Descent with Modification Flashcards
The wide interpretation of evolution
earth’s many species are descendants of ancestral species that were different from modern-day species
Narrow interpretation of evolution
change in the genetic composition of a population over generations
why are evolutionary relationships shown in the form of trees
it shows how each species branches off from a common ancestor
what do “nodes” represent in the context of phylogenies
represents the most recent common ancestor of two or more descendant lineages
how do nodes in an evolutionary tree yield info on the relatedness of taxa
Two species are more related if they have a more recent common ancestor, and less related if they have a less recent common ancestor.
influence of Cuvier on Darwin’s thinking
established proof that many species like dinosaurs had become extinct in ages past
Influence of Hutton on Darwin’s thinking
inspired Darwin to incorporate the concept of an “ancient” mechanism that had been at work since the beginning of the Earth
influence of Lyell on Darwin’s thinking
The same geologic processes are operating today as in the past and at the same rate
Lamarck’s ideas about evolution
- use and disuse
- inheritance of acquired characters
how did the voyage on the Beagle affect Darwin’s thinking about evolution
observed that fossils resembled living species from the same region AND living species resembled other species from nearby regions
what theme does this describe:
life on earth has descended from a common ancestor
unity and continuity of life
what does continuity among all living things stem from
inheritance of information encoded in DNA
what is the GUT of biology
evolution
________ provides framework for making sense of strang variation in nature
adaption
What is NOT an adaption
genetic drift
what do organisms interact with
one another and their enviroment
how must organisms acquire energy
from environment
examples of organism interactions
- competition
- mutualism
- predation
- parasitism
mutualism
interaction between individuals of different species that results in positive effects
predation
one organism kills and consumes another
parasitism
relationship between the two living species in which one organism is benefitted at the expense of the other
what definition of evolution is illustrated with treelike diagrams
broad definition
what definition of evolution suggests its role in the unity and diversity of all species
broad definition
evolution is something that happens to _____ NOT _____
populations and individuals
who advocated for catastrophism
Cuvier
catastrophism
each boundary between strata represents a catastrophe
who rejected the idea of evolution
Cuvier
are fossils in older strata the same as fossils in newer strata
NO
past mechanisms are the same as current mechanisms
FALSE
Who used uniformitarianism as the mechanism of change
Lyell
uniformitarianism
mechanisms of change are constant over time
what did Hutton and Lyell perceive about Earth
changes in earth’s surface can result from slow, continuous actions still operating today
did uniformitarianism influence Darwin’s thinking
YES
what era did Darwin usher in
era of evolutionary biology
evolution is also seen as
descent with modification
two different way evolution can be relate
pattern and process
the pattern of evolution is revealed by
data from a range of scientific disciplines
the data in the pattern of evolution refers to the
observations about the natural world
process of evolution is the
mechanisms that produce the observed pattern of change
what does Darwin’s view of evolution challenge
traditional view of Earth inhabited by unchanging species
was Darwin the first to suggest life changed gradually over time
NO
how did Aristotle view species
as fixed
how did Aristotle believe life forms could be arranged
on a ladder of increasing complexity
what was Aristotle’s view of life called
scala naturae (scale of nature)
scala naturae is a _____ hierarchy
linear
who developed the two-part binomial for naming species
Linnaeus
where are fossils found
sedimentary rocks formed from sand and mud that settled to the bottm of aquatic habitats
strata
new layers of sediments cover older ones and compress them into superimposed layers of rock
_____ provides info about what species lived while that layer was formed
fossils in a stratum
paleontology
study of fossils
According to Cuvier, the older the stratum the
more dissimilar the fossils were to current life
what was common from one layer to the next
extinction
use and disuse principle
parts of the body that are used more will become stronger and longer while those not used will deteriorate
inheritance of acquired characteristics
organisms could pass these modifications to its offsprings
Lamarck thought evolution happened because
organisms had a drive to become more complex
descent with modifications explains
adaptions of organisms and the unity an diversity of life
what did Darwin find with the Galapagos islands
Galapagos had been colonized by organisms that have stayed from South America and then diversified
adaption
inherited characteristics of organisms that enhance their survival and reproduction in specific enviroments
natural selection
process where individuals that have certain traits tend to survive and reproduce at higher rates
what is the product of evolution
life’s diversity
what three observations about nature did descent with modifications explain
- unity of life
- diversity of life
- match between organisms and their environment
phrase that summarizes Darwin’s view of life
descent with modification
unity of life is attributed to the
descent of all organisms from an ancestor that lived in the past
history of life was viewed as a
tree
each fork of the evolutionary tree diagram is the
most recent common ancestor
______ of all species that ever lived are now extinct
99%
The traits that are favoured depend on
the context the species live and mate
Natural selection can ONLY amplify or diminish heritable traits that
DIFFER among the individuals of a population
Natural selection was a mechanism proposed to explain
the observable patterns of evolution
what mechanism was proposed to explain the observable patterns of evolution
natural selection
artificial selection
Modified other species by selecting and breeding individuals that posses desired traits
results of artificial breeding have
little resemblance to wild ancestors
is this natural selection or artificial selection?
