Week 2: Living Primates 2

Question 1

classifications

tree of life

Answer 1

organisms can be classified hierachically based on similarities

Question 2

species concepts

biological species concept

Answer 2

groups of actually or potentially interbreeding populations that are reproductively from other groups

reproductive isolation is when members of a given group do not mate successfully with organisms outside that group

Question 3

species concepts

mate recognition species concept

Answer 3

the group of individuals sharing a common fertilization system

Question 4

species concepts

phylogenetic species concept

Answer 4

the smallest diagnosable cluster of individuals within which there is a parental pattern of ancestry and descent

Question 5

species concepts

phenetic fossil species concept

Answer 5

species defined morphologically should have approximately the same amount of metrical variation as extant populations

Question 6

classifying organisms

above species level

Answer 6

arranging organisms in a hierachical system
* traditionally: based on intuition
* phenetic: based on similarity
* phylogenetic: based on phylogeny
these methods lead to very different results

Question 7

hominids

Answer 7

comprises humans, their living relatives and fossil relatives and ancestors

Question 8

hominins

Answer 8

comprises humans, their fossil ancestors and fossil relatives

Question 9

reconstructing phylogeny

how are organisms related

Answer 9

• evolutionary systemics/phenetics: based on similarities
• cladistics: based on shared derived homologous traits

methods frequently leade to very different results

Question 10

building a tree

analogy and homology

Answer 10

similarities can exist for different reasons- either because they have been inherited from a common ancestor (homology) or they could have arisen independently (analogy)

impossible to differentiate

Question 11

reconstructing phylogeny

problem/solution with cladistics

Answer 11

• problem: for cladistic analysis you have to be able to distinguish between primative (plesiomorphic) traits and derived (apomorphic) traits
• solution: must either know last common ancestor (not usually possible) or have an outgroup that allows to reconstruct the primitive state

Question 12

symplesiomorph

Answer 12

shared primitive

Question 13

synapomorph

Answer 13

shared derived

Question 14

autapomorph

Answer 14

exclusively derived

Question 15

phylogenetic classification

monophyly

Answer 15

all species in a taxon must derive from a common ancestor

Question 16

phylogenetic classification

holophyly

Answer 16

all descendants of the common ancestor must be included in this taxon

Question 17

phylogenetic groups

monophyletic

Answer 17

descended from a common evolutionary ancestor or ancestral group, especially one not shared with any other group

Question 18

phylogenetic groups

paraphyletic

Answer 18

descended from a common evolutionary ancestor or ancestral group, but not including all the descendant groups

Question 19

phylogenetic groups

polyphyletic

Answer 19

derived from more than one common ancestor or ancestral group and therefore not suitable for placing in the same taxon

Question 20

from a paper on hemoglobin

the first description of the molecular clock

Answer 20

based on the observation that genetic mutations, although random, occur at a relatively constant rate

Question 21

molecular clock

Answer 21

a technique that uses the rate of molecular changes, like DNA or protein sequence mutations, to estimate the time since two or more species diverged

Question 22

molecular clock

molecular distance

Answer 22

difference in nucleotides, immunological response or similar

Question 23

linus pauling and emile zuckerkandl

Answer 23

put forward concept of molecular clock

Question 24

allan wilson and vince sarich

Answer 24

• “Immunological Time Scale for Hominid Evolution”
• the molecular clock in hominoid evolution

Question 25

elwyn and david pilbeam

Answer 25

the proponents of ramapithecus as a hominin

Question 26

allan wilson and vince sarich

Question 27

closest living relative

Answer 27

* flying lemurs or colugos * dermoptera * mammalian order closest related to the primates * live in southeast asia | neither lemurs nor flying

Question 28

other close relatives

Answer 28

* tree shrews and pen tailed shrews * other mammalian order closely related to the primates * live in southeast asia * serve as a good model for the earliest primates | neither shrews nor all aboreal

