# Exam 1 - Notes

# Chapter 26

## Overview

- Taxonomy and Systematics
- Phylogenetic Trees
- Horizontal Gene Transfer

### Taxonomy

The Science of describing, naming, and classifying living an extinct organisms and viruses.

#### Systematics

Study of biological diversity and the evolutionary relationships among organisms, both extinct and modern.

- Taxonomic groups are based on hypothesis regarding evolutionary relationships from systematics
- Hierarchical system involving successive levels
- Each group at any level is called a **taxon**
- Highest level is **Domain**
    - All life belongs to 3 domains
    - Bacteria, Archaea, and Eukarya 
        - The Eukarya Domain is often divided into Kingdoms in the next level  
            This is typically called the 4 Kingdom concept

[![Screenshot-from-2019-01-29-11-51-38.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/WkMUYtKa68gITVpG-Screenshot-from-2019-01-29-11-51-38.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/WkMUYtKa68gITVpG-Screenshot-from-2019-01-29-11-51-38.png)

## Four Kingdoms

- Domains Bacteria and Archaea 
    - Prokaryotic cells 
        - Lack nucleus
- Kingdom Protista, Fungi, Plantae, Animilia 
    - Eukaryotic cells 
        - True nucleus

### Types of cells

#### Prokaryotic 

- Lack Nucleus
- Lacks membrane-bound organelles
- Typically singled celled

#### Eukaryotic 

- Well defined nucleus
- Membrane-bound organelles
- internal membrane system (compartments)

## Binomial Nomenclature

- Genus name + Specific epithet 
    - ex. *Homo sapiens* ('wise humans')
- Genus name is always capitalized
- Specific epithet is never capitalized
- Both names are either *italicized* or <span style="text-decoration: underline;">underlined</span>

## Phylogenetic Trees

- Phylogeny 
    - Evolutionary history of a species or group of species
- To propose a phylogeny, biologist must use the tools of **systematics**
- Trees are usually based in morphological and genetic data 
    - Subjective vs. Objective data
- Diagram that describes the phylogeny
- A hypothesis of evolutionary relationships among various species
- Based on available information

#### Monophyletic Group or Clade

- Group of species (taxon) consisting of the most recent ancestor and all of its descendants
- Smaller and more recent clades are nested within larger clades that have a common ancestor

#### Paraphyletic group

- Contains a common ancestor and some, but not all of its descendants

[![Screenshot-from-2019-01-29-11-52-15.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/m2Obq2j58FU3mZ4U-Screenshot-from-2019-01-29-11-52-15.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/m2Obq2j58FU3mZ4U-Screenshot-from-2019-01-29-11-52-15.png)

- Over time, taxonomic groups will be reorganized so that only monophyletic are recognized
- Reptiles were a paraphyletic group because birds were excluded
- **In the class and lab, we are going to separate birds and reptiles**

[![Screenshot-from-2019-01-29-11-53-44.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/8Wv6XVyvrUgZQDcl-Screenshot-from-2019-01-29-11-53-44.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/8Wv6XVyvrUgZQDcl-Screenshot-from-2019-01-29-11-53-44.png)

## Systematics

### Morphological Analysis

- First systematic studies focused on morphological features of extinct and modern species
- Most of early classifications were based upon morphological features

### Molecular Analysis

- Analysis of genetic data (DNA, Amino Acids, rRNA) to identify and study genetic similarities and propose phylogentic trees
- DNA and Amino Acid sequences from closely related species are more similar to each other than sequences from more distantly related species

### Horizontal Gene Transfer

- any process in which an organism incorporates genetic material from another organism without being the offspring of that organism (by means of asexual reproduction)

### Vertical Evolution

- Changes in groups due to descent form a common ancestor (sexual reproduction)

# Chapter 27-31

## Prokaryotic Diversity

- Prokaryotes dated at 3.5 billion years old
- Modern Prokaryotes are most abundant, lacking sexual reproduction

### Domain Bacteria

- Proteobacteria 
    - "true bacteria"
- Cyanobacteria 
    - "Blue-Green bacteria"

### Domain Archaea

- Have and "almost" nucleus
- specialized membranes
- surrounded by a cell wall
- old, can live in extreme conditions

## Eukaryotic Diversity (Ch 28)

## Kingdom Protista

- Earliest eukaryotes in fossil record
- most are microscopic and found in moist environments
- DNA many separate groups
- Most artificial category 
    - "catch-all" category

