Biology Test 3 part 3

Arthropods use their exoskeleton of chitin for what purposes?

Protection and support for their body.

The fossils of Archaeopteryx had some characteristics of modern birds: (1)__________ along the wings and (2)___________ on the tail. Archaeopteryx also had reptilian characteristics, including: (1)___________________, (2)____________________, and (3)___________________.

(1)Feathers along the wings and (2) feathers on the tail. Archaeopteryx also had reptilian characteristics, including: (1)Teeth and jaw, (2) tiny claws in hand, and (3) long boney tail.

Which two groups of animals burn fuel to generate body heat?

(1)Mammals and (2)Birds. This raises their body temperature above the temperature of the external environment. Their insulating hair help them retain their body heat when it is cold outside. In birds, their features do this for them.

Why is Taktaalik considered to be a transitional fossil?

Because it shows both characteristics of a fish and a tetrapod-like land animal.

Describe the fossil bird, Archaeopteryx. Which of its characteristics were bird traits? Which characteristics were retile traits?

Bird- It was clearly a bird, with a birds skeleton and a birds feathers (the impressions of the feathers were preserved, thanks to the still, oxygen-free swamp into which the bird fell when it died). Retiles- But the bird, which would turn out to be 145 myo, also had teeth in its beak, claws on its hands on its wings, and a long, reptilian tail.

How was the forelimb of Acanthostega different from the forelimb of Tiktaalik?

Both had a radius and ulna, but Acanthostega had wrist bones, toes and fingers (phalanges).

Are amphibians still dependent on water? and how do they lay their eggs?

Even though amphibians are tetrapods, they are still dependent on water for reproduction. They lay their eggs in water and their young have to develop in water. Amphibians use both their skin and lungs to get oxygen from the air and get rid of carbon dioxide. This means they have to keep their skins moist or they will suffocate.

What two groups of fishes are the closest relatives to tetrapods?

Tulerpeton and Ichthyostega

What are other functions of mammals hair (other than insulation)?

Whales and armadillos even have hair, even though they may seem hairless. Another function of mammal hair is the color and pattern of the fur can provide camouflage as the mammal blends into its background. Many mammals use patterns to recognize members of their species.In fact, certain patterns may also allow mammals to recognize specific individuals, as had been suggested about zebra stripes.

Which group of ground-running dinosaurs had feathers?

ground-running theropods

Briefly describe the fish traits and the tetrapod traits of Acanthostega.

Fish: Fish-like tail, gills, and swimming creature Tetrapod: Hands (petal-shaped) *was basically a fish with fingers*

Compare the wing of a pterosaur to the wing of Archaeopteryx.

Pterosaur- 3 small digits, and a long one which attaches to a membrane which goes along its body and hindlimb. Archaeopteryx- 3 digits and their feathers attach individually along their arms and hand bone. *This information tells us they must have descended from different reptiles.*

All dinosaurs died at the end of the Cretaceous Period, 65 mya. Is this a true statement or not? Explain your answer.

*****Come back to ****

Like Archaeopteryx, the modern hoatzins also have ______________ fingers, each ending in _____________________, which allow young birds to __________.

-3 -hooked claw -remain secure on branches when trying to keep their balance.

Since ground-running dinosaurs could not fly, what are the other possibilities for the use of their feathers?

-Insulation -Attracting males -Hiding from predators -Insulating eggs: This probability is particularly striking when you consider a fossil discovery in 1993. A theropod known as the oviraptor lay over its nest of eggs, its arms spread out in much the same way modern birds spread their wings. -Need other possibilities?

Feathers first appeared in feathered theropods without wings. What could the feathers have been used for?

-Insulation : to keep them warm -Communication and Courtship : colorful feathers -Territorial displays * They were likely used for different roles at first and then were modified for flight*

Describe the characteristics of Taktaalik roseae fossils found on Ellesmere Island. How old are they? and, why was the discovery significant?

