ECO EVO Study Guide
1. Heritable variation – (genotype) models of 1-3 loci, usually 2 alleles, produce heritable phenotypes
2. Organisms engage in a struggle for existence – per capita growth rates from survival and reproduction
3. Heritable traits influence outcome of the struggle – variation affects the struggle; phenotypes (determined by genotypes) influence per capita growth rates
3 Big Questions Biologists seek to answer:
1. Diversity of life in time and space – the three domains; the grand procession of life
2. Distribution and abundance of species
3. Fit of form and function
Evolutionary Ecology ? relation between ecological processes and adaptive evolution. Examples of ecological processes are predation, competition, disease, mutualism, etc.
Fitness – per capita growth rate of species, gene, a phenotypic strategy , it is a rate
Guiding bedrock Principles:
1. Population of all organism can grow exponentially under ideal conditions: a. 1st Law of Ecology: “everything is connected to everything else”; Ecosystems are complex and interconnected. Humans and animals and nature depend on each other for a balance. If system is under extreme stress, can undergo catastrophe.
2. Populations of all organisms experience limits to growth: a. 2nd Law of Ecology: “Everything must go somewhere” matter and energy are preserved and waste produced in one ecological process is recycled in another. As resources are depleted, population growth rate slows and stops. Carrying capacity= number of individuals of a particular population that environment can support.
3. Heritable traits influence success of organisms in limiting environments
Terms to be Familiar with:
1. Phenotype: Outward, physical manifestation; physical parts, cells, structure, metabolism, tissues, behaviors, etc. Anything part of the observable structure 2. Genotype: “internally coded inheritable info”; blueprint; written in genetic code; are copied at cell division or reproduction 3. Germ Plasm: sex cells (gametes)
4. Soma: every other cell other than gamete
5. Gene: unit of heredity carried from parent to offspring
6. Chromosome: carries genetic information in form of genes. 7. Locus: specific location of a gene on a chromosome
8. Ploidy: number of sets of chromosomes in the nucleus of a cell a. Haploid: number of chromosomes in a gamete (n)
b. Diploid: two gametes form this with twice the number (2n) 9. Eukaryote: has nucleus, multicellular, membrane bound nucleus, has mitochondria, ex? animals and plants 10. Meiosis and gamete formation: a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores. 11. Errors of Meiosis:
a. Nondisjunction: The failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei. b. Trisomy’s: a condition in which an extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities. 12. Generation of Genetic Variability: The measure of the tendency of individual genotypes in a population to vary from one another. How much a trait tends to vary in response to environmental and genetic influences.
It is important for biodiversity because w/out variability it becomes difficult for a population to adapt to environmental changes and makes it more prone to extinction. a. Via meiosis: this is caused during meiosis when 2 homologous chromosomes from male and female parents cross over one another and exchange genetic material. The chromosomes then split and are ready to form offspring. b. Via mutation: through natural selection, if mutation increases the affected individual’s fitness and its effects will be minimized if mutation is deleterious. The smaller a population and genetic variation, the more likely the hidden mutations will show up causing genetic drift. DNA damaging, nonhomologous end joining are also examples of mutation.
13. Heritable Traits (continuous are referred to as quantitative) a. Discrete: humans: ability to smell, albinism, various diseases Peas: seed shape (wrinkly?); seed color
b. Continuous: humans: height, skin color, IQ
Agricultural plants/animals: crop yield, milk production
14. Mendelian Genetics:
a. Principle of Segregation: alleles inherited from each parent remain distinct and are selected randomly during gamete formation (meiosis); effects don’t blend b. Independent assortment: alleles at loci on different chromosomes are inherited independently 15.