Darwin and Evolution Flashcards
How long did Darwin travel on the ship?
5 years
What where Darwin’s 3 main observations?
- species vary globally
- species vary locally
- species vary overtime (fossils)
What did Darwin find on the Galápagos Islands?
Land tortoises
What varied among the tortoises from different islands?
Their shells
What varied between the finches on each island?
Their beaks
What did James Hutton do?
He proposed that the earth is shaped by geological forces that occur slowly.
What is another name for James Hutton’s theory?
Gradualism
What did Thomas Malthus do?
He was an economist that wrote a book stating that babies are being born faster than people are dying.
What was Thomas Malthus’s theory?
That if people are being born faster than they are dying eventually we will run out of resources.
What is exponential growth?
A large increase in the population.
Define point of crisis.
The point where resources run out and the population levels off.
Define carrying capacity.
The maximum number of individuals that an ecosystem can support.
Who was Jean-Baptiste Lamark?
In 1809 he developed a hypothesis that acquired traits could be passed from parents to offspring.
What are acquired traits?
A trait that you aren’t born with, but one that you learn.
What was Jean-Baptiste Lamark’s theory called?
The theory of use and disuse.
Is Jean-Baptiste Lamark’s theory correct?
No
What did Charles Lyell suggest?
Uniformitarianism
What is uniformitarianism?
It says that you must explain past events with processes that we can observe now.
What were the two main things Darwin learn?
- If the earth changes, animals my to
2. Is living things do change, it takes a long time
Who was Alfred Wallace?
A naturalist, that in 1858 sent Darwin a report containing his idea of evolution.
True or False?
Darwin’s idea of evolution was nearly identical to Wallace’s.
True
What was the name of Darwin’s book?
The Origin of Species .
What does natural selection cause?
No two organisms to be exactly the same or equal.
What is an adaption?
Any inheritable characteristic that allows organisms to survive and reproduce.
What does the theory of descent with modifications say?
Each living species has descended with changes from another species overtime.
What does a bell curve mean?
Natural selection is not occurring.
What is directional selection?
When the environment chooses one extreme form of a trait.
What does directional selection’s graph look like?
It is either extremely high or low.
What is disruptive selection?
When the environment uses both extremes of a trait.
What does disruptive selection’s graph look like?
One extremely high and one extremely low.
What does the Hardy-Weinburg principle assume?
That evolution does not occur (genetic equilibrium).
What are the conditions that must be met for the Hardy-Weinburg principle to work?
- random mating
- large population
- no migration
- no natural selection
- no mutations
Is it possible for the conditions that the Hardy-Weinburg principle requires to occur?
No
What is the equation for the Hardy-Weinburg principle?
p2+2pq+q2=1
What does p+q equal?
1
What does p equal?
The frequency of allele A.
What does q equal?
The frequency of allele a.
What does p2 equal?
The frequency of individual AA.
What does q2 equal?
The frequency of individual aa.
What does 2pq equal?
The frequency of individual Aa.
What are the four factors that affect evolution?
- natural selection
- mutations
- genetic drift
- migration
What is genetic drift?
When chance events alter allele frequency.
What is another name for genetic drift?
The bottleneck effect
True or false
Genetic drift affects large populations more than small.
False, it effects small populations more than large.
What is the founder effect?
Organisms, after a disaster, that rebuild a population.
What is another name for migration?
Gene flow
What are the 7 “proofs” of evolution?
- The fossil record
- Geographic distribution
- vestigial structures
- homologous structures
- analogous structures
- embryology
- molecular biology
What is geographic distribution?
Pangea moving apart
What are Vestigial structures?
Structures that no longer have a function in organisms.
What are analogous structures?
Similar structures in organisms that didn’t evolve from a common ancestor
Why do scientist think analogous structures occurred?
Similar habitats
What is speciation?
Process by which a new species is formed.
What are the 3 types of reproductive isolation?
- Reproduction isolation
- Geographic isolation
- Temporal isolation
What is an example of behavioral isolation?
Mating dances
What is an example of temporal isolation?
Different mating times (deals with time).
What are the three patterns of evolution?
- adaptive radiation
- convergent evolution
- coevolution
Is another name for adaptive radiation?
Divergent evolution
What is adaptive radiation?
occurs when a single species evolves into many different species due to natural selection.
What is convergent evolution?
Unrelated species evolve to look similar due to similar habitats
Is Coevolution?
Two species evolve in response to changes in each other overtime.
-ex. Butterflys and flowers
What are the two rates of evolution?
- gradualism
* punctuated equilibrium
What is Gradualism?
Species evolve at a slow, steady rate overtime.
What is punctuated equilibrium?
Species stay the same for long periods of time and then undergo “rapid” change
What is a molecular clock?
It uses mutation rates in DNA sequences to estimate the time that two species have been evolving independently.
What are neutral mutations?
They are mutations that accumulate overtime at about the same rate in all species, they have no effect.
What can you use neutral mutations to do?
Determine the amount of time that has passed since two species split.
Where did all these genes come from?
- Unequal swapping of DNA during crossing over.
2. Modification of existing genes
Charles Darwin was a naturalist on what?
A ship, the HMS Beagle.
What are the two main topics that Darwin’s discussed in his book, the origin of species?
- natural selection
* decent with modification’s
What does it mean for a population to be in genetic equilibrium?
The frequency an allele doesn’t change between generations.
What are the conditions required for natural selection to occur?
- variation
- reproduction
- the traits must be inherited
Why does genetic drift affect small populations more than large?
The fewer organisms there are, the easier it is for one type of trait to be completely eliminated from the population.
How can hox genes lead to evolution?
Hox genes determine the growth of arms, legs, ect. and their sizes, changes in these can result in new animals.
What are homologous structures?
Structures that are shared by related species and that have been inherited from a common ancestor.
