Anthro 2B Final (Egan) verified
answers and questions
2023/2024
macro-evolution evolution above the species level
micro-evolution evolution below the species level
speciation occurs when one species splits into two, which involves a reproductive
isolating mechanism
example of reproductive isolation but NOT speciation leopard frogs in Florida vs.
Maine, can still reproduce but just can't because they are isolated; gene flow can happen
extrinsic isolating mechanismfactors producing geographic isolation which physically
separates individuals (ex: movement of tectonic plates; mountains)
Intrinsic/ Pre-zygotic no a physical barrier separation; this isolating mechanism prevents
sperm from meeting egg; prevents zygote from ever forming
example of pre-zygotic isolating mechanism different pine tree species produce pollen at
different times of the year
post-zygotic a zygote forms but might have a mutation that will cause it to die after
examples of post-zygotic isolating mechansim infant can be born but is sick and dies;
the resultant offspring is sterile!
fundamental principle of natural selection rate of evolutionary change is directly
proportional to the degree of variability in the population
corollary natural selection principle fate of all evolutionary lineages is extinction; 99.9% of
all lineages ever existing on Earth went extinct
anagenesis change in a species over a long period of time; supports gradualism theory of
evolutionary change
cladogenesis sudden split results in formation of 2 species from 1 species; supports
punctuated theory of evolutionary change
phyletic gradualsim emphasizes anagenesis; slow change over time that leads to formation
of a new species
punctuated equilibrium emphasizes cladogenesis; evolutionary change from sudden
speciation events
adaptive radiation rapid expansion & diversification of a group of organisms as they
adapt to a newly available ecological space; involves rapid speciation/cladogenesis; occurs
from new changes that open up potential new habitats to a group of organisms
what type of theory of evolutionary change does a phylogenetic tree model? the
punctuated equilibrium theory of evolutionary change
example of adaptive radiation South American finch goes to Galapagos Islands (species with
HIGH adaptive potential invades a new local)
another example of adaptive radiation mutations produce major adaptive shift such as
the evolution of the amniotic egg; mutations give you a new way of using an environment
that no one else has
, generalized species able to exploit a wide range of ecological space; a jack of all trades
and ace of none
specialized species are specialized to a narrowly defined eco-niche; ace of one trade
generalized vs. specialized species generalized species tend to start adaptive radiation and
have more potential to survive/adapt; when species specialize, competition can cause
speciation
evolutionary homology useful similarity; similarities in structures due to COMMON
ANCESTRY; their similar structures have DIFFERENT functions
example of evolutionary homology human arm & bat wing are similar shapes and
FUNCTION DIFFERENTLY
evolutionary analogy (homoplasmy) independent evolution; didn't come from same ancestor;
misleading; structures have SIMILAR FUNCTIONS - use this when making phylogenetic
tree
example of evolutionary analogy bird wing and fly wing; both fly but are not from the
same ancestor
2 types of evolutionary analogy convergence & parallelism
convergence (a type of evolutionary analogy) drastically unrelated organisms
(ex: squid eye vs. human eye); not the same ancestor but eyes have same function -
MISLEADING
parallelism (a type of evolutionary analogy) closely related organisms (ex: incisors in lemurs
& Goeldi's monkey) - in the same order but evolved independently in both species
primitive/ancestral traits a trait retained in its ancestral form (polydactylyl; maintenance
of 5 digits)
derived traits trait that has been modified from ancestral form thru alterations via mutations
(gain, loss, or change of function); (ex: claws turn into nails; claws turn into hooves)
shared derived traits still just a derived trait, but know it is shared across species (ex: cloven
hoof found in cows, goats, deer, etc.)
what are characteristics of the Primate order 1. emphasis on vision/color vision
2. reduced snout
3. auditory bulla
4. prehensile hands/feet (precise grip)
5. larger brain/increased cerebral cortex
6. decreased litter size
7. post-orbital bar or septum
post-orbital bar a skeletal structure in form of a bar of bone, behind the eye that does
not close it off (strepsirrhines)
post-orbital septum/closure P-O septum (partial p-o bar); eye socket is entirely protected by
bone; P-O closure is when it is fully closed
Who has a P-O bar/P-O septum? strepsirrhines have a P-O bar, haplorrhines have a
partial/closed P-O septum
-simiiformes have full P-O closure
binocular/stereoscopic vision 2 eyes positioned facing forward; overlapping fields of vision;
both eyes focus on an object/eyes are in front of head; eyes send stimulatory signals to both
hemispheres of brain; provides depth perception
color vision abundance of cones in eyes; nocturnal primates are exception;
diurnal/crepuscular(twilight) organisms usually have color vision
night vision abundance of rods in the eye (not cones); allows nocturnal organisms to see at
night
Who is nocturnal/who isn't? Lorisiformes (under strepsirrhini) and Tarsiiformes (under
haplorrhini)
answers and questions
2023/2024
macro-evolution evolution above the species level
micro-evolution evolution below the species level
speciation occurs when one species splits into two, which involves a reproductive
isolating mechanism
example of reproductive isolation but NOT speciation leopard frogs in Florida vs.
