BIO 330 Unit 1 Elmhurst University

Monophyletic group

a group of organisms that includes a common ancestor and all of its descendants

synapomorphies

a characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants.

paraphyletic group

a collection of organisms that includes a single common ancestor and some, but not all, of its descendants

Polyphyletic group

a collection of organisms that do not share a single common ancestor but instead have multiple, independent evolutionary origins

contains various organisms with no recent common ancestor.

homologous traits

inherited from a common ancestor

Vertebral column

analogous traits

• not inherited from common ancestor

• Result of convergent evolution

• Wings

A phylogenetic tree is a…

hypothesis of evolutionary relationships

Deuterostomes

• echinoderms, hemichordates, and chordates belong to this group

• Monophyletic group

• Share a type of larval form

How an organism develops is an indicator of…

evolutionary relationships

blastopore

forms early in development

Becomes the anus in deuterostomes

Becomes the mouth in in protostome

Echinodermata

• Includes: Sea lilies, brittle and basket stars, sea cucumbers, sea urchins, and star fishes, along with many extinct taxa

• Marine

• Monophyletic

  • 2 synamorphies

    • Water vascular system and tube feet

Hemichordata

• two clades

  • Pterobranchs

  • Enteropneusts

• Marine

• 1 snyapmorphy

  • Tripartite body

    • Proboscis, collar, and turnk

Pharyngotremata

• hemi chordata + chordata

• Pharyngotremateshave

  • 1) A pharyngeal

    skeleton

  • 2) Ciliated pharyngeal

    slits

Chordata

• Monophyletic group Bios

• 5 synapomorphies

  • Pharyngeal pouches

    • Grow laterally from the pharynx and often open to the surface as pores or gill slits

  • Endostyle

    • Turns in to Thyroid gland

  • Notochord

    • A stiff, longitudinal rod of turgid cells along the dorsal part of the body

  • Dorsal nerve cord

    • A single, tubular nerve cord that is located dorsal to the notochord

  • Postanal tail

Somitochordata

• cephalochordata + craniata

• Synapomorphies

  • Somites

  • Retention of larval features as adults

    • Specifically notochord, neural tube, and tail

Cephalochordata

lancelets or amphioxus

Animals are pointed at each end

Have shorts, postanal tails, and distinct anterior ends, but no well developed head

Somites - segmented muscles in development

Craniata

Includes all animals having a skull (or cranium, hence their name), be it cartilaginous or bony

Craniata

The evolution of many characteristics of craniates is correlated with their relatively high level of activity and large sizes.

• Craniates are cephalized, and have a head, trunk and tail.

• Head houses the mouth and gill slits

• Head also contains well developed, paired sense organs- nose, lateral eyes and ears

Neurogenic placodes

Nose and ears develop embryologically from neurogenic placodes

• Neurogenic placodes are unique to craniates and invaginate to form sensory receptor cells and sensory neurons

The end of the dorsal nerve cord in cranaites becomes…

The rest of the dorsal chorse becomes the…

The Brain

Spinal cord

Craniata synapomorphies

Earliest somitichordates may have been derived from such an ancestor by Paedomorphic retention of three larval features

What are these 3 larval features?

• Notochord

• Numeral tube

• Elongate postanal tail

Fertilization

Union of haploid sperm and haploid egg to form a zygote

Different methods of cleavage

Tissues

Group of cells working together to perform a particular function

Tissues unite to form…

Organs, organs are bunch of tissues working together

Ectoderm, mesodermal, endoderm

Modes of neural crest formation

Anterior neural tube

3 primary vesicles

• prosencephalon

• Mesencephalon

• Rhombencephalon

Endoskeleton

• deeper part of skeleton

• Forms from Endochondral ossification

Endochondral ossification

cartilage → Endochondral bone

(Post cranial skeleton)

intramembranous ossification

connective tissue → bone

(Skull bones, clavicle)

dermal skeleton

• the pattern and from of bones derived from intramembranous ossification Endochondral ossification

• Develop as membrane bones or just beneath the skin

Chondocranium

Cranial skeleton that includes endoskeletal elements that encase and protect much of the brain, nose and inner ear

Function is protection

Most of it arises from neural crest cells

dermatocranium

dermal elements that surround other parts

• solid, hard

• Superficial dermal bones nearly completely cover the chondrocranium, splanchnocranium, jaw muscles, and eyeball

Splanchonocranium

• endoskeletal visceral arches

• Support’s marine life pharynx and gills

• Structure supports respiration and feeding

• Consists of a series of arches of cartilage or Endochondral bone

• For humans, we lose them, gradually reduce over time

Arches in Splanchnocranium

• mandibular arch

  • Part of jaw

  • Dorsal palatoquadrate cartilage

  • Lower mandibular cartilage

• Hyoid arch

  • Helps to suspend the jaw

  • Support throat

  • Hyomandibula

• Bronchial or gill arches

  • Nearly all jawed fishes have 5 brachial arches

Parts of dermatocranium

dermal roof - covers top and sides of head

Palatal series - develops in roof of the mouth

Lower jaw series

Opercular series

Gulag series

Epithelial tissue

covers body surfaces and lines hollow organs, body cavities, duct, and forms glands

connective tissues

protects, supports and binds organs

Stores energy as fat and provides immunity msu

muscular tissue

generates the physical force needed to make body structures move and generate body heat

nervous tissue

detect changes in body and responds by generating nerve impulses

Adductor mandibulae

mouth closing muscle for vertebrates

Cranium synapomorphies

1. Lose post temporal gene star

   1. Zygomatic arch

2. 3 middle ear ossicles

3. Dentary/squamosal jaw joint

4. Dentary is single element of lower jaw

Trends for cranial

1. Cranial complex expands relative to body size and facial complex