Chapter 26: Phylogeny and the Tree of Life Flashcards
What is phylogeny?
The evolutionary history of a species or group of related species.
The first part of a binomial is the name of the genus (plural, genera) to which the species belongs. The second part, called the specific epithet, is unique for each species within the genus. An example of a binomial is Panthera pardus, the scientific name for the leopard. Notice that the first letter of the genus is capitalized and the entire binomial is italicized.
Write the binomial name of the gray wolf following the rules for handwriting species names.
List the taxonomic levels in order from most inclusive (largest) to least inclusive (smallest).
“King Phillip came over for good sandwiches!” Kingdom, phylum, class, order, family, genus, and species. The classification system named after Linnaeus, the Linnaean system, places related genera in the same family, families into orders, orders into classes, classes into phyla (singular, phylum), phyla into kingdoms, and, more recently, kingdoms into domains (Figure 26.3). At each level, or “rank,” species are placed in groups within more inclusive groups.
What is a taxon?
The named group at any level of the hierarchy is called a taxon (plural, taxa).
What is morphological?
Provide two examples of morphological homologies.
Recall that phenotypic and genetic similarities due to shared ancestry are called homologies. For example, the similarity in the number and arrangement of bones in the forelimbs of mammals is due to their descent from a common ancestor with the same bone structure; this is an example of a morphological homology (see Figure 22.15). In the same way, genes or other DNA sequences are homologous if they are descended from sequences carried by a common ancestor.
Explain why convergent evolution leads to analogy.
Convergent evolution occurs when similar environmental pressures and natural selection produce similar (analogous) adaptations in organisms from different evolutionary lineages. For example, the two mole-like animals shown in Figure 26.7 look very similar. However, their internal anatomy, physiology, and reproductive systems are very dissimilar.
What is clade?
A group of species that includes an ancestral species and all of its descendants. A clade is equivalent to a monophyletic group.
Provide an example of a shared ancestral character in humans.
Which trait is a shared derived character unique to the clade that includes the turtle and leopard?
How many traits are shared ancestral character for turtles and leopards?
Explain, in your own words, the concept of maximum parsimony.
What must be predictable about a gene used as a molecular clock for it to be of practical use?
Which two domains are entirely single-celled organisms?
