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100 Cards in this Set
- Front
- Back
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A system of accepted assumptions and principles
that explains a specified set of facts |
Theory
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Provisional assertion or supposition!
used as basis for reasoning or experiment! Subject to testing ---> falsification or validation! |
hypothesis
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Something known with certainty
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fact
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Organisms are transformed through time,!
sometimes in ways that seem directional! The world is neither constant nor perpetually cycling! This theory was accepted rapidly among! both scientists and knowledgeable lay-persons! |
evolution
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a.k.a. branching
Species are related in a nested fashion: apes and humans have a common ancestor hominoids and Old World Monkeys have a common ancestor! etc etc back to animals and plants ……..! |
common descent
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similarity due to convergent evolution!
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homoplasy
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similarity (genetic!
or phenotypic) because of! descent from common ancestor! |
homology
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includes genera Homo, Pan, Papio
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primates
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includes Primates, Artiodactyla, Rodentia
*Mammals are a clade of warm-blooded amniotes. Among the features that distinguish them from the other amniotes, the reptiles and the birds, are hair, three middle ear bones, mammary glands in females, and a neocortex |
mammalia
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1. Struggle for existence; intense competition.!
2. Individuals within a population vary.! 3. This variation can be inherited, passed from parent! to offspring.! 4. Due to the variation in traits some individuals! are better able to survive and reproduce than others! (differential reproductive success) and are therefore! naturally selected.! |
Darwin’s Theory of Evolution by Natural Selection
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The relative ability of an organism !
to survive and transmit its genes! to the gene pool of the next generation! |
fitness
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useful feature shaped by natural selection!
promoting survival and reproduction |
adaptation
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Variation is new in each generation and selection!
can only work with what is present! |
selection is contingent
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Environmental (broadly defined) challenges!
constantly vary |
selection is opportunistic
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tend to be harder and more difficult to obtain!
as well as being of lower quality: hard seeds, etc.!(finches) |
fall back foods
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tend to be softer and easily obtained: !
fruits, flowers, nectar, pulp, blood, etc.!(finches) |
preferred foods
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Most controversial of!
Darwin’s theories.! Not universally accepted! for almost a century. ! Problems:! 1. Needed genetics ! 2. Extravagant traits |
natural selection
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Expressed in F1 generation!
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dominant trait
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Masked in the F1 generation
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recessive trait
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material particles of inheritance
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genes
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variants of genes
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Alleles
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individuals have 2 similar alleles
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Homozygous
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individuals carry 2 different alleles
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heterozygous
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The genetic composition of an individual,
or the genetic composition (DNA sequence) at a specific locus! |
genotype
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The observable characteristics of an
individual. Individuals with the same phenotype may have different genotypes. ! |
phenotype
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egg or sperm)
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gamete
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Each particle (gene) is equally likely to be
transmitted to sex cells (gametes). |
law of segregation
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carry hereditary material
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chromosomes
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Gametes are formed through
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meiosis
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In ____ organisms,
chromosomes occur in ____ pairs.! |
Diploid, Homologous
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• Particles or genes that control different traits
assort independently! • Sexual reproduction shuffles genes that affect different traits and thereby produces new combinations of traits, a phenomenon called recombination. Helps preserve variation |
Mendel’s Law of Independent Assortment!
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Two important properties of DNA
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1. Stability!
!Faithfully preserves the genetic message! 2. Replicability! !Ensures inheritance! |
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DNA codes for....
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protien
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are the constituents of all biological
structures. |
Protien
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Deviation from Hardy-Weinberg equilibrium implies!
a. Mendel’s experimental results were incorrect! b. No change in allele frequency has occurred in study population! c. The population is evolving! d. All of the above! e. None of the above! |
C. the population is evolving
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Natural selection usually acts on?
a. Genes b. Chromosomes c. Individuals d. Populations e. Species |
individuals
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Ancestral characters are traits that!
a. Have evolved after the last common ancestor of a particular collection of species! b. Characterize the last common ancestor of a particular collection of species! c. Are less well suited to the environment than derived characters! d. Are due to convergent evolution! e. Are less specialized than derived characters |
Characterize the last common ancestor of a
particular collection of species! |
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Which of the following is a primate characteristic?!
