Biology 100 Unit 19 Flashcards
Biologists have developed hypotheses for the evolution of chordate groups using
anatomical
molecular evidence
fossil evidence
Hagfishes and lampreys.
– have a notochord, but
– lack hinged jaws and paired fins.
– These are fish used to establish a lineage of other fish with heads
quickly diversified using their paired fins and tail to chase a wide variety of prey.
Jawed vertebrates:
Jaws may have evolved by modifications of skeletal supports of the _____________________________.
anterior pharyngeal (gill) slits
The remaining gill slits remained as sites of _______
______________.
gas exchange
What are the 3 lineages of jawed fishes with gills
- chondrichthyan
- ray-fined fishes
- lobe-finned fishes
examples of chondrichthyans
sharks and rays
examples of ray-finned fishes
tuna, trout, and goldfish
examples of lobe-finned fishes
coelacanths and lungfish
Jawed vertebrates with gills and paired fins include
sharks, ray-finned fishes, and lobe-finned fishes
sharks and rays are an example of
Chondrichthyans
Chondrichthyans have a flexible skeleton made of _______,
cartilage
Chondrichthyans have a ______________________ which contains sensory organs helping these organisms sense a change is temperature or water pressure.
lateral line system
Chondrichthyans have ________________ on their heads,
electrosensors
trout, tuna, goldfish, etc. are examples of
Ray-finned fishes
Ray-finned fishes have an internal skeleton reinforced with a hard matrix of
___________________, flattened scales covered with mucus,
calcium phosphate
Ray-finned fishes have an ______________ that covers a chamber of gills, and a a buoyant ____________
operculum, swim bladder
_________________ with gills and paired fins include sharks, ray-finned fishes, and lobe-finned fishes
Jawed vertebrates
Lobe-finnedfish: ____________________________ __________ that are supported by rod-shaped bones.
have muscular pelvice and pectoral fins
living deep in the oceans, were once
thought to be extinct,
coelacanths
which can gulp air into lungs, inhabit stagnant waters in the Southern Hemisphere, and
lungfishes
, adapted to life on land, include terrestrial vertebrates.
tetrapods
Tetrapods are _________________________________ ______________________________.
jawed vertibates with limbs and feet that can support wight on land
Tetrapods are considered to have evolved from a lineage of
lobe-finned fish.
_____________________________ in vertebrate history, and all subsequent groups are considered descendants of these early land-dwellers.
Adapting to life on land was a key event
Like plants, vertebrates faced _____________________
obsticles on land – gas exchange, – water conservation, – structuralsupport, – a means of locomotion, – adapting sensory organs that worked well in water but not on land, and – reproduction.
Amphibians are____________________—vertebrates with two pairs of limbs
tetrapods
salamanders, frogs, and caecilians,
Amphibians
Amphibians
– use their moist skins to supplement their lungs for gas
exchange,
– often have poison glands in their skins,
– usually return to standing water to reproduce,
– undergo metamorphosis from a larval stage to the adult
–Were the first tetrapod to move on land
–Were the first tetrapod to move on land
Amphibians
are amniotes—tetrapods with a terrestrially adapted egg
reptiles
Reptiles (including birds) and mammals are ____________
.amniotes
The major derived character of this clade is an amniotic egg with four internal membranes.
The amnion is a fluid-filled sac surrounding the embryo.
2. The yolk sac contains a rich store of nutrients for the developing embryo.
3. The allantois also helps dispose of metabolic waste
4. The chorion (and allantois) enable the embryo to obtain
oxygen from the air and dispose of carbon dioxide.
is a fluid-filled sac surrounding the embryo.
amnion
contains a rich store of nutrients for the developing embryo
yolk sac
also helps dispose of metabolic waste
allantois
(and allantois) enable the embryo to obtain
oxygen from the air and dispose of carbon dioxide.
chorion
lizards, snakes, turtles, crocodilians, birds, and extinct dinosaurs, are examples of
Reptiles
Reptiles have a skin covered with scales and waterproofed with
keratin
Reptiles use there __________ to obtain oxogen
lungs
reptiles are ____________ absorbing external heat rather than generating much of their own.
ectothermic,
Most birds can fly, and nearly every part of their bodies reflects features that enhance flight.
– The forelimbs have been remodeled as feather-covered wings that act as airfoils.
– Large flight muscles anchored to a central ridge along the breastbone provide power.
Many features help reduce weight for flight:
Present-day birds lack teeth.