-Lived underwater, but it had evolved some traits found in all land vertebrates, such as wrists and a neck. Looked like a fish with arms. Was about 3 feet from head to tail. Skull was flattened like a salamander. it had gills, like a fish, but its front pair of appendages could bend at the elbow, and could support the weight of its body. -Lived 375 million years ago -It helped people understand one of evolutions greatest transitions. It illuminates the transition of out ancestors from water to land.

Describe the echidna and its lifestyle.

-Mammal -Some of their hair has been strengthened and enlarged which turned into spines which give it a protective armor; it also helps to keep it warm and helps it to not lose valuable body heat to the cold air. -Food used to generate fuel to generate heat. -Smell guides them to food. -Strong Claws. -Beak with tongue. -Good eye sight and hearing. -When they find food they rip at the nests and tunnels with their claws. -Their beak-like snout can go into holes and out comes a tongue to pick up whatever worth eating. -Eating ants and termites, even climb trees to find them.

Describe the body features of Tiktaalik.

-Scales on back -Fins and webbing -Flat head with eyes on top -Bones that compare to our arms (wrists, elbow, and shoulder)

Lobe-fins include ____________________, ____________________, and ____________________.

-Tetrapods -Coelacanths -Lungfishes

When did mammals evolve? When do people believe they started to diversify?

-True mammals are 180 million years old. Some people believe they're 220 million years old, but other people say these were "protomammals" (ancestors of mammals), interpretation of these transitional fossils vary because there is no evidence of hair or mammary glands on these fossils. -We used to think the first mammals were small, shrew-like critters that scurried around in the dark to avoid dinosaurs. They started to diversify before the dinosaurs went extinct. After the demise of the dinosaurs, mammals rapidly diversified, occupying many new lifestyles that were precisely help by dinosaurs. Today there are 26-29 orders of mammals, both large and small, with varying lifestyles from flying bats to swimming whales, primates, grazing herbivores, and fierce predators.

What tetrapod-like features did Tiktaalik have?

-flat head with eyes on top -bones that compare to our arms

What fish-like features did Taktaalik have?

-scales -fins and webbing

What structures are found inside the fin of Tikaalik?

-shoulder -elbow -parts of the wrist

What are the two possible ways that flight might have evolved?

1. Australian Lizard- they spread their frill around their neck to scare off predators. It it doesn't work it runs away on its hind legs, if such a reptile were to develop feathery scales on its forelegs and spread them out then it might easily lift into the air and escape a land predator. 2. Maybe the early reptile climbed in the trees, searching for food, there is an animal now that can glide from tree to tree, developed wings that are flaps of skin, supported by elongated ribs. If that early reptile developed long enough feathery limbs it too could fly tree to tree.

Identify 7 characteristics that are unique to mammals. Briefly describe each characteristic. +extra information (read and memorize as well)

1. Hair- evolved as insulation and still serves this function in mammals with a thick coat, helps them retain their body heat. Whales and armadillos even have hair, even though they may seem hairless. 2. Mammary Glands- produce milk, a fluid rich in nutrients which provides newborn mammals with food. The mammary glands evolved from sweat glands in skin. 3. Diaphragm- muscular, below the rib cage and assists in breathing. 4. Specialized Teeth- incisors, canines, premolars, and molars. 5. Three Tiny Middle Ear Bones 6. Lower Jaw Made From One Bone 7. A Special Kind of Joint that Contains the Lower Jaw to the Upper Jaw *many characteristics used to study fossil mammals and to separate the mammals into different groups are based on bones, especially skulls and teeth** Reason= While hair and mammary glands may be lost in the fossil record, bony structures are often fossilized. Thus, you can tell when a fossil organism is a mammal based on unique bony structures (5-7^^).***

List several adaptations found in birds that reduce weight.

1. Light weight beak, but can't chew 2. Skeleton with fewer bones than mammals (lack some bone most mammals have) 3. Hollow bones (lattice inside to keep strong) 4. Feather structure, quills hollow with hooks to latch together.

What are the 3 main lineages of mammals and how are they distinguished?

1. Monotremes - egg laying 2. Marsupials - pouches 3. Placental Mammals - placentas They're distinguished by their methods of reproductions.

