Chapter 22: Descent with modification Flashcards
who published the Origin of Species
Charles darwin
what did the origin of species focus on
attention to the great diversity of
organisms
what did darwin note about current species
they are descendants of ancestral species
what did darwin use to define evolution
descendant with modification
what is the evolution of both of
a pattern and a process
what happened when the origin of species was published
started a scientific revolution
how did greek philosopher aristotle view species and how did he arrange them
as fixed (unchanging) arranged them on a scala naturae
what is scala naturae
scale that increases with complexity
who was farolus linnaeus
- founder of taxonomy
- developed binomial formal
what is taxonomy
the branch of biology concerned with classifying organisms
what does descent with modification mean
evolution is the process by which species accumulate differences from their ancestors as they adapt to their different environment
what is the pattern of evolution
revealed by scientific data showing that life has evolved over time
what is the process of evolution
consists of mechanims that cause pattern of change
how did studing fossils help darwin
helped lay the groundwork for darwins ideas
what are fossils
remains or tracs of organisms from the past
where are fossils usually found
sedimentary rock
what is paleontology
the study of fossils
what did geologists James Hutton and Charles Lyell say about the Earth
perceived that
changes in Earth’s
the surface can result from
slow, continuous actions
what was Lamarck’s hypothesis of evolution
species
evolve through use and disuse of body
parts and the inheritance of acquired
characteristics
what is use and disuse
body parts used extensively become larger and stronger and unused parts deteriorate
what is the inheritance of acquired characteristics
modifications acquired in one’s lifetime can be passed to offspring
what was wrong with lamark’s hypothesis
it was not supported by evidence
where did darwin travel and what did he do
- south america
- collected species of south American plants and aniamls
what did darwin observe while in the galapagos
fossils resembled libing species from the same speciess
what did darwin hypothesize in south america
species from south america had colonized the galapagos and speciated on the islands
what are adaptations
inherited characteristics that enhance an organism’s survival and
reproduction in specific environments
what did darwin say about new species and adaptations
that new species arise from ancestral forms through the gradual accumulation of adaptations
in 1844 what did darwin write an essay on
natural selection as the mechanism of descent with modificationq
what is natural selection
process in
which individuals with certain inherited
traits tend to survive and reproduce at
higher rates because of those traits
what are the 3 observations in descent with modification?
- unity of life
- diversity of life
- ways organisms are suited to life in their environments
what did darwin say about organisms that live in different habitats
they gradually accumulated diverse modifications to fit them in specific ways of life
what does a fork mean in the branch/ tree diagram
the most recent common ancestor
what explains the large morphological gaps between related groups
branching and extinction events
how do humans modify species
artificial selection, breeding only
what organisms have little resemblance to their wild ancestors
crops, livestock animals, pets
what are the 2 observations that Charles darwin observed
- Members of a population
often vary in their
inherited traits - All species can produce
more offspring than the environment can
support, and many of these offspring fail to
survive and reproduce
what is the inference of the observation: Members of a population often vary in their inherited traits
Individuals whose inherited traits gave them a higher probability of
surviving and reproducing in a given environment tend to leave more offspring
than other individua
what is the inference of the second observation: All species can produce more offspring than the environment can
support, and many of these offspring fail to survive and reproduce
The unequal ability of individuals to survive and reproduce will lead to the
accumulation of favorable traits in the population over generations
how many offpsring complete development and reproduce and what happens to the rest
only a fraction of offpsring
the rest are starved, eaten, unmated, diseased or intolerant of physical conditions
what are advantageous traits
: Favorable inherited traits that promote survival and reproduction
what do advantageous traits do
- increase the number of offspring that survive and reproduce
which means they appear at a higher frequency in the next generation - increase the frequency of the populations with favorable conditions
what can increase the proportion of favorable traits in the population
natural selection by predators, lack of food, adverse conditions
what does natural selection increase
the frequency of adaptations that are favorable in an environment
what is the main rule of evolution
- indiviudals do not evolve; populations evolve over time
what happens to natural selection when the environment changes
natural selection drives adaptations to new conditions and give rise to new species
how can natural selection control traits
can only increase or decrease heritable traits that are variable in a
population
how do favorable traits vary
they vary within the environment
what data documents the pattern of evolution
– Direct observations
– Homology
– The fossil record
– Biogeography
what is Staphylococcus aureus
a bacterium that is commonly found on and occurs on the skin or nasal passages of people
what is methicillian-resistant S. Aureus
one strained dangerous pathogen that can cause fatal infections
what are the characteristics of the methicillin
-works by inhibiting an enzyme used by bacteria to produce cell walls
what does the MRSA bacteria use
a different enzyme in the cell wall that is not affected by methicillin
what happens when MRSA strains are exposed to methicillin
MRSA strains are more likely to survive and reproduce than nonresistant S. Aureus strains
what has happened to antiobotic resistance over the decades
antibiotic resistance has spread faster than new antibiotics have been discovered
what does natural selection not create
new traits but edits or selects traits already present in the population
how fast is evolution by natural selection
fast in species with short generation times
what determines how the straits will be selected or not selected
the local environment
what is homology
similarity resulting from a common ancestor
what are homologous structures
anatomical resemblances that represent variations on a structural
theme present in a common ancestor
what is comparative embryology
reveals anatomical homologies not visible in adult organisms
what do all vertebrate embryos have
a post-anal tail and pharyngeal arches
what do the pharyngeal arches develop into
structures with very different functions in adults from different vertebrate groups
what are molecular homologies
genes shared among organisms inherited from a common ancestor
what are evolutionary trees
diagrams that reflect hypotheses about the relationships among the different groups
what is relatedness is determined by what
the recent common ancestor, not the proximity of the groups of the tree
what can well supported be used to make
predictions about organisms
what is convergent evolution
evolution of similar or analogous features in distantly related groups
what does convergent evolution not show
information about ancestry
when do analogous traits arise
when groups independently adapt to similar envionments in similar ways
what does the fossil record provide evidence of
the extinction of species, the origin of new groups, and changes within group over time
what can fossil document
important transitins such as the transition from land to sea in the ancestors of cetaceans
how do fossils provide evidence of cetaceans?
living cetaceans and their close relatives, are more different from each other today than were early cetaceans and even toed ungulates
what are the close relatives of cetaceans
what is biogeography
the scientific study of the geographic distribution of species and provides evidence of evolution
what influences species distributions
the continental drift
what is the continental drift
the gradual movement of earth’s landmasses
why is it important to understand the continent movement and the modern distribution of species
allows us to predict when and where different groups evolved