### Subgroups

#### Algae

- Plant-like organisms
- 10 groups
- autotrophic (self-feeding) 
    - most are photosynthetic
    - few ingest food
- cell wall with

#### Protozoans

- Animal-like
- mostly netraothrophic (food-eating)

#### Slime Molds

- Fungal-like Protist
- Mostly saprothrophic (absorb-feeding)
- mostly multicellular

## Kingdom Fungi (Ch 31)

- Conspicuous portion of the organism in the mushroom/yeast/mold/etc
- Saprothrophic (some are heterotrophic)
- Natures recyclers
- Composed of: 
    - Mycelium 
        - compacted mass of tubular filaments called hyphae
    - Fruiting body 
        - site of spore production
    - Cell wall 
        - composed of muramic acid/chitin

## Kingdom Plantae (Ch 29 &amp; 30)

- &gt;330,000 species
- eukaryotic and multicellular
- autotrophic (mostly) self-feeding 
    - capture sunlight to produce energy by photosynthesis
    - Food storage copound 
        - starch
    - cell wall 
        - cellulose
- Are referred to as "land plants"
- fossils dated to ~400mybp (million years before present)
- Ancestor stock 
    - probably a group of algae (green)
- Life on land requires special innovation 
    - Must be able to get water 
        - ROOTS!

### Phyla (divisions)

- 10 phyla
- Typically combine these into 4 broad categories for convenience

#### Bryophytes

- Phylum Hepatophyta 
    - Liverworts
    - ~6500 species
- Phylum Anthocerophyta 
    - Hornwarts
    - ~100 species
- Phylum Bryophyta 
    - Mosses
    - ~12,000 species

Referred to as "mosses and their friends"

##### Characteristics

- Reproduce by spores (not seeds)
- non-vascular plants 
    - lack conducting tissues 
        - xlem and phloem
- Small plants
- Require external H2O for reproduction

#### Pteridophytes

- Phylum Lycopodiophyta 
    - lychophytes
    - 1000 species
- Phylum Pteridophyts 
    - Ferns and allies
    - 12,000 species

##### Characteristics

- Sporangia 
    - Where the spores are produce
- Reproduce by spores 
    - no seeds
- vascular plants 
    - xylem 
        - water and minerals
    - phloem 
        - food and solutes
- true roots, stem, and leaves 
    - due to being vascular
- vascular allows for larger size
- Require external H2O for reproduction

#### Gymnosperms

- Phylum Cycadophyta 
    - cycads
    - 300 species
- Phylum Ginkophyta 
    - Ginko
    - 1 species
- Phylum Gnetophyta 
    - gnetophytes
    - 300 species
- Phylum Coniferophytes 
    - conifers
    - 500 species

Means "Naked seeds"  
Seeds are not enclosed

Biggest group are the conifers  
(Cone bearing trees)

- Oldest 
    - Bristle cone pine 
        - Over 4600 years
- Biggest 
    - Giant Sequoia 
        - estimated 600 tons
- Tallest 
    - Coastal Redwood
    - 180 meters in height

##### Characteristics

- Vascular 
    - more advanced that Pteridophytes
- Advance seed 
    - It has more survival value
    - Contains: 
        - Embryo 
            - Offspring
        - Stored food
        - Integument 
            - Seed coating
- Does not require external H2O for reproduction 
    - Pollen tubes deliver sperm to egg location

#### Angiosperms

- Phylum Anthophyta 
    - 300,000 species

##### Characteristics

- Enclosed seed
- produces flowers and fruits
- most advance vascular tissues
- Seeds advance 
    - Enclosed in a vesses (fruit) 
        - no survival value
    - Embryo
    - Stored food
    - 2 integuments 
        - Seed coats
- Does not require external H2O for reproduction
- Flowers 
    - Attract pollinators
- Fruit 
    - Enclose and protect the seed
    - assist with seed dispersal

# Chapter 32 & 33

## Kingdom Animilia

- Over 1.5 million species 
    - Estimated 73 million
- 35 Phylums 
    - Over half are insects
- More similarities within animal genomes than other kingdoms

### Characteristics 

- Multicellular
- Lack of cell wall
- Sexual reproduction 
    - mobile sperm
    - larger non-motile egg
- Nervous Tissue 
    - Complexity
    - Responsiveness
- Hox Genes 
    - Special clusters of genes associated with the planning of the body

