Slide 6 What accounts fo
BIOB51 – Lecture Notes Lecture 1: “Good fit” meaning adapted within their environment. Lecture 2: Slide 6 What accounts for the diversity of species and then the nested similarity within this diversity? Slide 7 Before Darwin, biologists were looking to answer these questions and didn’t really have a lot of information. Their answer to these kinds of questions was special creation. Slide 8 Special Creation is an idea that pervaded the globe. Slide 9 If we were to draw it out schematically, time is progressing and origin of all species (separately, recently and independently). Slide 10 Before Darwin, biologists made some observations that suggested that special creation wasn’t really the best idea for the answers for these questions. 1. Species didn’t remain exactly the same over time. 2. In the past, people might not have the information if a species has gone extinct. When the dodo bird went extinct, it was one of the first time biologists realized something can cease to exist. 3. A lot of study of fossils. Fossil record provides this idea there’s more to it than just an independent one-time creation event. 4. Important observation. Slide 11 Also thought of the evolution by natural selection. Slide 16 Definition answered the life and diversity questions but not the adaptation one. Slide 21
Wasps of same colony have different amount of black to help identify individuals apart. Variation in colours for these flowers in California. Slide 24 The plant aphid can reproduce parthenogenetically meaning female plant aphids don’t need to mate to reproduce. They can essentially clone themselves within their body. So their egg which has their genetic information can grow other plant aphids. They can start reproducing after 7 days of being born and can produce 14 offspring per day. Slide 26 1. Competition: offspring compete with each other for resources 2. P &P: Not all of them can survive b/c they’re eaten by other things Slide 27 1. Climate: some individuals have variation in their cold or heat tolerance 2. Catastrophic events: volcanos, floods, etc. 3. Habitat/food limitation: ie. deserts – not enough water for everything to live Slide 29 Stored fat related to an animal’s health and can be measured in bone marrow index. Impalas with low bone marrow index have eaten less; have less storage nutrients and generally doing less well in life than individuals with less stored fat. Random= random selection of impalas in the environment, random level of what the average store fat in the individuals in this population. This is taken from the bone marrow of the impalas that were hunted. The hunters aren’t making a selection of better or worse, they’re just hunting impalas and whoever they happened they kill, that’s whose bone marrow they measure. Prey= bone marrow of impala that became prey of the wild dogs. Less stored stored=more likely to get killed. Slide 31 Not only physical fitness traits but other traits as well can help in Darwinian fitness. Ie. Buffalos vs peacock spider Slide 32 Example: If endurance is an adaptation, will help win against other buffalo and gain access to females so it’ll increase its Darwinian fitness. Adaptiveness or advantage of adaptations is measured in lifetime reproductive success. Therefore, an adaptation isn’t anything les it contributes to an increase in offspring. It could be increase in number of offspring or quality of offspring but it has to increase something about the offspring production and survival.
Another example: Cuttlefish can swim really fast. Reason why it’s an adaptation is not b/c it swims really fast to escape predation (partly) but the point of it is that it swims really fats, escapes predation and is able to survive and consequently reproduce. The ones that can’t swim fast are more likely to be eaten and don’t reproduce. Slide 33 Phenotype: external appearance or external production of a trait Rundown: Fitness increases are really important Adaptations that increase fitness are favoured by natural selection Natural selection is the difference in reproductive success among individuals Slide 34 Two snakes. Predator, which is the bird. Green ones camouflage well against their environment while the red/orange ones stand out. Bird was able to take two red/orange snakes easily and one green one. Green ones survive and reproduce and so does the remaining red/orange. In this case, the one with the green phenotype have a higher likelihood of having lifetime reproductive success than on average of the red/orange individuals. Only true if colour is heritable. Slide 35 As environment changes, different things might become adaptive and those things might become more present in the population b/c of differential reproduction. Pay no attention to comic. Slide 39 *Textbook example* IMPORTANT FOR MIDTERM/FINAL! Slide 41 Darwin’s theory of evolution wasn’t accepted right away. Slide 44 Darwin was 26 when he started collecting research on evolution and he was 50 when he published his first book. Slide 50 Green snakes eating green mice. Red/orange snakes eating red/orange mice. Slide 51
