Chapter 19 Flashcards
Biologists have developed hypotheses for the evolution of chordate groups using
-Anatomical, molecular, and fossil evidence.
Hagfishes and lampreys
- have a notochard
- lack hinged jaws
- These are fish used to establish a lineage of other fish with heads (craniates)
Jawed vertebrates:
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 (gil) slits
The remaining gill slits remained as sites of ___________.
Gas exchange
3 lineages of jawed fishes with gills.
- chondrichthyans- sharks and rays
- ray-finned fishes- tuna, trout, and goldfish
- lobe-finned fishes- coelacanths and lungfish
Chondrichthyans
Sharks and rays
ray-finned fishes
tuna, trout, and goldfish
lobe-finned fishes
coelacanths and lungfish
Chondrichthyans have a flexible skeleton made of _______.
Cartiage
Chondrichthyans also have electrosensors on their _____.
head
Chondrichthyans have a ________________ which contains sensory ograns helping these organisms sense a change in temperature or water pressure.
lateral line system
Ray-finned fishes have an internal skeleton reinforced with a hard martrix of _____________.
calcium phosphate
Ray-finned fishes have flattened scales covered with mucus, an ___________ that covers a chamber of gills, and a buoyant ___________.
operculum
swim bladder
Lobe-finned fish
Have muscular pelvic and pectoral fins that are supported by rod-shaped bones
3 lineages of lobe-fins survive:
- coelacanths, living deep in the oceans, were once thought to be extinct.
- lungfishes, which can gulp air into lungs, inhabit stagnant waters in the Southern Hemisphere
- tetrapods, adapted to life on land, include terrestrial vertebrates
Tetrapods are
jawed vertebrates with limbs and feet that can support weight on land
Tetrapods are considered to have evolved from lineage of __________ fish.
Lobe-finned
________ was a key event in vertebrate history, and all subsequent groups are considered descendants of these early land dwellers.
adapting to life on land
Like plants, vertebrates faced obstacles on land for example
- gas exchange
- water conservation
- structural support
- a means of locomotion
- adapting sensory organs that worked well in water but on land
- reproduction
Amphibians
Salamanders, frogs, and caecilians
Amphibians use their moist skin to supplement their lungs for gas exchange, they also (4)
- often have poison glands in their skins
- usually return to standing water to reproduce
- undergo metamorphosis from a larval stage to the adult
Amphibians are
tetrapods
Reptiles are
Amniotes
Reptile (including birds) and mammals are _______
amniotes
In Amniotes the major derived character of this clade is an __________ with four internal membranes.
Amniotic egg
1)In Amniotes The ______ is a fluid-filled sac surrounding the embryo
amnion
2)in Amniotes The ______ contains a rich store of nutrients for the developing embryo
yolk sac
3) In Amniotes the allantois also helps dispose of __________
metabolic waste
4) In Amniotes the _______ (and allantois) enable the embryo to obtain oxygen from the air and dispose of carbon dioxide.
Chorion
Reptiles:
Lizards, snakes, turtles, crocodilians, birds, and extinct dinosaurs
Reptiles have skin covered with scales and waterproofed with ________.
Keratin
Reptiles obtain most of their oxygen using lungs, and are ________, absorbing external heat rather then generating much of their own.
Ectothermic
Most ___ can fly, and nearly every part of their bodies reflects features that enhance flight.
Birds
In birds their bodies reflect features that enhance flight 2)
- 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: (4)
- present-day birds lack teeth
- the tail is supported by only a few small vertebrae
- feathers have hollow shafts
- their bones have a hollow honey combed structure that make them strong but light weight
-were the first tetrapods able to move on land
Amphibians
Unlike reptiles, birds are __________ (warm bodied) using heat generated by metabolism to maintain a warm, steady body temperature.
endothermic
Birds have relatively large brains and display complex behavior. They have
- acute senses
- fine muscle control
- excellent eyesight
Birds are considered to have evolved from a lineage of small, two-legged dinosaurs called __________.
Theropods
________ is the oldest, most primitive known bird (150 million years old) with feathered wings.
Archaeopteryx
Mammals are endothermic amniotes with
- hair, which insulates their bodies and
- mammary gland, which produce milk
Mammals have efficient _______ and _______ systems that support their high rate of metabolism
Respiratory
circulatory
Monotremes are __________. living monotremes
egg-laying mammals
Platypus and echidnas
monotremes
unlike monotremes, the embryos of marsupials and eutherians are nurtured by a ________, in which nutrients from the mothers blood diffuse into the embryo’s blood,
Placenta
Marsupials
have a brief gestation and give birth to tiny, embryonic offspring that complete development while attached to the mothers nipples
Eutherians
are mammals that bear fully developed live young. They are commonly called plancental mammals because their placentas are more complex than those of marsupials
The mammalian order primates include
the lemurs, tarsiers, monkeys and apes
Primates probably arose as small arboreal mammals before ________, when dinosaurs still dominated the plant.
65 million years ago
Many primate characters are arboreal adaptations (4)
- 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 enchance depth percetion
A _________ shows that all primates are divided into three groups.
Phylogenetic tree
What are the three groups that the phylogenetic tree divide primates into
- lemurs, lories, and pottos
- tarsiers
- anthropoids, including monkeys and apes with a fully opposable thumbs in which the tip of all four fingers can touch the thumb
Monkeys are characterized in 1 or 2 groups
old world monkeys
new world monkeys
old world monkeys
lack a prehensile tail and have nostrils that open downward
new world monkeys
have a prehensile tail and nostrils that are wide open and farther apart
In addition to monkeys, the anthropoid group includes ____.
apes
Apes include
gibbons, orangutans, gorillas, chimpanzees, bonoboos, and humans
Lack a tail
have relatively long arms and short legs
have relatively larger brains with respect to size
Apes
Are monogamous and the only fully orborealapes
Gibbsons
are shy, solitary, and live in rain-forest trees and the forest floors
Orangutans
are the largest of the apes and fully terrestrial
gorillas
make and use tools
Chimpanzees
is the study of human origins and evolution, the brief history since the divergence of humans and chimpanzees lineages.
Paleoanthropology
Paleoanthropologists 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 up right and have larger brains
Brain size and ________ are features used to identify the evolution of hominins
bipedalism
__________ is considered to have evolved millions of years before larger brain size. Evidence of bipedalism includes morphology, fossils and fossilized footprints.
bipedalism
________ had such small brains (400-450cc) that they were too small to be members of Homo
Australopiths
_______ had a brain size of 510-690 cc. Their fossils are found with stone tools
Homo habilis
________ & ________ 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
______________ (neanderthals) 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
_________ has 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 women who lived 160,000-200,000 years ago.
