Bio Midterm 2 Flashcards
(49 cards)
1
Q
- Change in allel frequencies in a pop
- Shorter time
- Mutation, gen drift, gene flow and selection cause it
- Small changes hard to observe
- Can be applied to Hardy-Weinberg
A
Microevolution
2
Q
- Large visible changes that happen above species level
- Caused by extended microevolution
- Takes millions of years
- Visible through fossil records
A
Macroevolution
3
Q
Change in genetic make-up of populations over time, sometimes resulting in adaptation to the environment and the origin of new species.
A
Evolution
4
Q
Variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences, Response to environment
A
Environmental Variation
5
Q
Variation of genomes between individuals in the same species
A
Genetic Variation
6
Q
An organisms unique genetic makeup which cannot be observed. Like DNA or a flower being a BB vs Bb homozygote or heterozygote
A
Genotype
7
Q
An observable trait that is the result of genetics. If a BB flower is purple and a bb is white
A
Phenotype
8
Q
- Characteristics with distinct states (green vs blue eyes)
- Polymorphisms: Distinct variants of character (black vs red lady bugs and the benefit on their survival)
A
Qualitative Variation
9
Q
- Wide variation with minimal selective pressure
- Difference in things like height
- This similarity within a species is because the environment allows for only one colouration to be necessary as it allows for camouflage
A
Quantitive Variation
10
Q
- A characteristic, such as height or skin color, that is influenced by two or more genes. Because multiple genes are involved
A
Phenotypic Variation
11
Q
The presence of two or more variant forms of a specific DNA sequence that can occur among different individuals or populations
E.X
Indv 1: AACTTGG
Indv 2: AACTACG
A
Polymorphism
12
Q
- Alteration in gene frequency due to migration
- Occurs due to interbreeding with adjacent populations and the exchange of genes
- Happens more often in large populations
A
Genetic Flow
13
Q
- Alteration in gene frequency by pure chance
- Occurs to accidental and sudden elimination of a particular gene
A
Genetic Drift
14
Q
- An event that drastically reduces the size of a population such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms
A
Population Bottleneck
15
Q
- The reduced genetic diversity which results when a population is descended from a small number of colonizing ancestors.
A
Founders Effect
16
Q
- A mode of negative natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype
A
Directional Selection
17
Q
- A form of natural selection in which extreme values for a trait are favored over intermediate values, causing subpopulations of a single species within the same habitat to develop different adaptations. E.g white and black moths
A
Disruptive Selection
18
Q
- A form of natural selection that occurs when multiple alleles are maintained in a population, which can result in their preservation over long evolutionary time periods.
A
Balancing Selection
19
Q
What are the 5 conditions for Hardy-Weinberg
A
There must be:
1. Random mating
2. No mutation
3. No migration
4. No natural selection
5. A large sample size
20
Q
- A useless body part / function
A
Vestigial
21
Q
- Horizontal layering of sedentary rock with different fossils in different layers
A
Stratification
22
Q
- The process in which an organism is buried and filled with mineral rich waters and the tissue turns to stone (cells are filled with the water and become rock) resulting in fossils
A
Permineralisation
23
Q
- Visual diagram that represents hypotheses on evolution
- Branches represent time
- Combined with behaviour, ecology or morphological data
- Uses fossil record to determine time periods of speciation
A
Phylogenetic Trees
24
Q
- A lineage splits due to geological events (continents break up, new islands, mountain ranges that separate)
A
Vicariance
25
- Same structure but serve different purposes, result of common ancestor
Homologous Trait
26
- Traits with same function but with different origin (Not useful for phylogenetic trees)
Analogous Trait (Homoplasic)
27
- When two or more organisms independently evolve a trait that serves the same function (wings to fly)
Convergent Evolution
28
- The accumulation of differences between closely related populations within a species, leading to speciation.
- Like how finches have different beak shapes on the Galapagos
Divergent evolution
29
- Derived traits shared among a group of descendants and are viewed as evidence of the common ancestry of the group
- E.X mammary glands in mammals
Synapomorphy
30
- A novel character or character state that has evolved from its ancestral form (or plesiomorphy)
Apomorphy (derived trait)
31
- A group in a phylogenetic tree that requires two cuts from the root
- Consists of most recent common ancestor but not all of the descendants
- Homoplasic
Paraphyletic Group
32
- A group in a phylogenetic tree, sometimes called a clade, includes an ancestral taxon and all of its descendants.
- Homologous
Monophyletic Group
33
- A group in a phylogenetic tree of organisms, or other evolving elements, that is of mixed evolutionary origin, sharing more than one common ancestor. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution.
Polyphyletic Group
34
- The number of changes, or mutations which accumulate in the gene sequences of different species over time is relatively constant
- Each DNA sequence has a different clock tick (mosaic evolution)
- Can be calibrated to fossil record
- Molecular differences between pairs of species are proportional to the time of their separation and we can index the time of divergence between species
Molecular Clock
35
- A species is a group of organisms that share a distinct ecological niche
Ecological Species Concept
36
- A species is a group of organisms bound by unique ancestry
Phylogenetic species concept
37
- Occurs when individuals of different species are prevented from mating. Must breed in different places, different times
- Sexual selection - females only attract the same species, genetic incompatibility
- When does not exist, populations may successfully interbreed
- Gene flow then occurs and may erase distinctions between the two populations
- Other possible outcomes are reinforcement, development of hybrid zones
Prezygotic Isolation
38
- Occurs when individuals from dif pops do mate, but the hybrid offspring produced have low fitness and do not survive or produce offspring. Polyploid
Limitations are:
- The criterion of reproductive isolation cannot be evaluated in fossils or in species that reproduce asexually
- Can only be applied to populations that overlap geographically
Postzygotic Isolation
39
- When species live in separate areas
- _____ speciation results in genetic isolation, genetic divergence due to mutation, natural selection and genetic drift
Allopatry, Allopatric
40
- When species co-inhabit the same area
- Under some circumstances natural selection can overcome gene flow and cause _____ speciation
Sympatry, Sympatric
41
A geographic area where interbreed between two pops occurs and hybrid offspring are common
Hybrids often lead to extinction
Possible outcomes:
- Reinforcement
- Fusion
- Stability
Hybrid Zone
42
- Maintains speciation / divergence from common ancestor, hybrids have lower fitness. postzygotic isolation, strong natural selection against interbreeding. In sympatric species close relatives seldom willing to mate with one another. Allopatric species close relatives seldom are often willing to mate with one another
- Hybridisation is continuous and genetic distinctness decreases
Reinforcement
43
- Members of the two lineages mate together, forming hybrids with normal fitness, and eventually collapse into one species.
Fusion
44
- Each lineage maintains its own range separate of each other save for some areas of overlap. In those regions, the hybrids have reduced fitness and the hybrid zone is maintained by immigration from adjacent parent populations.
Stability
45
What is the order of animal kingdom classification
kingdom > phylum > class > order > family > genus > species
46
- The heritable condition of possessing more than two complete sets of chromosomes.
Polypoidy
47
- A type of prezygotic barrier where the gametes (egg and sperm) come into contact, but no fertilization takes place
Gametic Isolation
48
- A type of reproductive isolation mechanism among sexual organisms in which the differences in the timing of critical reproductive events prevent members of closely related species, which could otherwise breed with one another, from mating and producing hybrid offspring.
Temporal Isolation
49
- A character shared across clades in a phylogeny that don't share direct ancestry
Homoplasies
