Mr Kecman Microevolution Microevolution 5 types forces Mutation
- Slides: 30
Mr. Kecman Microevolution
Microevolution 5 types/ forces Mutation Gene Flow Non-random Genetic mating Drift Selection
Mutation Random change in the nucleotide sequence to create a new characteristic (eg. Hemoglobin)
Gene flow Migration of genes (alleles) between populations. The genes get into the other population and this levels the playing field (eg. Wolf pack)
Non-random mating Assortative mating by choosing a desired trait over a less desired trait (eg. Peacock)
Genetic Drift Changes due to either the environment, or separation. Doesn’t effect large populations as much, but in a small populations it has a drastic impact. Bottleneck effect/ founder effect
Natural Selection Four types: Stable Directional Diversifying Sexual
Video https: //www. youtube. com/watch? v=lk 4_a. Iocy. Hc
Wednesday Agenda: Take a look at Changes in gene pool handout Closer look at Genetic Drift (bottleneck/founder effect) Look at 4 types of Natural Selection Online Review homework posted package at back of room
Closer look at Genetic Drift (small sample size) Two types: Bottleneck effect and founder effect
Bottleneck effect: After a catastrophic event the population of the surviving population’s gene pool may no longer represent the original gene pools variation. By random chance a genes frequency may be drastically altered. If a particular gene’s frequency drops, then the other gene(s) frequency will increase. Thus the surviving population will have new ratios of genotypes and phenotypes. This type of event will diminish the genetic variety in the population and therefore diminish its genetic vigor.
Founder Effect A founder effect occurs when a new colony is started by a few members of the original population. This small population size means that the colony may have: reduced genetic variation from the original population. a non-random sample of the genes in the original population.
Founder Effect
Genetic Drift Vid https: //www. youtube. com/watch? v=mj. Q_y. N 5 znyk
Four Types of Natural Selection
Stabilizing Selection Culls extreme variants from the population, in this case, eliminating individuals that are unusually light or dark. The trend is toward reduced phenotypic variation and maintenance of the status quo.
very light-colored or very dark-colored oysters might be more frequently preyed upon by shore birds, simply because they are more obvious on the oyster bar; as a result, the intermediate hues become more common.
Directional Selection Shifts the overall makeup of the population by favoring variants of one extreme. In this case, the trend is toward darker color, perhaps because the landscape has been blackened by lava.
If thicker-shelled oysters are more resistant to breakage than thinner-shelled oysters, crabs will be less able to prey upon them, and thickershelled oysters will be more likely to survive to reproduce.
Diversifying/disruptive Selection Favors variants of opposite extremes over intermediate individuals. Here, the relative frequency of very light and very dark snails have colonized a patchy habitat where background of white sand is studded with lava rocks.
This might happen in shallow water among rocks. Light-colored oysters are more cryptic (less easy for a predator to see) because they match the rock color. Dark-colored oysters blend into the shadows cast by the rocks. In this case, intermediate-colored oysters would be most heavily preyed upon by the crabs, and very light and very dark oysters would survive to reproduce.
Sexual Selection Graph
Sexual Selection Draw The on back of sheet evolutionary fitness of an organism not only depends upon its ability to survive but also its ability to reproduce. To reproduce, an individual must obtain a mate and produce viable offspring. Natural selection favors traits that maximize the ability of an individual to compete for and attract mates, and/or the ability to produce offspring.
An example of sexual selection would be male to male competition, mating rituals, complex behaviors, appearance.
Selection Vid https: //www. youtube. com/watch? v=W 6 e. Z 7 z. IIOas
Work Time Please Also pull out “Founder Effect” handout. online homework assignment is posted
Thursday Agenda: Go over founder effect handout Learn Hardy-Weinberg and try handout Review booklet work period. Answers posted around walls
Hardy-Weinberg Equation
Natural Selection Vid https: //www. youtube. com/watch? v=R 6 La 6_k. Ir 9 g&t=356 s
- Any mistake or change in the dna sequence
- Macroevolution vs microevolution
- 3 mechanisms of microevolution
- Agents of microevolution
- Microevolution
- Microevolution
- Hardy weinberg equilibrium
- Point or frameshift mutation
- Types of mutation
- Chromosome mutation types
- Chromosome mutation types
- Resultant of like parallel forces
- The forces shown above are pushing/pulling forces
- Intra vs intermolecular forces
- Intermolecular forces vs intramolecular forces
- Covalent bond intermolecular forces
- Contact and non contact forces
- Unbalanced force
- What is constructive force
- Glu to val mutation
- Synonymous vs nonsynonymous mutation
- Chromosomal mutation deletion
- Deletion chromosomal mutation
- Hox gene mutation in drosophila
- Hox gene mutation in drosophila
- Kimura
- Section 4 gene regulation and mutations
- 02:05 / 08:02
- Vowel mutation
- Neutral mutation
- Transition vs transversion mutation