Northside AP Biology Weekly Homework Packet

Due before class starts on Wednesday, November 6, 2013.

Name: ________________________________Period: ________

Mr Burley

TOPICS FOR THE WEEK TERRESTRIAL EVOLUTION, MASS EXTINCTIONS, ADAPTIVE RADIATION, ECOLOGY, POPULATION DYNAMICS, POPULATION GROWTH CURVES, ECOLOGICAL INTERACTIONS

HW 2

IMPORTANT REMINDERS: SEND IN PICTURES FOR

THROWBACK THURSDAY REVIEW VOCABULARY! CHECK MASTERING

BIOLOGY SITE OFTEN. COMPLETE MASTERING BIOLOGY HOMEWORK IN A TIMELY MANNER

Big ideas and enduring understandings to focus on this week:Big idea 1: The process of evolution drives the diversity and unity of life.Big idea 2: Biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis.Big idea 3: Living systems store, retrieve, transmit and respond to information essential to life processes.Big idea 4: Biological systems interact, and these systems and their interactions possess complex properties.

Enduring Understandings:1.C Life continues to evolve within a changing environment.

2.D Growth and dynamic homeostasis of a biological system are influenced by changes in the system’s environment.

3.E Transmission of information results in changes within and between biological systems.

4.A Interactions within biological systems lead to complex properties.

4.B Competition and cooperation are important aspects of biological systems.

4.C Naturally occurring diversity among and between components within biological systems affects interactions with the environment.

Mr Burley

Nightly Readings and Questions:CC = Concept Check SSE = Scientific Skills ExerciseMB = Mastering Biology HW

TuesdayReading: 40.4–40.6Q: Ch. 40

CC 40.4 (1, 2) CC 40.5 (1, 2, 3) CC 40.6 (1, 2) SSE 40.5 (1, 2, 3)

MB Introduction to MasteringBiologyMB Ch. 27

WednesdayReading: TiktaalikMB Ch.23

ThursdayReading: Neanderthal MB Ch. 40

Friday & WeekendReading: Ch. 41.1 – 41.2Questions: Ch. 41

Mr Burley

CC 41.1 (1 - 3) SSE 41.1 (1 - 6) CC 41.2 (1 & 3)

MB Ch. 40

MondayReading: Ch. 41.3 – 41.5Questions: Ch. 41

CC 41.3 (3) CC 41.4 (1 & 2) CC 41.5 (1 & 2)

AMNH Field Trip Permission Slips Due

TuesdayNo school

WednesdayAMNH Field Trip and Report

Vocabulary:PRACTICE VOCABULARY FOR CHAPTERS 26, 27, 40, 41Utilize the flashcard tool and other resources on the student media CD to practice these words. Purposeful practice is the best way to learn new vocabulary!

Mr Burley

Create Flashcards to practice for Vocabulary Oral Drill. The following words will be tested:

Annotation:Using the system written below, identify the main ideas and points of each article, the evidence supporting the idea, and any words that you do not know.

Main point or scientific claim - boxed Quantitative evidence (numbers or data) supporting the

scientific claim - underlined and hash tagged (#) Qualitative evidence (qualities or description)

supporting the scientific claim - underlined and starred Words that you do not know the meaning of - circled Write two questions you have in the margin

Fossil Called Missing Link From Sea to Land AnimalsBy John Noble WilfordScientists have discovered fossils of a 375-million-year-old fish, a large scaly creature not seen before, that they say is a long-sought missing link in the evolution of some fishes from water to a life walking on four limbs on land.

In two reports today in the journal Nature, a team of scientists led by Neil H. Shubin of the University of Chicago say they have uncovered several well-preserved skeletons of the fossil fish in sediments of former streambeds in the Canadian Arctic, 600 miles from the North Pole.

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The skeletons have the fins, scales and other attributes of a giant fish, four to nine feet long. But on closer examination, the scientists found telling anatomical traits of a transitional creature, a fish that is still a fish but has changes that anticipate the emergence of land animals — and is thus a predecessor of amphibians, reptiles and dinosaurs, mammals and eventually humans.

In the fishes' forward fins, the scientists found evidence of limbs in the making. There are the beginnings of digits, proto-wrists, elbows and shoulders. The fish also had a flat skull resembling a crocodile's, a neck, ribs and other parts that were similar to four-legged land animals known as tetrapods.