[![Screenshot-from-2019-01-29-12-00-54.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/7svEQ3Ey5pguUaDH-Screenshot-from-2019-01-29-12-00-54.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/7svEQ3Ey5pguUaDH-Screenshot-from-2019-01-29-12-00-54.png)

[![Screenshot-from-2019-01-29-12-01-51.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/n9phZd3dW5Xva89B-Screenshot-from-2019-01-29-12-01-51.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/n9phZd3dW5Xva89B-Screenshot-from-2019-01-29-12-01-51.png)

### Metazoans

- All animals
- Multicellular animals
- Paratoans 
    - Sponges
- Eumetazoans 
    - "true" multicellular animals

### Classification/Systematics

- Old 
    - Morphology
    - Embryonic Development
- Recent 
    - Molecular genetics

### Body Plans

Morphological and Developmental Features

1. Body Symmetry
2. Number of tissue Layers
3. Patterns of Embryonic development

#### Symmetry

- Eumetazoa 
    - Divided by symmetry
- Radiata 
    - Radial symmetry
    - Often Circular or tubular
- Bilateria 
    - Bilateral symmetry
    - Dorsal 
        - Back
    - Ventral 
        - Front
    - Anterior
    - Posterior
    - cephalization 
        - enlarged head

[![Screenshot-from-2019-01-29-12-02-37.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/uWhuBNwMH0OUgRwt-Screenshot-from-2019-01-29-12-02-37.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/uWhuBNwMH0OUgRwt-Screenshot-from-2019-01-29-12-02-37.png)

#### Tissues

- Metazoa 
    - all animals
    - divided on weather or not they have specialized tissues
- Parazoa 
    - Porfera 
        - sponges
        - may have distinct cell types
- Enmetazoa 
    - more than one type of tissue
    - organs
    - all other animals

##### Germ Layers

- Radial 
    - 2 layers
    - Diploblastic 
        - endoderm
        - ectoderm
- Bilateral 
    - 3 layers
    - Triploblastic 
        - endoderm
        - ectoderm
        - mesoderm

[![Screenshot-from-2019-01-29-12-03-02.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/TFAhXfNlpGDLXT1R-Screenshot-from-2019-01-29-12-03-02.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/TFAhXfNlpGDLXT1R-Screenshot-from-2019-01-29-12-03-02.png)

##### Embryonic Development

- Protostome 
    - Blastopore becomes mouth
    - cleavage is determinate 
        - fate of embryonic cells are determined early
- Deuterostome (second opening) 
    - Blastopore becomes anus
    - cleavage is indeterminate
    - each cell produced by early cleavage can develop into a complete embryo

##### Other Morphological Characteristics

Used in classification

- Presence or absence or coelom
- Body segmentation

Molecular data suggest these features are unreliable in terms of understanding evolutionary history

##### Body Cavity

Coelom

- - a fluid-filled body cavity
- Coelomate or eucolemate 
    - true coelom
    - coelom completely lined with mesoderm
- Pseudocoelom 
    - coelom only partially lined with mesoderm
    - rotifers and roundworms
- Acoelomate 
    - lack of a body cavity and instead have mesenchyme
    - flatworms

[![Screenshot-from-2019-01-29-11-49-49.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/Ll8Gw0R3zNLygxCm-Screenshot-from-2019-01-29-11-49-49.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/Ll8Gw0R3zNLygxCm-Screenshot-from-2019-01-29-11-49-49.png)

Flatworm has no mesoderm

Functions of the Coelom

- Cushions internal organs
- Enables movements and growth of internal organs independent of the body wall
- Fluid acts as a simple circulatory system

Segmentation

- Body may be divided into regions called segments
- occurs in annelid worms, arthropods, and chordates
- allows specialization of body region

[![Screenshot-from-2019-01-29-11-48-35.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/8QttkWqKBKBu56Iy-Screenshot-from-2019-01-29-11-48-35.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/8QttkWqKBKBu56Iy-Screenshot-from-2019-01-29-11-48-35.png)

DO NOT worry about the number of species

## Molecular views of Animal Diversity

- Scientist now use molecular techniques to classify animals 
    - Compare similarities in DNA, rRNA, and Amino Acids
    - Closely related organisms have fewer differences than those more distantly related
- Advantages over morphological data in that genetic sequences are easier to quantify and compare 
    - Example: A,T,G, and C in DNA

### Genes used in Molecular Systematics

- Studies often focus on ribosomal RNA (rRNA) 
    - Universal in all organisms
    - changes slowly over time
- Hox genes also studied often 
    - Found in all animals
    - duplications in these genes may have led to evolution of body form
- Phylogenies constructed using rRNA and Hox genes are similar and often agree with those based on morphology

