exam 2 Flashcards
What is systematics? Taxonomy?
- Systematics studies the diversity and evolutionary relationships of organisms
- Taxonomy focuses specifically on classifying and naming them.
What are the 8 categories of taxonomic hierarchy (in order from species upward to broader classifications)? What are the three domains of life?
species
genus
family
order
class
phylum
kingdom
domain
bacteria
archaea
ekuryea
What are the two parts of any Latinized binomial name?
the genus first and then species
What are the three different types of phylogenetic groups?
- Monophyletic Group: includes all the species that share a common ancestor and no other organisms
- Paraphyletic Group: groups arise when some descendants of a common ancestor are excluded from the group due to the exclusion of certain species.
- Polyphyletic Group: polyphyletic group consists of species that do not share a common ancestor
What is a phylogenetic tree and what is it used for (or what is phylogeny)?
branching diagram or diagrammatic representation that depicts the evolutionary relationships among a group of organisms or taxa.
What are the two ways a new species can be formed?
- allopatric Speciation
- sympatric Speciation
What is Homology?
similarities among various species
derived for an common ancestor
What does cladistics compare?
Cladistics compares the evolutionary relationships between organisms based on shared, derived characteristics
What is the difference between a primitive character and a derived character?
- primitive character, also known as an ancestral character, is a trait that is shared by a group of organisms due to inheritance from a common ancestor.
- derived character, is a trait that is unique to a specific group of organisms and has evolved more recently within that group.
What is the Principle of Parsimony?
states that among competing hypotheses, the one with the fewest assumptions should be selected
What is the definition of evolution? What are the 2 mechanisms of evolution?
the process by which species of organisms change over successive generations, typically through the gradual accumulation of small genetic variations,
-natural Selection
- Genetic drift
Define Natural Selection.
the key mechanism of evolution, proposed by Charles Darwin, which occurs when certain heritable traits confer a survival advantage to individuals in specific environmental conditions. These individuals are more likely to survive, reproduce, and pass on their advantageous traits to the next generation,
What 2 observations the theory of natural selection based off of? What conclusion (inference) can be made from these two observations?
- variation: Individuals within a population exhibit variation in their traits, which can be inherited from their parents
-differential Survival and Reproduction: There is a struggle for existence within populations, as more individuals are born than can survive and reproduce
inference drawn is that over time, individuals with advantageous traits will contribute more offspring to the next generation, leading to a gradual change in the characteristics of populations
Identify and explain the 5 pieces of evidence for evolution we discussed in class. What is the transitional form when found as a fossil?
- fossil record
- comparative anatomy
- embryology
- molecular biology
- biogeography
What are the 3 types of homologies that are seen among species?
- anatomical
- developmental
- molecular
Explain a gene pool.
refers to the total collection of genetic information (alleles) present in a population of interbreeding organisms
What does endemic mean and provide an example?
- species or organism that is native to a specific geographic area and is found naturally nowhere else in the world.
What are the ultimate sources for all genetic variation?
mutation and recombination, are the primary drivers of genetic variation within populations and are essential for the evolution of organisms over time.
What is the symbol for the dominant allele frequency in a population? What about the recessive?
So, in a population with two alleles at a given gene locus, let’s say A and a, where A is the dominant allele and a is the recessive allele:
What is the Hardy-Weinberg formula? How can it be used?
Estimate allele frequencies:
Test for genetic equilibrium:
What are the conditions for Hardy-Weinberg Equilibrium?
- no new mutations
- no natural selection
- no migration
- random mating
- population large enough that allele frequency doesn’t change due to genetic drift
What is genetic drift? How can it influence allele frequencies in a population? What size populations are most susceptible to genetic drift?
random process that can cause changes in allele frequencies within a population
- occurs more prominently in smaller populations
what is gene flow? Does it increase or decrease genetic differences between populations?
movement of genes between different populations of organisms, typically through the migration
- increased genetic diversity
What is the difference between microevolution and macroevolution?
- Microevolution refers to changes in allele frequencies and traits within a population over relatively short periods of time
- Macroevolution, involves evolutionary changes that occur on a much larger scale, typically over geological time spans and involving the origin of new species