Question 29

# definition of primate order what are important primate characteristics

Answer 29

* can use feet and hands for grasping * most have flat nails, sensitive tactile pads with fingerprints * locomotion is hindlimb dominated * visual sense is highly developed. stereoscopic vision, orbits are at least partially closed * fairly unspecialized molar morphology * brains are large compared to brains of similarly sized mammals ## Footnote * primates are a rather nondescript mammalian order that cannot be characterized by a single derived feature shared by all members * definition requires combination of derived features

Question 30

# primate characteristics stereoscopic vision

Answer 30

* the brain takes the information from each eye and unites them into one picture, interpreting the slight differences between each view as depth * produces a 3D picture with height, width and depth

Question 31

# primate characteristics why is 3D vision important

Answer 31

* beneficial for a life in trees * makes it possible to move quickly among tree branches * stereoscopic vision is also good for catching prey

Question 32

dental formula

Answer 32

* 3 incisors, 1 canine, 4 premolars and 3 molars * 3.1.4.3 | describes number and type of teeth

Question 33

how are primates diverse

Answer 33

* locomotion; different ways of moving around * posture and diet; different feeding behaviours * social structure; different kinds of social groups * life history; gestation, growth and maturation

Question 34

types of locomotion

Answer 34

* arboreal quadrupedalism * terrestrial quadrupedalism * knuckle-walking quadrupedalism * leaping * suspensory climbing * bipedalism

Question 35

different social structures

Answer 35

* noyau * monogamy * polyandry * multimale group * one-male group * fission-fusion society * hamadryas baboons

Question 36

# features, dental formula strepsirhine

Answer 36

* sloping talofibular facet * reduced upper incisors * grooming claw * tooth comb * 2.1.3.3

Question 37

# features, dental formula cheirogaleids | mouse lemurs and dwarf lemurs

Answer 37

* most primitive family of lemurs * 2.1.3.3 * arboreal and nocturnal * rather small * mostly frugivorous and insectivorous * microcubus, cheirogaleus, phaner, allocebus

Question 38

# features, dental formula lemurids

Answer 38

* biggest family of lemurs * dental formula 2.1.3.3 * diurnal/cathemeral, both arboreal and terrestrial * frugivorous and foliovorous * includes; lemur, eulemur, lapalemur, varecia * also includes giant extinct lemur; megaladapis

Question 39

# features, dental formula lepilemurids

Answer 39

* only one living genus with seven species * 0.1.3.3/2.1.3.3 (lacking upper incisors) * nocturnal, arboreal * foliovorous

Question 40

# features, dental formula indriidae

Answer 40

* three similar genera, mostly differing in size * 2.1.2.3/1.1.2.3 (lost P2 lower incisor) * nocturnal (wooly lemurs), diurnal (indris and sifakas), arboreal verticle clinger and leapers * foliovorous * family also includes several large extinct taxa

Question 41

# features, dental formula daubetoniidae

Answer 41

* daubentonia madagascariense, probably the most specialized primate * 1.0.1.3/1.0.1.3 (lost I1, C, P2 and P3) * nocturnal arboreal insectibor * occupies the ecological niche of woodpeckers, but also eat fruits with hard shells

Question 42

# features, dental formula galagidae

Answer 42

* rather diverse group in Africa * 2.1.3.3/2.1.3.3 * nocturnal, arboreal insectivores/frugivores/gummivores * primarily leapers

Question 43

# features, dental formula lorisidae

Answer 43

* live in Africa and SE Asia * 2.1.3.3/2.1.3.3 * nocturnal, arboreal insectivores/furgivores/guummivores * primarily slow climbers

Question 44

prosimians vs anthropoids

Answer 44

* prosimians tend to be nocturnal and exhibit a smaller size and smaller brain than anthropoids

Question 45

# features, dental formula tarsiidae

Answer 45

* among the smallest and most unusual living primates * morphology combines many (primative) strepsirhine features and (derived) haplorhine features * 2.1.3.3/1.1.3.3 * nocturnal, arboreal insectivores from SE Asia * vertical clinger and leapers