Other scientists said that in addition to confirming elements of a major transition in evolution, the fossils were a powerful rebuttal to religious creationists, who have long argued that the absence of such transitional creatures are a serious weakness in Darwin's theory.

The discovery team called the fossils the most compelling examples yet of an animal that was at the cusp of the fish-tetrapod transition. The fish has been named Tiktaalik roseae, at the suggestion of elders of Canada's Nunavut Territory. Tiktaalik (pronounced tic-TAH-lick) means "large shallow water fish."

"The origin of limbs," Dr. Shubin's team wrote, "probably involved the elaboration and proliferation of features already present in the fins of fish such as Tiktaalik."

In an interview, Dr. Shubin, an evolutionary biologist, let himself go. "It's a really amazing, remarkable intermediate fossil," he said. "It's like, holy cow."

Two other paleontologists, commenting on the find in a separate article in the journal, said that a few other transitional fish had been previously discovered from approximately the same Late Devonian time period, 385 million to 359 million years ago. But Tiktaalik is so clearly an intermediate "link between fishes and land vertebrates," they said, that it "might in time become as much an evolutionary icon as the proto-bird Archaeopteryx," which bridged the gap between reptiles (probably dinosaurs) and today's birds.

The writers, Erik Ahlberg of Uppsala University in Sweden and Jennifer A. Clack of the University of Cambridge in England, are often viewed as rivals to Dr. Shubin's team in the search for intermediate species in the evolution from fish to the first animals to colonize land.

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H. Richard Lane, director of paleobiology at the National Science Foundation, said in a statement, "These exciting discoveries are providing fossil 'Rosetta Stones' for a deeper understanding of this evolutionary milestone — fish to land-roaming tetrapods."

The science foundation and the National Geographic Society were among the financial supporters of the research. Besides Dr. Shubin, the principal discoverers were Edward B. Daeschler of the Academy of Natural Sciences in Philadelphia and Farish A. Jenkins Jr., aHarvard evolutionary biologist. Casts of the fossils will be on view at the Science Museum of London.

Michael J. Novacek, a paleontologist at the American Museum of Natural History in Manhattan, who was not involved in the research, said: "Based on what we already know, we have a very strong reason to think tetrapods evolved from lineages of fishes. This may be a critical phase in that transition that we haven't had before. A good fossil cuts through a lot of scientific argument."

Dr. Shubin's team played down the fossil's significance in the raging debate over Darwinian theory, which is opposed mainly by some conservative Christians in this country, but other scientists were not so reticent. They said this should undercut the argument that there is no evidence in the fossil record of one kind of creature becoming another kind.

One creationist site on the Web (emporium.turnpike.net/C/cs /evid1.htm) declares that "there are no transitional forms," adding: "For example, not a single fossil with part fins, part feet has been found. And this is true between every major plant and animal kind."

Dr. Novacek responded: "We've got Archaeopteryx, an early whale that lived on land, and now this animal showing the transition from fish to tetrapod. What more do we need from the fossil record to show that the creationists are flatly wrong?"

Duane T. Gish, a retired official of the Institute for Creation Research in San Diego, said, "This alleged transitional fish will have to be evaluated carefully." But he added that he still found evolution "questionable because paleontologists have yet to discover any transitional fossils between complex invertebrates and fish, and this destroys the whole evolutionary story."

Dr. Shubin and Dr. Daeschler began their search on Ellesmere Island in 1999. They were attracted by a map in a geology textbook showing an abundance of

Mr Burley

Devonian rocks exposed and relatively easy to explore. At that time, the land had a warm climate: it was part of a supercontinent straddling the Equator.

It was not until July 2004, Dr. Shubin said, that "we hit the jackpot." They found several of the fishes in a quarry, their skeletons largely intact and in three dimensions. The large skull had the sharp teeth of a predator. It was attached to a neck, which allowed the fish the unfishlike ability to swivel its head.

If the animal spent any time out of water, said Dr. Jenkins, of Harvard, it needed a true neck that allowed the head to move independently on the body.

Embedded in the pectoral fins were bones that compare to the upper arm, forearm and primitive parts of the hand of land-living animals. The joints of the fins appeared to be capable of functioning for movement on land, a case of a fish improvising with its evolved anatomy. In all likelihood, the scientists said, Tiktaalik flexed its proto-limbs mainly on the floor of streams and might have pulled itself up on the shore for brief stretches.

