Evolution Flashcards
(103 cards)
1
Q
Allopatric speciation
A
- most common
- geographic barrier
- even if they rejoin, they will no longer interbreed
2
Q
Sympatric speciation
A
- side by side, changes their chromosomes/evolve due to micro habitat, food changes, etc.
3
Q
2 types of sympatric speciation
A
- ## AutoPolyploidy
- ## Allopolyploidy
4
Q
Intersexual selection
A
Between males and females
5
Q
Intersexual selection
A
Two or more males competing for mate
6
Q
Adaptive radiation
A
When members of a single species get new adaptations (morphological features) because of different environmental conditions
7
Q
List order of taxonomy
A
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
8
Q
Allele
A
Variant form of a gene
9
Q
Gene
A
A section of DNA that codes for a trait
10
Q
Gene locus
A
Position on chromosome where gene is located
11
Q
Polymorphism
A
Distinct variants of character (presence of spine yes or no)
12
Q
Balanced polymorphism
A
Maintaining variation
(Sickle cell and malaria), or negative frequency-dependent selection
13
Q
Comparative morphology
A
Structural similarities in “dissimilar” anatomies
14
Q
Is evolution a theory, law, or fact?
A
A theory, it is not a guess, it is well supported
15
Q
Law vs theory
A
Law describe, theory explains
16
Q
Micro vs macroevolution
A
Micro: changes within species, natural selection and other evolutionary forces
Macro: changes between species
17
Q
Transitional form example
A
(Whales were on land, but moved into water)
18
Q
Genotype vs phenotype relationship
A
Genotype is heritable portion of phenotype, and phenotype is affected by genotype and environment
19
Q
3 predictions for why we lost a chromosome
A
- We didn’t need it, it was lost
- The created distributed genes differently
- Fusion event
20
Q
Permineralization
A
Organism buried, deoxygenated environment w mud to make tissue into stone -> fossil
21
Q
5 types of fossil record
A
- Permineralization
- Imprints (underground aquifer)
- Petrified wood/plants
- Resin/sap turns to Amber
- Preserves from “recent time” (ice, permafrost, snow, peat moss)
22
Q
Radiometric dating
A
Using isotope half life to find precision on a particular finding
- use radiocarbon dating (C-14) for ~50,000 years
- use radioactive dating (Uranium - Lead) for >millions years
23
Q
What is half-life
A
Amt of time it takes for half of that isotope to change (C-14 -> N-14)
24
Q
Half life of C-14
A
5730 years
25
Transitional forms
Organisms that are long extinct but possess some combination of traits from different descendants
26
Retrodiction
Educated guess of past, based on what we know on evolution (used in biogeography)
27
Atavism
When a particular trait that was important in the past, in a mutant example, emerges in a common individual
28
Polytomy
Less studies, don’t know who is more closely related
29
Is phylogeny a law, theory, or hypothesis?
Hypothesis, that can change as we get new data
30
Vicariance
Lineage splits due to geological events (new islands, etc) not migration
31
Dispersal
Migration, gene flow, etc.
32
Sexual dimorphism
Differences in sizes of sexes
33
Homologous vs analogous
Homologous: same structure, look different
* similar origin
Analogous: same function, not same origin (evolved independently from common ancestor) -> convergent evolution
* similar function
34
Homoplasy
The outcomes of convergent evolution (analogous)
- not used in systematics
35
Convergent evolution. What can it be a result of?
2 or more different organisms independently evolve the ability to do the same thing
Can be a result of adaptive radiations that occur in allopatry (mammals and marsupials)
36
Gyroscope
To detect deviation of an object from its desired orientation (flies have 2 wings instead of 4)
37
Homoplasy example
Twisted winged parasite (only hindwings) and crane fly (only forewings)
38
Ancestral vs derived traits
Ancestral - trait present in ancestor of a group/clade
Derived - traits differs from close ancestral trait
-> derived traits are subset of ancestral (e.g. bird feathers are ancestral, but derived when considering all living vertebrates)
39
Synapomorphy
Derived traits shared among a group of descendants to show common ancestry
40
Monophyletic group
1 cut - includes common ancestor and ALL descendants
41
Paraphyletic group
2 cuts - includes common ancestor and some descendants
- reptiles
42
Polyphyletic group
3 or more cuts - does not include common ancestor
- flying, analogous structures
43
Morphological traits
- Features on skeletal system in vertebrates
- floral structures in plants
- exoskeleton in insects
44
Problems with morphology traits
- comparing distantly related species
- some variation due to environment
- some species look the exact same (few morphological differences)
45
Developmental traits. Problems?
