chapter 1-6

streamlined body

early whales to land artiodactyls

humans, swine and birds

Carl Linnaeus

streamlined body of shark and killer whale

whether or not the species is reproductively isolated from other species

procaryotes (bacteria & archea)

• shared derived characteristics 
• synapomorphies
• divergent evolution

at the beginning of a gene

duplicated genes

animals choosing mates with desirable characteristics

• the bees are not rewarded with
• either flower color, so they alternate visits to flowers with different colors,
• increasing the proportion of  visits to
• the flower color that occurs less frequently.

species have fixed properties and the number of species is fixed

all species were created individually by god

• earth species created separetly
• species do NOT change
• earth and life are young

• All species diverge with common ancestors and differences among them accumulate over time
• species evolve
• earth and life are old

• father of taxonomy
• believed all species were created separtely

• same process acted in the past as in the present
• geological features can be understood by the present day process
• suggested earth was old

• earth 19th century geologists 
• principle of uniformitarianism

• field of paleontologist
• different rock layers contained different groups of fossils
• opposed to evolution, believed species disappeared due to catastrophic events and new forms migrate from somewhere else

promoted the idea of inheritance of acquired characteristics

natural selection (mechanism to bring evolutionary change)

• have lost all or most of their functions
• useless wings in kiwi bird
• remnant of a hind lib in the boa
• tailbones and goosebumps

species are descended with modification from ancestors that lived in the same region

• species showing a mix of traits from the ancestral forms and later descendants
• EX: archaeopteryx, feathered dinosaurs and ancestral whales

adaptions among different populations of organisms with similar origins may not have the same function

*structural, developmental and molecular homologies evidence for common ancestries

arise when processed with mRNA are revered transcribed and inserted into the genome

*biologists can estimate their age by counting the number of mutations

chronology of earths history based on rock strata

dating rock samples based on parent to daughter radioactive isotopes present

diagram showing evolutionary relationship among different population of organisms

• Human immunodeficiency virus that causes AIDS (1981)
• closely related to SIV found in chimpanzees and monkeys

*evolved separately at least 4 TIMES!

• 1)HIV virion invades the host cell by binding to 2 proteins on the cell's surface
• 2)allows virion to spill its cell content
• 3)HIV reverse transcriptase makes copy of its viral DNA
• 4)inserts its DNA into the host cell
• 5)host's RNA polymerase transcribes it into mRNA
• 6)ribosomes transcribe mRNA into precursors proteins
• 7)HIV's protease cleaves the precursors, yielding mature viral proteins
• 8)new virons assemble in the host's cytoplasm and
• 9)bud from the host cell's membrane

• dendritic cells 
• ↳naive helper T cells 
• ↳memory cells and effector cells
• ↳B cells
• ↳antibodies

divide to produce memory and effector t-cells

• help fight virus
• ↳release signalling molecules (chemokines)
• ↳stimulate B cells to mature into plasma cells to produce antibodies

*can also stimulate macrophages

INGEST infected cells

keep the immune response under control

• the host shows general symptoms of a viral infection
• viral load spikes during acute phase
• patients CD4-T cells counts fall during acute phase and recover some what

viral load falls as the host mobilizes an immune response, but it climbs up again during the AIDS phase

• individuals in a populations are variable
• variations are passed from parents to offspring
• some individuals are more successful at surviving and reproducing in each generation
• individuals with favorable traits are the ones who survive to reproduce

traits that give certain individuals an advantage over another; allow some individuals to survive and reproduce more than individuals without the adaption

ability of an individual to survive and reproduce

*individuals that are able to survive and reproduce more show greater fitness and they pass more copies of their genes to the next generation

• acts on individuals but affects population
• acts on phenotypes but changes allele frequencies

