Exam 1 Flashcards
What is the most diverse species?
fishes
How old are the first vertebrates in the fossil record?
500 million years old
Why does similarity often occur among vertebrates?
“relatedness”
Is convergent evolution ancestry or relatedness? If not what is it?
it is not ancestry or relatedness, it is just a convergence of physical characteristics over time
How does diversity occur among vertebrates?
adaptation
Define extinct.
past organisms, no longer alive
Define extant.
present organisms, still living
What phylum are all vertebrates members of?
the phylum Chordata
What is the general definition of vertebrates?
animals with backbones
What are the 5 general groups of vertebrates?
fishes
amphibians
reptiles
birds
mammals
What is an example of “lower vertebrate” or “primitive” vertebrates?
fishes
What is an example of “higher vertebrate” or “advanced” vertebrates?
mammals
How were vertebrates classified in the older, traditional classification system?
kingdom; Animalia
phylum; Chordata
subphylum; Vertebrata
What are the 4 basic characteristics of chordates that distinguish them from other phyla?
notochord
dorsal nerve cord
pharyngeal gill slits
postanal tail
True or False. The spinal cord in humans in homologous with the notochord.
false
Is the notochord the vertebral column?
no, it is a rod like structure
What are some characteristics of the notochord?
consists of a semi-rigid group of cells surrounded by fibrous and elastic sheaths
muscles can act on it
allows for undulating body movements
Where does the notochord lie?
ventral to the “dorsal nerve cord”
Is the notochord present during embryonic development in all vertebrates?
yes
What are some examples of primitive vertebrates that the notochord remains in throughout their life?
hagfish and lampreys
In most vertebrates what is the notochord replaced with?
the vertebral column which forms around the notochord
What is the advantage of a stiff notochord in the body?
allows the side to side fish like movement
What is considered the most primitive living vertebrate?
hagfish
What forms the neural plate?
dorsal tubular nerve cord
What is an example of the dorsal nerve cord failing to seal itself?
spina bifida and anencephaly
What are gill slits used for?
respiration in lower vertebrates
Are gill slits also used for filter feeding in some lower vertebrates?
yes
What are post anal tails?
long tails that are good for animals movement, balance, etc
What are some additional similarities among the chordates?
segmented muscle mass
endoskeleton of cartilage/bone
bilateral symmetry
“closed” circulatory system
What are the characteristics of the hagfish?
notochord persistent throughout life
fibrous & cartilaginous skeleton
no jaws
no paired appendages
poorly developed brain and reproductive system
Define brackish.
combination of freshwater and saltwater organisms
What are some examples of fish that migrate from marine to freshwater?
salmon and american eel
What are some examples of animals that inhabit aquatic and terrestrial environments?
amphibians, turtles, marine iguana, sea birds, seals, sea lions, etc
Define gonochoristic.
animals with 2 separate sexes
Define hermaphrodite.
ability to change sex over life span or be both sexes at the same time
Define unisexual vertebrates.
when eggs develop into female without fertilization
What are the 4 eras in the fossil record time scale?
Cenozoic
Mesozoic
Paleozoic
Precambrian
How old is the Earth?
about 4.5 billion years old
What does the fossil record indicate?
that the diversity of vertebrates has gradually changed over time and that vertebrate diversity today is distinctly different from other time periods
The fossil record indicates that some species have gone _______ while others have _______ in the record over time.
extinct; appeared
What kind of animals were found in the precambrian time scale in the fossil record?
only aquatic invertebrates until approximately 500 million years ago
What was abundant in the middle of the Paleozoic time scale of the fossil record?
fishes
What do the fossil records from towards the end of the Paleozoic era indicate?
amphibians and reptiles were dominant terrestrial vertebrates
What animals are present in the fossil record toward the end of the mesozoic era?
peak of the dinosaurs
birds are present
small mammals
What animals are diverse and abundant in the Cenozoic era of the fossil record?
birds and mammals
When did the first hominid fossils appear?
about 5 million years ago
When did the first Homo sapiens begin to appear in the fossil record?