Similarities in development patterns
(Some have yolk at embryo stage, but lost after)
- complicated to quantify
46
Paleontological traits
Fossils provide info on morphology of past organisms
47
Behavioural traits. Problems?
Can be inherited or culturally transmitted (frog calls)
- may not be useful for phylogenies
48
Molecular character traits. Problems?
- most important
- DNA, DNA and amino acid changes reflect evolution
- no environmental effect
- problem is only 4 states in nucleotides, 20 amino acids
- base changes may have evolved independently
49
Molecular clock
Number of mutations occurring in a gene sequence over time (number of substitutions)
50
How do you know which tree is more parsimonious?
Less occurrences of convergent evolution (make traits exist at 1 location instead)
51
When is molecular data useful?
If species all looked the same
52
How did Linnaeus describe species?
Based on appearance -> MORPHOLOGICAL SPECIES CONCEPT
- members of species look alike bc they share many alleles
53
Problem with morphological species concept?
Males and females may not look alike, immature individuals do not look like parents, etc.
54
Biological species concept. Problems?
Species is a group of organisms that can interbreed and produce fertile offspring
- problems are species may hybridize and produce fertile offspring, but can be different (like sterile mule created)
- plant cultivars (types of veggies)
- asexual organisms
55
Ecological species concept
Species is a group of organisms that share a distinct ecological area (different species use environment differently, become divergent in behaviour thus isolation)
56
Phylogenetic species concept
A species is a group of organisms bound by a unique ancestry
57
Hair on mammals compared to other vertebrates is an example of a:
Shared derived character
58
Explain the 2 types of isolation (important for speciation)
1. Prezygotic
- occurs when individuals of different species are prevented from mating
- isolation prior to mating (making zygote)
2. Postzygotic isolation
- occurs when individuals of different populations mate, but hybrid offspring have low fitness and do not survive or reproduce
- isolation occurs after fertilization
- polyploidy***
- sterile mule from horse and donkey
59
Limitations of Postzygotic isolation
- cannot be evaluated in fossils or asexual species
- can ONLY be applied to populations that overlap geographically (sympatry)
60
Allopatry
Means separate (populations that live in different areas)
- can be due to physical isolation by dispersal (animals moving) or vicariance (land separating)
61
Allopatric speciation
Speciation that begins with PHYSICAL isolation (dispersal or vicariance)
62
Dispersal. Problems? How does it cause speciation?
Population moves to new habitat, forms new population
- can reduce gene flow, chance of genetic drift, natural selection etc.
- population may die, not enough mates, low genetic variation, bad environment, etc. (but may survive)
63
Vicariance. Give detailed example
Physical barrier splits population
- no gene flow, no mating
- continental drift: Gondwana (Africa) supercontinent where ratite bird lived. Broke apart 140 million years ago creating new bird species (ALLOPATRIC SPECIATION)
64
Most common type of speciation
Allopatric (geographic barriers)
But can also use sympatry (living together)
65
Example of sympatric speciation
Hawthorn maggot fly, tree co evolved with fly
66
3 ways for speciation to occur
1. Allopatric
2. Sympatric
3. Polyploidy (mutation on chromosome, not just gene)
67
Explain 2 types of polyploidy
1. AutoPolyploidy
- chromosome duplications within 1 species
- unreduced gametes, error in meiosis
- odd chromosome numbers usually sterile (except plants and fungi)
2. Allopolyploidy
- chromosome duplications between 2 different closely related species
- doubling of hybrid species chromosomes, make them FERTILE
- ANOTHER FORM OF POSTZYGOTIC ISOLATION (product of hybrids not viable)
- evolution of wheat is product of polyploidy
68
Chromosome alterations
Big mutations, closely related species differ in chromosomal arrangement (humans and chimps)
69
Possible outcomes for isolated populations coming into contact, and can interbreed?
