Chapter 25 - Phylogenies and the History of Life Flashcards
What is a phylogeny?
A phylogeny is the evolutionary history and relationships among species or groups of organisms.
True or False: Phylogenies are only based on morphological characteristics.
False
Fill in the blank: The study of evolutionary relationships is called _______.
phylogenetics
What is a common ancestor?
A common ancestor is an ancestral species from which multiple species have evolved.
Which of the following is used to construct phylogenetic trees? (A) DNA sequences (B) Morphological traits (C) Fossil records (D) All of the above
D) All of the above
What does a phylogenetic tree illustrate?
A phylogenetic tree illustrates the evolutionary relationships and divergence among species.
True or False: Clades are groups of organisms that include an ancestor and all its descendants.
True
What is the term for a branching diagram that represents the evolutionary relationships among organisms?
Phylogenetic tree
Fill in the blank: The _______ is the point in a phylogenetic tree where two lineages diverge.
node
What are homologous structures?
Homologous structures are anatomical features in different species that share a common ancestry.
Which type of data is commonly used to infer phylogenies?
Molecular data such as DNA sequences.
True or False: Convergent evolution can complicate the construction of phylogenetic trees.
True
What is the primary goal of constructing a phylogenetic tree?
To depict the evolutionary relationships among a group of organisms.
Which software is commonly used for phylogenetic analysis?
MEGA (Molecular Evolutionary Genetics Analysis)
What is the significance of a rooted phylogenetic tree?
A rooted tree shows the most recent common ancestor of all the taxa represented.
Fill in the blank: The process by which species evolve to become more different over time is called _______.
divergent evolution
What is a sister group in phylogenetics?
Sister groups are the closest relatives on a phylogenetic tree that share a common ancestor.
What does the term ‘monophyletic’ refer to?
A monophyletic group includes an ancestor and all its descendants.
True or False: Paraphyletic groups include some, but not all, descendants of a common ancestor.
True
What is the difference between homologous and analogous structures?
Homologous structures arise from a common ancestor, while analogous structures arise from convergent evolution.
Which method is used to determine the most likely phylogenetic tree among a set of species?
Maximum likelihood estimation
What is the role of fossils in phylogenetics?
Fossils provide historical evidence of evolutionary changes and relationships.
Fill in the blank: The _______ principle states that the simplest explanation is preferred when constructing phylogenies.
Occam’s razor
What is the purpose of molecular clocks in phylogenetics?
Molecular clocks estimate the time of divergence between species based on genetic mutations.
True or False: Phylogenetic trees can change with new scientific evidence.
True
What does ‘bootstrap analysis’ provide in phylogenetics?
Bootstrap analysis provides a measure of support for the branching patterns in a phylogenetic tree.
Fill in the blank: The _______ is the common ancestor of all life forms.
last universal common ancestor (LUCA)
What is a phylogenetic network?
A phylogenetic network is a graph that represents multiple potential evolutionary pathways among species.
Which type of data can lead to conflicting phylogenetic trees?
Incomplete lineage sorting
True or False: The concept of species is always clear and universally agreed upon among biologists.
False
What is the significance of the Cambrian explosion in the history of life?
The Cambrian explosion marks a rapid diversification of life forms and the appearance of most major animal phyla.
Fill in the blank: The _______ hypothesis suggests that life originated from simple organic compounds on early Earth.
abiogenesis
What does the term ‘phylogeography’ refer to?
Phylogeography studies the historical processes that may be responsible for the contemporary geographic distributions of individuals.
What is the significance of ribosomal RNA in phylogenetics?
Ribosomal RNA sequences are highly conserved and useful for inferring evolutionary relationships across diverse organisms.
True or False: All phylogenetic trees are drawn to scale.
False
Fill in the blank: The _______ tree represents the evolutionary relationships of organisms without regard to time.
unrooted
What does ‘speciation’ mean?
Speciation is the process by which new species arise from existing ones.