*increased depth of beak in finches produced by this process

• mutations
• gene flow
• recombination 
• genetic drift

• eye cave dwellers
• gut of tapeworm
• tails in humans

• struck down by supreme court in 1968
• prohibited public schools teachers from denying the biblical account of mans origin

first group in 1980 to try to include creationism in public schools

• proponent of irreducible complexity in certain adaptations 
• argues that complexity and perfection in nature is possible only with guidance by a supreme designer

believes that all species were created in 6 days

believes that species originated from episodes of creation and extinction

only a cup of light sensitive cells that allow the direction of light source to be perceived

has a slit over a cup of light sensitive cells to focus image of distant object

• relationships of different groups of organisms represented in genealogical (phylogenic) tree
• hypothesis of a group's pattern of evolution

a shared trait that was modified (changed from an older ancestral state) in the most recent common ancestor

*homologous traits; help identify monophyletic groups

shows ancestral relations between organisms, to represent evolutionary tree of life

• group of organisms that serves as a reference group for determination of the evolutionary relationship among three or more monophyletic groups of organisms
• in a cladogram related taxons are compared to an outgroup (possess ancestral characters)

trait or an organ that appears similar in 2 unrelated organisms

• *similarities due to convergent evolution NOT common ancestor
• (crocodile and hippos have skulls in which the eyes sit on top)

organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niche (role)

character shared by a set of species but not present in their common ancestor 

*analogies and reversals

the cladogram with the fewest number of character changes is chosen as the best one

• Perissodactyls: odd toed hoofed animals (horse)
• artiodactyls: even toed hoofed animals (cow)
• astragalus: high ankle bone with a pulley shape at bothe end (in artiodactyls, NOT in perissodactyls)

sines: short retrotransposable element (DNA sequence) that insert themselves in a new location

lines: long retotransposable element that insert themselves in a new location

naming and classifying of species

mono: all taxons with common ancestry included

para: ll taxons share a common ancestry but not all taxons derived from that common ancestor are included

technique use to estimate when divergence occurred for a certain taxa by analyzing molecular traits that change at a a steady rate

*when no fossil records are available

study of historical processes that may be responsible for the contemporary geographic distributions of individuals

*consider the geographic distribution of individuals in light of patterns associated with a gene genealogy

• change in the genetic composition of one species in response to a genetic change in another 
• symbiotic relationship and predatory/prey relations can result 

*malaria in humans, aphids and bacteria

• any change in the nucleotide base sequence of DNA
• ultimate source of new alleles and new genes
• result from errors during DNA copying

substitution of one base for another

• *chance errors during DNA synthesis or during repair of damaged DNA
• *create NEW alleles

results in the replacement of the amino acid being coded

no change in amino acids sequence of a protein (loss of function mutation)

• insertion or deletion of a nucleotide in a DNA sequence 
• disrupts the reading frame of the protein and results in a non functional protein 

*loss of function

• duplication of short stretch of DNA, creating and extra copy in the sequence 
• unequal cross over during meiosis or retrotransposition 
• redundant new genes may acquire new functions by mutations

• most common type of gene duplication
• occurs during meiosis 1 and results in one chromosome acquiring an extra copy of some regions of the DNA

duplicated genes that diverge in their nucleotide sequence within a species

• *alpha(3) and beta(5) globin genes in human
• *homologous genes that have evolved by duplication and code for protein with similar, but not identical functions

duplicated genes that diverge in their nucleotides sequence in a different lineage after speciation

• *beta globin genes in humans and mice
• *related by vertical descent from a common ancestor and encode proteins with the same function in different species

• duplicated chromosome breaks free, flips and is reinserted 
• breaks in DNA caused by radiation or other insults
• alleles inside the inversion are likely to be transmitted together

• organisms that have more than two chromosome sets 
• typically occur due to meiotic errors that result in diploid gametes
• *most common in plants

• addition of a complete set of chromosomes
• errors in meiosis (plants) or mitosis
• may create new species; massive gene duplication

examine variations in proteins or DNA

measure of how common one allele is relative to all other alleles of the same gene in a population

originated the science of biogeography

change in the gene pool of population over time