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Evolution Flashcards

(59 cards)

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1
Q

Genetic Bottleneck

A

Loss of genetic diversity in a population, usually due to some disaster, type of genetic drift

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2
Q

Assortative Mating

A

Mate selection based on a phenotypic trait, e.g. female mate choice, type of sexual selection

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3
Q

Inbreeding

A

Mating of closely related individuals, often detrimental, inbreeding depression, type of sexual selection

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4
Q

Founder Effect

A

A sample isolated from the parent population genetically diverges, type of genetic drift

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5
Q

Genetic Drift

A

Changes in allele frequencies due to random selection, greater effect in smaller populations, can lead to speciation

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6
Q

Gene Flow

A

Exchange of genes between populations, usually through migration (yet they must reproduce in the new population), can homogenize different populations and gene pools

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7
Q

Types of Natural Selection

A

Stabilizing, Directional, and Disruptive

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8
Q

Biological Species Concept

A

Reproductively compatible, can produce fertile offspring

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9
Q

Morphological Species Concept

A

Similar physical traits

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10
Q

Ecological Species Concept

A

Defined by the ecological niche

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11
Q

Phylogenetic Species Concept

A

Smallest group of individuals that share a common ancestor

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12
Q

Natural Selection

A

Frequency of traits changes in a population, reflects differences in survival and reproduction, leads to adaptation and possible speciation over time

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13
Q

Mutation

A

Alteration in DNA, introduces variation into the population, fundamental building block of evolution

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14
Q

Types of Evolutionary Mechanisms

A

Can either increase or decrease genetic diversity, mutation // natural selection // gene flow // genetic drift // sexual selection, only acts on a population scale

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15
Q

Vestigial Structures

A

Structures that are fully functional in one species and reduced or nonfunctional in another species

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16
Q

Endemism

A

Species found only in a specific geographical location, result of low dispersal rates often, stems from speciation

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17
Q

Analogous Structures

A

Similar in function, but not in structure, does not stem from shared ancestry, result of adapting to similar environmental pressures

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18
Q

Convergent Evolution

A

Distantly related species evolve similar traits to meet similar needs

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19
Q

Homologous Structures

A

Similar features now adapted for different functions, result of common ancestry

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20
Q

Divergent Evolution

A

Single species evolves into 2 or more distinct species with different traits, shared ancestry

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21
Q

Allopatric Speciation

A

The most common, result of a geographical isolated gene pool that prevents gene flow and leads to a new species, result of vicariance, or fragmentation caused by the environment

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22
Q

Peripatric Speciation

A

A small section of the original population separates and forms a new species, e.g. through colonization, not necessarily through an environmental change

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23
Q

Parapatric Speciation

A

A species within a large geographic area only interbreeds within sub-populations that are in the closest proximity to them, result of reproductive isolation and different habitats

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24
Q

Sympatric Speciation

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A

A new species evolves from an ancestral species without geographic isolation, both continue to occupy the same area, not from reproductive isolation either, it is debatable