about 300,000 years ago or less
What was the Cambrian explosion?
great increase in animals on the earth
What was the Devonian period also known as?
the age of fishes
What was the mesozoic era also known as?
age of the reptiles
Did mammals show up at the time of the dinosaurs?
yes
What happens to mammals once dinosaurs go extinct?
the species takes off
When was the CT (Cretaceous tertiary period) mass extinction?
mesozoic era
What did Carolus Linnaeus suggest?
that all animals were fixed, invariable, and did not change with time; they were created when the earth was created and have not changed since
What did Jean Baptiste de Lamarck suggest?
popularized the concept that species might actually change over time
What was the name of Lamarck’s concept?
inheritance of acquired characteristics
What were the 2 points of Lamarck’s theory?
- animals naturally progress toward a higher form, animals continually lose characteristics that aren’t needed and gain the ones that are useful
- proposed animals could acquire changes during their lifetime and that those changes were passed to their offspring
What is Lyell often referred to as?
father of modern geology
What did Lyell’s books hypothesize?
geological formation that we currently see on earth results from slow and gradual geological processes
Did Lyell’s book have a strong influence on Darwin?
yes
What are some examples of animals that were different on the Galapagos in comparison to those on the mainland?
iguanas
finches beak shape (Darwin’s finches)
tortoises shell shape
What are the 5 parts of Darwin’s theory of evolution by natural selection?
1.organisms are not static and can evolve over time/generations
2.changes in organisms appears gradual and continuous
3.concept of common descent
4.more individuals in a species are produced than can survive and its “survival of the fittest”
5.environment and nature determines who will survive
According to Darwin does the environment dictate which organisms are more “fit” and which traits are passed down to the next generations?
yes
What was the first bird in the fossil record?
archaeopteryx
What was the name of the ship Darwin was on for 5 years?
H.M.S Beagle
What did Thomas Malthus write an essay on? What theory came from the reading of this essay?
essay on the principle of population; survival of the fittest
Where are the Galápagos Islands located?
600 miles off of the coast of South America
How old are the Galápagos Islands?
1-4 million years old
Gould and Eldredge suggested what in contrast to phyletic gradualism?
punctuated equilibrium
What did Gregor Mendel do?
experimented on pea plants and developed basic genetic concepts such as dominant vs recessive alleles
What are Mendel’s concepts known as?
Mendelian Inheritance or Mendelian Genetics
What is the combination of Darwin’s theory combined with Mendelian Genetics referred to as?
Neo-Darwinism
Define evolution.
genetic composition of an animal can change over time specifically generations
Define natural selection.
the environment favors certain trait that are advantageous and increase the fitness of an organism in a given environment
Define fitness.
ability to survive and reproduce
What are examples of evidence cited in support of evolution and natural selection?
artificial or human selection
evolution of antibiotic resistance by bacteria
fossil record
comparative anatomy
comparative physiology
comparative embryology
molecular genetics
What does artificial or human selection reveal?
species can change over generations and that certain traits can be “selected”
What does the evolution of antibiotic resistance by bacteria reveal?
example of evolution and natural selection of bacteria; bacterial strains are evolving resistant to current antibiotics
What does comparative anatomy reveal?
“homologous” structures in different species
What does homologous mean?
similar structures in different species and these structures have the same embryonic origin
What does analogous mean?
structures which may be similar in structure or function but are of different embryological origin
What does comparative physiology reveal?
homologous physiological systems and molecules in different species
What does comparative embryology reveal?
early stages of embryonic development of various vertebrates show many similarities
What did Ernest Hackel hypothesize?
the homologous embryonic structures may represent developmental remnants related to an animals ancestry
What was Hackels theory known as?
Haeckel’s Biogenetic Law; hypothesized that ontogeny recapitulates phylogeny
What does molecular genetics reveal?
allows genetic comparison of the relatedness of specific animals
Who was known as Darwin’s bulldog?
Thomas Henry Huxley
What did Alfred Wallace do?
independently came up with concept of evolution by natural selection
What is evolution?
change in an organisms genotype to change over time
What are the characteristics of a species?
