Studied by 1 PersonTags & Description
incomplete metamorphosis
A type of development in certain insects in which development from larva to adult is achieved by multiple molts, but without forming a pupa
absence of teeth, honeycombed bones, and acute sight
Which of the following traits support(s) advanced flight capabilities in modern birds?
monkeys and apes
The two major groups of anthropoids are
ectotherm
Referring to organisms for which external sources provide most of the heat for temperature regulation
endotherm
Referring to organisms that use heat generated by their own metabolism to maintain a warm, steady body temperature
notochord
Which characteristic is unique to Chordata (it is a diagnostic feature) and is evident at some stage of the life cycle in all chordates?
notochord definition
A flexible, cartilage-like, longitudinal rod located between the digestive tract and nerve cord in chordate animals; present only in embryos in many species
swim bladder and opercula
Two features of ray-finned fish NOT found in sharks are
protostome
A mode of animal development in which the opening formed during gastrulation becomes the mouth. Animals with the protostome pattern of development include the flatworms, molluscs, annelids, nematodes, and arthropods
deuterosome
A mode of animal development in which the opening formed during gastrulation becomes the anus. Animals with the deuterostome pattern of development include the echinoderms and the chordates
Homo habilis
first hominin known to make tools
tetrapod
A vertebrate with two pairs of limbs. include mammals, amphibians, and birds and other reptiles.
eumetazoa
Clade of “true animals,” the animals with true tissues (all animals except sponges).
chordate
a phylum of animals having at least at some stage of development a notochord, dorsally situated central nervous system, and gill slits and including the vertebrates, lancelets, and tunicates
arthropod
most diverse phylum in the animal kingdom, characterized by a chitinous exoskeleton, molting, jointed appendages, and a body formed of distinct groups of segments
invertebrates
are most animals vertebrates or invertebrates?
hair and mammary glands
the two distinguishing features of mammals
Cambrian explosion
happened more than 500 million years ago. It was when most of the major animal groups started to appear in the fossil record, a time of rapid expansion of different forms of life on Earth
lancelet
is a chordate, but not a vertebrate (One of a group of small, bladelike, invertebrate chordates)
complete metamorphosis
A type of development in certain insects in which development from larva to adult is achieved by multiple molts that are followed by a pupal stage. While encased in its pupa, the body rebuilds from clusters of embryonic cells that have been held in reserve. The adult emerges from the pupa.
adaptive radiation
Period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill new or vacant ecological roles in their communities
strata
rock layer formed when a new layer of sediment covers an older one and compresses it
homology
similarity in characters resulting from a shared ancestry
homologous structures
structures in different species that are similar because of common ancestry
vestigial structures
remnants of features that served important functions in the organism's ancestors
analogous structures
The similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait
convergent evolution
The evolution of similar features in different evolutionary lineages, which can result from living in very similar environments
pseudogenes
A DNA sequence that resembles a gene but has been mutated into an inactive form over the course of evolution. It often lacks introns and other essential DNA sequences necessary for function
evolutionary tree
branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms
Main points of Natural Selection
populations, not individuals, evolve over time
can only amplify or diminish heritable traits, not one's attained over a parent's lifetime
does not make perfect organisms
evolution
change over time
diversity
adaptation to existing conditions, getting what is needed, divergence
unity
traits passed from parent to offspring
hominoid
a primate of a group that includes humans, their fossil ancestors, and the anthropoid apes (includes lesser apes)
hominid
the great apes: orangutans, gorillas, chimpanzees and humans
hominin
the group consisting of modern humans, extinct human species and all our immediate ancestors (including members of the genera Homo, Australopithecus, Paranthropus and Ardipithecus)
ecdysis
the process of shedding the old skin (in reptiles) or casting off the outer cuticle (in insects and other arthropods)
bilateral symmetry
An arrangement of body parts such that an organism can be divided equally by a single cut passing longitudinally through it. A bilaterally symmetric organism has mirror-image right and left sides
radial symmetry
An arrangement of the body parts of an organism like pieces of a pie around an imaginary central axis. Any slice passing longitudinally through a radially symmetric organism’s central axis divides the organism into mirror-image halves
The Five Vertebrate Groups
Fish, Amphibians, Reptiles, Birds, Mammals
4 characteristics of a vertebrate
notochord, pharyngeal slits, dorsal hollow nerve cord, post-anal tail
porifera
These are pore-bearing multicellular animals. The body has no organs. They exhibit holozoic nutrition. The body is radially symmetrical. They can regenerate their lost parts
cnidarians
an animal characterized by cnidocytes, radial symmetry, a gastrovascular cavity, and a polyp and medusa body form. include the hydras, jellies, sea anemones, corals, and related animals.