## Invertebrates

- "without backbone"
- +95% of all species

### Phylum Porifera

- Sponges
- lack tissues (organs)
- multicellular
- pores 
    - filter H2O and food
- Invertebrates

### Phylum Cnidaria

- Jelly fish, corals, anemones
- Diploblastic development 
    - Two tissue layers
- Mesoclea 
    - gelatinous covering
- Nerve net 
    - interconnected nerve cells
    - no brain
- One opening with gastrovascular cavity
- Protostomes
- Invertebrates
- Radial symmetry
- Salt and fresh water
- Stingers

### Phylum Ctenophora

- Comb jellies
- Same characteristics as Cnidaria
- Strictly salt water
- No Stingers

### Phylum Platyhelminthes

- Flatworms, tapeworms, flukes
- Triploblastic
- Organs and organ systems
- Enhanced nerve net 
    - 2 cerebral ganglia
- One opening with gastrovascular cavity
- Protostomes
- invertebrates
- bilateral symmetry
- Acoelomate

### Phylum Rotifera

- rotifers
- pseudocoelomate
- Triploblastic
- Two openings 
    - complete gut tract
    - alimentary canal
- Protostomes
- Corona
- simple brain
- invertebrates

### Phylum Mollusea

- Snails, slugs, oysters, octopus, squid, clams, muscles
- Triploblastic
- Eucoelomate
- Complete gut tract
- Protostomes
- Invertebrates
- Three part Body 
    - Foot
    - Visceral mass
    - Mantle 
        - Many have outer shells

### Phylum Annelida

- Segmented ring worms
- Triploblastic
- Eucoelomate
- Complete gut tract
- Protostomes
- Enhanced nervous system
- Invertebrates

### Phylum Nematoda

- Roundworms
- Triploblastic
- Pseudocoelomate
- Complete gut tract
- Protostomes
- Invertebrates

### Phylum Anthropoda

- Insects, crustaceans, spiders, ticks
- Highest diversity of animals 
    - &gt;1.5 million species
- Hardened Exoskeleton
- Protostomes
- Invertebrates
- Eucoelomate
- Triploblastic
- Complete gut tract
- Enhanced nervous system 
    - Insects, in particular, have an enhanced brain
- segmented appendages

### Phylum Echinodermata

- sea stars, urchins, sea cucumbers, sand dollars
- Triploblastic
- Eucoelomate
- Complete gut tract
- Deuterostomes
- Simple nervous system
- Endoskeleton 
    - series of plates

## Phylum Chordata

- Deuterstomes
- Complete gut tract
- Endoskeleton
- Few invertebrates 
    - Mostly vertebrates
- Eucloemates
- Triploblastic

## Four Critical Innovations of Chordate Body Design

1. Notochord
2. Dorsal, hollow nerve cord
3. Pharyngeal gill pouches
4. Post-anal tail

- These four features are exhibited at some point of life history/development 
    - Only some Fishes exhibit all four

### Notochord

- Cartilaginous supporting rod along the dorsal axis
- Replaced by jointed "backbone" 
    - Vertebral column of hardened cartilage or bone

### Dorsal, hollow nerve cord

- Expanded at the anterior end 
    - Brian
- Enclosed/supported/protected by the Notochord

### Pharyngeal gill pouches

- Gill slits
- pharynx 
    - back of mouth cavity

### Post-anal Tail

- Tail extends posterior of the anus

#### Humans

##### Notochord

- replaced by vertebrae
- only pieces left are the inter-vertebral discs between vertebrae

##### Nerve cord

- Dorsal, hollow with largest brain capacity (compared to body size)

##### Pharyngeal Pouches

- Embryonic Development
- 1 pair retained as Eustachian tubes

##### Post-anal Tail

- One vertebra as a tail bone (coccyx)

### Subphylum Urochordata

- tunicates
- invertebrates
- ~3000 species
- Marine
- Filter feeders

[![Screenshot-from-2019-01-29-11-47-27.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/inQ83f0n1DNhLdpF-Screenshot-from-2019-01-29-11-47-27.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/inQ83f0n1DNhLdpF-Screenshot-from-2019-01-29-11-47-27.png)

