Charles Darwin
British naturalist who developed the theory of evolution in the mid-1800s. He researched life on the Galapagos Islands. Darwin published his findings in his book "On the Origin of Species" in 1859.
Natural Selection
survival of the fittest"; the change in a population that occurs when organisms with favorable adaptations survive, reproduce, and pass these genes/traits to the next generation
Antibiotic resistance
the ability of bacteria and other microorganisms to survive when exposed to an antibiotic
Vancomycin
antibiotic of last resort; controlled by the CDC, this antibiotic is only used when all other antibiotics have been tried
Fitness
Ability of an organism to survive and reproduce in an environment
cladogram
a diagram which shows evolutionary relationships among organisms
Mimicry
when an organism copies the appearance or behavior of another species
Camouflage
enables an organism to blend in with it's environment and evade predators
Evolution
descent with modifications; genetic change in a species over time
Penicillin
The oldest antibiotic used to treat bacterial infections; discovered in 1928 and first used to treat infection in 1942. Most bacteria is now resistant to this antibiotic.
Fossil/ Fossil record
trace of once living organism; used as evidence of evolution. examples are foot imprints, molds, resin, teeth, and bones
Homologous structures
structures that are similar in stucture but different in function; examples are the limbs of the human, cat, bat, whale
Analogous Structures
an organ or body part that is similar in function but different in structure; example: the wings of birds and butterflies
Vestigial Structures
a body part used by the ancestor but is reduced in function or no longer in use EX. human tailbone, wisdom teeth, pelvic bone in whales and some snakes
Embryology
the study of embryos and their development.; many different species have embryos which develop in similar ways Ex. Fish, chicken, turtles, and human embryos look similar in early stages
Genetic Comparisons / DNA
Most reliable evidence of evolution; the sequences of nucleotides can tell how closely related species are within a kingdom
Ex. Phylogenetic tree or cladograms
Evidences for Evolution
Fossil/ Fossil record
Homologous and Analogous Structures
Vestigial Structures
Embryological Development
Genetic Comparisons
Zone of inhibition
area around an antibiotic disk where bacteria does not grow; the greater the zone of inhibition, the more effective the antibiotic is
Gene Pool
all of the genes present in a population
Theory of Evolution: part 1
organisms produce more offspring than can survive
Theory of Evolution: part 2
All species have genetic variation (differences)
Theory of Evolution: part 3
there is competition and a struggle for existence within a population
Theory of Evolution: part 4
Organisms better suited to their environment as a result of variations will survive. (survival of the fittest)
Theory of Evolution, part 5
Living species today are descended with modifications from common ancestral species that lived in the past
MRSA
methicillin-resistant Staphylococcus aureus; a strain of common skin bacteria that is resistant to many antibiotics, including methicillin
antibiotic
a medicine (such as penicillin) that stops the growth of or destroys bacteria; NOT used to treat viral infections such as the flu or colds
speciation
the evolutionary process by which new biological species develop because of geographic isolation
competition
in the struggle for existence, all organisms compete for food, water, shelter, space, and a mate
Convergent Evolution
process in which organisms not closely related (like birds and butterflies), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.
Divergent evolution
the accumulation of differences between populations which can lead to the formation of new species, usually a result of isolated environments
adaptation
a trait that is common in a population because it provides some improved function or contributes to survival; it is produced by natural selection
gene flow
is the transfer of alleles or genes from one population to another (also known as gene migration)
genetic drift
the change in the frequency of a gene (allele) in a population due to chance, not natural selection
mutation
a change in the DNA sequence; occurs naturally or by some environmental factor such as x-rays or UV radiation from the sun
stasis
a long time period of little or no evolutionary change in a species
punctuated equilibrium
a theory which proposes that most species will exhibit little evolutionary change for most of their geological history, remaining in an extended state of stasis, and when significant evolutionary change occurs, rapid (on a geologic time scale) speciation
gradualism
a theory which proposes that profound change in a species (evolution) is the cumulative product of slow but gradual changes
Hardy-Weinberg equilibrium
The Hardy-Weinberg principle states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of evolutionary influences. These influences include non-random mating, mutation, natural selection,
population
members of the same species living in the same place at the same time; example is all of the cotton-tailed rabbits living in the same field in Plano
descent with modification
Charles Darwin's definition for the evolution of a species; offspring are always genetically unique from their parents and over time these genetic changes accumulate in a population
biodiversity
the large numbers of different species found in an area
variation
a genetic difference among organisms in the same species; for example, some horses have very long legs and some have shorter legs.
theory
well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.
