Ch. 17-3 - Darwin's Theory: Natural Selection Flashcards
to study for Evolution test
How long did Darwin wait to publish his ideas? Why?
20 years, because many people ridiculed Lamarck’s ideas, and Darwin’s ideas were even more radical. So Darwin wanted to have as much evidence as he could before showing his ideas to the world.
What caused Darwin to publish his book on evolution?
reading an article by Alfred Russel Wallace expressing ideas about evolution similar to those of Darwin’s
name of Darwin’s book on evolution
On the Origin of Species
Though Wallace had the right idea, Darwin had…
data & observations (evidence) to support his ideas
Darwin’s book used arguments also used by which two scientists?
Thomas Malthus
Jean-Baptiste Lamarck
What’d Darwin call the competition between members of a species for resources?
the struggle for existence
What’d Darwin hypothesized about variation in relation to fitness?
Individuals with certain variations are better suited to their environment than other individuals are
What do you call traits that help an individual survive and reproduce in its environment? Can they be passed on to the next generation(s)?
Adaptations.
Yes they can
what can adaptations involve/be?
- body parts or structures
- colors
- physiological
- behaviors
define fitness
how well an individual can survive & reproduce in its environment
Individuals with adaptations that benefit them have ____ fitness, and those with characteristics that disadvantage them have ____ fitness
high; low
True or False: Individuals with adaptations that are a detriment to them produce many offspring
False
another term for differential reproductive success
survival of the fittest
define natural selection
the process by which individuals in nature with variations best suited to their environment survive and have more offspring
In both artificial & natural selection…
only certain individuals have offspring
Who is the breeder in artificial selection? In natural selection?
Artificial selection: farmer or animal breeder
Natural selection: nature
the 3 conditions form a situation natural selection WILL occur in
- more individuals are born than can live (struggle for existence)
- natural, heritable variation affects the ability to survive & reproduce (variation & adaptation)
- fitness varies among individuals (differential reproductive fitness)
True or False: natural selection applies only to heritable traits
True
True or False: natural selection makes organisms better and happens in a fixed direction
False
Do adaptations have to be perfect or just good enough to be passed on?
good enough
Say the environment changes. Will traits useful in the previous environment still be useful.
not necessarily
If the environment changes faster than a species can adapt, what may happen to the species?
It may go extinct
True or False: Natural selection is the only mechanism that leads to evolutionary change
False
What did Darwin argue about the descent of species? What is this idea called?
He argued species have descended from a common ancestor and have changed over time.
This is called descent with modification
