diversifying selection (disruptive selection)
selection that favors two or more distinct phenotypes (up, down, up)
stabilizing selection
selection that favors average phenotypes (up, down)
directional selection
selection that favors phenotypes at one end of the spectrum or existing variation (opposite of beginning; if before is up, down then after is down, up)
spp
multiple species
pheromones
a communication chemical used within a species; intraspecific communication
sexual dimorphism
males and females different sizes
parasitoids
parasite that kills its host
ovipositor
egg laying "device" on creature
gall
leads to decrease in genetic diversity (stabilizing selection)
coevolution
organisms affecting each other's evolution (galling selects for specialized enemies)
symbiosis
any type of a close and long-term biological interaction between two different biological organisms
mutualism
++
commensalism
+0
parasitism
+-
drivers of diversification
environmental, genetic, organismal
genetic code
refers to the instructions contained in a gene that tell a cell how to make a specific protein; three letter codes that specify amino acid production (A-adenine, C-cytosine, G-guanine, T-thymine)
point mutation
a place where the A,C,G,T is changed/translated incorrectly
polypeptides
chain of amino acids
single nucleotide polymorphism
a germline substitution (type of mutation) of a single nucleotide at a specific position in the genome (>1% to be qualified polymorphism)
DNA damage
cellular metabolism, UV light exposure, ionizing radiation, chemical exposure, replication errors
DNA repair
direct reversal, base excision repair, nucleotide excision repair, mismatch repair, double strand break repair (homologous recombination or non-homologous end joining)
apoptosis
self-destruction of a cell; programmed cell death; plays a role in preventing cancer
UVA/UVB
found in lower atmosphere
UVC rays
filtered out in higher atmosphere
initiation
irreversible
promotion
reversible
order of cell things
complete repair, apoptosis, initiation, promotion, progression
new genes arise via mutation
deleterious, neutral, adaptive
deleterious
random changes in an evolved system, most common
neutral
a mutation that isn't good or bad
adaptive
a mutation that is helpful
multiniche polymorphism
some better at hunting, some better at foraging
Mendel
genetic breeding pea man
mendelian
recessive and dominant
Carl Correns, Hugo de Vries, Erich von Tschermak
found the same conclusions as Mendel
horizontal gene transfer
the sharing of genetic material between organisms that are not in a parent offspring relationship
transformation
the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surrounding through the cell membrane
transduction
a mechanism of genetic recombination that occurs in bacteria where the incorporation of host cell DNA and the bacteriophage genetic material occurs, which results in the formation of recombinant DNA
conjugation
temporary union or permanent fusion as a form of sexual reproduction in certain algae and fungi
virus
a submicroscopic infectious agent that replicates only inside the living cells of an organism
phage (bacteriophage)
a virus that infects and replicates within bacteria and archaea; ubiquitous viruses (found wherever bacteria exist); infection begins by attachment of the phage particle to its host cell through specific recognition of a receptor on the host surface, followed by delivery of the phage nucleic acids into the infected cell, then it hijacks its cellular components and shuts down its defense mechanisms
prion
misfolded proteins that have the ability to transmit their misfolded shape onto normal variants of the same protein
microevolution
the theory that connects population change over time
macroevolution
big divergences in fossil record or geologic record, the process that gave rise to new species and higher taxonomic groups with wider divergent characters
Dawkins
famous evolutionary biologist
Pax 6 transcription factor
the eye gene
duplication events
genes getting two copies instead of one; biggest is entire genome mutation; most cases, second copy does nothing but sometimes it can have a new function via mutation: neofunctionalization
mutations are ultimate source of new genes
can occur during DNA replication; duplication mutations result from abnormal cell division either during mitosis or commonly during metaphase 1 in meiosis
polyploidy
whole genome duplication is now recognized as being present in almost all lineages of higher plants with multiple rounds of polyploidy occurring in more extant species
gametes
eggs and sperm
zygote
combination of two haploid cells (single cell, once split occurs, then embryo)
hemoglobin
has two parts that come from different chromosomes
epigenetics
the study of heritable phenotype changes that do not involve alteration in DNA sequence
allopatric speciation
physical barrier or something for dispersal
vicariance
the geographical separation of a population, typically by a physical barrier such as a mountain range or river, resulting in a pair of closely related species
dispersal
part of a population is moved from one place to far away; no longer connected to gene pool at original place
sympatric speciation
the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region; doesn't imply complete species isolation
maintaining reproductive isolation in sympatry