In their report, the scientists concluded that Tiktaalik was an intermediate between the fishes Eusthenopteron and Panderichthys, which lived 385 million years ago, and early tetrapods. The known early tetrapods are Acanthostega and Ichthyostega, about 365 million years ago.

Tiktaalik, Dr. Shubin said, is "both fish and tetrapod, which we sometimes call a fishapod."

1. Choose five of the words from the reading that you did not know. Look up those words in a dictionary and write the word and definition here.

a. __________________________________________________________________________________________________________________________________

Mr Burley

b. __________________________________________________________________________________________________________________________________

c. __________________________________________________________________________________________________________________________________

d. __________________________________________________________________________________________________________________________________

e. __________________________________________________________________________________________________________________________________

2. What was the significance of Tiktaalik?_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________3. What traits allowed Tiktaalik to move between land and

water?______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. How did Tiktaalik pave the way for other terrestrial vertebrates to colonize land?

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Mr Burley

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Neanderthals: Facts About Our Extinct Human Ancestors

By Jessie Szalay

Neanderthals (or Neandertals) are our closest extinct human relatives. There is some debate as to whether they were a distinct species of theHomo genus (Homo neanderthalensis) or a subspecies of Homo sapiens. Our well-known, but often misunderstood, fossil kin lived in Eurasia 200,000 to 30,000 years ago, in the Pleistocene Epoch.

Neanderthals’ appearance was similar to ours, though they were shorter and stockier with angled cheekbones, prominent brow ridges, and wide noses. Though sometimes thought of as dumb brutes, scientists have discovered that they used tools, buried their dead and controlled fire, among other intelligent behaviors. It is theorized that for a time, Neanderthals, humans and probably other Homo species shared the Earth.

Discovery

In 1856, a group of quarrymen discovered remnants of a skeleton in the Neander Valley near Dusseldorf, Germany (hence their name). In a limestone cave, they found 16 pieces of bone, including a skull. Thinking the bones belonged to a bear, the quarrymen gave them to local teacher Johan Karl Fuhlrott. From him, the bones found their way to scientists, and it was eventually determined that they were ancient human relatives. The publication and popularization of Charles Darwin’s "The Origin of the Species" in 1859 helped inform the discovery. Since that day in the Neander Valley, more than 400 Neanderthal bones have been found.

The original cave men

Neanderthals lived during the Ice Age. They often took shelter from the ice, snow, and otherwise unpleasant weather in Eurasia’s plentiful limestone caves. Many of their fossils have been found in caves, leading to the popular idea of them as “cave men.”

Mr Burley

Like humans, Neanderthals originated in Africa but migrated to Eurasia long before humans did. Neanderthals lived across Eurasia, as far north and west as the Britain, through part of the Middle East, to Uzbekistan. Popular estimates put the peak Neanderthal population around 70,000, though some scientists put the number drasticallylower, at around 3,500 females.

Their short, stocky stature was an evolutionary adaptation for cold weather, since it consolidated heat. According to the Smithsonian Institution, the wide nose helped humidify and warm cold air, though this assertion is debated. The American Museum of Natural History states that other differences from humans are a flaring, funnel-shaped chest, a flaring pelvis, and robust fingers and toes. Their brains, however, grew at a similar rate to humans’ and were about the same size or larger. Approximately 1 percent of Neanderthals had red hair, light skin, and maybe even freckles.

For a long time, scientists and anthropologists theorized that Neanderthals grew up faster than humans, reaching maturity sooner and dying younger, as chimps do. In 2008, however, Proceedings of the National Academy of Sciences published evidence that humans and Neanderthals matured at the same rate.

Social structure

Neanderthals lived in nuclear families. Discoveries of elderly or deformed Neanderthal skeletons suggest that they took care of their sick and those who could not care for themselves. Neanderthals typically lived to be about 30 years old, though some lived longer. It is accepted that Neanderthals buried their dead, though whether or not they left carved bone shards as grave goods is more controversial.

It is not known if they had language, though the large size and complex nature of their brains make it a likely possibility.

