Do NowDo now: Explain the ancestral evolution of Lulu. What species would have been her preliminary ancestry and what were the steps of evolution that created her

species?

Daily Quiz 16

1. Take a moment to reflect on this past unit. What accomplishment(s) are you proud of?

2. If you could go back to the beginning, what would you change?

3. What are you going to do differently this unit to ensure success in Zoology?

Animal Classification: Taxonomy & Phylogeny

Where We’re Headed… Unit 3: Evolution & Genetics

SC.912.L.15.4 Describe how and why organisms are hierarchically classified and based on evolutionary relationships

SC.912.L.15.5 Explain the reasons for changes in how organisms are classified.

SC.912.L.15.1Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology, biogeography, molecular biology, and observed evolutionary change.

SC.912.L.15.13 Describe the conditions required for natural selection, including: overproduction of offspring, inherited variation, and the struggle to survive, which result in differential reproductive success.

SC.912.L.15.6 Discuss distinguishing characteristics of the domains and kingdoms of living organisms.

SC.912.L.15.3 Describe how biological diversity is increased by the origin of new species and how it is decreased by the natural process of extinction.

SC.912.L.15.14 Discuss mechanisms of evolutionary change other than natural selection such as genetic drift and gene flow

SC.912.L.15.15 Describe how mutation and genetic recombination increase genetic variation.

SC.912.L.15.11 Discuss specific fossil hominids and what they show about human evolution.

The Standard

SC.912.L.15.4 Describe how and why organisms are hierarchically classified and based on evolutionary relationships

FLASH CARD ALERT!!!!!

SpeciesSpecies: A group of populations in which genes are actually, or potentially, exchanged through multiple generations. **Mules?**

TaxonomyTaxonomy: The description of species and the classification of organisms into groups that reflect evolutionary relationships

PhylogenyPhylogeny: The evolutionary relationships among species… like evolutionary genealogy

CladogramCladogram: Diagram depicting the evolutionary history of taxa… like a family tree

Vocab continued…

CladeClade: A subset of organisms in a phylogenetic group that share a certain synapomorphy (derived character)

Derived CharacterDerived Character: Character that has arisen since common ancestry with an outgroup

OutgroupOutgroup: A group that shares an ancestral characteristic with the study group

CHARACTER/TRAITCHARACTER/TRAIT Any discrete feature or attribute that exhibits variation

Why focus on EVOLUTION? Evolution is a unifying theme in all of the biological

sciences and helps to explain observations in ecology, zoology… even medicine! (AIDS, MRSA)

Evolution helps explain the appearance of new species and the extinction of others.

Evolution helps us understand specie’s relationships, similarities

Taxonomy: a method of organization Taxonomy is a method of organizing/naming

content. For example if you wanted to classify music by genre, you

might come up with such names as: classical, jazz, rock, rap, country, etc. A single area such as "classical" might be further classified into concertos, sonatas, symphonies, and so on. How would you break down “rap”?

What does it mean for a song to be a “rap” song? A country song? Classical?

What would you expect from these types of music?

Taxonomy continued…

Similarly, animals are grouped together, named, and

classified based on evolutionary relationships This is a HIERARCHICAL way to organize

the animal kingdom FLASHCARD ALERT:

HIERARCHICAL: organized in order of rank. Broad specific

Organized and informational way to group species together

How does it work? It’s HIERARCHICAL! Kingdom (ie. Plant, Animal, Bacteria) Phylum Class Order Family Genus Species

It just keeps getting more specific…

Car Example

Imagine…

You represent one species. Every other person on Earth represents a

different species. Starting with “Earthling”, see if you can come

up with 7+ hierarchical steps to narrow down the possible “species” to just you.

Don’t skip any “steps”!

It’s like a family tree… in names

What determines “relatedness”?

Example: The American Lobster Animalia Arthropoda Malacostraca Decapoda Nephropidae Homarus americanus

Example: Market Squid (Similar?) Animalia Mollusca Cephalopoda Decapoda Loliginidae Loligo opalescens

Example: Virginia Oyster

Animalia Mollusca Bivalvia Pterioida Ostreidae Crassostrea virginica

How are you going to remember the classifications for taxonomy? King Kingdom Phillip Phylum Came Class Over Order For Family Great Genus Sandwiches Species

Why is taxonomy so specific?

“Without a set of international rules to follow, the results of taxonomy would be confusing at best. The rules of zoological nomenclature are contained in a document known as the International Code of Zoological Nomenclature (ICZN). The object of the code is to promote stability and universality in the scientific names of animals. All names must be unique, universal, and show stability.

Uniqueness Every name has to be unique. If several names have been given to the same taxon, priority decides which name will be the valid name.

Universality Zoologists have adopted, by international agreement, a single language to be used on a worldwide basis. All animals are given a generic and specific name in Latin. These names are in italics or are underlined (i.e. Homo sapiens).

Stability The ICZN attempts to prevent the frequent changing of names to provide stability.”

CFUs

What is Taxonomy? Why are there rules in taxonomy? What are the divisions in taxonomic

classifications? What’s the mnemonic for remembering

them?

Phylogeny

Evolutionary relationships between animals are depicted on a phylogenetic tree.

Phylogenetic trees can give us a lot of information, if we know how to interpret them…

Phylogeny

Phylogeny

Cladograms: Phylogenetic Trees Cladograms can give us information about

how closely related different species are and how similar their characteristics are

You want a cladogram to be AS SIMPLE AS POSSIBLE… this is a concept called parsimony: parsimony: a rule used to choose among possible

cladograms, which states that the cladogram implying the least number of changes in character states is the best.

Cladograms: Phylogenetic Trees Cladograms show evolutionary relationship

between different animals What traits evolved in their past over time

At the end of a cladogram: the result: specific animal, plant, organism (species)

At the beginning: single branch As you move along the try you see the

adaptations that developed over time The closest relative is the closest branch to the

end species

Every number on a cladogram represents an evolutionary change; evolution is complicated… you want there to be the fewest number of required adaptations

VERTEBRATA

GNATHOSTOMA

TETRAPODA

AMNIOTA

SAUROPSIDA

http://www.amnh.org/ology/features/treeoflife/pages/howtoreadclado.php

BASED ON EVOLUTIONARY RELATIONSHIPS: In reality, you need to keep groups together

based on evolutionary relationships… not necessarily how they look. Looks can be deceiving! (Ever had someone say you and a friend look like brothers or sisters?)

Monophyletic groups…specific and clear grouping

Polyphyletic group…TOO BROAD of a grouping!

VERTEBRATA

GNATHOSTOMA

TETRAPODA

AMNIOTA

SAUROPSIDA

1. What is Taxonomy?2. Describe how animals are named. Include

the types of classification.3. Why are there rules for naming animals?4. What is a cladogram? 5. What kind of information can be depicted on

a cladogram?6. Why is frugality an important consideration

when making a cladogram?

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