1
Q
be able to define evolution.
A
- change over time
- descent with modification
- change in genetic composition of a population from generation to generation
- species change over time - the accumulation of inherited changes within populations over time
2
Q
know the difference between a population and a species
A
- Population: a group of one species that live in the same geographic area at the same time
- Species: group of individuals with similar structure, function, and behaviors that have the ability to interbreed with one another
3
Q
know the observations of Darwin’s theory of evolution
A
- the many shared characteristics (unity) of life; he attributed unity to common ancestry
- the ways in which organisms are suited for life in their environments; he suggested descendants live in a variety of environments and accumulate adaptations
- adaptations - inherited characteristics of organisms that enhance their survival and reproduction in a specific environment
- the rich diversity of life; over long periods of time descent with modification led to diversity
4
Q
know Lamarck thinking and why it is incorrect
A
- theory - that the use and disuse of body parts - of the body that are used extensively become larger and stronger (known as acquired or learned characteristics), while those that are not used deteriorate. that organisms can pass on acquired characteristics to their offspring
- the is false because inherited traits are determined by genes of parents not acquired traits during the parents life
5
Q
be able to define natural selection and adaptation
A
•a process in which better adapted organisms are more likely to survive and become the parents of the next generation because of those adaptations
6
Q
know the evidence that supports the theory of evolution
A
- direct observations - ie introduced plant species and soapberry bug beaks (the beak size changed in result in the new food) or drug resistant bacteria (MRSA)
- comparative anatomy of species - homologous structures (homology); homoplastic (analogous) structures (the result of convergent evolution); anatomical similarities in vertebrate embryos; vestigial structures
- Fossil record - remains or traces of previously existing organisms
- biogeography - the distribution of living things; influenced by continental drift, the slow movement of earth’s continents over time
- molecular comparisons - proteins, DNA and RNA; shows how closely related; genetic code is universal indicating a common ancestor; used to create evolutionary trees
7
Q
be able to explain the four observable patterns of the natural world that Darwin’s Theory of Evolution explains
A
- overproduction - organisms are capable of producing more offspring than can survive to reproductive age
- variation inherited - members of a population vary and some of these variations are heritable
- competition - resources available to a population are limited
- differential reproductive success - individuals that are well suited to their environment tend to leave more offspring than other individuals. Over time, favorable traits accumulate in the population
8
Q
what are homologous features?
A
•similar structures that may have different functions but have common ancestor
9
Q
what are homoplastic features?
A
•similar structures and functions but not common ancestry
10
Q
what is convergent evolution?
A
•independent evolution of similar structures in distantly related organisms
11
Q
what are vestigial structures?
A
- remnants of features that served important functions in the organism’s ancestors
- structures persist as there is no selective pressure to eliminate them
12
Q
why are the theories of continental drift and plate tectonics important to the theory of evolution? (biogeography)
A
- Since the the slow movement of the Earth’s continents over time influences the evolution of living things.
- How what was once a connected land mass is divided taking the animals with it
13
Q
what is phylogeny?
A
•the evolutionary history of a species or group of related species
14
Q
how is molecular data used to support evolution?
A
- Analysis of nucleotide and amino acid sequences; can see how protein evolved; shows how closely related
- Genetic code is universal indicating common ancestor
15
Q
how can evolutionary hypothesis be tested?
