Exam 1 PPTs - 1 Flashcards
Evolution:
- means change in living things by …
- is one of the most powerful ideas in all areas of science, and is the only theory that can seriously claim to …
- is one of the pillars of … -
“Nothing in biology makes sense except in the light of evolution”
descent with modification;
unify biology;
natural sciences
Evolution means …
change between generations
key concepts of evolution:
- …
- … and …
- …
- …
nonlinear tree-like process;
natural selection; adaptation;
random drift;
speciation
Evolution is not a …, … process
linear;
directional
All living things share a …
common ancestor
Adaptation:
example: camouflage
- appearance similar to …
- protection from ..
surroundings;
predators
Genetic drift - bottleneck effect
start with parent population, then bottleneck occurs (…)
The … then make up the next generation
drastic reduction in population;
surviving individuals
Speciation: ... ... ... ...
allopatric;
peripatric;
parapatric;
sympatric
allopatric speciation:
initial step of speciation entails … formation, leading to populations …
this results in new … after equilibration of new ranges
barrier;
in isolation;
distinct species
peripatric speciation:
initial step of speciation - … entered
evolution of reproductive isolation in …
new distinct species formed after equilibration of new ranges
new niche;
isolated niche
parapatric speciation:
initial step of speciation - …
evolution of reproductive isolation in …
new distinct species after equilibration of new ranges
new niche entered;
adjacent niche
sympatric speciation:
initial step of speciation - …
evolution of reproductive isolation …
new distinct species after equilibration of new ranges
genetic polymorphism;
within the population
A short history of evolutionary biology:
- evolutionary and … ideas before Darwin
- … (1859)
- the … of Darwin (1880-1920)
- the … (1920s to 1950s)
non-evolutionary;
Darwin’s theory;
eclipse;
modern synthesis
Most biologists in the years just before Darwin, accepted that species …
Jean-Baptiste Lamarck (1744-1829): ….
do not evolve;
transformism
Lamarcks’ transformism:
two mechanisms:
- …
- inheritance of …
"internal force"; acquired characters (characteristics);
Lamarcks’ transformism:
“In his famous discussion of the giraffe’s neck, he argued that ancestral giraffes had stretched to reach leaves …Their longer necks were … by their offspring, who thus started life with a propensity to … than their parents”
higher up;
inherited;
grow even longer necks
Darwin’s theory:
- … voyage 1832-37
- Finches … from island to island
- These observations of … probably first led Darwin to accept that species can …
- Organisms are beautifully adapted to their …
Beagle; varied; geographic variation; change; habits of life
Darwin’s theory:
species change -> …
Why species change? What is the mechanism of change?
- struggle for … (Malthus’s Essay on Population)
- “it at once struck me that under these circumstances favourable variations would tend to be … and unfavourable ones to be …”
- mechanism of change -> ..
evolution; existence; preserved; destroyed; natural selection
Darwin’s theory:
Natural selection:
- because of the struggle for existence, forms that are better adapted to survive will … and automatically … from one generation to the next
leave more offspring;
increase in frequency
Darwin’s theory:
Natural selection:
- As the environment changes through time (for example, from humid to arid), different forms of a species will be … than were the forms in the past. The better adapted forms will …, and the now poorly adapted forms will …
- “the result of this would be the …”
better adapted to it;
increase in frequency;
decrease in frequency;
formation of a new species
Darwin’s theory:
Evolution:
- Many biologists came to accept evolution but they imaged evolution as … and …
- thought that evolution should have an …, …, … pattern
one-dimensional; progressive; unfolding; predictable; progressive
Darwin’s theory:
- Evolution is not inherently or automatically …
- the species does not have an inherent tendency to …
progressive;
rise to a higher form
Darwin’s theory:
- Natural selection was … by most scientists
- This is because there was no satisfactory theory of …
- … and the … were unknown
- the existence of … was considered inconsistent with the theory
rejected; heredity; genes; DNA; gaps between forms
Darwin’s theory:
- … ideas were rediscovered in 1900-1920
- Modern synthesis put together by …, … and …
Mendel’s;
RA Fisher; JBS Haldane; Sewall Wright