– The tail is supported by only a few small vertebrae.
– Feathers have hollow shafts.
– Their bones have a honecomb structure that makes them strong but light
are feathered reptiles with adaptations for flight
Birds
Flight is very costly, and present-day birds have a high rate of
metabolism
Unlike reptiles, birds are ______________(warm-blooded), using heat generated by metabolism to maintain a warm, steady body temperature.
endothermic
Birds have relatively large brains and display complex behaviors. They have
– acute senses,
– fine muscle control, and – excellent eyesight.
Birds are considered to have evolved from a lineage of small, two-legged dinosaurs called ______________.
therapods
__________________ is the oldest, most primitive known bird (150 million years old), with feathered wings.
archaepotenyx
are amniotes that have hair and produce milk
mammals
Mammals are endothermic amniotes with
– ________, which insulates their bodies, and
– ______________________, which produce milk.
hair, mamary glands
Mammals have______________________________ that support their high rate of metabolism
efficient respiratory and circulatory systems
are differentiated for many kinds of diets.
Mammalian teeth
Monotremes are ____________________________. Living monotremes include
egg laying mamels
ex: – the duck-billed platypus and echidnas.
Unlike monotremes, the embryos of marsupials and eutherians are nurtured by a________________________ in which nutrients from the mother’s blood diffuse into the embryo’s blood.
placenta,
have a brief gestation and give birth to tiny, embryonic offspring that complete development while attached to the mother’s nipples.
marsupial
are mammals that bear fully developed live young. They are commonly called placential mammals because their placentas are more complex than those of marsupials.
Eutherians
includes the lemurs, tarsiers, monkeys, and apes.
The mammalian order Primates
Primates probably arose as small arboreal mammals before ___________________, when dinosaurs still dominated the planet.
65 million years ago
these are an example of: ______________
– Shoulder and hip joints allow climbing and brachiation.
– Grasping hands and feet are highly mobile and flexible.
– Sensitive hands and feet aid in manipulation.
– A short snout and forward-pointing eyes enhance depth perception.
Many primate characters are arboreal adaptations.
A phylogenetic tree shows that all primates are divided into three groups:
- lemurs, lorises, and pottos,
- tarsiers,
- anthropodes including monkeys and apes with a fully opposible thumbs in which the tip of all four fingers can touch the thumb.
Monkeys are characterized as either
2 groups
lack a prehensile tail, and
– have nostrils that open downward.
old world monkeys
have a prehensile tail and
– nostrils that are wide open and farther apart.
new world monkeys
In addition to monkeys, the anthropoid group includes ____________ gibbons, orangutans, gorillas, chimpanzees (and bonobos), and humans.
apes:
lack a tail and
– have relatively long arms and short legs,
– have relatively larger brains with respect to size.
apes
Gibbons are monogamous and the only fully _____________.
arboreal apes
are shy, solitary, and live in rain-forest trees and
the forest floor.
Orangutans
Gorillas are the largest of the apes and _______________.
fully terestrial
make and use tools.
Chimpanzees
is the study of human origins and evolution, the brief history since the divergence of human and chimpanzee lineages.
Paleoanthropology
Paleo anthropologists have identified about 20 species of extinct _____________, which are considered a species that are more closely related to humans than to chimpanzees.
hominins
Although humans and chimpanzees are similar in many respects, they also differ in that humans ______ ___________________________.
walk upright and have larger brains
the location of what dictates the posture of an organism
pheraminmagnum
are features used to identify the evolution of hominins
Brain size and Bipedalism
_________________ is considered to have evolved millions of years before larger brain size. Evidence of _________________ includes morphology, fossils, & fossilized footprints.
Bipedalism
had such small brains (400–450 cc) that they were too
small to be members of Homo.
Australopiths (means handy man)
had a brain size of 510–690 cc. Their fossils are found
with stone tools
Homo habilis (handy man)
had a brain size ranging from 750 to 850 cc. Fossils are found with more sophisticated stone tools and long, slender legs for extensive walking
Homo ergaster & Homo erectus (upright man)
considered to have lived up to 28,000 years ago. They had brains as large as modern humans, and multiple tools hunted large animals
Homo neanderthalensis (Neanderthal man)
has a brain size of around 1,300 cc.
homo sapiens
Analysis of mtDNA and Y chromosomes suggests that all living humans
inherited their mtDNA from a woman who lived 160,000–200,000 years ago.