Neanderthals used stone tools similar to and no more sophisticated than the ones used by early humans, including blades and scrapers made from stone flakes. As time went on, they created tools of greater complexity, utilizing materials like bones and antlers. Evan Hadingham of PBS’s NOVA even reports that Neanderthals used a type of glue, and later pitch, to attach stone tips to wooden shafts, creating formidable hunting spears.

Mr Burley

Neanderthals had some control of fire, and it is even theorized that they built boats and sailed on the Mediterranean.

Neanderthals were primarily carnivorous, and the harsh climate caused them to resort occasionally to cannibalism. Recently, however, scientists have found that Neanderthals actually ate cooked vegetablesfairly regularly. 

Human-Neanderthal interbreeding

Probably the most debated aspect of Neanderthal life in recent years is whether or not they interbred with humans. The answer remains ambiguous, with scholarly opinions ranging from belief that they definitely interbred to belief that the two groups didn’t exist on earth at the same time.

Neanderthal expert Erik Trinhaus has long promoted the interbreeding hypothesis, but the theory really caught fire when a 2010 study published in Science magazine determined that Neanderthal DNA is 99.7 percent identical to modern human DNA (a chimp’s is 99.8 percent identical). Researchers of the Neanderthal Genome Projectfound that 2.5 percent of an average non-African human’s genome is made up of Neanderthal DNA. The average modern African has no Neanderthal DNA. This information could support the interbreeding hypothesis because it suggests that humans and Neanderthals only bred once humans had moved out of Africa, into Eurasia. They could have interbred as recently as 37,000 years ago.

A 2012 study led by Dr. Rachel Wood, however, cast doubt on that theory. Researchers re-examined bones from southern Spain that were used in earlier studies with new radiocarbon dating techniques. They discovered that the Neanderthal bones were more than 50,000 years old. Humans aren’t believed to have settled in the area until 42,000 years ago, meaning that it may be unlikely that they lived together and interbred.

If humans and Neanderthals didn’t interbreed, the similar genomes of humans and Neanderthals could be the result of both groups having a common African ancestor.

Extinction

No one knows exactly why Neanderthals went extinct and why humans survived. Some scholars theorize that gradual or dramatic climate change led them to their demise, while others blame dietary deficiencies. Some theorize

Mr Burley

that humans killed the Neanderthals. Until recently the hypothesis that Neanderthals didn’t go extinct but simply interbred with humans until they were absorbed into our species was popular.

1.Choose five of the words from the reading that you did not know. Look up those words in a dictionary and write the word and definition here.

a. __________________________________________________________________________________________________________________________________

b. __________________________________________________________________________________________________________________________________

c. __________________________________________________________________________________________________________________________________

d. __________________________________________________________________________________________________________________________________

e. __________________________________________________________________________________________________________________________________

2. How were humans and Neanderthals similar? How were they different? What traits do you believe led to increased fitness?

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Mr Burley

3. How do you believe evolution and natural selection led to the development of two separate species that were so similar?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

What Happened to the Neanderthals?

By Katarina HavartiThe last appearance date of Neanderthals is commonly cited as ca. 30 thousand years ago (ka). This date follows the emergence of modern humans in Europe by several millennia, but our understanding of the exact timing and duration of this interval is obscured by the limitations of our dating methods. For example, peaks in atmospheric radiocarbon production during this time result in a large degree of uncertainty in the relevant radiocarbon dates (Conard & Bolus 2008). The two species may have coexisted in Europe for up to ten millennia, and possibly came across each other during this time, although the duration of this coexistence is debated, as is contact between the two (e.g., Finlayson 2000, Pinhasi et al. 2011). The question of what may have happened during these

Mr Burley

encounters and what the role of the early modern humans could have been in the Neanderthal extinction, have been the subject of intense discussion and a focal point in Neanderthal research.

