Chapter 22
Describe Lamarck’s view of the mechanism of evolution
Lamarck’s theory of evolution, proposed in 1809, suggests that organisms evolve through a conscious "striving" to adapt to their environment, driven by two main mechanisms: the law of use and disuse, and the inheritance of acquired characteristics. He argued that frequently used body parts grow stronger and larger, while unused parts wither, and these changes are passed directly to offspring
What is the smallest unit of evolution?
Microevolution: change in the allele frequencies of a population over generations
What is the difference between microevolution and macroevolution?
Microevolution refers to small-scale genetic changes in allele frequencies within a single population or species over a short time (e.g., antibiotic resistance). Macroevolution refers to large-scale evolutionary changes occurring above the species level over geological time, resulting in new species or lineages. Both are driven by the same fundamental mechanisms (mutation, selection, drift)
Which Conan Gray song mentions not being surprised by being hurt by bad guys?!
Nauseous!
Describe Darwin's view of the mechanism of evolution
Charles Darwin’s mechanism of evolution, known as natural selection, proposes that species change over generations because individuals with heritable traits better suited to their environment are more likely to survive and reproduce. This process relies on variation, differential survival, and heredity, leading to adaptation
What are three sources of genetic variation?
Point mutations: changes in one base (eg. sickle cell)
Chromosomal mutations: delete, duplicate, disrupt, rearrange 🡪 usually harmful
Sexual recombination: contributes to most of genetic variation in a population
Crossing Over (Meiosis – Prophase I)
Independent Assortment of Chromosomes (during meiosis)
Random Fertilization (sperm + egg)
What is the biological concept of a species?
The biological species concept defines a species as a group of organisms that can actually or potentially interbreed in nature to produce fertile offspring, and are reproductively isolated from other such groups. It focuses on genetic compatibility and reproduction rather than appearance, meaning members of a species share a common gene pool.
Where did Noah and his friend drive aimlessly along!?
The twin state lines OBVIOUSLY
What is the role of adaptation in evolution?
Adaptation is the primary mechanism driving evolutionary change, enabling organisms to become better suited to their environments through natural selection. It acts as a process where beneficial, heritable traits—structural, physiological, or behavioral—increase an organism's chances of survival and reproduction, passing these advantageous traits to future generations, which ultimately shapes the genetic makeup of populations over time
What is the Hardy-Weinberg Principle?
Hardy-Weinberg Principle: The allele and genotype frequencies of a population will remain constant from generation to generation
…UNLESS they are acted upon by forces other than Mendelian segregation and recombination of alleles
What are prezygotic and postzygotic barriers that maintain reproductive isolation in natural populaitons?
Reproductive isolation is maintained by prezygotic barriers (preventing fertilization) and postzygotic barriers (reducing hybrid viability/fertility). Prezygotic mechanisms include habitat, temporal, behavioral, mechanical, and gametic isolation. Postzygotic mechanisms include hybrid inviability, hybrid sterility, and hybrid breakdown, preventing gene flow between species.
Finish the quote: "I tried to be a showgirl but really I am a..."
TORTURED POET
What is the role of variation in evolution?
Genetic variation is the fundamental, indispensable raw material for evolution, allowing populations to adapt to changing environments and survive. It provides the diversity in traits (phenotypes) that natural selection acts upon, enabling advantageous, heritable traits to become more common over generations. Without it, populations cannot evolve
What are the conditions for HARDY-WEINBERG EQUILIBRIUM? WHY IS IT CAPS? I DON'T KNOW BUT I AM TOO LAZY TO CHANGE IT!
No mutations.
Random mating.
No natural selection.
Extremely large population size.
No gene flow.
If at least one of these conditions is NOT met, then the population is EVOLVING!
How do allopatric and sympatric speciation are similar and different?
Allopatric and sympatric speciation are both processes creating new species through reproductive isolation. They differ primarily in that allopatric speciation requires a physical, geographic barrier (e.g., rivers, mountains), while sympatric speciation occurs within a single population in the same location due to genetic or behavioral shifts.
Finish the quote "I'm not okay! Look at me! I'm..."
Friggen disintegrating
What are the roles of reproductive success and heritability in evolution?
Reproductive success and heritability are the essential drivers of natural selection and evolution. Reproductive success dictates which advantageous traits increase in frequency by favoring individuals with better survival/mating, while heritability ensures these beneficial traits are passed from parents to offspring, allowing populations to adapt over generations.
What is the Hardy Weinberg equation?
P2 +2pq+q2=1
Calculates genetic variation in a population, where p and q are allele frequencies
THIS IS MAKING ME SICK WHO CARESSSSSSSSSS
How do autopolyploid or an allopolyploid chromosomal change can lead to sympatric speciation?
Autopolyploid and allopolyploid chromosomal changes lead to sympatric speciation by creating immediate reproductive isolation within a shared habitat. A change in chromosome number (polyploidy) through meiotic errors allows the new organism to produce fertile offspring with others of its type, but renders them reproductively incompatible with the parent species.
Which episode of the Middle has Mike Heck driving himself home from an eye appointment and swirving?
Hecks on a Plane!