BIO 201 Lecture Notes - Lecture 25: Triploblasty, Parapodium, Synapomorphy
BIO 201
Lecture 25
Animals
● Fungi: Importance
○ Original source of antibiotics for humans (and source of new antibiotics)
○ Ecological importance for recycling living matter (particularly cellulose)
○ Major destroyer of human food, particularly angiosperm grains (aflatoxin)
○ Form symbiotic relationships with algae and plants - aitai the world’s forest health
○ Unique genetic system - n+n, illustrating different ways of evolving a life cycle
○ Illustrate that unicellular species have evolved from multicellular ancestors
Diversity: Animals
● Choanoflagellates and early animals
● Common ancestor: protist
● Outgroup of animals: flagellated protist
○ The common ancestor of animals was probably a colonial flagellated protist, similar to
choanoflagellates
● Evolution: Multicellular and Unicellular
○ Fugi: Multiellular → uiellular
○ Aials: Uiellular → ultiellular
● Porifera: Most ancient living animals
○ Sponges do not have tissues; but rather loosely arranged cells
● Which features occur in BOTH fungi and animals?
○ Heterotrophy and haploid cells
● Porifera: Sponges
○ No symmetry (a few have radial symmetry)
○ No tissues
○ No nervous systems
○ No coelom (internal body cavity)
○ No appendages
● Animal body plan: 5 key characters
○ Symmetry - absent, radial, bilateral
○ Body cavity type - coelom absent, present
○ Segmentation - absent, present
○ External appendages - absent, present
○ Nervous system - absent, net, central
● Body Symmetry
○ Bilateral symmetry is associated with cephalization: concentration of sensory organs
and nerve tissues at the anterior end or head.
○ The anterior end encounters the environment first. Cephalization has been
evolutionarily favored.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Original source of antibiotics for humans (and source of new antibiotics) Ecological importance for recycling living matter (particularly cellulose) Major destroyer of human food, particularly angiosperm grains (aflatoxin) Form symbiotic relationships with algae and plants - (cid:373)ai(cid:374)tai(cid:374) the world"s forest health. Unique genetic system - n+n, illustrating different ways of evolving a life cycle. Illustrate that unicellular species have evolved from multicellular ancestors. The common ancestor of animals was probably a colonial flagellated protist, similar to choanoflagellates. Sponges do not have tissues; but rather loosely arranged cells. No symmetry (a few have radial symmetry) Body cavity type - coelom absent, present. Bilateral symmetry is associated with cephalization: concentration of sensory organs and nerve tissues at the anterior end or head. The anterior end encounters the environment first. Body cavities cushion organs, and separate external and internal movement. Body cavities can also act as hydrostatic skeletons.
