Chapter III: The Diversity of Life Flashcards
What conditions favor the preservation of soft parts as fossils within sediment?
Oily, water-repellent matter; Lack of oxygen; fine grained, impermeable sediment
What are the three domains of the tree of life?
Prokaryotes: organisms who’s cells lack certain internal structures, including a nucleous. Unicellular
(Archaea)
(Bacteria)
Eukarya: all other known organisms
What major groups of Eukarya are important in the fossil record?
Mollusks and Arthopods
What is the value of derived traits for the reconstruction of phylogenies?
derived traits mark branching points in cladograms
How did the evolution of certain reproductive features allow early plants and animals to invade the land?
Rigid stems and roots; enabled plants to stand up outside of water
Roots; Provided access to nutrients and water from soil
Vascularity; (not all) for transport of water through the plant
Internal Fertilization; protection of seeds and more compatible fertilization method (not all)
In what way do animals participate in the reproduction of seed plants?
Eating seeds and spreading them in droppings. Getting seeds stuck to fur and carrying them. Aiding in transport of pollen for fertilization.
What is a colonial animal?
collective life forms; coral, anemones, moss animals etc.
What kinds of animals are included among the arthropods? What kinds are included among mollusks?
Arthropods:
animals with “jointed feet” (functioning as legs usually) and segmented bodies; crustaceans and insects;
Mollusks:
shelled animals; respire with featherlike gills; beginning of the Cambrian era
How do lobe-finned fishes differ from ray-finned fishes and why were the ray-finned forms unlikely to give rise to terrestrial animals?
Fleshy fins vs boney fins respectively; evolution of limbs and lungs; heavier bones due to lack of bones in the fin
How do mammals differ from reptiles?
Greater differentiation of teeth; warm-blooded; hair/sweat for temperature control; advanced locomotion
First mammals mesozoic era;
Which well-known group is ancestral to all living birds? What evidence in the fossil record supports this conclusion?
Dinosaurs; theropod dinosaurs.
How do scientist arrange organisms in taxonomic groups?
physical and genetic relationships
What are the three domains of life?
Archaea, bacteria, (Prokaryotes), and Eukaryotes.
What kinds of organisms constitute the protists?
mostly single celled but some multicellular; loose grouping of eukaryotic lineages which are not green plants, fungi, or animals.
What are the major invertebrate groups of animals?
Cnidarians, mollusks, arthopods, brachiopods, segmented worms, bryozoans, sponges
What are the relationships among the major vertebrate groups of animals?
Fish gave rise to amphibians which gave rise to reptiles which gave rise to therapsids and birds, mammals evolved from therapsisds
Permineralization
spaces within the cell walls of organic tissue is filled with inorganic materials, most commonly chert, to produce petrified wood or fossils
Mold
negative space left by decomposed organic tissue
Impressions
2D molds
Carbonization
Carbon concentration which leaves a residue after other compounds have been lost
trace fossils
reveal aspects of behavior of extinct animals through tracks, trails burrows, or other structures left by animal activity.
Biomarkers
chemical residue left behind by dead organisms decaying within sediment.
Taxonomic Categories Within Eukarya
Domain, Kingdom, Phyla, Class, Order, Suborder, Superfamily, Family, Genus, Species
Phylogeny
tree of life
Clade
cluster of species which share an ancestry
derived vs ancestral
ancestral traits appear early in a a group while derived evolved later, only present in some groups
molecular phylogeny
use of genetic information to construct cladograms rather than anatomical information. More accurate
cyanobacteria
photosynthetic bacteria which have left especially important fossil records
stromatolites
earliest definitive life on earth, matts of cyanobacteria
monophyletic vs paraphyletic
monophyletic are clades which represent all descendants of a single common ancestor while paraphyletic only represent some descendants.
protozoans
animal like protists
unicellular algae
3 groups; originated in the mesozoic era; most prominent producers in modern seas
dinoflagellates
2 flagella; form cysts when conditions are unfavorable for survival.
diatoms
flourish in certain geological times, dead bodies produce layers of sediment > chert
Rhizaria
Phanerozoic Eon
Foraminifera
used widely to date rocks; used in search of petroleum; useful due to small size (does not require large coring sample) and abundance.
Gymnosperms
plants which produce seeds that are exposed to the environment; Conifers; Dominant large plants in the mesozoic era but lost dominance in the cenozoic era
angiosperms
flowering plants which produce protected seeds; double fertilization; greatly outnumber gymnosperms today
Suspension Feeders
strain small particles of food from water
cnidarians
corals; jellyfish; radial symmetry
Monoplacophorans
ancestors of all living mollusk groups
gastropods
snails; paleozoic era
cephalopods
squids; octopi; phanerozoic eon rock dating
byrozoans
moss animals; calcified skeletons make excellent fossils; ordovician period-late cambrian
Brachiopods
most conspicuous fossils in paleozoic age
trilobites
cambrian period
3 groups of mammals
monotreme; egg laying
marsupial; pouches due to immature offspring at birth
placental mammals; mature, live birth
Therapsids
ancestral to mammals; evolved from reptiles; late paleozoic-early mesozoic