gastrovascular cavity
A central compartment with a single opening, the mouth; functions in both digestion and nutrient distribution and may also function in circulation, body support, waste disposal, and gas exchange.
ecdysozoans
A lineage of bilaterian animals that includes the nematodes and arthropods, animals with external skeletons that must be shed
examples of protostome animals
including the arthropods (e.g., insects, crabs), mollusks (clams, snails), annelid worms, and some other groups
examples of deuterosome animals
vertebrates, sea stars, and crinoids
vertebrate
A chordate animal with a backbone, including hagfishes, lampreys, chondrichthyans, ray-finned fishes, lobe-finned fishes, amphibians, reptiles (including birds), and mammals
invertebrate
An animal that lacks a backbone
characteristics of an animal
multicellular, true tissues, motile, reproduce sexually, lack cell walls, heterotrophic
phylogeny
The evolutionary history of a species or group of related species.
phylogenetic tree
A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms, may be built using morphological (body shape), biochemical, behavioral, or molecular features of species or other groups.
the eons
Hadean, Archaean, Proterozoic, Phanerozoic
the mass extinctions
Ordovician, Devonian, Permian, Triassic, Cretaceous
pre-cambrian, around 770-800 mya
when did animals first appear in fossil record
3.5 bya
when did prokaryotes first appear in fossil record
2.7 bya
when did single celled eukaryotes appear in fossil record
600 mya
when did multicellular eukaryotes appear in fossil record
divergent evolution
the evolutionary pattern in which species sharing a common ancestry become more distinct due to differential selection pressure which gradually leads to speciation over an evolutionary time period
Oparin Haldane Hypothesis
life arose gradually from inorganic molecules, with “building blocks” like amino acids forming first and then combining to make complex polymers
Miller-Urey Experiment
The Miller-Urey experiment was a simulation of conditions on the early Earth testing the idea that life, or more specifically organic molecules, could have formed by nothing more than simple chemical reactions.
geologic eras
precambrian, paleozoic, mesozoic, cenozoic
stratigraphy
the branch of geology concerned with the order and relative position of strata and their relationship to the geological time scale
Relative time
the physical subdivision of the rocks found in the Earth's geology and the time and order of events they represent
absolute time
the measurement taken from the same rocks to determine the amount of time that has expired, usually using radiometric dating
radiometric dating
A method for determining the absolute ages of fossils and rocks, based on the half-life of radioactive isotopes
permineralization
type of fossilization that happens when minerals transported by water fill in all the open spaces of an organism or organic tissue. Within these spaces, mineral deposits form internal casts
What conditions make it more likely that an organism will form a fossil?
rock types
igneous, sedimentary, metamorphic
how sedimentary rocks are formed
Pieces of rock are loosened by weathering, then transported to some basin or depression where sediment is trapped. If the sediment is buried deeply, it becomes compacted and cemented, forming sedimentary roc
trace fossil
tracks, trails, and burrows of long-dead organisms
body fossil
the remains of actual organisms, include molds and casts
instantaneous speciation
the production of a single individual (or the offspring of a single mating) that is reproductively isolated from the species to which the parental stock belongs and that is reproductively and ecologically capable of establishing a new species population
allopatric speciation
The formation of new species in populations that are geographically isolated from one another
sympatric speciation
The formation of new species in populations that live in the same geographic area
punctuated equlibria
In the fossil record, a long period in which a species undergoes little or no morphological change (equilibrium), interrupted (punctuated) by a relatively brief period of sudden change
speciation
The evolution of a new species
different species concepts
biological, morphological, phylogenetic, ecological
phylogenetic species concept
A definition of species as the smallest group of individuals that shares a common ancestor, forming one branch on the tree of life
morphological species concept
A definition of species in terms of measurable anatomical criteria.
ecological species concept
A definition of species in terms of ecological niche, the sum of how members of the species interact with the nonliving and living parts of their environment
biological species concept
Definition of a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring but do not produce viable, fertile offspring with members of other such groups.
gene flow
The transfer of alleles from one population to another as a result of the movement of individuals or their gametes
genetic drift
A change in the gene pool of a population due to chance. Effects of genetic drift are most pronounced in small populations