Tree of life Flashcards
What is phylogeny?
-Phylogeny is the evolutionary history of a species or group of related species
What is the field of systematics about? What are they using?
- The discipline of systematics classifies organisms and determines their evolutionary relationships
- Systematists use fossil, molecular, and genetic data to infer evolutionary relationships
What is Taxonom?
- The science of classifying (naming) organisms
- Tells us about the degree of relation between different organisms
Who developed Binomial Nomenclature?
- Developed by Swedish biologist Carolus Linnaeus (1707 — 1778)
- Binomial naming system
How is a species defined?
-A species is both defined by its genus name and specific name
-Ex. Panthera tigris
Panthera- genus name
tigris- species name
Give the order of the taxonomic rank used in the biological classification
-species Keep plates Clean or family gets sick
What are biological species?
-Organisms that are genetically similar, and have ability to interbreed and produce viable (lebensfähige) , fertile offspring
Are subspecies able to interbreed?
-Might interbreed if a barrier or other challenge was removed (such as distance)
The hybrid offspring is? Give an example for hybrid offspring
- sterile
- panthera tigris+ panthera Leo -> tigon
- horse+ donkey -> mule
- horse+zebra -> zebroid
What can you say about the steps for giving a name?
-Language: Latin or Latinized
-Giving names:
A highly technical process
Name is author’s choice
-could include:
commemorate people, descriptive, geographic location, humor)
Name some animals which commemorate people
- gardenia jasminoides (dr. Alexander Garden)
- camellia japonica (Joseph Kamel)
- Siegesbeckia orientalischer (Dr. Siegesbeck)
Name some animals whose name descriptive is
- Cardinalis cardinalis (red)
- Railus aquaticus (watery)
- Passer domesticus (house)
Name some animals whose name a geographic location is
-Kuhlia sandwicensis (Hawaii)
-Periplanata americana
(American cockroach)
-Zosterops japonica
(Japanese white-eye)
Describe the three domain system
- prokaryotes: bacteria
- extremophiles: archaea
- eukaryotes: eukarya
Where do systematists depict evolutionary relationships?
- in branching phylogenetic trees
- Linnaean classification and phylogeny can differ from each other
What does the PhyloCode recognize?
-Systematists have proposed the PhyloCode, which recognizes only groups that include a common ancestor and all its descendents
What is polygamy?
-Polytomy is a term for an internal node of a cladogram that has more than two immediate descendents (i.e, sister taxa)
What Can we (and Cannot )Learn from Phylogenetic Trees
- Phylogenetic trees do show patterns of descent
- Phylogenetic trees do not indicate when species evolved or how much genetic change occurred in a lineage
- It shouldn’t be assumed that a taxon evolved from the taxon next to it
How did systematics inferred phylogenies?
- To infer phylogenies, systematists gather information about morphologies (structure), genes, and biochemistry of living organisms
- Organisms with similar morphologies or DNA sequences are likely to be more closely related than organisms with different structures or sequences
What is difference between homology and analogy?
- Homology is similarity due to shared ancestry like between a wolf and a coyote
- Analogy is similarity due to convergent evolution, similar conditions/adaptations
What do you have to keep in mind if it is about analogous structure?
- look similar on the outside
- Same function
- different structure & development on the inside
- different origin
- no evolutionary relationship
How can you distinguish between analogy and homology?
- Homology can be distinguished from analogy by comparing fossil evidence and the degree of complexity
- The more complex two similar structures are, the more likely it is that they are homologous
How does evaluating molecular homologies work?
- Systematists use computer programs and mathematical tools when analyzing comparable DNA segments from different organisms
- Molecular systematics uses DNA and other molecular data to determine evolutionary relationships
How do cladistics gourd organisms? What is a clade?
- by common descent
- a group of species that includes an ancestral (Ahnen) species and all its descendants (nachkommen)
What does “A valid clade is monophyletic” mean?
-signifying that it consists of the ancestor species and all its descendants
What is a paraphyletic grouping?
-a group which consist of an ancestral species and some, but not all, of the descendants
What is the opposite of paraphyletic?
-polyphyletic: group consisting of various species that lack a common ancestor
What can the branch length in phylogenetic trees show?
- can reflect the number of genetic changes that have taken place in a particular DNA sequence in that lineage
- In other trees, branch length can represent chronological time, and branching points can be determined from the fossil record
The best hypotheses for phylogenetic trees fit which data?
-morphological, molecular, and fossil
What does phylogenetic bracket allow us?
- Phylogenetic bracketing allows us to predict features of an ancestor from features of its descendents
- > This has been applied to infer features of dinosaurs from their descendents: birds and crocodiles
In what way is an organism’s evolutionary history documented in its genome? (DNA/mtDNA)
- Comparing nucleic acids or other molecules to infer relatedness is a valuable tool for tracing organisms’ evolutionary history
- DNA that codes for rRNA changes relatively slowly and is useful for investigating branching points hundreds of millions of years ago
- mtDNA evolves rapidly and can be used to explore recent evolutionary events
-How do the different kingdom system look like?
- five K: monera, protista, plantae, fungi, Animalia
- six K: monera divides inro: eubacteria, archaebacteria,
- three domain system: protista, plantae, fungi, Animalia are called together eukarya
- eight K: Protista is divides into archezoa, chromista, protista
Which two domains are closest related?
-eukaryotes and archasea
On what is the tree of life based?
-rRNA genes; they have evolved slowly
The tree of life as a ring??
- Some researchers suggest that eukaryotes arose as an endosymbiosis between a bacterium and archaean
- If so, early evolutionary relationships might be better depicted by a ring of life instead of a tree of life
Where can orthologous genes or paralogous genes be found?
- orthologous genes:are found in a single copy in the genome and are homologous between species
- paralogous genes: result from gene duplication, so are found in more than one copy in the genome