When did the first platypus appear in the fossil records?

100 Million Years Ago

What does theory mean to a scientist? Contrast this with the use of theory by most people in everyday speech. and, Why is a good theory superior to facts?

A theory is an overarching set of mechanisms or principles that explain a major aspect of the natural world. A theory makes sense of what would otherwise seem like an arbitrary, mysterious collection of ideas. And a theory is supported by independent lines of evidence. Many people think a theory is simply a hunch: a vague guess based on little evidence. When they hear scientists speak of "the theory of evolution," they assume that its mere speculation, far less certain than a fact. A good theory is superior to facts because it organizes them, changing them from a loose collection of details into a meaningful, well-supported picture.

Tetrapods

Animals with a backbone (vertebral column), four limbs, and a body that is modified for life on land. Modern tetrapods include amphibians, reptiles (including birds), and mammals.

A lineage is a line of direct descent from an ancestor. Mammals are one lineage. Besides humans, what other animals belong to this lineage?

Any animals that are vertebrates with hair or fur. Warm blooded, 4 heart chambers, feed their young with milk, and the young of most mammals are born alive. (on tree it just says milk and hair)

How are early dinosaur feathers similar to the feathers found on todays birds?

Close analysis revealed that features on them today only on feathers such as, vanes, barbs, and a central stalk. Not only did the feathers have the same structures as feathers on birds, but one fossil of a dinosaur even have raised bumps, just like the quill nodes one bird bones where feathers are anchored. Closer relatives of birds had many types of feathers, while more distantly related theropods only had simple tufts.

Describe the similarities between Archaeopteryx and Compsognathus.

Compsognathus' hand also had 3 digits, hollow bones and stood on 2 legs, these similarities led him to believe birds are relative to the branch of reptiles called dinosaurs.

Describe the similarities between Archaeopteryx and Deinonychus.

Deinonychus was small, with a delicate build, it ran upright on 2 legs, had a long stiff tail for balance. Both had lightly built hollow bones, long arms, similar hip and shoulder bones.

The similarities between Archaeopteryx and Compsognathus indicated that birds were related to which branch of the reptiles?

Dinosaurs.

What is phylogeny?

Evolutionary relationships of a group of organisms is known as their phylogeny. Darwin envisioned it as being like branches on a tree.

Describe the platypus and its lifestyle.

Feeds on small invertebrates, looks for them underwater, once he got a mouth full he takes them up to the surface and grinds them to a pulp. Doesn't have any teeth but there are horny plates inside the bill that do the job.

Based on Jenny Clack's research, which came first: fish moving onto land or fish developing forelimbs?

Fish developed forelimbs then moved onto land.

What fossil evidence supports the idea that dinosaurs incubated their eggs?

Fossil discovery in 1993. A theropod known as a oviraptor lay over its nest of eggs, its arms spread out in much the same way modern birds spread their wings.

Describe reproduction of a wildebeest.

Grows young in a placenta. Then they give birth to a large highly developed baby and brings strain on the mother. Pretty traumatic for the baby too. Once baby is born it can get up on its feet within minutes and be feed by its mothers milk.

How is the hair of the echidna modified?

Hair was enlarged and strengthened and turned into spines which act as a protective armor and helps it to keep warm.

Does Eusthenopteron (385 mya) does a humerous, radius and Ulna, Wrist bones, and/or Phalanges?

Humerous - Yes Radius and Ulna- Yes Wrist Bones- No Phalanges- No

Does Acanthostego (365 mya) have a humerous, radius and ulna, wrist bones, and/or phalanges?

Humerous- Yes Radius and Ulna- Yes Wrist Bones- Yes Phalanges- Yes

Does Tiktaalik (375 mya) have a humerous, radius and ulna, wrist bones, and/or phalanges?

Humerous- Yes Radius and Ulna- Yes Wrist Bones- Yes Phalanges- No

There is a common misconception that there are no transitional fossils that show the evolution of tetrapods from lobe-finned fishes. Based on the phylogenetic tree on page 67 in the textbook, does fossil evidence support the evolution of tetrapod limbs from lobe-finned fishes? Explain your answer.