A
- basically the scientific studies:
- direct observations
- comparative anatomy of species
- fossil records
- biogeography
- molecular comparison
16
Q
be able to define taxonomy and taxon
A
- Taxonomy: science of naming and classifying organisms
* Taxon: a taxonomic unit at any level of hierarchy
17
Q
describe the binomial system of naming organisms
A
- two parts names for species consist of a genus and specific epithet name
- both names used together to correctly identify the organism
18
Q
know the 3 domains of life, and the 6 kingdoms
A
- Domains: bacteria, archaea, eukarya
* Kingdons: eubacteria, archaeabacteria, plantea, fungi, animilia, protista
19
Q
be able to interpret phylogenetic trees (cladograms), describing the meaning of its specific nodes branches
A
•a phylogenetic tree represents a hypothesis about evolutionary relationships
•each branch point represents the divergence of two evolutionary lineages from a common ancestor
•hatch mark represents a homologous characteristic shared by all the groups to the right of the mark
•sister taxa are groups that share an immediate common ancestor
a rooted tree includes a branch to represent the last common ancestor of all taxa in the tree
•a basal taxon (out group) diverges early in the history of a group and originates near the common ancestor of the group
•a polytomy is a branch from which more than two groups emerge
•tree branches can by rotated around a branch point without changing their evolutionary relationships
•the more recent the ancestor you share the more closely related
20
Q
be able to define systematics
A
•discipline which classifies organisms based on shared characteristics to depict their evolutionary relationships
21
Q
be able to define and identify on a phylogentic tree shared ancestral (primitive) character, shared derived character, sister taxa, and basal taxon.
A
- Phylogenetic tree: a diagram that reflects evolutionary relationships among groups of organisms
- shared ancestral (primitive) character: traits that originated in the ancestor of the taxon
- shared derived character: an evolutionary novelty unique to a group
- sister taxa: groups that share an immediate common ancestor
- basal taxon: diverges early in the history of a group and originates near the common ancestor of the group
22
Q
contrast monophyletic, paraphyletic, and polyphyletic taxa
A
- monophyletic group (clade): a group of species that includes an ancestral species and all of its descendants
- paraphyletic group: a group that contains a common ancestor and some, but not all of its decendants
- polyphyletic group: consists of several evolutionary lines and not including a common ancestor
23
Q
know the difference between genotype, phenotype, allele and gene.
A
- genotype :genetic markeup, combination of alleles
- phenotype: physical appearence
- allele is the genes governing variation of the same character that occupy corresponding psitions (loci) on homologous chromosomes
- gene is a segment of DNA that serves as a unit of hereditary information; includes transcribable DNA sequences that yields a protein or RNA product with a specific function.
24
Q
be able to define gene pool, fitness, microevolution, and mutation
A
- gene pool: all of the alleles for all loci in a population
- fitness: an individuals reproductive succes, measured by the number of viable offspring it produces
- microevolution: small-scale evolutionary change caused by changes in allele or genotype frequencies that occur within a population over a few generations
- mutation: a change in nucleotide sequence of DNA
25
what is genotype frequency?
•proportion of a particular genotype in the population
26
what is allele frequency?
•proportion of a particular allele in the population (# of a particular allele/ total number of alleles for that loci in ht population)
27
what is genetic equilibrium?
•a condition of a population that is not undergoing evolutionary chance (like for generation to generation)
28
what is the Hardy-Weinberg principle?
•the frequency of allels and genotypes in a population will remain constant from generation to generation if the population is stable and in genetic equilibrium
29
Know the Hardy-Weinberg equations
•p^2+2pq+q^2=1; p+q=1; (population)#x2=(#alleles)
30
what are the 5 conditions for gentic equilibrium?
* random mating
* no net mutation
* large breeding population
* no migration
* no natural selection
31
what is inbreeding?
•mating of genetically similar individuals. homozygosity increase with each successive generation of inbreeding
32
what is assortative mating?
•individuals tend to choose mates similar to their selves
33
when can mutation be beneficial to a population?
* increase variation within a population
| * provide the raw material for evolution as it introduces variation
34
what is genetic drift?
•random events change allele frequencies
35
what occurs when a population experiences bottleneck?
•a sudden reduction in population size due to a change in the environment
36
what is the founder effect?
•occurs when a few "founders" establish a new colony
37
How does natural selection work?
* over time, natural selection can increase the match between organisms and their environment
* natural selection does not create new traits, but edits or selects for traits already present in the population
* the local environment determines which traits will be selected for or selected against in any specific population
38
what are the three types of natural selection?
