12.1 Study Guide Flashcards
(25 cards)
Define Biological Evolution.
Descent with Inherited Modification
The change in the heritable characteristics of biological populations over successive generations.
This change can result in the appearance of new species or the alteration of existing ones.
Evolution is driven by processes like natural selection, genetic drift, and mutation.
Two Misconceptions about Evolution
- Evolution and Religion are Incompatible
- Evolution is Just a Theory
Describe what descent with inherited modification (evolution) means over a short period of time.
The changes in frequency of alleles in a population from one generation to the next.
Describe what descent with inherited modification (evolution) means over a long period of time.
The descent of different species from a shared ancestor over many generations.
Evolution occurs when there is a change in ______________________________.
the heritable information passed from one generation to the next. Examples include a trait becoming more common or a mutation appearing.
What does this Levels of Biological Order mnemonic mean? Kings Play Chess On Fancy Green Squares
Kingdom
Phylum
Class
Order
Family
Genus Species
Classification of living things reflects their_____________?
Evolutionary Relationship
What evidence is used to determine the relationship between species?
physical traits
behavioral traits
genetic data
What is Occam’s razor?
Occam’s razor (also known as the ‘law of parsimony’) is a philosophical tool for ‘shaving off’ unlikely explanations. Essentially, when faced with competing explanations for the same phenomenon, the simplest is likely the correct one.
What does IBE stand for?
Inference to the Best Explanation
Review Slide 11
DNA Sequence and Phylogenetic Trees
What are five pieces of evidence used to form IBE for Evolution?
- Fossil Record
- Biogeography
- Molecular data - DNA and protein analysis
- Anatomical Similarities and Differences
- Patterns in Development
Evolution can be defined as: “Change in the gene pool over time.” What does that mean?
The genetic makeup of a population of organisms shifts and adapts across generations.
What are the five fingers of evolution?
- Mutation
- Natural Selection
- Non-random Mating
- Gene Flow
- Small Population Size/ Genetic Drift
What is natural selection?
The process by which individuals with traits better suited to their environment tend to survive and reproduce more successfully, passing on those traits to their offspring.
What is non-random mating?
Individuals choose mates based on specific traits, which can alter the genetic makeup of a population.
What is gene-flow?
The transfer of genes from one population to another, often through migration, which can introduce new variations or alter existing allele frequencies.
What is small population/ genetic drift?
In small populations, random fluctuations in allele frequencies can occur due to chance events, leading to a change in the gene pool over time.
What are the basic steps of evolutionary science?
- Make Observations
- For Hypothesis
- Find evidence to support or reject our hypothesis
- Infer the best explanation with the current evidence at the time
What are two questions we can ask to determine which evolutionary hypothesis are better when there are conflicts?
- Which fits more or all of the existing evidence?
- Which is the simplest and therefore most probable?
What is a phylogenetic tree used to illustrate?
Do the trees represent a hypothesis or fact?
What do the following key features of a tree represent: Tips, Branches, Nodes, Root, Clades, Monophyletic Groups,
The evolutionary relationships among different groups of organisms. It represents how species or other taxa are thought to have diverged from common ancestors.
These trees are hypotheses, not definitive facts, and are based on observable traits and genetic evidence.
Key Features of Phylogenetic Trees:
Tips:
The tips of the branches represent the specific species or other groups being studied.
Branches:
The branches represent lineages that have evolved over time.
Nodes:
A node represents a point where a lineage split, giving rise to two or more descendant lineages.
Root:
The root of the tree represents the common ancestor of all the groups being studied.
Clades:
A clade is a group of organisms that includes a common ancestor and all of its descendants.
Monophyletic groups:
A monophyletic group is a clade that includes all the descendants of a common ancestor.
Describe what a mutation is and how it may affect an individual’s survival and reproduction depending on environment
A mutation is a change in a DNA Sequence of an organism.
Mutations can be beneficial, harmful or neutral depending on how the phenotype interacts with the environment.
Evolution through natural selection is driven by the interplay of three key factors: variation, selection, and time fuel the process of evolution through natural selection describe how for each of the tree factors.
Variation provides the raw material for evolution, as individuals within a population exhibit differences in their traits.
Selection favors individuals with traits better suited to their environment, leading to differential survival and reproduction.
Time allows these selective processes to accumulate beneficial traits over generations, gradually changing the characteristics of populations.
Natural selection causes changes in allele frequency of a population over time by doing what?
Favoring individuals with traits that enhance survival and reproduction.
Over time, these beneficial traits, determined by specific alleles, become more common in the population, while detrimental traits become less prevalent.