temporal isolation (prezygotic): time habitat isolation: space behavioral isolation: reproductive barriers prezygotic isolation: gametic barriers postzygotic barriers: hybrid sterility and zygote failure (mules)
prezygotic isolation
genetic barriers: eggs and sperm can't reach
postzygotic barriers
hybrid sterility and zygote failure
species
groups of interbreeding natural populations that are reproductively isolated from other such groups
epi
"on top of" or "in addition to" the traditional genetic basis for inheritance
gene expressions
the process of turning on a gene to produce RNA and protein
transcription
the process of making an RNA copy of a gene's DNA sequence
transcription factors
proteins involved in the process of converting or transcribing DNA into RNA; factors initiate and regulate the transcription of genes; signals from the environment or cells activate transcription factors; these bind to regulatory regions and determine transcription level
closed DNA
transcription cannot occur
open DNA
transcription factors bind and induce gene expression; environmental signals can open DNA to transcription
bacteria on organism chart
bacteria is further away and more diverse; archaea and eukaryota are closer
prokaryote reproduction
reproduce asexually by mitosis
eukaryote reproduction
many can reproduce asexually or sexually
parthenogenic
the production of clones as a result of asexual reproduction
mitosis
division of sematic cells; two daughter cells have the same number and kind of chromosomes as the parent cell
meiosis
haploid gamete; four daughter cells each have half the cells as the parent cell, as in the production of gametes
two fold cost of males
sexual females must spend 50% of the resources making sons which cannot themselves make offspring, the growth rate of sexual populations is predicted to be half that of the asexual population
HGT
genome diversification in prokaryotic species
plasmid
small double-stranded unit of DNA, usually circular but sometimes linear, exists independent of the chromosome and is capable of self replication; small circular molecule of double stranded DNA from larger plasmids that occur naturally in bacteria; transferred from cell to cell via conjugation
vertical transmission
plasmid transferred during replication to daughter cells
horizontal cells
plasmid transferring to bacteria of same generation
pilus
surface appendage of some prokaryotes used for attachment to surfaces including other prokaryotes
bacterial conjugation
the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like contact or by a bridge-like connection between two cells
auxin
a plant hormone which causes the elongation of cells in shoots and is involved in regulating plant growth
cytokinins
promote cell division in roots and shoots
opines
used by bacteria for energy, carbon, and nitrogen
transfer of T-region
mediated by gene products encoded by the virulence genes located in the vir-region of Ti plasmid
relaxosome
the complex of proteins that facilitates plasmid transfer during bacterial conjugation
genes that code for relaxosome components
TraH: stabilizes the relaxosome's structural formation TraI: enforces the relaxase protein TraJ: recruits the complex to the oriT site TraK: increases the "nicked" state of the target plasmid TraY: imparts single-stranded DNA character on the oriT site TraM: plays a particularly important role in relaxase interaction by stimulating "relaxed" DNA formation
genetic competence
the ability to undergo transformation
competent bacteria
possess highly specialized machines to transport DNA into their cytoplasm
horizontal gene transfer: transformation
for transformation to take place, the recipient bacteria must be in a state of competence, which might occur in nature as a time-limited response to environmental conditions such as starvation and cell density, and may also be induced in a lab
productive infections
when infection of a cell by a bacteriophage results in the production of new virions
lytic cycle
when virions are released by bursting the cell
lysogenic cycle
when a temperate bacteriophage infects a bacterial cell
prophage
when the phage DNA is incorporated into the host-cell genome
latency
when viruses can exist in nervous tissue for long periods of time without producing new virions, only to leave latency periodically and cause lesions in the skin where the virus replicates
horizontal gene transfer: transduction
phage invades donor bacterial cell
bacterial chromosome is broken down
transducing particles are assembled and the cell lyses
transducing particle invades new cell
donor DNA integrates into cell chromosomes
CRISPR
sequences derived from DNA from DNA fragments of bacteriophage; used to detect and destroy DNA from similar bacteriophages during subsequent infections; eliminates new phage material from being conjugated inside; molecular adaptive immune system of prokaryotes
totipotency
(of an immature or stem cell) capable of giving rise to any cell type or (of a blastomere) a complete embryo
Leeuwenhoek
17th century microscope maker/researcher
Brownian Motion
the erratic random movement of microscopic particles in a fluid as a result of continuous bombardment
molecular adhesion
cell surface proteins that mediate the interaction between cells; the amount charged particles can be stuck to others