* directional selection
* disruptive selection
* stabilizing selection
39
what is sexual selection?
•form of selection is which individuals with certain inherited characteristics are more likely than other individual to obtain mates
40
why is genetic variation a benefit to a population and how is it preserved?
* variation in heritable traits is a prerequisite for evolution
* preservation of genetic variation: diploidy maintains genetic variation in the form of hidden recessive alleles; balancing selection occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population
41
what is the heteroxygote advantage?
•heterozygote advantage - occurs when heterozygotes have a higher fitness than do both homozygotes
42
give an example of frequency-dependent selection
* means the fitness of a phenotype depends on how common it is in the population
* IE scale eating fish; the fitness of a phenotype declines if it becomes too common in the population; prey with uncommon characteristics may be ignored by predators
43
what is species?
•a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring
44
understand the biological species concept
* different species do not breed sucessfully with other populations
* gene flow....the absence there of plays a key role in the formation of new species as well as in keeping them apart once their potential to interbreed has been reduced
45
understand the morphological species concept.
* defines a species by structural features
| * it applies to sexual and asexual species but relies on subjective criteria
46
understand the ecological species concept (note: definded in lecture notes)
* views a species in terms of its ecological niche
| * the sum of how members of the species interact with the nonliving and living parts of their environment
47
understand the phylogenetic species concept
* defines a species as the smallest group of individuals on a phylogenetic tree
* can be difficult to determine the degree of difference required for separate species
48
why do modern biologist use the biological species concept more than the evolutionary species concept?
•it is difficult to decide if evolutionary similar based on genetics
Where if we say if organisms interbreed and produce fertile offspring they are will be genetically similar
49
what is reproductive isolation?
•the existence of biological factors (barriers) that impede two species from producing viable, fertile offspring
50
what effect does reproductive isolation have on evolution?
•the barriers block gene flow allowing for differences in evolving species
51
what is a prezygotic barrier to reproduction?
•blocks fertilization from occurring by impeding different species from attempting to mate
52
know the different types of prezygotic barriers
* habitat isolation: two species encounter each other rarely, or not at all, because they occupy different habitats even though not isolation by physical barriers
* temporal isolation: species that breed at different times of the day, different seasons, or different years cannot mix their gametes
* behavioral isolation: courtship rituals and other behaviors unique to a species are effective barriers
53
do either pre- or postzygotic barriers ever result in offspring? If so, which one(s)?
* postzygotic barriers could result in offspring
* reduced hybrid fertility, like Mules, are sterile
* hybrid breakdown like certain rice it starts to break down after the 2nd or 3rd generation
54
what is the difference between hybrid sterility and hybrid breakdown?
* Hybrid sterility is when the first generation hybrid may be robust but can not produce offspring
* hybrid breakdown is when the first-generation hybrids are fertile, but when they mate the offspring of the next generation are feeble or sterile
55
what is speciation?
•the process by which one species splits into two or more species
56
what is allopatric speciation?
•gene flow is interrupted or reduced when a population is divided into geographically isolated subpopulations
57
what is sympatric speciation?
•speciation takes place in geographically overlapping populations
58
which type is more common (allopatric or sympatric)? Why?
•allopatric speciation since sympatric is by chance in plants only
59
what is polyploidy?
•the condition of having more than two sets of chromosomes per nucleus
60
what types of organisms are typically polyploids?
•typically plants
61
how does polyploidy occur?
•when meiosis goes wrong and chromosomes do not separate correctly
62
what is hybridization?
•when two different species produce an offspring
63
know the difference between puncturated equilibrium and gradualism.
* punctuated equilibrium: describes periods of apparent stasis punctuated by sudden change
* Gradulism: species diverge from one another continuously over time
64
what is macroevolution?
•is the evolution of the entire population over time
Biology 212
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