Unit 7 Quiz 2 Part 2 Flashcards
What is speciation?
The formation of a new species from a common ancestor.
What leads to speciation over time?
Evolution.
What must happen for speciation to occur?
Two populations of organisms must become reproductively isolated from each other.
True or False: Speciation can occur even if two populations can still mate and produce living offspring.
False.
Fill in the blank: Speciation occurs when two populations of organisms become _______ isolated from each other.
reproductively
What is an example of reproductive isolation in speciation?
The two populations can no longer mate and produce living offspring.
What is a common ancestor?
A species of organism from which one or more new species evolves.
What evidence supports that all living organisms share a distant common ancestor?
All organisms share the same fundamental molecular and cellular features.
What fundamental genetic material do all living organisms use?
DNA for storing genetic material.
What metabolic pathway is utilized by all organisms?
Glycolysis.
What do all living Eukaryotes share as evidence of a common ancestor?
They all have membrane-bound organelles.
What type of chromosomes do all living Eukaryotes contain?
Linear chromosomes.
What genetic feature do the genes of all living Eukaryotes contain?
Introns.
What determines how closely related two species are?
How recently they shared a common ancestor.
A more recent common ancestor indicates a closer relationship.
What does a more recent common ancestor imply about species relationship?
More related to each other.
This is in contrast to a less recent common ancestor, which indicates a lesser relationship.
What type of diagrams illustrate common ancestry?
Cladograms.
Cladograms are also known as phylogenetic trees.
Fill in the blank: A common ancestor is shared by two species to determine how _______ they are.
[related]
True or False: A less recent common ancestor means the species are more closely related.
False.
A less recent common ancestor indicates a lesser degree of relatedness.
What are 5 pieces of evidence supporting common ancestry among species
Biogeography
Anatomical Homologies
Developmental Homologies
Molecular Homologies
Fossil record
What’s biogeography
What’s anatomical Homologies
What’s a homologous structure
What’s a vestigial structure
What’s developmental Homologies
What’s molecular similarities
If you have more differences in amino acid sequences that’s means you ___ related to other species
Less
What are fossils
What is the fossil record?
The fossil record is a strong evidence for evolution because it shows the order in which ancient species evolved.
Why is the fossil record important?
It is important for identifying extinct species that no longer exist.
What can the fossil record show about species?
The fossil record can show the different patterns species evolved in.
What are the three evolution patterns identified in the fossil record?
- Adaptive Radiation
- Gradualism
- Punctuated Equilibrium
What is Adaptive Radiation?
A single species or small group of species evolves during a short time period into many different species in different habitats.
This process often occurs when a species colonizes a new environment with diverse ecological niches.
Define Gradualism.
Slow steady rate of evolution in a single line of descent of species.
This concept suggests that evolutionary changes occur gradually over long periods.
What is Punctuated Equilibrium?
Species experiences periods of stasis (no evolution occurring) which are interrupted by periods of rapid evolutionary change.
This theory contrasts with Gradualism by proposing that most evolutionary changes occur in relatively short bursts.
What is a primary reason populations of organisms continue to evolve?
Allele frequencies change from generation to generation
This change can lead to adaptations and variations within the population.
Does the evolution of populations imply that all populations are speciating?
No
Speciation is a specific process that does not occur in all evolving populations.
What evidence supports the idea that evolution is a continuing process?
Evidence includes:
* Changes in DNA sequences in species over time
* Changes in the fossil record
* Emergence of genetic resistances in various species
Name two types of genetic resistances that have emerged in various species.
Examples include:
* Antibiotic resistance
* Pesticide resistance
Fill in the blank: Changes in _______ sequences in species over time provide evidence for evolution.
DNA
True or False: All populations that evolve will eventually lead to new species.
False
Evolution does not necessarily lead to speciation.
What is one example of resistance that has been observed in insects?
Pesticide resistance
This resistance allows insects to survive despite exposure to chemical treatments.
How can changes in the fossil record provide evidence for evolution?
They show the morphological changes in species over time
Fossils can indicate how species have adapted or evolved.
Fill in the blank: The emergence of genetic resistances to _______ treatments is an example of ongoing evolution.
chemotherapy
What have extinction events done throughout Earth’s history?
Occurred many times
Extinction events are significant reductions in biodiversity, leading to the loss of species.
What is the relationship between ecological stress and extinction rates?
High ecological stress = high rate of extinction, Low ecological stress = low rate of extinction
Ecological stress can result from various factors including climate change, habitat loss, and pollution.
What role does human activity play in extinction?
A huge contributor to ecological stress
Human activities such as deforestation, industrialization, and overfishing exacerbate ecological stress.
What is a positive aspect of extinction in ecological terms?
Allows for the opening of ecological niches
Ecological niches are roles or positions that species occupy within an ecosystem, and their opening can lead to increased biodiversity.
Why are species with higher genetic diversity less likely to go extinct?
Better able to survive changes to the environment
Genetic diversity increases the adaptability of species to changing environmental conditions.
