Evolution Final Flashcards
1
Q
evolutionary relationships of taxa organized into a nested hierarchy
A
Phylogeny
2
Q
Evolution is directional and works toward a goal. IT DOES NOT!
Linear progression
A
Orthogenesis
3
Q
any named group or organisms
A
Taxon
4
Q
base of the tree; represents ancestral lineage
A
Root
5
Q
moves forward from the root
A
Time
6
Q
divergence points representing last common ancestor
A
Nodes
7
Q
Represents evolutionary path
A
Branches
8
Q
descendant taxa
A
Tips
9
Q
continuous line of descent from ancestor to descendant. Each branch represents part of a longer lineage
A
Lineage
10
Q
nested group that includes common ancestor and descendants
A
Clade
11
Q
splitting of ancestral lineage into >1 descendant lineage, thus forming a clade
A
Cladogenesis
12
Q
inferred from the divergence (node) that connects them
A
Most Recent Common Ancestor (MRCA)
13
Q
traits in common because inherited from common ancestor
A
Character
14
Q
Requirements for characters: (3)
A
Independent
Heritable
Variable
15
Q
Types of characters: (5)
A
Morphological structures
DNA sequences
Chromosome numbers
Behavior
Chemical compounds
16
Q
evolutionary changes from the Ancestral to the Derived State
A
Character State Transitions
17
Q
state of that trait in the ancestor
A
Ancestral
18
Q
how that trait has changed in the descendant lineage
A
Derived
19
Q
derived trait unique to a clade or lineage; distinguishes it from ancestors
A
Apomorphy
20
Q
- Apomorphy that is shared by multiple taxa as a result of shared, most recent ancestry
- Used to group taxa into clades
- Among 2+ taxa
A
Synapomorphy
21
Q
unique state for 1 taxon
A
Autapomorphy
22
Q
ancestral state
A
Plesiomorphy
23
Q
Plesiomorphy in 2+ taxa
A
Symplesiomorphy
24
Q
Groups that includes common ancestor and all its descendants
Taxa can be members of multiple, nested monophyletic groups
A
Monophyletic Groups (Clades)
25
group that includes common ancestor + some descendants, excludes some descendants
Paraphyletic groups
26
group that includes some descendants, excludes common ancestor and some descendants
Polyphyletic group
27
similarity due to common ancestry
Synapomorphies, symplesiomorphies
Homology
28
similarity due to independent evolution of a character state – not from a common ancestor
Homoplasy
29
3 types of homoplasy
Convergence, Reversal, convergent reversals
30
independent evolution of a similar character
Convergence
31
loss of a derived trait and reversal to ancestral state
Reversal
32
loss of derived trait, happening over and over
Convergent Reversals
33
calculating genetic similarity
Fast, easy, but less robust
Genetic Distance
34
minimizing the total number of synapomorphic transitions
Parsimony
35
maximize homology and minimize homoplasy
Maximum Parsimony
36
closely-related taxon used to determine polarity and root the tree
Outgroup
37
Parsimony-Informative Characters Criteria:
> or equal to 2 states
For at least 2 states, each must be in at least 2 taxa
38
incorporate models, but computationally expensive
Maximum Likelihood
39
statistical support using pseudoreplicate data
Bootstrapping
40
mutations accumulate at a constant(ish) rate
More time = more mutations
Molecular Clock
41
inferring change since divergence
Scaled branch length are calibrated to substitutions
Branch Length
42
Steps toward speciation (3)
Isolation
Divergence
Secondary contact (reinforcement)
43
What can happen to lineages over time? (3 possibilities)
Change
Diverge
Independent evolutionary path
44
Distinct phenotypic traits
Aligns with what we see
Apply to asexual and extinct species
Social amoebas - Asexual
Limitations - no common criteria, homoplasy, polyp (asexual stage), sexual dimorphism
Cryptic Species:
Morphological
45
3 Ways to Diagnose a Species
Morphological, Behavioral, and Phylogenetic
46
Species that are indistinguishable morphologically, but divergent in other traits
Cryptic Species
47
