Intro to Life & Evolution Notes PDF

# Intro to Life ## All Life Shares: - Growth - Reproduction - Sexual (Gametes) & Asexual (Binary Fission, Budding, & Cloning) - Homeostasis - Homeothermic (Warm blooded) or Ectothermic (Cold blooded) - Response to Stimuli - Obtaining or Using Energy - Heterotrophs or Autotrophs ## Genetics - **Hom...

# Intro to Life ## All Life Shares: - Growth - Reproduction - Sexual (Gametes) & Asexual (Binary Fission, Budding, & Cloning) - Homeostasis - Homeothermic (Warm blooded) or Ectothermic (Cold blooded) - Response to Stimuli - Obtaining or Using Energy - Heterotrophs or Autotrophs ## Genetics - **Homozygous Dominant** - Two dominate alleles (AA) - **Recessive** - (aa) - **Allele** - The individual gene you receive from a parent. - **Genotype** - What the two alleles make when they come together. Ex: AA or Aa - **Phenotype** - The physical trait that you see from the gene. Ex: White fur. - **Heterozygous** - One dominate & one recessive allele. Ex: Aa ## Allele Frequency: - How often you see the allele in a population. ## Two Equations - p + q = 1 - p^2 + 2pq + q^2 = 1 # Evolution - **Populations** evolve through time, **not the individual**. - **Evolution by natural selection** is the most important idea in biology. - **Paleontology** - Found by Georges Cuvier after finding fossils. ## Lamarck - Thought that what happens in your life passes onto offspring. Ex: Poking your eye out → Offspring. ## Darwin - Made the terms **natural selection** and **speciation**. - Discovered **artificial selection** through the breeding of dogs. - **Fitness** - Being able to pass on genes and successfully live. ## Microevolution - Changing allele frequency. - The process by which gene frequencies change within populations. ## Hardy-Weinberg Principle - Says that allele pools will stay equal as long as these 5 are met. - **No Mutations** (Mutations are random) - **No Gene Flow** (Creates more variation). - **Random Mating** (Selecting for traits). - **No Genetic Drift** (Reduces traits). - **No Selection** ## Terms - **Immigration** - Individuals entering a population. - **Emigration** - Individuals leaving a population. ## Mutations - Provide more variation for the members of a population to act on. - Ex: Bees like orange flowers better. ## Gene Flow - Increases variation within a population but after time it reduces the differences. - Ex: Moth colors. ## Non-random Mating - The mate selects which individual they want to mate with. - Ex: Peacocks' feathers attracting mates. ## Genetic Drift - Alleles change over time depending on which traits survive, usually in small populations. Ex: The crayfish (removing genes). ## Founder Effect - Rare alleles happen in a higher frequency because they are an isolated population. - Ex: Dwarfism, Polydactyly, or Heart Defects. ## Directional Selection - Occurs when an extreme phenotype is favored. Ex: Drug resistance in bacteria & pesticide resistance in insects. ## Stabilizing Selection - Occurs when an intermediate phenotype is favored (The most average). Ex: Birds lay 4-5 eggs. ## Disruptive Selection - 2 or more extreme phenotypes are favored over any average phenotype. - Ex: The same snail species have 2 different shell patterns. ## Sexual Selection - One sex wants to mate with another individual because they have specific characteristics they want. - Ex: Male birds are pretty to attract females. ## Macroevolution - Large changes over a very long period of time. ## Biological Species Concept - A group of interbreeding populations which are reproductively isolated from other groups. ## Allopatric Speciation - Take a population & physically split them apart to see if the two groups change & if they can still have viable babies. ## Sympatric Speciation - A change in a species without having a physical barrier. ## Reproductive Isolation - **Prezygotic Barriers** - Before the egg is fertilized. - **Postzygotic Barriers** - After the egg is fertilized. ## Temporal Isolation - Two species live together but do not mate at the same time. ## Behavioral Isolation - Differences in behavior prevent mating. ## Mechanical Isolation - Their reproductive structures aren't compatible. ## Gametic Isolation - Mating can occur, but the sperm can't fertilize the egg. ## Postzygotic Barriers - **Spontaneous Abortion **- The female body rejects the zygote because it was not right. - **Hybrid Sterility** - The hybrid organism is formed, but they cannot reproduce. - **Hybrid Inviability** - The hybrid organism is formed but they do not live long enough to reproduce. - **Hybrid Breakdown** - The hybrid organism is formed, but they do not survive for a long period of time. - **Generalists** - Their diet are very diverse & their species live for a very long time. - **Specialists** - Their diet is very specific & their species don't live for long. ## Genetic Variation ### Genome - Made by replicating DNA and RNA. ### Karyotype - You can learn the gender. - Visually abnormal chromosomes, deletion of chromosomes or parts, but you **can't** tell eye color, IQ, height, etc. ### Gene - A portion of DNA on the chromosomes (determines traits). ### Mutation - A permanent change in an organism's DNA leading to modifications in a cell information archive (random). - **Point Mutation** - Results from a single base change. Ex: The fat cat ate the rat. The fat cap etc. - **Frame Shift Mutation** - Results when deleting a letter of code. ### Proteins - Formed by amino acid chains ### Chromosomal Mutations - Deletions 0000 - Additions 00 - 00 - Duplications 00 ← - Inversion 00 → - Translocation 00 00 ←