Chapter 4 Page 63- I'm a little confused about stabilizing and directional selection. In the example of directional selection using microevolution with the use of pesticides, when pesticides is sprayed and if some insects form a resistance to the pesticide, that is directional selection, but if those insects reproduce, and they all have that resistant trait to pesticides, is that an example of stabilizing selection? Page 68- Is there a reason as to why negative assortative mating is not usually common in nature? Does it have to too much genetic variation? Page 68-69- When talking about a mixed ESS, would that be similar to how learning can be modified when situations change in order to minimize unnecessary energy to get to the same outcome?
Chapter, page 67: With the blue jay study discussed, the book says the jays picked the most common moth form, and then would switch to other forms once the first was depleted. The experimenters also changed the background though, so were the jays picking truly the most common form, or just whatever form was the most visible? Chapter 4, page 68: I went to a program about raptors once, and the presenter said that some barn owls have a lot of spots on their chest, and others have few. Apparently, it's been noticed that owls with fewer spots choose to mate with owls with more spots, an example of negative-assortative mating. It sounded like a somewhat recent observation, so is it that this type of mating is uncommon for a reason, or that we just haven't picked up on it in many species? Chapter 4, page 76: This question is probably very closely linked with learning, but the cost-benefit study section is what made me think of it. Will an animal always try to find the most efficient cost-benefit ratio? With humans, sometimes we find a way of doing things that work, and we know it works, so we stick with it. We don't always try one way, see that it works, and then risk another way in the event it might fail. Whenever I read about cost-benefit analysis, it sounds like animals always find the most efficient way, and I was wondering how true that is.
Chapter 4 1. Page 58. The authors definition of evolution that it is a change in frequency of alleles in a population of organisms over generations, but what I don't understand is that doesn't the environment have an effect on evolution? And doesn't it also have to do with learning things to adapt to a situation? 2. Page 68. While I somewhat understand what negative assosiative-matting is. I still don't get it or how it works, what exactly does it mean/ entail? Does it mean that oppisites attract or is that wrong?
Chapter 4 1. Page 58. The authors definition of evolution that it is a change in frequency of alleles in a population of organisms over generations, but what I don't understand is that doesn't the environment have an effect on evolution? And doesn't it also have to do with learning things to adapt to a situation? 2. Page 68. While I somewhat understand what negative assosiative-matting is. I still don't get it or how it works, what exactly does it mean/ entail? Does it mean that oppisites attract or is that wrong?
Cage 63: I have always been a little iffy on the different between gene flow and genetic drift. Gene flow happens between populations, while genetic drift occurs on one population (well many may be effected but the focus is on each individual population), right? Page 67: how does rarity give an allele a greater selective advantage? This seems like a never ending cycle because with greater advantage it would be selected more and then become common. Is this like the new technology, allele, that gets discovered and then becomes outdated until another new, or rare allele, comes along? Page 73: aren't all experiments comparative at some level? They are all based on previous research and then compare their results to those?
1) Chapter 4, page 60: It is stated that the phrase "for the good of the species" should be avoided, because natural selection doesn't act on a species as a whole, but rather at an individual level. The author mentions that a trait that is favorable to an individual may increase even though it is not favorable to the population/species. My question here is does natural selection ever actually lead to the extinction of a species? Most of the time it seems that species usually go extinct due to external causes, such as habitat loss or hunting. But can natural selection actually cause a species to be depleted substantially if the traits are extremely unfavorable to the population over time?
2) Chapter 4, page 62-63: On the topic of genetic mutations and variations the author discusses how mutation is the ultimate source of variation, which is what allows evolution and natural selection to be at work. I was wondering what would happen to a species/population if no mutations were to occur? If there was no variation within a population and evolution was unable to occur what would happen to that population? Would they eventually die out if their traits were unable to evolve to increase individual fitness? In other words, do species need genetic mutations/variation in order to maintain their population over time?
3) Chapter 4, page 68: When it comes to negative-assertive mating, do the animals make a conscious decision to mate with others who have a different phenotype than their own? Or is it more of an unconscious/ instinctual decision? Does negative-assertive mating only occur in certain species? Or are all species capable of doing this but only do it if it provides a benefit for them at the time?
Shapter 4, page 57: Although the Kittiwake gulls are seen to be less "tidy" with their nests and seen to be more careless than herring gulls because they leave eggshells and droppings in the vicinity of their nest, would this help them to distinguish between the nest to find witch one belongs to them.