Directional selection
a mode (type) of 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.
Disruptive selection
changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups.
stabilizing selection
the opposite of disruptive selection, stabilizing selection favors the intermediate variants. It reduces phenotypic variation and maintains the status quo.
taxonomy
the science of classifying living things and assigning each species a unique scientific name
classify/classification
to categorize or put into groups
dichotomous key
tool used to identify organisms that are similar. At each step, it splits characteristics into two categories: "has" or "does not have
kingdom
large taxonomic group in Linneaus' system; in evolutionary order the 6 Kinddoms are: Archaea, Bacteria, Protista, Fungi, Plantae, Animalia
phylum
a group of closely related classes (for example: Chordata, Mollusca, Porifera, etc)
class
a group of closely related orders
order
a group of closely related families (for example: Order Carnivora - animals that eat meat)
family
a group of closely related genera (for example: Family Felidae (cats) or Family Canidae (dogs))
genus
a group of closely related species. The first part of a scientific name. Always capitalized (example: Homo in Homo sapiens)
species
a group of similar organisms that can interbreed and have fertile offspring. The second part of a scientific name. Always lower case. (example: sapiens in Homo sapiens)
binomial nomenclature
2-name scientific naming system developed by Carolus Linneaus. (example: Homo sapiens - humans or Panthera tigris - tiger)
Archae
Kingdom containing single-celled prokaryotes (no nucleus) that live in harsh conditions (very salty, no oxygen, very hot); the oldest form of life.
Bacteria
Kingdom containing single-celled prokaryotes (no nucleus); common bacteria such as E. coli are members of this kingdom
Protista
Kingdom containing single or multicellular organism kingdom; eukaryotes (cells have nucleus), live in pond water, can move, some are photosynthetic. examples are algae, diatoms, paramecium.
Fungi
Kingdom containing single or multicellular organisms; eukaryotes (have nucleus), heterotrophs (eat others), cell walls of chitin, can't move (non-mobile)
Plantae
Kingdom containing organisms that are multicellular, eukaryotes, photosynthetic, cell walls of cellulose, non-motile (can't move)
Animalia
Kingdom containing multicellular, eukaryotes, heterotrophs, no cell walls, most can move (motile or mobile)
traits
features, qualities or characteristics; examples are cells having cell walls
cellulose
sugar molecule in plant cell walls and in the cell wall of some protists
chitin
sugar molecule found in fungi cell walls
cell wall
strong layer outside the cell membrane which provides extra protection for the cell
multicellular
organism that has more than one cell in its body; example are plants and people (animals)
unicellular
one celled organism; bacteria are always unicellular; most Protists are unicellular
Carolus Linnaeus
scientist who developed the classification system in use today; the system has seven levels: Kingdom, Phylum, Class, Order, Family, Genus, Species
prokaryote
a cell without a nucleus; the simplest, least complex cells; Bacteria and Archaea kingdoms are made up of species that are prokaryotic.
eukaryote
a cell WITH a nucleus; cells that are complex and have many different organelles. Four kingdoms are made up of species that are eukaryotic--Protista, Fungi, Plantae, Animalia.
chemotrophic
an autotrophic organism that can obtain energy from the chemicals (organic and inorganic compounds) in their environment.
autotroph
An organism capable of synthesizing (making) its own food from inorganic substances using light or chemical energy. Green plants, algae, and certain bacteria are autotrophs.
heterotroph
An organism that cannot manufacture its own food and instead obtains its food by eating other living things. All animals, fungi, and most bacteria are heterotrophs.