- group of individuals with similar characteristics
- capable of interbreeding
- reproductively isolated from similar groups
Who popularized the “biological species concept”?
Ernst Mayr
What is the modern definition of a species?
“genetically distinct” group of organisms which is also “genetically isolated” from other groups
Allopatric speciation.
due to geographic isolation; subpopulations are geographically separated from one another so each subpopulation evolves on its own in a different environment and eventually becomes genetically distinct
Sympatric speciation.
speciation occurring in the same location; subpopulation may become isolated due to ecological or behavioral differences
What is an example often used for sympatric speciation?
Lake Baikal sculpins
What is Lake Baikal commonly referred to as?
Galapagos of Russia
What is systematics?
classifications vertebrate species
Who was one of the first systematists (person who classifies living organisms)?
Carolus Linnaeus
Who is the Father of modern Taxonomy?
Carolus Linnaeus
What is the order of the heirarchial system of taxonomy?
kingdom, phylum, class, order, family, genus, species
What did Carolus Linnaeus use for Taxonomy?
binomial nomenclature
How is binomial nomenclature used?
genus then specific epithet
Define primitive characteristic (plesiomorphy).
characteristic that is the same as it was in an ancestor
Define derived characteristics (apomorphy).
new characteristic only present in specific group of organisms
Does each characteristic in Cladistics have equal weight?
yes
What is the grouping of organisms based off of?
based on organisms characteristics
Describe traditional systematics.
based of analysis of animal characteristics, does not consider ancestry of the organism or trait
What is the goal of cladisitics?
group organisms based on how closely related they are to one another, how recently they had a common ancestor
What is a monophyletic group?
group that contains all members of a group that are hypothesized to be derived from a common ancestor
What is a paraphyletic group?
groups that do not contain all members hypothesized to be derived from a specific common ancestor
When was radiometric dating developed of and refined?
between 1911 and 1950s
What is the half life of Uranium-Lead dating?
713 million years
What is the half life of Potassium-40?
1.28 billion years
What does Uranium 235 decay into?
Lead 207
What does Potassium 40 decay into?
argon 40 then calcium 40
What is the half life of carbon 14?
5730
What does carbon 14 decay into?
nitrogen 14
What is carbon 14 used for and where is it found?
found in organic material, it is useful for dating organic material less than 60,000 years old
How old is the Earth approx.?
4.5 billion years old
What are Earth’s 4 major eras?
precambrian, Paleozoic, mesozoic, and Cenozoic
Why is Charles Walcott known?
the Cambrian explosion
What is Pikaia?
considered one of the oldest known chordates in the fossil record
What characteristics did Pakaia fossils show?
notochord, segmented muscles, head and tail regions
What age/era/period were the first vertebrate fossils found?
late Cambrian, early ordovician
When did the first terrestrial plants appear in the fossil record for the first time?
ordovician period
When did the first jawed fishes appear in the fossil record?
silurian period
What was the Great Permian Extinction?
mass extinction occurred at the end of the Permian, estimated that 90% of marine invertebrates and 70% of terrestrial species went extinct
What are Lake Baikal sculpins an example of?
sympatric speciation
Who developed binomial nomenclature?
Carolus Linnaeus
What is carbon-14 dating good for?
dating organic material of approx 60,000 years of age or less
When did the first amphibian like tetrapods show up in the fossil record?
the Devonian era
What does Paleozoic mean?
old animals
In what era of the fossil record are fossil fuels found?
the Carboniferous era
When do the first reptiles appear in the fossil record?
the Carbiniferous era
Were there also giant insects in the Carboniferous era?
yes
When does the radiation of reptiles begin?
the permian era
When do the first mammal like reptiles appear in the fossil record?
the permian era
What is dimetrodon?
a reptile that is very similar to mammals
What was at the end of the Permian era?
the great permian extinction
What is the Mesozoic era also known as?
the age of reptiles
When do the first dinosaurs and mammals appear in the fossil record?
the triassic period
Is the pterodactyl classified as a dinosaur?
