19.1 - Verbrate Evolution and Diversity

How long ago did humans and chimpanzees diverge from a common ancestor?

between 5 and 7 million years ago.

Australopiths were _____ and had ____ brains.

bipedal, large.

What are the three lineages of jawed fishes with gills and paired fins?

chondrichthyans, ray-finned fishes, and lobe-finned fishes.

What are examples of lobe-finned fishes?

coelacanths and lungfishes

What are three lineages of lobe-fins?

coelacanths, lungfish, and tetrapods.

What makes rays well adapted for life on the bottom of the ocean?

dorso-ventrally flattened bodies and eyes on the top of their heads

Mammals have _________ that support their _____________.

efficient respiratory and circulatory systems, high rate of metabolism.

What is a chorion?

enable the embryo to obtain oxygen from the air and dispose of carbon dioxide (also done by allantois).

Mammals or birds require about ___ as many calories as the same sized reptile.

10x

When did marsupials diverge from eutherians?

180 mya.

When did the first fossil records of the genus Homo appear?

2 to 4 mya

How long ago did jawed vertebrates appear in the fossil record?

470 million years ago

Humans and chimpanzees share __% of their genes.

96%.

What are tetrapods?

A line of lobe-finned fish with limbs and feet that can support weight on land.

What is a yolk sac?

A membrane in an amniotic egg that contains a rich store of nutrients for the developing embryo as well as albumen (egg yolk/white)

What is a placenta and which mammals use them?

A membrane, used by marsupials and eutherians, which nurtures the embryo. The mother's blood diffuse into the embryo's blood (similar to yolk in an egg).

How tall were the hobbits?

About 1 meter tall.

How large were the brains of the hobbits?

About chimp size.

What were the first tetrapods that were able to move on land?

Amphibians.

What is the most primitive known bird with feathered wings? What were its feathers originally for?

Archaeopteryx (150 million years old). Its feathers were originally for courtship displays.

What discovery showed that humans stood up first?

Australopithecus afarensis, aka, Lucy.

Why has discovery of new species increased recently?

Better access to remote areas, new technology.

Which came first: bipedalism or larger brain size?

Bipedalism

What is one idea as to how jaws evolved?

By modifications of skeletal supports of the anterior pharyngeal (gill) slits. The remaining gill slits were sites of gas exchange.

_________ use and make tools.

Chimpanzees.

Why are tetrapods notable in evolution?

Development of limbs/feet was key adaptation to life on land. All subsequent groups are descendants of early tetrapods.

Define monotremes.

Egg laying mammals, including duck-billed platypus and echidnas.

Unlike other living reptiles, birds are _____.

Endothermic

What are mammals?

Endothermic amniotes with hair and mammary glands.

What are some traits of birds?

Endothermic, exhibit complex behaviors (especially when mating), and have a highly efficient circulatory system to support metabolism.

What are some traits of sharks?

fast-swimming predators, sharp vision, and a keen sense of smell

What is an amnion?

Fluid fill-sac surrounding the embryo in an amniotic egg.

What is the only fully arboreal ape?

Gibbons

What is the only non-human ape that is monogamous?

Gibbons.

___, ___, and ___ exhibit a high degree of social organization.

Gorillas, chimpanzees, and humans.

What is the largest ape?

Gorillas.

Which ape is fully terrestrial?

Gorillas.

What are some traits of lungfish?

Gulps air into lungs, inhabit stagnant waters in the Southern Hemisphere

____ and _____ are craniates, have a notochord, and lack hinged jaws and paired fins.

Hagfishes and Lampreys

When did mammals undergo an adaptive radiation, giving rise to large terrestrial carnivores and herbivores, bats, and aquatic whales and porpoises.

Happened following the Cretaceous extinction of dinosaurs.

What is an allantois?

Helps egg embryo dispose of metabolic waste.

What evidence supports that bipedalism came first?

Hominin footprints and fossil skeletons

What was the first hominid to leave Africa?

Homo erectus.

What was particularly interesting about the hobbit's skull?

It had human-like traits.

How many species of Homo existed by 1 mya?

Just one: sapiens

Which is verbrate: lampreys or hagfish?

Lampreys

Primates are divided into what three groups?

Lemurs, lorises, and pottos, Tarsiers, anthropoids.

What are some traits of coelacanths?

Live deep oceans, once thought to be extinct

Give three traits of non-human apes.

Live only in Africa and Southeast Asia, in tropical forests. They have a smaller geographic area than monkeys. Most are highly endangered.