group of interbreeding organisms that can produce viable and fertile offspring and are reproductively isolated from all other such groups
Strengths: meaningful diagnostic criteria
Limitations: extinct taxa, asexually reproducing, geographically separated (allopatry), huge gray area in “fertile” and “viable”
Biological
48
Limitations to Biological
Extinct taxa, asexually reproducing, geographically separated, huge gray area in "fertile" and "viable"
49
Strengths of Biological
meaningful diagnostic criteria
50
Limitations of Morphological
no common criteria, homoplasy, polyp (asexual stage), sexual dimorphism
51
Smallest monophyletic group
Strengths: based on what has occurred
No/little gene flow (isolated)
Long enough for synapomorphies to arise
Irreducible group
Descent from a common ancestor
Unique character states
Applies to:
Extinct species
Asexual species
Cryptic species
Phylogenetic
52
Limitations to Phylogenetic
Phylogenies are hypothesis
Can lead to A LOT of recognized species
53
Geographic isolation of populations
Allopatric speciation
54
2 categories of allopatric speciation
dispersal and vicariance
55
portion of ancestral species crosses a barrier
Dispersal
56
ancestral species split by barrier
Vicariance
57
Isolation of populations within the same geographic range
Sympatric speciation
58
Drivers of sympatric speciation (4)
Polyploidy, Phenology, Adaptation to different habitats, Sexual selection/assortative mating
59
Stronger in sympatry
Maintaining separate evolutionary lineages during secondary contact
Reinforcement of Divergence
60
no parental competition
Novel habitat
61
outcompete parentals
Transitional habitat
62
2 categories of hybridization
Novel habitat and transitional habitat
63
a geologic process by which one plate of the earth’s crust is forced below the edge of another plate
Subduction
64
Can’t self replicate
Can’t store and transmit information
Proteins
65
Can’t independently express phenotype
DNA
66
Very unstable
RNA
67
Stores information → nucleotides
Part of cellular machinery → ribosomes
Base molecule for bioenergy → ATP, GTP
Found in all life
RNA World Hypothesis
68
Evidence: variation in catalyzing rate based on genotype
Fast = favored
Genes increase in frequency
RNA World Hypothesis
Ribozyme
69
extra-terrestrial origins
Panspermia
70
Panspermia
Complex organic molecules
Amino acids (L and R)
Hydrocarbons
Liquid water
Panspermia Molecular Seeding
71
Cellular
DNA-based genome
Protein
1.Ribosomes for protein synthesis
2.Universal Genetic Code (20aa)
3.Only Use L-isomer Amino Acids
4.ATP/GTP bioenergy
Last Universal Common Ancestor (LUCA)
72
Mineralized remains of past (& ancient) life
Major evolutionary events
Origins of key traits
Diversification
Extinction
BIG patterns of macroevolution
Fossils
73
the study of fossilization
Taphonomy
74
Types of Fossils:
Organics replaced with minerals
Can detail internal anatomy
Permineralization
75
Types of Fossils:
Portions of original organism
Amber, freezing, desiccation
Preserved Organic Material
76
Types of Fossils:
Organics decay
Impression filled in with minerals
Details of surface of organism
Casts & Molds
77
Evidence of behavior/activity
Not organism directly
Trace
78
Form under the same conditions
But SMALL: <1mm
Microfossils
79
Rapid divergence and diversification
Most modern animal phyla
Cambrian Explosion
80
Hypotheses for Cambrian rapid diversification
1. Rise in O2 (increase in photosynthetic bacteria)
2. Allowing animals to catch and eat each other - Evolutionary Arms Race
3. Ecological Niches
81
ancestral lineage rapidly diversifies into multiple descendent lineages due to novel selective trigger
Adaptive Radiation
82
2 types of adaptive radiation
1. Ecological Opportunity
2. Morphological Innovation
83
Reptile-like traits (symplesiomorphies)
Synapsid skull (synapomorphy)
Stem Animals
84
Middle ear bones in mammals are similar to skull bones in reptiles
Bone Homology
85
Graphical representation of the range of morphological diversity
Morphospace