### Subphylum Cephalochordata

- Lancelets
- Invertebrates
- 25 species
- marine
- Filter feeders

[![Screenshot-from-2019-01-29-11-45-01.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/Nuxg9xz3SwNgJgm8-Screenshot-from-2019-01-29-11-45-01.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/Nuxg9xz3SwNgJgm8-Screenshot-from-2019-01-29-11-45-01.png)

# Chapter 34

## Subphylum Vertebrata

- Vertebrates
- Chordates with a backbone

Chordate features as well as:

1. Vertebral column 
    - Series of cartilaginous or bony elements
2. Cranium
3. Endoskeleton or cartilage or bone
4. Hox genes (lots of them)
5. Neural crest

[![Screenshot-from-2019-01-29-11-59-40.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/WnHIpkqEgDgAE0Qr-Screenshot-from-2019-01-29-11-59-40.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/WnHIpkqEgDgAE0Qr-Screenshot-from-2019-01-29-11-59-40.png)

[![Screenshot-from-2019-01-29-12-07-52.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/HnAoBE4j1MFZmLVK-Screenshot-from-2019-01-29-12-07-52.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/HnAoBE4j1MFZmLVK-Screenshot-from-2019-01-29-12-07-52.png)

### Cyclostomes

- Jawless Fishes

#### Class Myxini

- Hagfishes
- lack jaws, eyes, fins vertebrae
- skeleton comprised of notochord and cartilaginous skull
- covered in slime

#### Class Cephalospidomorphi

- Lampreys
- Has notochord, and cartilaginous vertebral column
- lacks jaws and appendages (fins)
- Oldest fossil records 510 mybp

### Class Chondrichthyes

- Cartilaginous fishes
- Sharks, skates, rays
- Cartilaginous skeleton and notochord as adults
- jawed fishes
- paired appendages (fins)
- &lt; 900 species

### Class Osteichthyes

- Bony fishes
- Most diverse vertebrate group with &lt; 26,000 species
- Bony skeleton (most do have this)
- Jawed
- paired appendages (fins)

## Tertapod: Gnathastomes

- Four limbs with jawed mouth
- Transition to land involved adaptions for locomotion, reproduction, desiccation (drying out) prevention, and gas exchange
- Sturdy lobe-finned fishes became animals with four limbs
- Vertebral column strengthened, ship and shoulder bones braced against backbone
- relatively simple changes in gene expression, especially Hox genes

### Class Amphibia

- &gt;4000 species
- Amphibios 
    - greek - "living double life"
    - split their life between aquatic and terrestrial stages
- Successfully invaded land but reproduce in water
- Lunges are and adaption to semi-terrestrial lifestyle
- Three chambered heart 
    - Fishes only have a two chambered heart
- External Fertilization
- Larval stages are aquatic 
    - Undergo metamorphosis
- Not completely separated from water

[![Screenshot-from-2019-01-29-12-33-08.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/SlypUH0QiIkh947E-Screenshot-from-2019-01-29-12-33-08.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/SlypUH0QiIkh947E-Screenshot-from-2019-01-29-12-33-08.png)

#### Order Anura

- Frogs and toads
- Nearly 90% of amphibians
- Carnivorous adults 
    - Herbivorous tadpoles

#### Order Apoda

- Caecilians
- Nearly blind tropical burrowers
- Secondarily legless

#### Order Urodela

- Salamanders
- Often have colorful skin patterns
- Most have four limbs

[![Screenshot-from-2019-01-29-12-33-21.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/nX9GLgeq5Sx2Mdqq-Screenshot-from-2019-01-29-12-33-21.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/nX9GLgeq5Sx2Mdqq-Screenshot-from-2019-01-29-12-33-21.png)

## Amniotes

- Tetrapods with a desiccation resistant egg
- Critical innovation 
    - Development of a shelled egg
- Amniotic egg 
    - Broke the tie to water
    - Three internal membranes
- Shell is permeable to Oxygen and CO2 
    - Birds 
        - Hard and Calcareous
    - Reptiles 
        - Soft and Leathery
    - Most Mammals 
        - Embryo embeds in uterine wall
        - Only three species lay eggs 
            - These eggs are soft and leathery

[![Screenshot-from-2019-01-29-12-33-34.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/flHkihcFr9Y2C9EF-Screenshot-from-2019-01-29-12-33-34.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/flHkihcFr9Y2C9EF-Screenshot-from-2019-01-29-12-33-34.png)

#### Other Key Innovations of the Amniotes

- Desiccation resistant skin 
    - contains keratin
- Thoracic breathing 
    - Negative pressure sucks air in
- Water conserving Kidneys 
    - Concentrate waste prior to elimination
- Internal fertilization

