b51 1 Flashcards
whales, dolphins, and porpoises are known as
cetaceans (because they are members of the order Cetacea)
in phylogenetic trees, a ______ represents a speciation event, when a lineage of organisms splits into two groups
this results in two new species
node
in a phylogenetic tree, represent the populations of organism through time as they pass their genetic information forward through time
branch
a group of species with a common ancestor
clade
any change in the inherited traits of a population that occurs from one generation to the next (that is, over a time period longer than the lifetime of an individual in the population)
biological evolution
why is it often difficult to conceptualize biological evolution?
because
- it is hard to describe
- we have issues with scale and concept of time (evolution is not linear)
- its hard to demonstrate and observe evolution
What is the relationship between theory and law?
laws describe (more of a statement) and theories explain (explain why)
refers to the similarity of characteristics resulting from shared ancestry
homology
occurs when populations are in the same geographic area at the same time
sympatry
a derived form of a trait that is shared by a group of related species (that is, one that evolved in the immediate common ancestor of the group and was inherited by all its descendants)
synapomorphies
occurs when different species independently evolve similar traits due to similar environmental pressures, rather than inheriting them from a common ancestor
homoplasy/convergent evolution
refers to the similarity of characterisitcs resulting from shared ancestry
homology
How was 18O/16O used in our understanding of saltwater and freshwater cetaceans?
terrestrial animals drink freshwater, marine animals drink saltwater
- 18O and 16O ratio is higher in saltwater, also higher in the teeth and bones of marine animals (fossils)
Saltwater:
More oxygen atoms with 10 neutrons
High ratio of 18O/16O
18O is heavy oxygen
16O is normal oxygen
Freshwater:
Less oxygen atoms
Low ratio of 18O/16O
From these ratios we can determine what the animals drank, was it freshwater or saltwater (get the ratio from their bones)
the process by which organisms with traits that enhance survival and reproduction are more likely to pass those traits on to the next generation
natural selection
true or false whales and humans share a common ancestor
true
Who first studied the Galapoagas islands
Charles Darwin
wheres one place in the world that acts like a laboratory of evolution for scientists
- its an an isolated example of how life has changed over millions of years
Galapogas islands
the study of prehistoric life
paleontology
Argued that complex species had evolved from simple ones
Jean-Baptiste Lamarck
theory that describes how lower forms of life become higher (ex. humans come from microbes)
the Great Chain of Being
the first geological map of fossils and rock layers was developed by
William Smith
proposed that new varieties of species could arise in response to new habitats, but he did not believe that species could arise this way
Georges-Louis Buffon
first compelling evidence for extinction came from research conducted by
Georges Cuvier
Envisioned a world with a deep history shaped by gradual transformations of landscapes through imperceptibly slow changes, small changes accumulate over time
James Hutton
Invented a system to classify biological entities into Groups based on their similarities.
Carolus Linnaeus
groups of organisms that are judged to be a unit, such as a species or order
taxa (plural), taxon (singular)
the science of describing, naming, and classifying species of living or fossil organisms
taxonomy
________ is the study of layering in rock (stratification)
stratigraphy
refers to the passing of traits from parents to offspring. Darwin recognized that, over time, this process could account for gradual change in species’ traits and homology.
Descent with modification
any change in our genomic DNA
mutation
heritable variation ultimately beings with what
mutation
what are the three types of organic molecules that play the most direct roles in evolution?
- DNA
- RNA
- protein
what is the central dogma of molecular biology
describes the forward transition from DNA to RNA to protein
DNA replication, transcription, translation
number of copies of unique chromosomes in a cell (in other words the number of sets of chromosomes)
ploidy
segment of DNA whose nucleotide sequences code for proteins or RNA or regulate the expression of other genes
gene
a type of RNA that plays a role in splicing
snRNA - small nuclear RNA
which cetacean have the largest brains
dolphins (developed larger brains after their return to the water, they can solve problems, live in groups, etc thats why they have large brains)
In influenza strains, such as H1N1, the H stands for:
hemagglutinin
a technique that allows geologists to estimate the precise ages at which one geological formation ends and another begins
Radiometric dating
how old is the earth
4.56 billion years old
a line on a graph, connecting points at which an event occurs simultaneously
isochron
a technique to measure the age of rocks by determining how ratios of isotopes change in them over time
isochron dating
is a site with an abundant supply of unusually well-preserved fossils often including soft tissues from the same period of time
Lagerstatte
a lagerstatte in Canada in which there is a wealth of preserved fossils from the Cambrian period
Burgess Shale
a molecular evidence of life in the fossil record.
__________ can include fragments of DNA, molecules such as amino acids, or isotopic ratios
Biomarker
what is coal
the remains of dead plants
What is the MOST important character state paleontologists can evaluate to make inferences about the intelligence of fossil cetaceans?
brain size to body size ratio
a type of nucleic acid, such as RNA, surrounded by a protein coat.
viral particles
the type of whale that grow teeth and use sonar
odontocetes
the type of whale that grow baleen plates to use for filter feeding
mysticetes
a lineage evolving through time that connects successive speciation or other branching events
branch
the terminal end of an evolutionary tree, representing species, molecules, or populations being compared
tips
a node that occurs within a phylogeny and represents ancestral populations or species
internal node
a node and all its descendants
clade
when a phylogenetic tree only shows the relationship among species it is called a
cladogram
describes the reversion of a derived character state to a form resembling its ancestral state.
Evolutionary reversal
the earliest animal life resembles what
sponges (650 million years ago)
- biomarkers and fossils demonstrate existence of sponges 650 million years ago
the burgess shale is a result of
the Cambrain Explosion
- happened 505 million years ago
- more than 65 000 specimens
- around 93 species discovered
shale is very thin layers of rock, basically sand
Burgess shale: in British Columbia
organisms with notochord (beginning of spinal cord)
chordates
coincides with early Cambrian
- 515 mya
Embryos all have: notochord, pharyngeal gill slits, post anal tail
notochord: hollow nerve chord
when did the transition to land happen
2.6 billion years ago
prokaryotes first to colonize terrest4rial habitatis
represents a speciation event
node
is the ability of a single genotype to produce different phenotypes in response to environmental conditions. It allows organisms to adapt to changing environments without requiring genetic changes.
Phenotypic plasticity
RNA envolved in gene regulation
miRNA, micro RNA
change in nucleotide but no change in amino acid
synonymous mutation/silent
change in the nucleotide base that cases a change in the amino acid sequence
nonsynonomous mutation/ missense
the new codon is a stop codon; there is premature termination of translation
nonsense mutation
insertions or deletions in coding regions are often called
indels
serine to proline (albinism) or proline to serine (webbed digits) changes often leads to what
kinks in the proteins
what are examples of trans regulatory elements
transcription factors, activators, and repressors (TAR)
trans-regulatory bind to cis-regulatory elements
what are examples of cis-regulatory elements
promoters, enhancers, silencers (PES)
near/within the focal gene
