Evidence for Evolution
Natural Selection
Speciation
Origin of Life
Vocabulary and Human Evolution
100
List 3 types of evidence for evolution at the time of Darwin
Fossil record, homologous structures (pentadactyl limb), embryological development, geographic distribution of organisms, animal breeding, vestigial characteristics
100
Why is variation important for natural selection?
There must be variation so that there is actually genetic differences among individuals that can be selected for
100
List 3 types of reproductive isolation
behavioral, temporal, geographic
100
Who was the scientist who did the experiment with "swan-necked" flasks to disprove spontaneous generation?
Louis Pasteur
100
The cumulative change of heritable characteristics of a population. (vocabulary, this is a definition of what?)
evolution
200
How does the fossil record give evidence for evolution?
Evidence of very different organisms that don't currently exist (change over time), we can use radiometric dating to see that these organisms occurred a LONG time ago, the fossil record can provide missing links to show progression of changes (although many missing links have not been found), fossils are geographically distributed
200
What are the causes of variation among organisms?
Mutation, during meiosis, crossing over and independent assortment, sexual reproduction brings together gametes from completely different parents
200
What type of selection acts to remove intermediate varieties?
Disruptive selection
200
Describe early Earth.
Chaotic, outgassing from volcanoes provides water for oceans and early atmosphere (mostly nitrogen and carbon dioxide). Lots of lightning and bombardment by rocks and ice.
200
"Different country"
allopatric
300
How does animal breeding give evidence for evolution?
Through artificial selection, humans are able to pick desirable traits that they want in animals (cows, chickens, cats, dogs) and quickly change the characteristics of the animals. Look at all the different dog breeds! If it is possible to make such changes in such a short time, then natural selection could do the same over a long time interval
300
What is an adaptation?
A characteristics that makes an individual suited to its environment or way of life
300
Give an example of stabilizing selection.
Mass of babies: too big is too big to get out of womb and too small leads to health problems (vulnerability to infection). Clutch size of birds. Many more!!
300
List the 4 things needed for the formation of the first cells on Earth.
Non-living formation of simple organic molecules, assembly of these molecules into polymers, formation of membranes, and development of mechanism of inheritance (self-replicating molecules)
300
List 4 characteristics that define humans as primates.
Opposable thumbs, arms that rotate in 3 planes (swinging!!), stereoscopic vision (gives 3-D), and modifications for upright posture
400
Explain the process of industrial melanism. Go through all the steps.
In pre-industrial England, light-colored peppered moths blended in with the light trees and were common. Darker (melanic) moths stood out on the trees and were eaten and thus had a lower frequency. With industrialization trees became darker and the melanic moths blended in with the trees, while the peppered moths stood out and got eaten. The frequency of melanic moths went up and peppered moths went down. After the polution was cleaned up, the reverse occurred and peppered moths again become common.
400
Why is overproduction of offspring necessary for natural selection to occur?
Natural selection requires differential survival of organisms with different traits. As we saw on Daphne Major, during times of plenty, lots of birds survived, but when the going got tough (the drought) many birds died and the characteristics of the population changed
400
Explain an example of sympatric speciation.
Can occur through different mating rituals. Different dances or songs keep species apart, even when they live together. Different mating seasons can keep species apart. Polyploidy can occur and prevent animals or plants from breeding because different numbers of chromosomes fail to line up in a zygote.
400
Describe the Miller-Urey experiment and state what it proved.
Mixed methane, ammonia, hydrogen, water in a flask, heated it and gave it electrical impulses to simulate lightning. Within a week the solution was brown and cloudy and tested positive for many amino acids. This proved that the spontaneous origin of life was possible in early Earth conditions.
400
List 4 essential features of humans that have changed over time.
larger cranial capacity!!, more vertical forehead, smaller jaw, smaller molars, reduced brow ridge, foramen magnum moved more central,
500
Discuss the modern example of antibiotic resistant bacteria.
Antibiotics are given to kill bacteria, and they will kill most bacteria, but every now and then there are some bacteria that have mutated to have resistance to that antibiotic. While most of the bacteria die, these resistance ones survive and because there is no competition and they reproduce very quickly, the percentage of antibiotic resistant bacteria in the population increases. This process is increased by overuse of antibiotics (often used for viral illnesses, even though viruses don't respond to antibiotics). We have to switch which antibiotic we use and now we have bacteria that are resistance to multiple antibiotics.
500
Give a detailed example of natural selection.
Answer varies, but can include examples from Beak of the Finch, peppered moths, giraffe's long neck, and many more. Make sure that you include the original phenotypes, the change that occurred, why one phenotype is favored over another, differential survival, reproduction of one phenotype over another, and the resulting change in the gene pool.
500
Discuss gradualism in speciation and punctuated equilibrium, giving examples of where each might occur.
Gradualism is slow but constant change over time leading to gradual changes that occur on the way to becoming a new species. Darwin supported this model. In punctuated equilibrium, speciation can occur quickly in response to a changing environment. For example, if new niches open up, speciation can occur quickly. The model has quick changes followed by periods of stability. The fossil record has many gaps and some of this could be explained by punctuated equilibrium. (But remember, it is relatively rare to have fossils left behind, so missing fossils doesn't necessarily imply punctuated eq.).
500
Describe the endosymbiotic theory of the origin of eukaryotic cells, including evidence for the model.
Mitochondria and chloroplasts were prokaryotic organisms that were engulfed by a larger prokaryote. Rather than being digested, the 2 cells formed a symbiotic relationship. In the situation of mitochondria, it carried out cellular respiration and contributed ATP to the larger cell, while the larger cell provided food and protection for the smaller cell. Evidence for this model is that both mitochondria and chloroplasts have their own naked DNA, they have their own 70 S ribosomes, they can make their own proteins, and they have double membranes (from being engulfed)
500
What are the 5 assumptions that must occur for the Hardy-Weinberg equation to be used? If p and q don't stay equal, what does that mean?
population is large, random mating, no mutation, no net immigration or emigration, no natural selection. If p and q change, that means that one or more of the assumptions was not met. In our simulation, it could have failed because of our small sample size. In large open populations with changing p and q, it is proposed to be because of natural selection (differential survival)
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