no
Are ichthyosaurs dinosaurs or reptiles?
reptiles
In what period were marine and flying reptiles abundant?
the jurassic period
When did the first birds appear in the fossil record?
the jurassic period
When was the climax of dinosaurs and large marine reptiles?
the cretaceous period
What happened at the end of the Cretaceous period?
a mass extinction (K/T extinction) of many vertebrates and invertebrates
What is the K/T mass extinction thought to have been caused by?
a huge asteroid
What era is known as the age of mammals?
the Cenozoic era
Define epochs.
subdivisions within the periods of eras
In what period do mammals radiate?
the tertiary period
When do the first placental mammals occur and radiate?
the tertiary period
How many ice ages did the Pleistocene epoch of the quaternary period include?
at least 4 ice ages
What sediments were human and human like fossils found?
Pleistocene and Holocene sediments
Who is Alfred Wallace?
co-developer of the theory of evolution by natural selection
What was Wallace interested in?
the worldwide distribution of animals
What is the Wallace line?
where there was a distinct change in the types of animals but not the geography
Where were the effects of the Wallace eline particularly evident?
between Indonesia and Malaysia
Who proposed the theory of continental drift?
Alfred Weneger
What did Alfred Weneger suggest?
that continents move over time and suggested the idea of a supercontinent in prehistoric times
What is sea floor spreading?
where 2 plates are moving farther apart from one another
What is an example of sea floor spreading?
mid Atlantic ridge
What process of plate tectonics forms mountains?
convergence
What is the name of the supercontinent Weneger suggested?
Pangea
When was Pangea hypothesized to exist?
during the triassic period
Pangea broke into a northern and southern part, called what?
Laurasia and Gondwana
Did Gondwana and Laurasia split into the present day continents?
yes
What was the first group of bony fishes in the fossil record that appeared in the late Cambrian/ early Ordovician era?
Ostracoderms
Describe the plate tectonic theory.
indicates that the earths surface is composed of rocky plates which float on material in the earths mantel
What is Walcott famous for?
the Burgess Shale where he looked at the invertebrate fossils
When did Pangea break into Laurasia and Gondwana?
during the Jurassic period
When did Pangea exist?
in the Triassic
Why is it hypothesized that continental movements over the geologic time scale has significantly affected vertebrate diversity?
- isolation of vertebrates (allopatric speciation)
- environmental changes associated with the movement and location of continents would have necessitated that the animals had adapt to specific environment or go extinct in those environments
What are examples of the most recent geological events that have also affected animal distribution?
- Isthmus of Panama
- land bridge in the Bering Strait connecting North America and Asia
What animals migrated to north america due ot the isthmus of Panama?
opossum, armadillo, and porcupine
What animals migrated to North America due to the land bridge in the bering strait?
buffalo and mammoths
What are protostomes?
invertebrates
What are some examples of protostomes?
annelida, Mollusca, arthropoda
What are deuterostomes?
vertebrates
What are some examples of deuterostomes?
echinodermata, hemichordate, chordata
Why are chordates classified as deuterostomes?
because of the embryological and morphological characteristics
What are the 2 invertebrate deuterostome groups?
tunicata and cephalochordata
What are tunicates and cephalochordates collectively known as?
protochordates
What is a common name for Tunicata?
sea squirts
An example of the class Thaliacea is…
a salp
Can sales be solitary and colonial?
yes
What are some characteristics of the class Thaliacea?
filter feeders
normally hermaphroditic with external fertilization
adult tunicates have little resemblance to chordates
Why are tunicates considered chordates?
because the swimming larvae have basic chordate characteristics
What lead to the Garstang Hypothesis of Vertebrate Origin?
observations of tunicate larvae and metamorphosis
Who came up with the Garstang Hypothesis on Vertebrate Origin?