Chapter 4 page 63: In the maintenance of variation section it asks the questions, "Why hasn't it eliminated from the population those individuals that bare other traits?", and "given that mutations are rare, why do we still see variation in most populations?". would it be possible to answer the question of why do we still see variation in most populations by saying that without the species that are not able to survive natural selection, then the ones who do survive would have no means for competition and no means for worrying about dying and not passing on their genes to the next generation.
Chapter 4, Page: 73: In the discussion of phylogeny it is stated that since phylogeny are hypothesis and the more reconstructed data we have the more "stable" the data set would be. is it saying that we are able to make assumptions on what family a specific animal belongs to due to elimination because of what other species displayed the same characteristics? (this is probably very confusing, and i am happy to ask it again tomorrow after or during class, and hopefully make more sense of it)
1. Page 60. The book is discussing macroevolution and states that it is large scale changes over geological time. What makes macroevolution different from gene flow? Doesn't gene flow cause large scale changes in species as well because the genes are altering due to the environment? It also states that evolution is the change in allele frequencies but wouldn't gene flow be changing that too? (And then I read what gene flow is) Can macroevolution cause species to become closer to each other as well?
2. Page 65. The book discusses genetic drift and how it causes a change in behavior do to a change in allele frequencies from chance events. Are there times where not all members of a population are effected by genetic drift? Would the species who did not experience the behavior change learn the change form the others? Or would they be exiled?
3. Page 68. I'm a little confused about negative-assortative mating. What is this actually saying? I'm reading that it is when an animal choose a mate with a different phenotype, but doesn't this always happen? Or is it saying that it is closing a mate in terms of recessive and dominant genes. For instance if I had a white strip and white strips were more apt to caring for offspring a mate would choose me over another? I'm just confused but I thought this was always or most often the case.
Chapter 4, page 59-60. Adaptations are traits that have evolved to help individuals reproduce and survive better. Natural selection is when traits are naturally chosen and evolve to help better an individual. Are the traits chosen in natural selection always adaptations? Chapter 4, Page 62, While reading about recombination, I am a little confused. Is this process how most offspring are made? Sharing half of your DNA with each parent? Chapter 4, Page 67, Not really sure how Frequency dependent selection works. One allele is favored and used the most until the alternate allele is favored. How does this switch work?
Chapter 4
ReplyDeletePage 63- I'm a little confused about stabilizing and directional selection. In the example of directional selection using microevolution with the use of pesticides, when pesticides is sprayed and if some insects form a resistance to the pesticide, that is directional selection, but if those insects reproduce, and they all have that resistant trait to pesticides, is that an example of stabilizing selection?
Page 68- Is there a reason as to why negative assortative mating is not usually common in nature? Does it have to too much genetic variation?
Page 68-69- When talking about a mixed ESS, would that be similar to how learning can be modified when situations change in order to minimize unnecessary energy to get to the same outcome?
Chapter, page 67: With the blue jay study discussed, the book says the jays picked the most common moth form, and then would switch to other forms once the first was depleted. The experimenters also changed the background though, so were the jays picking truly the most common form, or just whatever form was the most visible?
ReplyDeleteChapter 4, page 68: I went to a program about raptors once, and the presenter said that some barn owls have a lot of spots on their chest, and others have few. Apparently, it's been noticed that owls with fewer spots choose to mate with owls with more spots, an example of negative-assortative mating. It sounded like a somewhat recent observation, so is it that this type of mating is uncommon for a reason, or that we just haven't picked up on it in many species?
Chapter 4, page 76: This question is probably very closely linked with learning, but the cost-benefit study section is what made me think of it. Will an animal always try to find the most efficient cost-benefit ratio? With humans, sometimes we find a way of doing things that work, and we know it works, so we stick with it. We don't always try one way, see that it works, and then risk another way in the event it might fail. Whenever I read about cost-benefit analysis, it sounds like animals always find the most efficient way, and I was wondering how true that is.
Chapter 4
ReplyDelete1. Page 58. The authors definition of evolution that it is a change in frequency of alleles in a population of organisms over generations, but what I don't understand is that doesn't the environment have an effect on evolution? And doesn't it also have to do with learning things to adapt to a situation?
2. Page 68. While I somewhat understand what negative assosiative-matting is. I still don't get it or how it works, what exactly does it mean/ entail? Does it mean that oppisites attract or is that wrong?
Chapter 4
ReplyDelete1. Page 58. The authors definition of evolution that it is a change in frequency of alleles in a population of organisms over generations, but what I don't understand is that doesn't the environment have an effect on evolution? And doesn't it also have to do with learning things to adapt to a situation?
