MonthDayLecture Oct13Fungi 16The coral reef 18Animals—worms 20Animals—bugs to primates 23Human evolution 25Biodiversity revisited 27Exam review 30Exam

Trichoplax adhaerens

Animals... Monophyletic

Animals... Monophyletic Multicellular Eukaryotes

Animals... Monophyletic Multicellular Eukaryotes High cellular differentiation

Animals... Monophyletic Multicellular Eukaryotes High cellular differentiation Chemoheterotrophs

Animals... Monophyletic Multicellular Eukaryotes High cellular differentiation Chemoheterotrophs Feed by ingestion and digestion

Animals... Monophyletic Multicellular Eukaryotes High cellular differentiation Chemoheterotrophs Feed by ingestion and digestion Exhibit complex behavior

Chordates Echinoderms Arthropods Annelids Mollusks Rotifers Roundworms Flatworms Cnidarians Sponges Multicelled Ancestry Radial Ancestry Bilateral Ancestry Coelomate Ancestry Single-celled, protistanlike ancestors

Phylum Porifera: sponges

Phylum Cnidaria: jellyfish, corals, sea anemones

Phylum Ctenophora: comb jellies

These animals are... Radial and biradially symmetrical Most other animals are bilaterally symmetrical

Radial symmetry posterior anterior Bilateral symmetry dorsal ventral

Chordates Echinoderms Arthropods Annelids Mollusks Rotifers Roundworms Flatworms Cnidarians Sponges Multicelled Ancestry Radial Ancestry Bilateral Ancestry Coelomate Ancestry Single-celled, protistanlike ancestors

Bilateral symmetry and cephalization

Phylum Platyhelminthes: flatworms

Life cycle of Schistosoma japonicum Phylum Platyhelminthes: flatworms

Phylum Nematoda: roundworms

These animals are... Acoelomate: no enclosure around the gut Most other animals are coelomate: enclosure around gut

epidermisgut cavity no body cavity; region between gut and body wall packed with organs Acoelomate organism (flatworm)

epidermis gut cavity peritoneum lined body cavity (coelom); lining also holds internal organs in place Coelomate organism (human)

Chordates Echinoderms Arthropods Annelids Mollusks Rotifers Roundworms Flatworms Cnidarians Sponges Multicelled Ancestry Radial Ancestry Bilateral Ancestry Coelomate Ancestry Single-celled, protistanlike ancestors

Phylum Nemertea: the Spiralians

Phylum Annelida: the segmented worms

Phylum Mollusca: the mollusks

Chordates Echinoderms Arthropods Annelids Mollusks Rotifers Roundworms Flatworms Cnidarians Sponges Multicelled Ancestry Radial Ancestry Bilateral Ancestry Coelomate Ancestry Single-celled, protistanlike ancestors And relatives The “Ecdysozoans”

The “Ecdysozoans”—moulting animals Exoskeleton –flexible but tough laminate –Protects from damage, water loss Segmented joints for movement

Exoskeletons

The “Ecdysozoans”—molting animals Exoskeleton –flexible but tough laminate –Protects from damage, water loss Segmented joints for movement Molting allows growth

adultyoungegg Growth and molting adultnymphsegg Incomplete metamorphosis adultlarvaeegg Complete metamorphosis

Worm-like ecdysozoans

Onychophorans

Tardigrades (waterbears)

Arthropod: “Jointed foot” Dominant species on earth –1.5 million species –10 18 individuals

Arthropod: “Jointed foot” Dominant species on earth –1.5 million species –10 18 individuals Spiders and their relatives –Aquatic and terrestrial

Arthropod: “Jointed foot” Dominant species on earth –1.5 million species –10 18 individuals Spiders and their relatives –Aquatic and terrestrial Crustaceans –Aquatic

Arthropod: “Jointed foot” Dominant species on earth –1.5 million species –10 18 individuals Spiders and their relatives –Aquatic and terrestrial Crustaceans –Aquatic Uniramia: the insects –Terrestrial

Vertebrates Crustaceans Insects Mollusks Roundworms Plants Fungi Protozoans ,2001,600 Number of species (x 1,000) over 4 million Red = Known species Gold = Estimated number of species not yet discovered Current species diversity

Characteristics of arthropods Rigid exoskeleton with chitin Jointed appendages moved by muscles

Spider relatives

Arachnids-the true spiders

Crustaceans

Myriapod: “countless feet”

Insects: group 1

Insects: group 2

Insects: group 3