Exam 1 Flashcards
characteristics of life
metabolism, mobility, response to stimuli within environment, growth and development, highly ordered and organized into cells, reproduction, contain genetic material within their cells that is passed on to the next generation, evolution and adaptation
eukaryotes have this kind of genetic material
DNA and RNA
prokaryotes have this kind of genetic material
either DNA or RNA, not both
steps of scientific method
observation, question, hypothesis formation, prediction, empirical tests, conclusions, publish
scientific theory
a general principle about nature that is highly tested and never disproven, yet
taxonomy
formal system for naming and classifying species
systematics
classifies organisms and determines their evolutionary relationships
phylogeny
the evolutionary history of a species or group of related species
who came up with the classification system to organize the diversity of nature?
Carolus Linnaeus
binomial nomenclature
every organism has 2 proper names: /Genus species/
standard grouping order:
Domain, Kingdom, Phylum, Class, Order, Family, Genus, species
Domains
Archaea, Bacteria, Eukarya
Kingdoms
Plantae, Animalia, Fungi, Protista
phylogenetic tree
represent a hypothesis about evolutionary relationships
what does each branch point in a phylogenetic tree represent
the divergence of two evolutionary lineages from a common ancestor
sister something
groups that share an immediate common ancestor that is not shared by any other group
homology
similar structure with similar uses due to shared ancestry
analogy
different structures with similar uses due to convergent evolution, not shared ancestors
survival of the fittest
the individual that reproduces the most reproducing offspring is the fittest
Lamark’s contribution to evolution
came up with the idea of Inheritance of Acquired Characteristics
Inheritance of Acquired Characteristics
the subconscious “desires” of an organism can cause changes in the traits of that organism, and those changes caused by increased use or disuse will be passed onto the offspring of that individual
Darwin’s background
-studied medicine and theology
-was the naturalist on a 5-year voyage on the HMS Beagle (1831)
-wrote “The Origin of Species” (1859)
Darwin and Wallace
-Wallace was working on the same idea as Darwin but gave the credit to Darwin due to him putting in more work and research
evolution
genetic change in organisms through reproduction
main points of evolution
-populations evolve, not individuals
-occurs mainly through natural selection
-the main unifying theme of all of biology
first requirement of natural selection
variations in form and behavior between members of a species exist
second requirement of natural selection
variations are inheritable from one generation to the next
third requirement of natural selection
there is competition between individuals of a population or species
fourth requirement of natural selection
individuals with adaptable variations will be more likely to reproduce (differential reproductive success) and pass those adaptive variations on with greater frequency to future generations
differential reproduction success
individuals with adaptable variations will be more likely to reproduce
evidence of evolution
- fossil record
- artificial selection
- evolution in action
- comparative anatomy
- comparative embryology
- biochemistry and DNA
- biogeography
what are fossils?
evidence of past living organisms
what do fossils tell us?
-past organisms are different from today’s living ones
-fossil layers show a trend in evolution from simple to more complex (generally)
-intermediate (missing links) fossils are being found now
artificial selection
shows that change can occur and the environment can cause it
-many examples from our domestication of plants and animals
evolution in action
pesticide resistance to insects, bacterial and viral resistance to medicine
comparative anatomy
-figuring out common ancestors and relatives
-comparing the structures of organisms to see if the individuals are related or not
three types of structures in evolution
homologous, analogous, vestigial
homologous structures
structures that have the same framework (internal structure)
-function doesn’t matter
analogous structures
structures that don’t have the same framework
-function doesn’t matter
vestigial structures
structures that have no apparent use in the present owner but are used in related organisms
comparative embryology
compare embryos to see if we have similar DNA
-for the first 3-6 weeks as an embryo, all vertebrates look the same
biochemistry and DNA
-shows which organisms are related to each other
-closer ancestral relationship = more similar DNA
biogeography
the study of where living things exist on the planet, why they exist there, when they got there
causes of microevolution
genetic drift, gene flow, mutation, nonrandom mating, natural selection
genetic drift
-random change in small gene pool due to sampling errors in propagation of alleles
gene flow
changes in gene pools due to immigration or emigration of individuals between populations
mutation
-change in allele frequencies that are passed on to the offspring due to net mutation
-common
-most are neutral
nonrandom mating
-inbreeding or selection of mates for specific phenotypes (assortive mating) reduces frequency of heterozygous individuals
-individuals mate with others of the same genotype
-increases homozygous genotypes
-does not change allelic frequencies
natural selection
-differential reproductive success increases frequencies of some alleles and diminishes others
types of mutations
-lethal (usually kills you before you can reproduce)
-adaptive (allows you to reproduce more)
-neutral (no effect)
subtypes of genetic drift
-founder effect
-bottleneck effect
founder effect
mainly occurs on islands when a small group of individuals colonize a new habitat and thrive, becoming a new population
bottleneck effect
when there is a severe reduction in population size, the resulting population will have less genetic variation and more similar traits
-beginning of extinction
types of natural selection
-stabilizing selection
-directional selection
-disruptive selection
stabilizing selection
intermediate forms are favored and extremes are eliminated; occurs when the individuals of a population with the most common trait survive and reproduce the most thus, the offspring of that population will have the common (best) traits of the parents
directional selection
allele frequencies shift in one direction
disruptive selection
individuals with either extreme trait are favored and thus reproduce more (allele frequencies shift in two directions)
-causes 2 new species when it becomes macroevolution
special population selection models
-sexual selection
-balanced polymorphism
sexual selection
when one form or sex chooses its mate based on fitness of that individual
-causes a huge amount of genetic change within 1 generation of a population
-requires sexual dimorphism
sexual dimorphism
two forms of sex appearance
balanced polymorphism
when there are two forms of a trait that are maintained within a population year after year
macroevolution
-large scale genetic change
-development of a new species
species
a group of interbreeding individuals that are reproductively isolated from other such groups
reproductive isolation
prezygotic isolation or postzygotic isolation
types of prezygotic isolation
-behavioral
-ecological
-temporal
-mechanical
-gametic
behavioral prezygotic isolation
the mating behavior between species keeps them from reproducing
ecological prezygotic isolation
species live in different habitats
temporal prezygotic isolation
the mating seasons are different
mechanical prezygotic isolation
the reproductive parts don’t fit
gametic prezygotic isolation
the sperm does not survive in the female’s environment
types of postzygotic isolation
-zygotic
-hybrid inviability
-hybrid sterility
zygotic postzygotic isolation
the embryo dies before birth
hybrid inviability postzygotic isolation
the embryo does not survive well and dies before reproduction age
hybrid sterility postzygotic isolation
the offspring is sterile and can’t pass on the new genetics
speciation
natural selection and other microevolutionary processes can lead to this
speciation models
-allopatric speciation
-sympatric speciation
allopatric speciation
the development of a new species by a physical seperation from the original species
sympatric speciation
development of a new species, within the same environment as the original species
rates of speciation
-gradualism
-punctuated equilibrium
types of extinctions
-local extinctions
-species extinctions
-mass extinctions
local extinctions
only certain populations of a species are gone
species extinctions
entire species is gone
mass extinctions
lots of species going extinct
what did primates evolve from?
Dryopithecus
types of fossils
-eggs in nest
-fossilized feces
-bones
-footprint
-skin impression
vestigial structures examples
-legs in snakes
-ear muscles in humans
-appendix in humans
-tailbone in humans