2. Page 68. While I somewhat understand what negative assosiative-matting is. I still don't get it or how it works, what exactly does it mean/ entail? Does it mean that oppisites attract or is that wrong?
Cage 63: I have always been a little iffy on the different between gene flow and genetic drift. Gene flow happens between populations, while genetic drift occurs on one population (well many may be effected but the focus is on each individual population), right?
ReplyDeletePage 67: how does rarity give an allele a greater selective advantage? This seems like a never ending cycle because with greater advantage it would be selected more and then become common. Is this like the new technology, allele, that gets discovered and then becomes outdated until another new, or rare allele, comes along?
Page 73: aren't all experiments comparative at some level? They are all based on previous research and then compare their results to those?
Q1: Yup!
DeleteQ2: You're right about the cycle here as well; we'll look at an example this week.
1) Chapter 4, page 60: It is stated that the phrase "for the good of the species" should be avoided, because natural selection doesn't act on a species as a whole, but rather at an individual level. The author mentions that a trait that is favorable to an individual may increase even though it is not favorable to the population/species. My question here is does natural selection ever actually lead to the extinction of a species? Most of the time it seems that species usually go extinct due to external causes, such as habitat loss or hunting. But can natural selection actually cause a species to be depleted substantially if the traits are extremely unfavorable to the population over time?
ReplyDelete2) Chapter 4, page 62-63: On the topic of genetic mutations and variations the author discusses how mutation is the ultimate source of variation, which is what allows evolution and natural selection to be at work. I was wondering what would happen to a species/population if no mutations were to occur? If there was no variation within a population and evolution was unable to occur what would happen to that population? Would they eventually die out if their traits were unable to evolve to increase individual fitness? In other words, do species need genetic mutations/variation in order to maintain their population over time?
3) Chapter 4, page 68: When it comes to negative-assertive mating, do the animals make a conscious decision to mate with others who have a different phenotype than their own? Or is it more of an unconscious/ instinctual decision? Does negative-assertive mating only occur in certain species? Or are all species capable of doing this but only do it if it provides a benefit for them at the time?
Shapter 4, page 57: Although the Kittiwake gulls are seen to be less "tidy" with their nests and seen to be more careless than herring gulls because they leave eggshells and droppings in the vicinity of their nest, would this help them to distinguish between the nest to find witch one belongs to them.
ReplyDeleteChapter 4 page 63: In the maintenance of variation section it asks the questions, "Why hasn't it eliminated from the population those individuals that bare other traits?", and "given that mutations are rare, why do we still see variation in most populations?". would it be possible to answer the question of why do we still see variation in most populations by saying that without the species that are not able to survive natural selection, then the ones who do survive would have no means for competition and no means for worrying about dying and not passing on their genes to the next generation.
Chapter 4, Page: 73: In the discussion of phylogeny it is stated that since phylogeny are hypothesis and the more reconstructed data we have the more "stable" the data set would be. is it saying that we are able to make assumptions on what family a specific animal belongs to due to elimination because of what other species displayed the same characteristics? (this is probably very confusing, and i am happy to ask it again tomorrow after or during class, and hopefully make more sense of it)
1. Page 60. The book is discussing macroevolution and states that it is large scale changes over geological time. What makes macroevolution different from gene flow? Doesn't gene flow cause large scale changes in species as well because the genes are altering due to the environment? It also states that evolution is the change in allele frequencies but wouldn't gene flow be changing that too? (And then I read what gene flow is) Can macroevolution cause species to become closer to each other as well?
ReplyDelete2. Page 65. The book discusses genetic drift and how it causes a change in behavior do to a change in allele frequencies from chance events. Are there times where not all members of a population are effected by genetic drift? Would the species who did not experience the behavior change learn the change form the others? Or would they be exiled?
3. Page 68. I'm a little confused about negative-assortative mating. What is this actually saying? I'm reading that it is when an animal choose a mate with a different phenotype, but doesn't this always happen? Or is it saying that it is closing a mate in terms of recessive and dominant genes. For instance if I had a white strip and white strips were more apt to caring for offspring a mate would choose me over another? I'm just confused but I thought this was always or most often the case.
Chapter 4, page 59-60. Adaptations are traits that have evolved to help individuals reproduce and survive better. Natural selection is when traits are naturally chosen and evolve to help better an individual. Are the traits chosen in natural selection always adaptations?
ReplyDeleteChapter 4, Page 62, While reading about recombination, I am a little confused. Is this process how most offspring are made? Sharing half of your DNA with each parent?
Chapter 4, Page 67, Not really sure how Frequency dependent selection works. One allele is favored and used the most until the alternate allele is favored. How does this switch work?