Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
40 Cards in this Set
- Front
- Back
|
Evolution
|
Change over time
|
|
|
Analogous Structures
|
Structures that have the same function, but not the same components or developmental.
Ex. Bird wings and butterfly wings. |
|
|
Eusthenopteron
|
transition period between fish and amphibians
|
|
|
Vestige
|
Structure in different species that are similar in form, position and development because they are a result of common ancestry and genetic basis
|
|
|
transitional forms
|
organisms that are intermediate in characteristics between two major groups
|
|
|
How does evolution as a term differ from evolution as a theory?
|
Is just a term to explain change over time.
|
|
|
Why did Darwin wait 20 years after returning from his voyage on the Beagle in 1836 to publish On The Origin of Species in 1859?
|
For fear of how his ideas will be received, how his wife and children will be treated – ideas are considered heresy!
|
|
|
What does it mean to say that Darwin was a special creationist when he set sail on the Beagle?
|
*
|
|
|
Was he hired as the ship's naturalist?
|
Due to his rich background he was hired on the ship to keep the captain company.
|
|
|
Describe some of the ideas popular in Victorian England that made Darwin wary of how the theory of evolution by natural selection would be published.
|
1.The earth was thought to be 6000 years old (not 4.5 billion)
2. Man was not considered an animal 3.Species were considered immutable = incapable of change |
|
|
Who was Alfred Russel Wallace?
|
Independently arrives at same set of ideas as Darwin and help motivate Darwin to publish.
|
|
|
the set of premises on which the theory of evolution by natural selection is based.
|
Natural populations nonetheless tend to remain stable = many individuals do not survive and/or reproduce
|
|
|
Strata
|
show gradual changes in org. over time
|
|
|
How does examining strata give evidence for evolution?
|
show gradual changes in org. over time, with layers of rock laid down one on another.
|
|
|
What kinds of changes have occurred in the evolution of horses over time?
|
1. grad. increase in size of teeth
2. reduction in # of toes 3. increase in body size |
|
|
Does the fossil record give a thorough picture of the history of ancient life? Explain.
|
The fossil record is incomplete and has many gaps - can tell only a small fraction of history of life on earth from fossil record alone
|
|
|
Why are Archaeopteryx and Eusthenopteron important fossil organisms?
|
Because they are transitional forms sometimes found in fossil record = organisms intermediate between two major groups
example transitional between reptile and bird |
|
|
How do homologous structures differ from analogous structures in the way they originate and in the information they yield? Give an example of a pair of each.
|
-transitional between fish and amphibians
fins w/ primitive bone structure, skull and amphib. features. -structures in different species that are similar in form, position and development because they’re the result of common ancestry and genetic basis |
|
|
Describe several examples of vestigial structures or behaviors.
|
arrector pili muscles in mammals - “goosebumps” in humans
femur and pelvic bones in whales and snakes the appendix –contains cellulose- digesting bacteria in herbivorous mammals |
|
|
Give several examples of how comparative embryology is used as evidence for evolution.
|
the early embryos of all of the vertebrates look very similar
|
|
|
Give several examples of how comparative biochemistry demonstrates evolutionary relationships among organisms.
|
homologies exist even at the molecular level
1. Hox (homeobox) genes that lay down head to tail axis similar in all animals, lined up on chromosomes in same order 2. the genetic code set of nucleotide triplets that “spells” is universal in living things |
|
|
Artificial Selection
|
breeders select which members of a population shall reproduce & which shall not to produce tremendous variation in organisms over time
|
|
|
Comparative Anatomy
|
in organisms that are very different in size, shape, way of life, are nonetheless very similar structures called
|
|
|
Theory of Evolution by Natural Selection is based upon these observations
|
1. Natural populations have the potential for explosive growth -
2. Natural populations nonetheless tend to remain stable = many individuals do not survive and/or reproduce 3. Variation exists among individuals, and at least some of that variation is heritable = has a genetic basis 4. Individuals with variations that make them more suited (better adapted) to a particular environment are those that survive and reproduce 5. These favorable variations thus become more common in future generations |
|
|
Evolution
|
the change in the gene frequencies of a population over time
|
|
|
gene frequency
|
how common a gene is in the population relative to other genes (given as a decimal)
|
|
|
natural selection
|
differential survival and reproduction of some individuals over others, so that their genes become more common in the next generation
|
|
|
genetic drift
|
changes in gene frequencies due to chance events
|
|
|
founder effect
|
when a small pop. splinters from a large, gene freq. can be over or under- represented
|
|
|
gene flow
|
movement of alleles into or out of a population, due to:
-immigration and emigration of individuals -movement of gametes |
|
|
alcohol dehydrogenate
|
the same gene and enzyme that helps humans break down alcohol is also found in fruit flies
|
|
|
bottleneck effect
|
a large population drastically reduced in size by some disaster will lose genetic diversity, resulting uniformity can leave populations vulnerable
|
|
|
How does natural selection work in terms of changing gene frequencies?
|
populations are the smallest units with a gene pool that can have a gene frequency
|
|
|
Why is the statement “survival of the fittest” incomplete in describing natural selection?
|
“survival of the fittest” incomplete – selection doesn’t favor survival alone, will even favor reproduction at the expense of survival
|
|
|
Why are mutations so important to evolutionary change?
|
What mutations do is provide variety natural selection then acts on
|
|
|
Why, in of themselves, are mutations not a principal cause of evolutionary change?
|
They’re random changes, don’t occur as needed or in response to some pressure
|
|
|
Take the example of the evolution of the giraffe’s long neck and describe the Lamarckian vs. the Darwinian view of how such a structure developed.
|
-Those with longer necks who could reach more food were more likely to survive and reproduce
-Long neck genes thus become more common in the next generation -The giraffe's did not stretch their as Lamarckians thought. |
|
|
For both the peppered moth and Darwin’s finches examples of natural selection, describe what kind of change took place over time, why this change happened, and what the selective agent was in each case
|
White moths hid better on the trees, unlike the black moths.
Once the trees blacken from pollution of the industrial revolution, the white moths were not longer hidden the black moths were. The selective agents predators, environment. |
|
|
What kind of change can be observed in the alcohol dehydrogenase genes in a population of fruit flies fed alcohol, and why?
What do these changes look like on a graph? |
Some alleles produce enzymes that are much more effective than others, in order to survive
- Pops. of flies fed alcohol show dramatic increase in freq. of more effective allele in just 50 generations |
|
|
What is the difference between evolutionary changes that occur due to drift rather than natural selection?
|
drift- changes in gene frequencies due to chance events
natural selection- differential survival and reproduction of some individuals over others, so that their genes become more common in the next generation |