I think it does. It shows fins changing to arms and legs, loss of scales, loss of gills, and the evolution of fingers and toes, and ankles and wrists, etc.

What was significant about the Acanthostega fossil that Clack found?

It had bones that showed it had hands.

What are synapsids?

Mammals and relatives of mammals. A clade of tetrapods that emerged 300 mya and that includes mammals.

What two mammal branches are eutherians?

Marsupials (pouch) and Placenta Mammals (placenta).

Describe the 3 main lineages of mammals. (monotremes, marsupials, and placental mammals)

Monotremes- mammals that lay shelled eggs. More similar to early mammals than to other living mammals. Have mammary glands and hair. Their mammary glands lack well-developed nipples so the offspring lap the milk off the mother's fur as it oozes out. The only living monotremes are the duck-billed platypus and two kinds of spiny anteaters (also called echidnas). The platypus is found only in Australia and spends most of its time in the water. The echidnas live in Australia and New Guinea. They use their claws to burrow and to dig for insects, especially ants and termites. Marsupials- pouches mammals. Their young are born at a very early stage of development and must crawl up the body of the mother into the pouch. Once inside the pouch, the tiny marsupials attach to the nipples and finish developing in the pouch. Marsupials evolved about 100 million years ago, probably somewhere in North America or possibly South America. Modern marsupials are found mostly in Australia, Central and South America, except for our North American opossum. Placental Mammals- evolved about the same time as marsupials. Characterized by the presence of the placenta-- which is a vascular organ that connects the developing fetus with the mothers uterus, provides a link between the embryo and the mother's body, delivers food and oxygen to the offspring while picking up carbon dioxide and waste products---and takes place inside the mother's body instead of inside an egg or pouch. As a result, the young mammals are much more developed at birth. Which dramatically increases the survival of the young. 17 of the 19 modern groups of mammals are placenta mammals. However, there are disadvantages to the placental method of reproduction. For example, just watch a pregnant women waddling, then think about trying to escape from a predator. Also, birth is very traumatic for both the mother and the baby.

How does the platypus bill differ from a duck bill?

Not hard like a ducks bill, its rubbery.

Describe amniotes, amniotic egg, and the function of each membrane.

Some Tetrapods that evolved adaptions for life on land that allowed them to be less dependent on water. In addition to a waterproof skin, these animals have eggs that do not need to be laid in water. The eggs themselves have a little "pond" of water inside a shell. These tetrapods are called the amniotes. Two main lineages evolved from the amniote ancestor: one leading to mammals, the other to reptiles. The amniotic egg has 4 membranes that are outside of the embryo: 1. The amnion that makes amniotic fluid to bathe the embryo and cushion it. 2. The chorion that is involved in gas exchange. 3. The allantois that is involved in metabolic waste disposal. 4. The yolk sac contains yolk which provides the embryo with nutrients. In most amniotic eggs, a leathery or brittle shell surrounds the embryo and these 4 membranes. In shelled amniotic eggs, the egg white is the main water supply and functions as a shock absorber. In birds, the egg white also stabilizes temperature when the incubating parent leaves the nest. In most mammals, the placenta is derived from structures in the amniotic egg but the shell is lost.

What does the increasing size of the nasal cavity in mammal skulls indicate about their bodies?

That their bodies temperature was rising, allowing them to warm air as they breathe in.

What evidence found in mammal embryos today supports the idea that the middle ear bones were once attached to the lower jaw?

The evidence for this transition also comes from living mammals when the bones of the ear first developed in mammal embryos, they are anchored to the lower jaws, as they were in the ancestors of mammals and other tetrapods. Only later do they break free. Also, paleontologists have documented many of the steps in this transition with fossils of extinct relatives of todays mammals.

Explain the role of the placenta and umbilical cord.

The placenta is a circular pad, rich in blood vessels and is connected to the baby by a cable, the umbilical cord, to which they feed the growing baby. Blood vessels from the baby run up through the cord to the placenta and pass so close to those of its mother that they're able to absorb nutrients from her blood and carry it back to the unborn infant.

