Evolution Definitions
Define "Natural Selection"
Organisms who are better suited to live in their environment have a higher chance of survival and reproduction - also known as "survival of the fittest".
What is a mutation?
Change in DNA sequence
What is relative age?
Age of rock, fossil, geologic features or events, RELATIVE to other rock, fossil, geologic features or events - not in exact years
Who proposed the theory of natural selection?
Charles Darwin
What is an adaptation?
an inherited trait that has become common in a population because it is a selective advantage
An organism's ability to pass its genes down to the next generation through reproduction is known as its _________.
Fitness
A change in allele frequencies due to chance events describes ______
Genetic drift
Absolute dating is a method of estimating the age of a fossil in _______.
Years
Who proposed the theory of Inheritance of Acquired Characteristics?
Jean Baptiste Lamarck
How do cladograms or phylogenetic trees show evolutionary relationships?
The branching diagrams map how populations diverge into new species, with closer branches indicating a more recent common ancestor and greater genetic or structural similarity
Define "Bottleneck"
A drastic decrease in the size of a population due to environmental events and human activities, leading to a loss of diversity.
What kind of mating involves organisms choosing their mates based on certain traits
Nonrandom mating
What is a half-life?
The amount of time it takes for half of the unstable atoms in a sample to decay.
What do creationists believe?
each species is a devine creature unchanging as it was originally created
Describe the two Tempos of Evolution
Gradualism – gradual change over long period of time leads to formation.
Punctuated – periods of rapid change separated by period of little of no change. Major environmental change sparks evolution.
What type of genetic drift happens when when a small, non-representative group of individuals splits off from the larger group they are a part of to form their own, new colony
Founder effect
Evolution happens where there is a change in ________ in a ______ over time.
gene frequency; population
What is the Law of Superpositioning?
The youngest layer of rocks or sediment is at the top.
Describe Lamarck’s theory of acquired characteristics
the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime
Ex: developing skin cancer would make it possible to pass it to your offspring
Describe one of the three types of postzygotic barriers.
Hybrid Inviability: The hybrid embryo does not develop properly or dies,
Hybrid Sterility: The hybrid reaches maturity but is unable to produce offspring. A classic example is the mule, produced by a donkey and a horse,
Hybrid Breakdown: The first generation is fertile, but subsequent generations are weak or sterile
Define Vestigial structures
Vestigial - anatomical features, behaviors, or genes that have lost most or all of their original, ancestral function through evolution
Describe one of the three types of Natural Selection
Directional - selection against an extreme
Disruptive - selection against the mean/for BOTH extremes
Stabilizing - selection against both extremes/FOR the mean
How much radioactive material is left after three half-lives if you start with 80 grams?
10 grams
Summarize one of the four main points of Darwin’s theory of evolution by natural selection
Variation: Individuals within a species or population exhibit individual variations in their traits (e.g., size, shape, color).
Heritability: Some of these variations are heritable and can be passed on to offspring.
Overproduction/Competition: In each generation, more offspring are produced than can survive, creating a "struggle for existence" where resources are limited.
Differential Survival and Reproduction: Individuals with traits better suited to the environment are more likely to survive and produce more offspring than those without these traits.
Describe one of the four types of prezygotic barriers
Geographic (Habitat) Isolation: Species occupy different habitats, preventing them from encountering each other. For example, lions (grassland) and tigers (forest) generally do not interbreed.
Temporal Isolation: Species breed at different times (seasons, times of day). For example, leopard frogs and wood frogs reach sexual maturity at different times in the spring.
Behavioral Isolation: Unique mating rituals or songs prevent interbreeding. For example, female fireflies only respond to specific light flash patterns from males of their own species,
Mechanical Isolation: Physical incompatibility of reproductive organs. For example, certain damselfly species have differently shaped reproductive organs that do not fit together