Phylogeny and the Tree of Life

Set of flashcards covering key concepts from the lecture on phylogeny and the evolutionary relationships of organisms.

What is phylogeny?

Phylogeny is the study of evolutionary relationships among biological species.

How are phylogenetic trees inferred?

Phylogenetic trees are inferred from data on morphology, genes, and biochemistry of organisms.

What distinguishes derived characters from ancestral characters?

Derived characters are evolutionary novelties unique to a particular clade, while ancestral characters originated in an ancestor of the taxon.

What does a phylogenetic tree represent?

A phylogenetic tree represents a hypothesis about evolutionary relationships among organisms.

What is systematics?

Systematics is the discipline focused on classifying organisms based on their evolutionary relationships.

Who developed the system of binomial nomenclature?

Carolus Linnaeus developed the system of binomial nomenclature in the 18th century.

What are the two parts of a scientific name in binomial nomenclature?

The two parts are the genus (capitalized) and the specific epithet (italicized).

What is a clade?

A clade is a group of species that contains an ancestral species and all its descendants.

What is the difference between homology and analogy?

Homology is similarity due to shared ancestry, while analogy is similarity due to convergent evolution.

What are orthologous genes?

Orthologous genes are homologous genes resulting from a speciation event found in different species.

What role does horizontal gene transfer play in evolution?

Horizontal gene transfer allows the movement of genes between different organisms, impacting evolutionary history.

What is cladistics?

Cladistics is a method of classification that uses the proportion of measurable characteristics that organisms share.

Why are traits like porcupine quills and cactus spines considered analogous?

They are considered analogous because they evolved independently due to similar environmental pressures.

What evidence does a genome provide about evolutionary history?

A genome can reveal relatedness between groups that are morphologically dissimilar or poorly represented in fossil records.

What is the significance of branch length in phylogenetic trees?

Branch length can indicate the number of genetic changes that have occurred in each lineage.