Lecture 4 Flashcards
polyphyletic group
grouping of all the descendants that CANNOT be traced back to a common and unique ancestor
phylogeny
the representation of the evolutionary history and relationships between groups of organisms
systematics
the study of the relationships between organisms, including their evolutionary history, to understand how different species are connected and how they evolved over time
cladogram
a model for animal relatedness where each clade traces back to a unique common ancestor
clades
a group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics.
synapomorphy
Synapomorphy is a relative term denoting a homologous character that originated or was fixed in an ancestral species of a monophyletic group and which provides evidence that all members of that group share the common ancestor.
opisthokont
flagellum on the rear pole
multicellular
cells grouped in larger units for specialized functions, (size, partition, function, environmental) also usually YOU CAN SEE MULTICELLULAR
fitness
passing on genetic material to offspring that enables organisms to survive/function/withstand change and achieve greater size
multiple germ layers
Endoderm, mesoderm, ectoderm - layers formed during embryo stage of development, different layers form different sorts of cells with different functions
invagination
the gastrula folds inward creating a blastopore that gives rise to endoderm
endoderm
cells of the alimentary canal, other tissues and organs
mesoderm
muscles, bones, connective tissue, blood, dermis of skin (NOT epidermis)
ectoderm
epidermis and derivatives, nervous system, and endocrine system
radial symmetry
mirror image in multiple planes (jelly fish, mushrooms)
FITNESS - sense environment in 360
bilateral symmetry
mirror image in one plane only
FITNESS: forward motion, sense environment as they move unidirectionally, leads to cepalization
Coelomate
internal cavity within the mesoderm layer. us, earthworms
FITNESS: protection maybe?
psuedocoelomate
coelom is lined with mesoderm on one side and endoderm on the other (round worm)
acoelomate
does not have a coelom (planaria)
segmentation
a linear series of body segments having the same or similar structure and function. (segments in worms, ribs, muscle layers in salmon)
protostome
blastopore becomes anterior end of digestive system
FITNESS: ???? lol
duterostome
blastopore becomes posterior end of digestive system
FITNESS: ????
Lophotrochozoa
ciliated tentacles surrounding the mouth, or with trochophore larvae - snails, octopus, slug - mollusk
Ecdysozoa
Molting of exoskeleton, IE arthropod (insects, lobsters)
Chaetognatha
arrowworms,
pharyngeal slit
piercing or near piercing of pharynx (commonly called throat)
FITNESS: feeding initially, later respiration
Dorsal Nerve Cord
bundle of neurons for sensory, motor and memory storage. Located dorsal to the gut track, ectoderm derived
Echinodermata
Starfish, Sea Urchins
Hemichordata
proboscis worms
Notochord
fibrous rod, attachment site for muscles, mesoderm derived
FITNESS: Coordinated movement (undulation, swimming)
Post Anal Tail
internal support for structures and muscles
FITNESS: mobility or burrowing initially, other derived functions like stability and balance, communication, protection
Chordata
phylum containing animals with notochord, DNC, endostyle, pharyngeal slits, and post-anal tail
