Ch 26 Flashcards
(24 cards)
What is systematics? How is it used to develop phylogenetic trees?
a discipline focused on classifying organisms and determining their evolutionary relationships - use data ranging from fossils and molecules to infer
Every organism on Earth may be referred to by a unique binomial, or a two-part name. These are in Latin, or latinized. What is your binomial? What does it mean?
homo sapiens means “wise man”
What are the two components of every binomial?
genus + species
Taxonomy uses hierarchical categories that nest within each other. Label each taxonomic category. (Dear King Phillip Comes Over For Good Spaghetti)
domain kingdom phylum class order family genius species
So, which are more closely related, organisms in the same phylum, or those in the same order?
Order
Homologous structures
show evidence of relatedness
whale fin, bat wing
Homologous structures
shared ancestry + show evidence of relatedness (whale fin, bat wing)
Analogous structures
convergent evolution + similar solutions to similar problems but do not indicate close relatedness (bird wing, butterfly wing)
What is a clade?
group of organisms which includes ancestral species and all of its descendants
Monophyletic
an ancestral species and ALL of its descendants
Paraphyletic
consists of an ancestral species and some of its descendants
Polyphyletic
includes descendants of two or more common ancestors
Clades are derived by using shared derived characters. What are these?
character shared by all mammals but not in there ancestors
hair in mammals
Explain why for mammals, hair is a shared derived character, but a backbone is not.
backbone predates the branching off the mammalian clade (all vertebrates have it). called a shared ancestral character: a character that originated in an ancestor of the taxon.
vs
hair is a character shared by all mammals but not in there ancestors. this is called a shared derived character. unique to a particular clade
Explain why for mammals, hair is a shared derived character, but a backbone is not.
backbone- shared ancestral character originated in an ancestor of taxons
hair- character shared by all mammals but not found in their ancestors
DNA that codes for ribosomal RNA (rRNA) changes relatively _____ and is useful for
investigating relationships between taxa that diverged hundreds of millions of years ago.
slowly
DNA that codes for mitochondrial DNA (mtDNA) evolves _____ and can be used to explore recent evolutionary events.
rapidly
Which method reveals that fungi are more closely related to animals than to green plants?
rRNA sequences
morphological comparison
Which kingdom is made obsolete by the three-domain system? Why?
Monera (prokaryotes), because it would have members in two domains
Which kingdom crumbled because it is polyphyletic?
Protista. includes members that are more closely related to plants, fungi or animals that to other protists
large and diverse group of eukaryotic microorganisms
Which method reveals that the Pima of Arizona and Yanomami of Venezuela are descendents of the same N.A. that crossed the Bering Land Bridge 13,000 years ago?
mtDNA sequences
mitochondrial dna
What are molecular clocks?
a yardstick for measuring the absolute time of change based on observations
If we use a molecular clock, approximately when did HIV emerge?
1930’s
Which two domains are more closely related?
Archaea and Eukarya