- Reinforcement (process of speciation where natural selection increases the reproductive isolation between two populations of species)
- development of hybrid zones
- speciation by hybridization
70
Hybrid zone
Where hybrid offspring are made (2 species come back together after isolation)
71
Reinforcement
Maintains speciation (Postzygotic isolation) -> hybrid offspring don’t develop or reproduce normally (STRONG NATURAL SELECTION AGAINST INTERBREEDING)
72
Sympatric vs. allopatric species
Sympatric - close relatives living in same area and rarely mate
Allopatric - close relatives living in different areas and can mate
73
Are protists mono, para, or polyphyletic?
Paraphyletic (cut out fungi, plants and animals)
74
When did protists evolve?
1.5 - 2 billion years ago
75
Are protists more related to humans or bacteria?
Humans
76
Why are protists different from plants and animals?
- unicellular
- can also live as heterotrophs
- no embryo protection (seed)
- no digestive tract, no collagen
77
Sexual reproduction with meiosis (in protists)
- can live in haploid phase or diploid phase more (if it’s not safe, stay in haploid phase - less food and energy needed)
78
Contractile vacuole
How protists expel waste (pumps water to prevent lysis)
79
Pellicle
Layer of supportive protein fivers under plasma membrane in protists (supportive / protective structure)
80
Pseudopodia
Motility by moving cell wall
81
Symbiosis
When individuals of 2 different species live in physical contact (mutually benefit each other)
82
Endosymbiosis
When organism of one species lives within another organism
83
Endosymbiosis theory
Proposes that mitochondria originated / evolved when bacterial cell took up residence inside eukaryote 2 billion years ago
84
What causes evolution?
Endosymbiosis
85
What organelle followed same endosymbiosis theory as mitochondria?
Chloroplasts
86
Opisthokonta
Eukaryotes including animals and fungi
- have single posterior flagellum at some stage in life cycle (sperm -> haploid stage in animals)
87
Choanoflagellata
- collar of microfilm surrounding flagellum
88
List the 3 super kingdoms
1. Opisthokonta
2. Amoebozoa
3. Archaeplastida
89
Amoebozoa
- Amoebas
- found in marine, people, soil
- some parasitic
- heterotrophs (feed on bacteria, other protists, organic matter)
- asexual, single celled
- key trait: shapwshift
- plasmodia slime moles
-> exist in haploid phase and undergo repeated mitosis to become large cell w MANY nuclei
- produce spores
90
Coenocytic
Contain many nuclei within one giant cell
91
Archaeplastida
- includes plants
- red algae, mostly marine (saltwater), multi cellular -> walls made of cellulose
- green algae, mostly aquatic, symbiotic relationships w fungi (lichen) or animals
***genomes most similar to true plants)
92
Stramenopiles
- another mostly photosynthetic kingdom
- brown algae, photoautotrophs
- multicellular marine forms (including kelp)
93
Kelp
Largest, most complex protists
94
Genetic tool kits
Turn developmental genes on or off (NEVER CHANGE) selection is so strong to keep it regular
95
Form and development in variation
Variation in form comes from variation in development
96
“Evo-Devo”
Evolutionary developmental biology
- evolution in genes of embryonic development
-> also regulate morphology
97
Homeotic genes
- control transcription of developmental genes (turn on or off)
- small changes can make large changes in morphology
98
Hox genes
Control animal body plan (type of homeotic gene)
99
Homeobox in Hox genes
180 specific nucleotide DNA sequence
- shared by several genes in morphogenesis (origin and devel. of morphological traits)
- codes for homedomain proteins -> turn gene expression on in early embryonic development
100
Gene for formation of appendages in many species
Distal-less (dll)
101
What genes influence spine development?
Pitx1 in mice, early embryos
102
What fish has variation in spines. How?
Stickleback
- degeneration of Pitx1 leads to decrease in expression in hindlimb
103
Genome
Entire set of DNA / genetic info of an organism