Maine, can still reproduce but just can't because they are isolated; gene flow can happen
extrinsic isolating mechanismfactors producing geographic isolation which physically
separates individuals (ex: movement of tectonic plates; mountains)
Intrinsic/ Pre-zygotic no a physical barrier separation; this isolating mechanism prevents
sperm from meeting egg; prevents zygote from ever forming
example of pre-zygotic isolating mechanism different pine tree species produce pollen at
different times of the year
post-zygotic a zygote forms but might have a mutation that will cause it to die after
examples of post-zygotic isolating mechansim infant can be born but is sick and dies;
the resultant offspring is sterile!
fundamental principle of natural selection rate of evolutionary change is directly
proportional to the degree of variability in the population
corollary natural selection principle fate of all evolutionary lineages is extinction; 99.9% of
all lineages ever existing on Earth went extinct
anagenesis change in a species over a long period of time; supports gradualism theory of
evolutionary change
cladogenesis sudden split results in formation of 2 species from 1 species; supports
punctuated theory of evolutionary change
phyletic gradualsim emphasizes anagenesis; slow change over time that leads to formation
of a new species
punctuated equilibrium emphasizes cladogenesis; evolutionary change from sudden
speciation events
adaptive radiation rapid expansion & diversification of a group of organisms as they
adapt to a newly available ecological space; involves rapid speciation/cladogenesis; occurs
from new changes that open up potential new habitats to a group of organisms
what type of theory of evolutionary change does a phylogenetic tree model? the
punctuated equilibrium theory of evolutionary change
example of adaptive radiation South American finch goes to Galapagos Islands (species with
HIGH adaptive potential invades a new local)
another example of adaptive radiation mutations produce major adaptive shift such as
the evolution of the amniotic egg; mutations give you a new way of using an environment
that no one else has
, generalized species able to exploit a wide range of ecological space; a jack of all trades
and ace of none
specialized species are specialized to a narrowly defined eco-niche; ace of one trade
generalized vs. specialized species generalized species tend to start adaptive radiation and
have more potential to survive/adapt; when species specialize, competition can cause
speciation
evolutionary homology useful similarity; similarities in structures due to COMMON
ANCESTRY; their similar structures have DIFFERENT functions
example of evolutionary homology human arm & bat wing are similar shapes and
FUNCTION DIFFERENTLY
evolutionary analogy (homoplasmy) independent evolution; didn't come from same ancestor;
misleading; structures have SIMILAR FUNCTIONS - use this when making phylogenetic
tree
example of evolutionary analogy bird wing and fly wing; both fly but are not from the
same ancestor
2 types of evolutionary analogy convergence & parallelism
convergence (a type of evolutionary analogy) drastically unrelated organisms
(ex: squid eye vs. human eye); not the same ancestor but eyes have same function -
MISLEADING
parallelism (a type of evolutionary analogy) closely related organisms (ex: incisors in lemurs
& Goeldi's monkey) - in the same order but evolved independently in both species
primitive/ancestral traits a trait retained in its ancestral form (polydactylyl; maintenance
of 5 digits)
derived traits trait that has been modified from ancestral form thru alterations via mutations
(gain, loss, or change of function); (ex: claws turn into nails; claws turn into hooves)
shared derived traits still just a derived trait, but know it is shared across species (ex: cloven
hoof found in cows, goats, deer, etc.)
what are characteristics of the Primate order 1. emphasis on vision/color vision
2. reduced snout
3. auditory bulla
4. prehensile hands/feet (precise grip)
5. larger brain/increased cerebral cortex
6. decreased litter size
7. post-orbital bar or septum
post-orbital bar a skeletal structure in form of a bar of bone, behind the eye that does
not close it off (strepsirrhines)
post-orbital septum/closure P-O septum (partial p-o bar); eye socket is entirely protected by
bone; P-O closure is when it is fully closed
Who has a P-O bar/P-O septum? strepsirrhines have a P-O bar, haplorrhines have a
partial/closed P-O septum
-simiiformes have full P-O closure
binocular/stereoscopic vision 2 eyes positioned facing forward; overlapping fields of vision;
both eyes focus on an object/eyes are in front of head; eyes send stimulatory signals to both
hemispheres of brain; provides depth perception
color vision abundance of cones in eyes; nocturnal primates are exception;
diurnal/crepuscular(twilight) organisms usually have color vision
night vision abundance of rods in the eye (not cones); allows nocturnal organisms to see at
night
Who is nocturnal/who isn't? Lorisiformes (under strepsirrhini) and Tarsiiformes (under
haplorrhini)