25
Microevolution
Small-scale changes in allele frequency, few generations, within a population, observable
26
Macroevolution
Large-scale changes in allele frequency, at or above the species level, and not directly observable
27
Acclimation
Also known as phenotypic plasticity, often reversible phenotypic changes corresponding to environmental conditions
28
Adaptation
Permanent phenotypic expression, resulting from specific environmental conditions
29
Evolution
A change in inherited traits within a population, individuals do not evolve, only populations through gene pools
30
Taxonomic Hierarchy
Broad to narrow: Domain // Kingdom // Phylum // Class // Order // Family // Genus // Species, last two make up binomial nomenclature
31
Taxon (plural: taxa)
Grouping of organisms, broad or specific
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Phylogeny
Classifications based on evolutionary history, also broad to narrow, based on hypotheses of relatedness
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Ancestral (Primitive) Characters
Originated in an ancestor
34
Derived Characters
Unique evolutionary novelties and traits for that branch
35
Cladograms
Show evolutionary relationships by branching at derived characters (nodes) to demarcate different groups
36
Clade
A shared group on a cladogram, so all of the descendants with a certain trait or suite of traits
37
Evolution
A change in inherited traits within a population, individuals do not evolve, only populations (gene pools), often random
38
Why Study Evolution
Conservation efforts, ecology can affect evolutionary change and vice versa, adaptive evolution allows the exploitation of new environments
39
Causes of Speciation/Endemism
Geologic age of an area (e.g. “ancient lakes”), geographic isolation (physical barriers), lack of dispersal ability
40
Allopatric Pathway
Barrier formation, then in isolation
41
Peripatric Pathway
New niche entered, then in isolated niche
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Parapatric Pathway
New niche entered, then in adjacent niche
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Sympatric Pathway
Genetic polymorphism, within the population
44
Infraorder Cetacea (higher taxa)
Animalia (kingdom), Chordata (phylum), Mammalia (class), Artiodactyla (order)
45
Infraorder Cetacea (lower taxa)
Parvorders: Archaeoceti (extinct), Mysticeti (baleen whales), Odontoceti (toothed whales, dolphins, and porpoises)
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Infraorder Cetacea (traits)
Blowhole, dorsal fins, flippers, flukes // Baleen in mysticeti // Melon and teeth in odontoceti // Evidence of hindlimbs in embryos and as vestigial bones
47
Family: Raoellidae
ONE 1 Earliest relative of the cetaceans, yet not a true cetacean // Found in the Himalayas (Pakistan and western India), mostly terrestrial // Heavy bones like aquatic waders (osteosclerotic limbs) // Signature shape of ear bone to later cetaceans (thicker inner ear wall than external ear wall) // Known from teeth and jaw bones From Order: Artiodactyl
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Genus: Indohyus
From the family raoellidae
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Parvorder: Archaeoceti
Earliest cetaceans were amphibious, ancestors similar to small deer, fossils in India and Pakistan (Tethys Sea)
50
Family: Pakicetidae
TWO 2 Pakistan and India, comprise three genera (Ichthyolestes, Pakicetus, Nalacetus), eyes close together towards the top of the skull, wear on teeth indicates piscivore diet, shallow water waders, ear and bones the same
51
Family: Ambulocetidae
THREE 3 Pakistan & India, walking and swimming, same bones, ambush predators, similar limb proportions to river otters, muscular tail and short and powerful legs, lived in brackish waters
52
Family: Remingtonocetidae
FOUR 4 Pakistan, India, & Egypt, all characterized by a long snout (2/3 of the skull), different diet from earlier cetaceans, very small eyes and large ears, short legs and a very long, strong tail
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Family: Protocetids
FIVE 5 Found in Asia, Africa, Europe, & North America, 15 genera with diverse features, all have similar eye morphology and nasal opening located more posteriorly Could still move on land but spent a lot of time in water, near shore species
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Family: Basilosauridae
SIX 6 Global distribution, first obligate aquatic cetaceans [blowhole, flippers for forelimbs, small tail fluke, tiny hind limbs], still have heterodont dentition
55
Two Main Body Types of Basilosauridae
Long and snakelike // Short(er) and dolphin-like
56
Modern Cetaceans (Neocetes)
SEVEN 7 Global distribution, mysticeti and odontoceti are the two parvorders, yet tens of different species
57
Mysticeti
Baleen whales, the baleen is a keratinous plates, earliest mysticetes had teeth, baleen evolution and filter feeding occurred in stages
58
Odontoceti
Includes dolphins, porpoises, and other whales that still have teeth, more diverse than mysticeti, echolocation is key in their evolution and diversification, bioonar used in finding prey, development of melon results in unique skull
59
Operational Taxonomic Units
Particularly in the case of microbes, a classification that avoids definitive statements on evolution

Life Aquatic (18 decks)

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