a. Well-developed visual abilities! b. Increased litter size! c. An extended period of juvenile development! d. All of the above! e. A and C only! |
A and C only
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List the four tenets of Darwin’s theory of natural
selection.! 1.! 2.! 3.! 4.! |
1. Struggle for existence; intense competition.!
2. Individuals within a population vary.! 3. This variation can be inherited, passed from parent! to offspring.! 4. Due to the variation in traits some individuals! are better able to survive and reproduce than others! (differential reproductive success) and are therefore! naturally selected.! |
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describes the acquisition of the same biological trait in unrelated lineages.
The wing is a classic example . Flying insects, birds, and bats have all evolved the capacity of flight independently. |
convergent evolution
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one population of one species became two species while in the same geographic region with no physical separation
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sympatric
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is a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction.
Favors extreme phenotypes by moving the mean phenotype and acting against another extreme |
Directional selection
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favors intermediate phenotype by acting against extreme phenotypes
The phenotype frequency curve will have one hump in the middle |
stabilizing selection
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Ex. the average weight of a newborn human is 7.02lbs. Those born weighing less than 4.5lbs. or above 10lbs. tend to have a lower survivability than those born around the mean weight
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stabilizing selection
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Ex. a group of plants lives in an area where there is usually very little wind. If suddenly a lot of heavy wind blows on the plants, then the phenotype frequency curve will most likely shift towards shorter plants, since they can withstand wind better than tall plants
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Directional selection
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evolutionary change that occurs because
of variation in (often male) ability to acquire mates. ! Emphasizes mate acquisition (not survival): how you attract mates and/or keep sexual rivals from mating. ! |
Sexual Selection
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Each allele is equally likely to be transmitted to gametes:!
1. Only one homologous chromosome is inherited from each parent! 2. Each chromosome is equally likely to appear in offspring! |
Mendel’s law of segregation
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Daughter cells possess
exact copies of parent cell’s chromosomes! |
Mitosis
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Daughter cells (gametes)
contain only half the number of chromosomes in parent! |
meiosis
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generates new
combinations of genes and hence new variation. |
crossing-over
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meiosis, however,
chromosomes sometimes ______, with genes from one chromosome shifted over to the homologous chromosome. |
cross over
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Each gene occurs at a specific site called a
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locus
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Each of the 20 _____ is determined by a
sequence of 3 of the 4 DNA base |
amino acids
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three-nuclotide sequence on messenger RNA that codes for a single amino acid
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codon
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DNA that codes for proteins
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exon
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noncoding regions of DNA
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introns
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Molecular geneticists estimate that 95% of DNA is
found in introns. Thus, evolution of the vast majority of human DNA is not affected by natural selection. This is important because it allows us to date distant evolutionary events using changes in the DNA molecule |
molecular clock
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In populations of interbreeding individuals
that follow the laws of Mendelian inheritance, and who mate randomly, gene frequencies remain constant over generations, i.e. they remain at equilibrium |
Hardy-Weinberg Law
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The movement of genes in and out of a population
Increase genetic variance Lack of ____ between two closely related populations maintains a species. |
Gene Flow/ Migration
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What factors cause evolutionary change?!
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1. Natural selection!
2. Mutation! 3. Migration -- Gene flow! 4. Genetic drift (founder effect)! 5. Non-random (assortative) mating! Modern synthesis! |
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1. Natural selection
2. Mutation 3. Migration -- Gene flow! 4. Genetic drift 5. Non-random mating These forces change gene frequency through time. These ________processes affect morphology, physiology, and behavior of individuals within populations. |
Microevolution
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process account for the evolution of new species and higher taxa.