The Neanderthal disappearance is viewed by some as a true extinction. Others however, contend that Neanderthals did not become extinct, but instead were assimilated into the modern human gene pool. The fossil record is ambiguous on this point: a few European Upper Paleolithic modern human specimens have been proposed as potential Neanderthal-modern human hybrids, but this interpretation has been questioned (e.g., see Smith 2005, Harvati et al. 2007). Analysis of Neanderthal and Upper Paleolithic modern human mitochondrial DNA shows no indication of interbreeding (e.g., Ghirotto et al. 2011). However, recent research on Neanderthal nuclear DNA has found evidence for limited admixture: a small portion (up to ~4%) of the genomes of non-Africans so far examined may derive from Neanderthals, suggesting that interbreeding probably occurred in the Near East during the earliest dispersal of modern humans out of Africa, but prior to their arrival in Europe (Green et al. 2010). Demographic modeling of admixture combined with territorial expansion, however, indicates that this level of introgression would be produced under very low (<2%) interbreeding rates and strong barriers to reproduction between Neanderthals and modern humans, arguing against assimilation (Currat & Excoffier 2011). Pending the completion of the Neanderthal genome and ancient DNA analyses of early modern Europeans dating to the Upper Paleolithic, and following the recent discovery of a third possibly coexisting species from Denisova cave (Krause et al. 2010), it is premature to conclude that the currently observed level of admixture constitutes assimilation. Regardless of this small contribution to the modern human gene pool, Neanderthal populations across Europe vanished abruptly in the fossil record, and several scenarios have been proposed to account for this observation. Most invoke a degree of competition, either direct or indirect, with modern humans, or alternatively, deteriorating environmental conditions, as major factors.

Hypotheses advocating competition have proposed several possible modern human competitive advantages. These include technological advances, such as 1) better clothing and shelter, 2) improved hunting techniques and more diverse subsistence strategies, which included the consumption of birds and fish, 3) social differences, such as larger group sizes and more elaborate social networks among modern humans, and 4) demographic factors, possibly including differences in birth and mortality rates or in interbirth intervals of the two species (see references in Harvati 2007). Indeed important differences

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have been found between Neanderthals and modern humans in their life history and demography, including faster growth and possibly shorter life expectancy in Neanderthals (see Harvati 2007, Smithet al. 2010), as well as a much higher population density among Upper Paleolithic modern humans compared to Neanderthals (Mellars & French 2011).

The relevance of climate in this debate was until recently discounted, as Neanderthals disappeared in Oxygen Isotope Stage 3 (OIS 3) when conditions were thought to be relatively stable (Stringer et al. 2003). Some recent hypotheses, however, consider climatic instability during the millennia building up to the last glacial maximum to have been a driving force in the Neanderthal extinction. One model postulates that habitat degradation and fragmentation occurred in the Neanderthal territory long before the arrival of modern humans, and that it led to the decimation and eventual disappearance of Neanderthal populations. In this view modern humans would have arrived in areas previously occupied by Neanderthals after the latter were already extinct, and the two species would never have met in Europe (Finlayson 2000). A similar model considers the Neanderthal demise as only one of the many Late Pleistocene megafauna extinctions caused by the loss of an environment with no modern analogue (Stewart 2005). Support for a significant climatic effect comes from recent detailed palaeoclimatic records, according to which OIS 3 was dominated by much more unstable climatic conditions than previously thought (van Andel & Davies, 2003) and may have been precipitated by unusually intense volcanic activity (Golovanova et al. 2010). Modeling of climatic stress (defined as the indirect effects of environmental change) based on these new data found two stress peaks at ~65 and ~30 ka, the second appearing to be more prolonged and severe than the first, and possibly related to the Neanderthal extinction (Stringer et al. 2003). This may have been precipitated by the coeval eruption. However, as Neanderthals had survived previous cold phases, it is difficult to accept climate change as the sole reason for their demise. Furthermore, no association has been found between proposed dates for the last Neanderthal appearance and major climatic events, suggesting that Neanderthals did not become extinct following a catastrophic climatic event (Tzedakis et al. 2007). If climate played a significant role, therefore, it would be a more complex one, perhaps involving environmental deterioration in combination with the advent of modern humans, and therefore

Mr Burley

with increased competition for limited resources. In this view it is the interaction between the effects of fluctuating climate and environment and of competition with modern humans that would have led to the eventual Neanderthal extinction.

1. Choose five of the words from the reading that you did not know. Look up those words in a dictionary and write the word and definition here.

a. __________________________________________________________________________________________________________________________________

b. __________________________________________________________________________________________________________________________________

c. __________________________________________________________________________________________________________________________________

d. __________________________________________________________________________________________________________________________________

e. __________________________________________________________________________________________________________________________________

2. What are the three major theories behind Neanderthal extinction?

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Mr Burley

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3. Which theory do you most agree with? Give evidence to support your argument.

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Mr Burley

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Mr Burley