Walter Garstang
What did Walter Garstang hypothesize?
that the first vertebrates could have evolved from larvae such as tunicate larva that did not undergo metamorphosis
What is another name for Garstangs hypothetical process?
paedomorphosis
What is an example of paedomorphosis?
retention of larval traits in adulthood
What is another thing Garstang hypothesized?
neotenic larval tunicates could be the ancestors of the earliest known vertebrates
What has genomic analysis of tunicates provided?
information on the relatedness of the various chordate groups
What is the common name for cephalochordata?
lancelets
Where do all lancelets live?
in the marine environment
How do lancelets reproduce?
have separate sexes (gonochoristic) and use external fertlization
Lancelets muscles are segments and arranged into what?
myotomes
What is another name for ostracoderms?
shell skinned
What is another name for the pineal complex or pineal eye?
the “third” eye
What are the characteristics of ostracoderms?
no jaws
circular/slit like mouth with no teeth
filter feeders
distinct tail and lack of pair fins
Has there been a fossil record to indicate a specific invertebrate ancestor?
no
What are ostracoderms hypothesized to be derived from?
a protochordate
When were birds radiating?
cenozoic era
Where did Ostracoderms first occur?
first appear in marine environments
What was the height of the last ice age?
18000 years ago
True or False. Alfred Weneger came up with the theory of continental drift.
true
What did Ostracoderms have covering their bodies?
boney plates
Where was Pikaia found?
Burgess Shale
What is cephalization?
distinct head with brain and eyes
What are the 2 subgroups of protochordates?
urochordata and cephalochordata
What species of fishes are highly derived and specialized?
teleost fish
What are the hagfish and lamprey?
agnathans
How many species of vertebrates are there living right now?
about 60,000
What are Gnathostome fishes?
jawed fishes
What are Chrondrichthyes?
jawed fish with cartilaginous skeletons
What are the 2 subgroups within Chondrichthyes?
Elasmobranchs
Holocephali
What fishes are Elasmobranchs?
sharks, skates, and rays
hat fishes are Holochephali?
chimeras “ratfish”
What was the traditional grouping of bony fishes?
Osteichthyes
What are the 2 basic groups of bony fishes?
Sarcopteygii and Actinopterygii
What are Sarcopterygii?
fleshy/ lobed finned fishes
What are the 2 living groups of Sarcopterygii?
coelacanth and lungfish (also includes Osteolepiforms )
What are Actinopterygii?
ray finned fishes
What are the most successful group of fishes?
ray finned fishes
What are the 2 general groups within Actinopterygii?
Chondrostei and Neopterygii
What fishes are Chondrosteis?
sturgeon, paddlefish, and bicher
What are the groups within Neopterygii?
Early Neopterygii and Teleostei
What are fishes of Early Neopterygii?
gar and bowfin
What are the Teleostei?
advanced ray finned fishes
What are hagfish classified as?
Myxini
How many species are there of Actinopterygii?
30,000
What are lampreys classified as?
Petromyzoniformes
When do the fossil of the Hagfish and Lamprey dat back to in the fossil record?
Carboniferous period of the Mesozoic era
What are some Sarcopterygii closely related to ?
amphibians
What are the general morphological characteristics of hagfish and lampreys?
no jaws
cartilaginous skeletons
persistent notochord
no paired fins
no scales
eel like bodies
no gas bladder
What are the general nervous system characteristics of hagfish and lampreys?
dorsal nerve cord & distinct brain
brain has distinct lobes
advanced brain
10 cranial nerves
1 nostril leading to olfactory sac
semicircular canals
pineal & pituitary gland in brain
What are the general digestive system characteristics of hagfish and lampreys?
no stomach
feed on decomposing organic material
What are the general circulatory system characteristics of hagfish and lampreys?
one main heart “2 chambered”
RBC and WBC
coldblooded
What are the Neopterygii?
new Actinopterygii (gar and bowfin)
What kind of teeth do hagfish have?
muscular tongue with keratinized teeth for rasping tissue
What is a hagfishes mouth surrounded by and for what?
tentacles for touch
Do hagfish have a keen sense of smell and touch and why?
yes; because they have degenerate eyes covered by thick skin
How many gill slits do hagfish have on either side?
1 to multiple
Are vertebrates apparent in lampreys?
no