What does arboreal mean?

Lives in trees

What are eutherians?

Mammals that bear fully developed live young. They are commonly called placental mammals because their placentas are more complex than those of marsupials.

What are marsupials?

Mammals with a brief gestation period. Gives birth to tiny, embryonic offspring that complete development while attached to the mother's nipples

How have birds adapted to the cost of flight

Modern birds have a high rate of metabolism

What is the oldest lineage of mammals?

Monotremes.

___ world monkeys are ALL arboreal.

New

___ world monkeys have a prehensile tail.

New

___ world monkeys have nostrils that are wide open and far apart.

New

What are some traits of amphibians?

Often have poison glands, usually return to standing water to reproduce, undergo metamorphosis from a larval stage to the adult form.

___ world monkeys have nostrils that open downward.

Old

___ world monkeys lack a prehensile tail, and thus only some are arboreal.

Old.

Which of the four groups of apes are shy, solitary, and live in rain forest trees and the forest floor?

Orangutans.

How have birds adapted for flight?

Remodeled forelimbs (airfoil shape), Large flight muscles, and features that reduce weight.

The oldest known hominin is _________, which lived about _______.

Sahelanthropus tchadensis, 7 to 6 mya.

What are examples of amphibians?

Salamanders, frogs, and caecilians.

What are examples of chondrichthyans?

Sharks and rays

What were possibly the first true mammals and when did they arise?

Small, nocturnal insectivores. Arose 200 mya

What are amniotes? what is their major derived character?

Tetrapods with a terrestrially(land) adapted egg, including reptiles, birds, and some mammals. Their major derived character is an amniotic egg.

What is paleoanthropology?

The study of human origins and evolution.

Why did jawed vertebrates quickly diversify?

Their paired fins and tail helped them to quickly diversify

What are some traits of chondrichthyans?

flexible skeleton made of cartilage, electrosensors on their heads, and a lateral line system.

What are unique about mammal's teeth?

They are differentiated for many kinds of diets.

What are some traits of reptiles?

They have a skin covered with scales and waterproofed with keratin, obtain most of their oxygen using lungs, and are ectothermic, absorbing external heat rather than generating much of their own

How did amphibians adapt to breathing on land?

They used their moist skins to supplement their lungs for exchange.

What is the order of evolution for chordates?

Tunicates (larvae), brains skull backbone (vertebrates) jaws lungs tetrapods amniotes

When did primate probably arise?

When dinosaurs still dominated the planets, as small arboreal mammals.

What is an opposable thumb and why is it useful?

Where the thumb can touch the tip of all the fingers. Allows a 'power grip' for most primates, for humans it allows precise manipulation

What are 6 obstacles faced by vertebrates trying to adapt to land?

gas exchange water conservation structural support (could no longer use the water) a means of locomotion adapting sensory organs that worked well in water but not on land reproduction.

Give five examples of apes.

gibbons, orangutans, gorillas, chimpanzees (and bonobos), and humans.

Describe four traits of ray-finned fish

internal skeleton reinforced with calcium phosphate, flattened scales covered with mucus, an operculum that covers a chamber of gills, and a buoyant swim bladder (derived from an ancestral lung).

What is an amniotic egg?

a shelled egg with four internal membranes: an amnion, yolk sac, allantois, and a chorion.

How many new species were discovered in 2007?

about 18,000.

What are some traits of tetrapods?

adapted to life on land, include terrestrial vertebrates

Biologists have developed hypotheses for the evolution of chordate groups using

anatomical, molecular, and fossil evidence

What are four traits of apes?

lack a tail have relatively long arms and short legs, have relatively larger brains with respect to size more flexible behavior.

What features have helped reduce a birds weight for flight?

lack of teeth. The tail is supported by only a few small vertebrae. Feathers have hollow shafts bones have a honeycombed structure that makes them strong but light

The mammalian order Primates includes __________________________(4 things).

lemurs, tarsiers, monkeys, and apes.

What are examples of reptiles?

lizards, snakes, turtles, crocodilians, birds, and extinct dinosaurs.

What is a distinct characteristic of lobe-finned fish?

muscular pelvic and pectoral fins that are supported by rod-shaped bones

Jawed Vertebrates with gills and paired fins include _____.

sharks, ray-finned fishes, and lobe-finned fishes

Birds evolved from a lineage of small, two-legged dinosaurs called _____.

theropods

What are examples of ray-finned fishes?

tuna, trout, and goldfish