### Class Reptilia

- &gt;8000 living species
- turtles, crocodilians, lizards, snakes
- Can live away from water
- thicker skin and scales
- larger brain
- larger limbs with muscles
- enhanced kidneys
- Amniotic egg 
    - "indoor pond"

## Vertebrate Reproductive Modes

1. Oviparous 
    - Egg laying outside of the body
2. Ovoviviparous 
    - live baring wuth retention of eggs
    - No maternal connection
3. Viviparous 
    - live bearing with egg retained
    - Maternal connection

### Class Aves

- Birds
- Evolved form small dinosaurs
- Fossils 150mybp
- Adaptions for flight 
    - Feathers
    - Modified front limbs
    - Lightweight skeleton
    - Organ reduction
    - Lungs and air sacs 
        - more gas exchange
- Oviparous 
    - all leg layers
- Bill beak 
    - Encloses mouth and nasal cavity
    - Adapted for environment

[![Screenshot-from-2019-01-29-13-16-50.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/zbb1SszkDwvQJVu5-Screenshot-from-2019-01-29-13-16-50.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/zbb1SszkDwvQJVu5-Screenshot-from-2019-01-29-13-16-50.png)

### Endothermic

- "Internal temperature"
- Body temperature is primarily controlled by trapped metabolic heat.
- Birds and mammals

### Ectothermic

- "External temperature"
- Body temperature is primarily related to external temperature
- Metabolic heat is generated but difficult to capture/maintain the heat
- Fishes, amphibious, reptiles

## Class Mammalia

- Milk producing Amniotes
- Evolved from amniote ancestors (reptiles) earlier than birds
- &gt;6000 species
- Appeared ~ 225mybp 
    - Evolved from small mammal-like reptiles
- After dinosaur extinction, mammals flourished
- Range of sizes, body forms, and complexity unmatched

[![Screenshot-from-2019-01-29-13-17-55.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/7WdVRMuItPyYC12W-Screenshot-from-2019-01-29-13-17-55.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/7WdVRMuItPyYC12W-Screenshot-from-2019-01-29-13-17-55.png)

- Fish-like mammals 
    - Marine mammals
- Bird-like mammals 
    - Bats
- Reptile-like mammals 
    - Three egg layers

#### Distinguishing Characteristics

- Mammary Glands 
    - Secrete milk
- All have hair 
    - In varying amounts
- Only vertebrate with multiple dentitions 
    - Heterodont 
        - Different types of teeth
        - incisors, canines, molars, premolars
    - Thecodont 
        - Teeth with long roots embedded in sockets of jawbone
    - Diphyodont 
        - Milk teeth that are mostly replaced by "adult" teeth later in life
- Pinna 
    - Flap of cartilage and lose connective tissue to channel and funnel sound
    - The "outer ear"
- Three middle ear ossicles (bones)
- Enlarged Skull 
    - Brain enlarged in large skull
    - Larger Cerebrum
    - Single lower Jawbone (Dentary)
- Anucleate red blood cells

[![Screenshot-from-2019-01-29-13-18-32.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/4T0eaG8FZ1VQCGsf-Screenshot-from-2019-01-29-13-18-32.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/4T0eaG8FZ1VQCGsf-Screenshot-from-2019-01-29-13-18-32.png)

### Order Primates

- Primarily tree dwelling species
- grasping hands with opposable thumbs
- Large brain
- Some digits with flat nails 
    - Not claws
- Binocular vision
- Complex social behavior and well-developed parental care
- Enhanced sense of touch

[![Screenshot-from-2019-01-29-13-22-59.png](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/scaled-840-0/pABbbU53BdQRpHGJ-Screenshot-from-2019-01-29-13-22-59.png)](https://bookstack.aronwk.com/uploads/images/gallery/2019-01-Jan/pABbbU53BdQRpHGJ-Screenshot-from-2019-01-29-13-22-59.png)

## Taxonomy of Humans

- **Kingdom** *Animalia*
    - **Phylum** *Chordata*
        - **Subphylum** *Vertebrata*
            - **Class** *Mammalia*
                - **Order** *Primates*
                    - **Suborder** *Anthropoidea*
                        - **Superfamily** *Hominoidae*
                            - **Family** *Hominidae*
                                - **Subfamily** *Homininae*
                                    - **Tribe** *Hominini*
                                        - **Genus** *Homo*
                                            - **Species** *Homo* s*apiens*