ^0.75
Fallback foods
foods that become important during periods when preferred foods are scarce
Anti-predator strategies
taste disgusting, avoid detection, nocturnal, congregate with other members of the species
Why do most primates live in groups?
DILUTES predation risk, improves predator DETECTION, and collective DETERRENCE (mobbing)
Tradeoffs for large groups
Need to visit more feeding patches, increased daily travel distance, fission-fusion
Large primates
low quality diets and large groups
Small primates
high quality diets and small groups
What shapes adaptations for food processing?
fallback foods
Feeding competition affects:
group size and social relations
Predation affects
primate evolution (favors group-living)
Contest competition males
increase mating success by preventing other males from mating
Contest competition females
increase feeding success by preventing other females from feeding
Scramble competition males
increase mating success by getting access to females first
Scramble competition females
increase feeding success by getting access to food first
Ecological constraints
ecological conditions deter individuals from breeding independently so individuals breed cooperatively to make the best of a bad situation
What affects female strategies & distributions?
distribution of resources and predation risks
What affects male strategies?
female distribution and need for parental care
What may have selected for larger brains?
coalitions
Teleology
study of ends or purposes by looking at results
Exaptation
adaptation co-opted for something other than what it was favored by natural selection
Naturalistic fallacy
the belief that just because something evolved some way it is “good”
Co-evolve
traits that evolve together OR traits the evolve reciprocally in two different species
Phenotypic plasticity
ability of individual genotypes to produce different phenotypes in different environmental conditions
Hominins have traits that are:
- Ancestral and shared with Apes
- Derived traits
Important features of human life history, cognition, and body morphology…
co-evolve
How can we reconstruct the past of our species?
socio-ecological theory, life history theory, theoretical simulations, fossil record, genetic data
PEOMPPH
paleocene, eocene, oligocene, miocene, pliocene, pleistocene, holocene
Niches
role of an organism in a community
Stratigraphy
branch of geology that deals with the study of nature, distribution, and relations of stratified rocks in the earth’s crust
Relative time
rate time passes based on your frame of reference
Strata
stacked up layers of sedimentary rock
Absolute time
progresses at a consistent pace independently of events or processes
Half-life
average amount of time until half the atoms in the sample have decayed
When did primate evolution begin
> 65 Ma
Where/how did initial primate evolution take place
Cenozoic and proceeds as a series of radiations
When did hominin evolution diversify geographically
1.9 Ma
What derived features have hominids evolved?
bipedalism, reduced sexual dimorphism, large brains, difficult birth, long life histories & cumulative culture
Bipedalism
walking upright on 2 legs
Distance running traits
more balanced head during running, larger glutes, arched feet, longer legs
Bicondylar angle
angle that serves to place the knee and foot under the body’s center of gravity
Genera
singular term for genus
Prognathic
bottom of the face just out
Splitters
taxonomist who attaches more importance to differences than to similarities in classification
Lumpers
taxonomist who attaches more importance to similarities than to differences in classification
What is one of the earliest derived traits of hominins?
bipedalism
Why did bipedalism evolve?
adaptation to different habitats that arose from global changes in climate
When is evidence of bipedalism present in the fossil record?
~4Ma, some suspect 7Ma
Early hominids may have been less efficient ______&_______ than later hominins, and they likely spent a considerable amount of time _________
Walkers & runners, climbing trees
Paleontological
study of fossils to learn about non-human life
Archaeological
study of human made artifacts and structures to learn about ancient people and cultures
Social intelligence hypothesis
bigger brains evolved in response to challenges associated with social complexity
Extractive foraging hypothesis
bigger brains arose as a result of high-energy foods and intelligent tool use to get them
Cultural brain hypothesis
bigger brains are a result of social learning and shared culture
Taphonomic
study of processes that affect animal and plant remains as they become fossilized
Altricial
hatched or born helpless requiring significant care
The hominin fossil record documents the mosaic (piecemeal) appearance of…
human traits
When do bipedalism and reduced canine size appear?
early
When did increases in brain size relative to body size occur?
late in human evolution
Which traits likely co-evolved in humans?
brain size, foraging & hunting technologies, life histories, and sexual dimorphism
Which fossil might have been the only hominin with as slow life histories as ours?
H.sapiens