Brings changes dramatic changes in short periods of time
artificial selection
natural selection should be capable of doing what
substantial changes over long periods of time
what individuals have a higher probability of survival and reproducing offspring
those with more advantageous traits
what leads to the accumulation of favourable traits in population
unequal ability of indivduals to survive and reproduce
______ is a characteristic of all species
overreproducing
Organisms’ heritable traits can influence both
its own performance AND how well its offspring cope to environmental challenges
what is the evidence that all life arose from a common ancestor
the gradual accumulation of modifications over millions of years leads to adaptions and biodiversity
how do fossils of extinct species document the divergence of extant groups
Shows that overt time descent with modification produced increasingly large differences among related groups of organisms
how do soapberry bugs illustrate the main concept of natural selection
Soapberry bugs feed best when their beak matches the depth of seed found in the fruit = natural selection determines the length of their beaks
how does the rise of MRSA constitute a direct observation of evolutionary change
genetic mutations in MRSA allow it to evolve and become more resistant to antibiotics such as penicillin
two evidence of closer evolutionary relationship between crocodiles and birds COMPARED to mammals and crocodiles
- birds have evolved from reptiles
- crocodiles share a more recent ancestor with birds than mammals
- have more similar DNA sequences/anatomical characteristics
how do fossils support the idea that cetaceans evolved from terrestrial mammals
The earliest cetaceans lived 50 to 60 million years ago at a time when most mammals were terrestrial
why would one predict the oldest horse should be found in North America
At the time, the continents of South America and North America were not connected so the horses found in North America could NOT cross to South
what is a common misconception in the understanding of evolution via natural selection?
a population will change because it wants to better survive in response to environmental changes INSTEAD natural selection is RANDOM
four types of data that document the pattern of evolution and how it occurs
- direct observations of evolutionary change
- homology
- fossil record
- biogeography
natural selection is a process of ______ not a ______
editing NOT a creative mechanism
species that produce new generations in short periods of time can have evolution happen
very fast by natural selection
natural selection depends on what
time and place
natural selection favours traits that would be
advantageous to that environment
homology
similarities between different organisms that result from common ancestry
characteristics can be similar but with different functions in _____ species
related
is this homology or analogous?
features share common ancestry but NOT always the same function
homology
species that are closely related share
similar features
homologous structure
variations on a structural theme that was preset in their common ancestor
vestigial structure
Remnant features that served a function in the organism’s ancestors but not today
what is evidence that all life descended from common ancestors
All forms of life use the same genetic code
Homologous characteristics form a _______ pattern
nested
what does a nested pattern of characteristics look like
All life shares the deepest layer and each successive smaller group adds its own homologies to the ones shared with a larger group
Evolutionary tree
A diagram that reflects evolutionary relationships among groups of organisms
convergent evolution
independent evolution of similar features in different lineages
based on convergent evolution, distantly related organisms can
resemble one another
is this analogous or homologous
share similar function but NOT common ancestry
analogous
analogous species share features because of
convergent evolution
how can distantly related organisms resemble one another
Species that have evolved independently of each other but adapted to similar environments in similar ways
Biogeography
Study of the geographic distribution of species
Pangaea
Movement of plate tectonics that united earth’s landmasses into a single large continent 250 mya
endemic
species found nowhere else in the world
example of endemic species
island plants and animals
inference from
members of a population often vary in their inherited traits
individuals whose inherited traits give a higher probability of survival and reproduction = more offspring than other individuals
what observation does this describe
individuals whose inherited traits give a higher probability of survival and reproduction = more offspring than other individuals
members of a population often vary in their inherited traits
inference from :
all species can produce more offspring than the environment can support
the unequal ability of individuals to survive and reproduce = accumulation of favourable traits in the population over generations
Observation from :
the unequal ability of individuals to survive and reproduce = accumulation of favourable traits in the population over generations
all species can produce more offspring than the environment can support
in order for natural selection to act, traits must be _____
- inheritable
- beneficial
- variation
how does homology support evolutionary description of descent with modification
hypotheses about relationships among different groups
evolutionary trees
how did Pangaea separate
continental drift
understanding continent movement and modern species distribution allows us to
predict when and where different group evolved
who disproves Lamarck
August Weismann
speciation vs adaption
Speciation leads to the diversification of lineages, whereas adaptation maximizes the survival and reproductive success of organisms in an ever-changing environment
what locations does the Wallace Line show similarities between species
An imaginary line that runs between Bali and Lombok and represents the similarities between faunas.
macroevolution
speciation event
macroevolution can occur by
consistent small microevolutionary events (BUT NOT ALWAYS)
what level is macroevolution measured at
population level
the narrow definition of evolution is based on _____ measurements
quanitative
what does a change in allele/gene frequency indicate
microevolution