_______ questions: 1. How are new species created? 2. How do species change over time? |
macroevolution
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Species = groups of potentially or actually inbreeding
organisms that are reproductively isolated from others This definition emphasizes reproductive isolation. It emphasizes gene flow / migration, the movement of genetic material between populations. |
biological species concept
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geographical isolation between two or more populations leads them to diverge and form new species
Emphasizes the interruption of gene flow as the cause of the origin of new species. Occurs when a subpopulation is isolated physically from mother population and diverges. |
Allopatric speciation
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the total range of conditions under which the
individual or population lives and replaces itself.! |
niche
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the process whereby a single species diversifies to fill several open niches
happen when there are many empty niches. |
Adaptive radiation
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taxonomic units
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species
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relatedness
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Cladogram
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ancestor-descendent relationships
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Phylogeny
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are superficial similarities of features
based on common function, not common ancestry |
analogies
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with respect to our new
exclusive set of species (porpoise, baboon, human) mammary glands are an ancestral homology |
symplesiomorphy
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In order to get an even more exclusive set
of species (baboon, human), we need to find another derived homology |
synapomorphy
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molecular biology technique that measures the degree of genetic similarity between pools of DNA sequences. It is usually used to determine the genetic distance between two species
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DNA - DNA hybridization
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heterozygote advantage
When heterozygotes have a higher fitness that either homozygote, natural selection maintains a balanced polymorphism. |
Heterosis
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a disease caused by a single
locus for hemoglobin. |
sickle-cell anemia
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the proportion of phenotypic variation
due to the effects of genes |
Heritability
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is the most important
determinant of skin pigmentation:more ____ = darker skin |
Melanin
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from sunlight
penetrates skin and can damage DNA leading to skin cancer Melanin absorbs ____from sunlight, thereby protecting skin! |
UV radiation
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The body uses cholesterol in the skin +
UV radiation to synthesize _____. _____ important bone growth and important during pregnancy and lactation |
Vitamin D
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When heterozygotes have a higher fitness that either
homozygote, natural selection maintains a |
balanced polymorphism.
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____ seeks correlated
patterns of evolution of morphology, life history, behavior, and ecology to explain adaptation. |
The comparative method
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1.Orbits encircled by bone
(post-orbital bar) 2. Nails instead of claws 3. Grasping hand with opposable thumb 4. Reliance on vision (stereoscopic) 5. Less reliance on olfaction 6. Relatively large brains 7. Extended ontogeny 8. Altricial 9. Single births (often) |
Primate characteristics
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hypothesis for the origin of primate adaptation that focuses on the value of grasping hands and stereoscopic vision for life in the trees
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Arboreal Hypothesis
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hypothesis for the origin of primate adaptation that focuses on the value of grasping hands and stereoscopic vision for catching small prey
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Visual Predation Hypothesis
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- more simple ancestral traits
- scent more emphasized - arboreal - generally nocturnal - dental comb - Lemurs, Lorises, Galagos |
Strepsirhini (Prosimians)
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includes humans, apes, monkeys. Rounded brain cases, reduced non mobile outer ears and relatively small faces.
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Haplorrhine(anthropoid)
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new world monkeys
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Platyrrhine
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Old World Monkey, narrow nostril, down facing, dental formula
2-1-2-3 both herborial and terrestrial |
Catarrhine
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are nocturnal, solitary insectivores
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small prosimians and
tarsiers |
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diurnal, mostly frugivores, and they live on Madagascar. They have a grooming claw and tooth comb
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Lemurs
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suspensory, most eat rite fruit, and they are found in
Africa and Asia.! |
apes
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black and white colobus, langers, presbytis
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colobines
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are a subfamily of the Old World monkeys, that includes in its roughly 71 species the baboons, the macaques and the vervet monkeys
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cercopithecines
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1. Long arms
2. Dorso-ventrally compressed thorax 3. Short lumbar region 4. Broad pelvis 5. High limb mobility 6. No tail 7. Large bodied 8. Large brains 9. Fruit 10. Extended juvenile period (slow growth) |
homoniod traits
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is a group that contains all the descendants of a common ancestor: the group will have a common ancestor unique to itself. Note: this is the only group that is recognized by cladist
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Monophyletic group
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are traits that are shared by an organism passed down from a common ancestor like blue eyes or skin color
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ancestral traits
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evolved in one species after it branced off from others.
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derived traits
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formed from a single zygotep fertilized egg
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monozygotic twin
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formed from two separate zigots
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disygotic twin
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the variation of heritable characteristics present in a population of the same species. It serves an important role in evolution by allowing a species to adapt to a new environment and to fight off parasites.
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Genetic diversity
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