Green or red/orange can produce either phenotype b/c it depends on what their baby snakes eat. Bird comes and picks off the same proportion (3 red/orange snakes and one green snake). Slide 52 Still the same proportions of green and red/orange in population. Doesn’t depend on heritable difference but depends on what the babies’ eat. Slide 55 Acquired traits don’t go on to the next generation. Ie. Muscles TEXTBOOK Slide 40: A great example can be found in your TEXBOOK: sec 3.4 (8190) Slide 46: See others on p. 9094 Slide 58: See bottom of page 96 for a restatement of Darwin’s 4 postulates
Wasps of same colony have different amount of black to help identify individuals apart. Variation in colours for these flowers in California. Slide 24 The plant aphid can reproduce parthenogenetically meaning female plant aphids don’t need to mate to reproduce. They can essentially clone themselves within their body. So their egg which has their genetic information can grow other plant aphids. They can start reproducing after 7 days of being born and can produce 14 offspring per day. Slide 26 1. Competition: offspring compete with each other for resources 2. P &P: Not all of them can survive b/c they’re eaten by other things Slide 27 1. Climate: some individuals have variation in their cold or heat tolerance 2. Catastrophic events: volcanos, floods, etc. 3. Habitat/food limitation: ie. deserts – not enough water for everything to live Slide 29 Stored fat related to an animal’s health and can be measured in bone marrow index. Impalas with low bone marrow index have eaten less; have less storage nutrients and generally doing less well in life than individuals with less stored fat. Random= random selection of impalas in the environment, random level of what the average store fat in the individuals in this population. This is taken from the bone marrow of the impalas that were hunted. The hunters aren’t making a selection of better or worse, they’re just hunting impalas and whoever they happened they kill, that’s whose bone marrow they measure. Prey= bone marrow of impala that became prey of the wild dogs. Less stored stored=more likely to get killed. Slide 31 Not only physical fitness traits but other traits as well can help in Darwinian fitness. Ie. Buffalos vs peacock spider Slide 32 Example: If endurance is an adaptation, will help win against other buffalo and gain access to females so it’ll increase its Darwinian fitness. Adaptiveness or advantage of adaptations is measured in lifetime reproductive success. Therefore, an adaptation isn’t anything les it contributes to an increase in offspring. It could be increase in number of offspring or quality of offspring but it has to increase something about the offspring production and survival.
Another example: Cuttlefish can swim really fast. Reason why it’s an adaptation is not b/c it swims really fast to escape predation (partly) but the point of it is that it swims really fats, escapes predation and is able to survive and consequently reproduce. The ones that can’t swim fast are more likely to be eaten and don’t reproduce. Slide 33 Phenotype: external appearance or external production of a trait Rundown: Fitness increases are really important Adaptations that increase fitness are favoured by natural selection Natural selection is the difference in reproductive success among individuals Slide 34 Two snakes. Predator, which is the bird. Green ones camouflage well against their environment while the red/orange ones stand out. Bird was able to take two red/orange snakes easily and one green one. Green ones survive and reproduce and so does the remaining red/orange. In this case, the one with the green phenotype have a higher likelihood of having lifetime reproductive success than on average of the red/orange individuals. Only true if colour is heritable. Slide 35 As environment changes, different things might become adaptive and those things might become more present in the population b/c of differential reproduction. Pay no attention to comic. Slide 39 *Textbook example* IMPORTANT FOR MIDTERM/FINAL! Slide 41 Darwin’s theory of evolution wasn’t accepted right away. Slide 44 Darwin was 26 when he started collecting research on evolution and he was 50 when he published his first book. Slide 50 Green snakes eating green mice. Red/orange snakes eating red/orange mice. Slide 51
Green or red/orange can produce either phenotype b/c it depends on what their baby snakes eat. Bird comes and picks off the same proportion (3 red/orange snakes and one green snake). Slide 52 Still the same proportions of green and red/orange in population. Doesn’t depend on heritable difference but depends on what the babies’ eat. Slide 55 Acquired traits don’t go on to the next generation. Ie. Muscles TEXTBOOK Slide 40: A great example can be found in your TEXBOOK: sec 3.4 (8190) Slide 46: See others on p. 9094 Slide 58: See bottom of page 96 for a restatement of Darwin’s 4 postulates