86
Changes occur gradually and are unrelated to speciation events
Morphological diversity spreads out both horizontally and vertically
Changes occur within a lineage until speciation
Phyletic gradualism
87
Long periods of stasis followed by rapid change and speciation
Morphological diversity spread out ONLY horizontally
Vertical branches stay in the same morphospace until speciation
Punctuated equilibrium
88
Patterns of macroevolution and what they differ in
Same amount of change
Differ in:
Time for change to accumulate
What happens between divergence events (nodes)
89
tarsiers, lemurs, and lorises
Prosimians
90
gorillas, humans, chimpanzees & bonobos, orangutans, gibbons & siamangs, Old World & New World Monkeys
Anthropoids
91
Synapomorphies of the Apes
Relatively large brains
“Absence” of tail
More erect posture
Increased hip and ankle flexibility
Increased wrist & thumb flexibility
92
Synapomorphies of African Great Apes
Enlarged ovaries & mammary glands
Fusion of some wrist bones
Enlarged brow ridges
Shortened canine teeth
Elongated skulls
93
Differences in Gene Expression in Humans and Chimpanzees
Humans make more miRNA (micro RNA) = more genes suppressed in humans
94
Molecular Evidence = Human and Chimp
- Mitochondrial genes
Maternal inheritance
- Gene on Y chromosome
Parental inheritance
- Nuclear, autosomal genes
Biparental inheritance
95
descendent lineages inherit different subsets of the original alleles from the ancestral population
Incomplete lineage sorting
96
humans and all species more closely related to humans than to chimps
Hominins
97
directly descended from (i.e. parents and grandparents)
Ancestor
98
share a common ancestor with (i.e. aunt and cousins)
Relative
99
species formation through gradual transformation from ancestral form (no branching)
Anagenesis
100
formation of new taxa evolutionary divergence from an ancestral form
Cladogenesis
101
4.2-1.9 mya → eastern Africa
Gracile Archaic Hominins
Diagnostic traits
Bipedalism
Flatter faces; smaller canines
Australopithecus
102
Robust Archaic Hominins
2.7-1.0 mya → eastern & southern Africa
Diagnostic Traits
Megadont teeth
Robust jaws with massive jaw muscles
Sagittal crest
Wide, dish-shaped face
Paranthropus
103
Possible First Humans
2.4-1.6 mya → eastern & southern Africa
Diagnostic Traits
Larger brains
Rounder skull & Flatter faces
Stone tools → butchered prey
Transitional Homo (e.g. Homo habilis)
104
1.7-0.4 mya → Africa & Asia
Definitive Pre-Modern Humans
Diagnostic traits
Smaller, flatter faces, teeth, jaws
Taller with longer legs
Reduced sexual dimorphism
Homo erectus / ergaster
105
600-30 kya (k=thousand) → Africa, Asia, Europe
Definitive Pre-Modern Humans
Sister taxa to us
Diagnostic morphological traits:
Massive brains - larger than modern
humans
Heavy brow ridge
Short, stocky bodies
Diagnostic Cultural Traits
Used fire
Buried dead
Lived in shelters
Made and wore clothing
Made symbolic objects
Homo neanderthalensis / heidelbergensis
106
Definitive Pre-Modern Humans
300-400 kya → Asia, Melanesia
Sister taxa to Neanderthals
Deisovans
107
Anatomically-Modern Humans
200 kya - present → everywhere
Diagnostic traits
Large brains
Flat face with high forehead & chin
Lighter in weight skeleton
Definitive art, music, clothes, fire, bury
dead, religion, etc.
Homo sapiens
108
Hypotheses for Origin of Homo sapiens
Out of Africa and Multi-regional
109
Evolved in Africa, the dispersed to other regions; subsequently replacing other species in the process OR hybridizing and assimilating
Out of Africa Hypothesis
110
Evolved concurrently in different regions but maintained species cohesion via gene flow
Multi-regional
111
Traits that entered the human gene pool from Neanderthals:
Bitter Taste Perception
Some aspects of
Immune response
Lipid metabolism
Skin & hair pigmentation
112
Traits that entered the human gene pool from Denisovans:
Cold tolerance genes
High altitude genes
Immune response
Genes for sense of smell