What is the big advantage of placental reproduction?

There are many animals around that a calf would make a welcome meal. But the newborn baby, with the help from the placenta is able to get up on its feet within minutes of its birth. While its finding balance its mother is there to defend it. Being protected in the mother for longer gives babies an invaluable start in life.

The similarities between Archaeopteryx and Deinonychus indicated that birds were related to which specific group of dinosaurs? What additional evidence had been discovered to support this relationship?

Theropods. Discovery that theropods had a feature of birds not previously found-a wish bone. Compared bones- a chicken foot to T-Rex- 3 forward facing (feet)digits and in the back a much smaller one, also a forward facing neck. Then, they found out that dinosaurs nested in colonies, cared for their young, brought food to their babies, then for many years they would come back to the same site and do it over and over again (nesting ground). Also ? Sinosauropteryx did not have scales, it was covered in some kind of primitive kind of feather, chicken size was the first of many discovered.

How was the forelimb of Tiktaalik different from the forelimb of Eusthenopteron?

They both had a radius and ulna but only the Tiktaalik had wrist bones.

Describe reproduction in the echidna.

They don't give birth to live babies, they lay eggs. The egg is hidden in her fur in a shallow depression on her underside. The egg is no bigger than a marble, and inside a young echidna is slowly developing. After the baby hatches she carries it around in her underside for around 50 days until it begins to develop spines. She then deposits it in a burrow, where it stays and grows for nearly 7 months.

How does a platypus find its food in the water?

They find food by closing their white eyelids so they can't see anything, and use their remote sensing device, their bill. They sweep it side to side (like a metal detector) and the sensors in it pick up the infinite tiny electric currents that are given off by all living things.

Describe reproduction in the platypus.

They lay eggs, and have nests underground. They provide milk for their young. It oozes through their skin. Their babies are naked and blind, and they have an egg tooth they use to get out of the egg and hatch.

Describe reproduction in the grey kangaroo.

They produce young without protective shells. When they give birth the young is tiny, underdeveloped, little worm. Weights less than a lump of sugar, no back legs, but has forelegs which are strong enough to pull it through its mothers fur. It climbs upward to the smell of the pouch. It then finds the pouch and goes down in it to safety inside. Then attaches to the nipple and takes its 1st meal of milk. As it grows the milk changes to insure it gets the nutrients it needs through every stage of development. By the time its 9 months old its getting a little cramped in the pouch and its time to enter the outside world, almost like a second birth. Now its known as a Joey. It then goes back into the pouch, take another year before it is fully independent.

What changes occurred in the skulls of mammals, with respect to: a. the dentary b. middle ear bones c. other bones in the lower jaw

a. the dentary: As the ancestors of mammals evolved, the dentary became larger. Its growing size may have been an adaption to chewing, because a single large bone could provide more strength than a group of smaller bones. As dentary expanded, the bones in the back of the jaw shrank. At first they still helped to anchor the lower jaw to the skull, but eventually the dentary took over this job completely. b. middle ear bones: The bone in the middle ear started out as part of the lower jaw. In the early synapsids, the jaw was a collection of interlocking bones. The front most bone, the dentary, held many teeth while the bones in the ear formed a hinge against the back of the skull. Like many reptiles today, early synapsids had simple ears. They may have picked up vibrations through their jaws that were then relayed back to the middle ear. c. other bones in the lower jaw In some time, some of the bones at the rear of the lower jaw disappeared. Others took on a new role. They became part of the system of bones in the ear. These old jaw bones made the mammal ear a better listening organ. They evolved into a series of levels that could amplify faint high-frequency sounds. At first, the fossils show, this chain of bones remained tethered to the lower jaw. But in the ancestors of the living mammals, it eventually broke free.

vertebrates

animals with backbones, descended from animals similar to Pikaia. All vertebrates are members of one lineage of animals, the chordates. Modern vertebrates include lampreys, sharks and rays, bony fishes (ray-finned and lobe-finned) and tetrapods.