Thursday, April 15, 2010

Darwinism vs. Social Darwinism

Darwinism is what is known as the commonly accepted modern theory of evolution. The term was not coined by Darwin himself, but it represents the idea that evolution is the summation of adaptations proven to be advantageous to survival through natural selection. Synonymous with the term Darwinism is the concept of "survival of the fittest". Starting in the late 1800's the idea of Social Darwinism surfaced which promoted this same "survival of the fittest" among people. To what degree are the two terms alike? To what degree are they different? Is Social Darwinism an accurate example of how the strongest people in society survive, specifically in the late 1800's? If it is not, explain how possible arguments that could be made by creationists in reference to Social Darwinism are invalid in the argument of evolution.


Do you think you're special?

It's easy to see human's as a prevailing species on earth. We build sky scrapers, we can destroy the entire planet on a whim, surviving and reproducing usually aren't our chief motivators. Does that make us special? Coyne asks "does our existence have any purpose or meaning that distinguishes us from other creatures?" and adds "If humans are just one of many outcomes of natural selection, maybe we aren't so special after all" (xvii).

I do not intend for this to be an open, theological forum. My challenge is this:
Based on what we know about the different theories of evolution, how would each view point feel about the above question? What aspects of human anatomy, fossil record, and sociology would affect these views. Please compare Creationism, Intelligent Design, and forms of Darwinian evolution.

Then, BRIEFLY share your own views on man's place in the universe.

Dogs

On page 125 Coyne talks about the breeding that humans have done of the domestic dog in relation to evolution by selection. The dogs all come from ancestors of other animals that were not forced to live in captivity and when they were evolved into the dogs that we know today. These include around 150 breeds of dogs that were created due to human action. "Breeders have virtually sculpted these dogs to their liking..." (126). Was this human influence on dog evolution harmful to the ancestors that they came from? Should the breeding of dogs for things like the shade and thickness of their coats be allowed even though it may cause health problems and interferes with natural selection? Discuss the effect that this evolution by selection has on the process of natural selection and give other examples of evolution by selection. How do wild dog breeds and domestic dog breeds differ and relate to each other? Contrast and compare artificial selection versus natural selection.

Wednesday, April 14, 2010

Native groups to oceanic islands

On page 104, Coyne has a chart of native groups in oceanic islands and groups that are usually missing. Plants, birds, and insects are in the native group and land mammals, reptiles, amphibians and freshwater fish are in the missing category. Coyne explains that this is because the native species can colonize the oceanic island trhough long-distance dispersal. What are some examples of species that have been found on oceanic islands that would fit into the missing group? How did they get there? How are they able to sustain their population?

Rapid microevolution in nature

As Coyne stated on pg. 132, humans want to see a natural population meet a natural challenge, and they want to see the population evolve to meet it before their eyes. They want to see it occur without human interferrence and not in bacteria, but in "higher" plants and animals. Since humans have no control in this, it has to be nearly impossible to observe this, yet we have. A finch in the Galapagos Islands was observed to have evolved to a 10 % larger beak size in one generation after a drought made them find nutrution in larger and harder seeds than normal. Coyne states that this is "far larger than anything we see in the fossil record" (134). What other examples exist of microevolution, not man-made, that has been observed in nature in a very short period of time? Also, why is it that there is no past evidence of evolution occuring so quickly (as in one generation)? Could it be that the selective pressures are increasing? What could this mean for future evolution?

Is medicine bad?

The medical field creates a large amount of jobs for the general public. These jobs help the economy flourish, but what about the human species? Because of new medicine keeping people alive when they should have died out, and allowing them to reproduce, what problems does this pose on the evolution of the human race? This may be a very cynical view of medicine, but ultimately for evolution to work natural selection must occur - the ones not fit for survival must die out - and progress can be made. Another problem within medicine is the constant "arms race" between the doctors and pathogens. What methods/practices of medicine could eliminate or severely limit the ability of viruses and bacteria to mutate into stronger organisms. Also, due to medicine increasing lifespans and overall age, what are some potential implications overpopulation may have on the long term health of society and the Earth itself? Are there even any benefits overpopulation may have?

The Importance of Communication

We use language in our everyday lives to ask for something, exchange opinions, and learn about different ideas. Language is obviously very important, but why did it evolve in the first place? Better yet, why do we have so many languages instead of simply one? Wouldn’t it be easier to communicate with all different people without this language barrier? In addition to broaden the subject, in the Campbell Biology book we read about how different organisms communicate. One of creatures was the honeybee, which dances in order to exchange information with its hive about the location of food. The honeybees don’t simply point a direction, but they also give the distance of the food with their extravagant “waggle dance”. What are other ways organisms communicate that don’t use speech like we do? Give an example and, if possible, the reason it may have evolved.

Is Genius Dumb?

Many of us are intrigued to hear about certain quirks people have in their brains. Some of us, like Blumenfeld, are geniuses, and have some of these traits, be it photographic memory, perfect pitch, or, I guess I'll throw in synesthesia after today's conversation in class. I am talking about things that are associated with being smart. If these really do generally correlate with being smarter than average, what is advantageous about them? It seems natural to assume that they would have evolved at times when human beings were not civilized, observing the very little time on an evolutionary scale that we have had civilization. Assuming that "smarter" implies forward evolutionary progress, what makes it more advantageous to be able to instantly memorize entire pictures rather than tiny bits of information? Shouldn't this involve the use of a large amount of energy that, at the time, we wouldn't really have needed to use? What could have been advantageous about perfect pitch? Why would it matter for someone to be able to remember the exact pitch of a sound? A huge amount of the sounds we make with our vocal chords are not even what one would call "notes," anyway. And especially synesthesia: Wouldn't it be better to completely separate our senses, so as not to cause confusion?

Tuesday, April 13, 2010

Evolution vs ID in public education

There is an ongoing debate in the real of public education of whether or not ID/ Creationism should be taught in public high schools or not. In general, what do you think about this debate? Is allowing creationism in schools necessarily a bad thing when taught in conjunction with evolution?

http://www.npr.org/templates/story/story.php?storyId=4630737
This is a list of 16 states that directly or indirectly encourage ID to be taught in schools, Not the geography of the states and comment on why you think the distribution is so.


http://debatepedia.idebate.org/en/index.php/Debate:Creationism_vs_evolution_in_schools
From here, take several ideas from the creationist side and refute them using either examples from the book but also using the idea that evolution is a science.

evolution or a creator?

Scientists claim that Intelligent Design theory is a theological argument without scientific basis. Evolutionists seem to think that ID proponents are only out to villainize the scientific community and those who believe in Intelligent Design claim that the unsubstantiated imperfections in neo-darwinist evolutionary theory provide enough basis to refute it as 'potentially unvalid'. To those of you who have identified yourselves as theistic evolutionists (or who would simply like to comment) - how is it that we can reconcile religion/creationism with evolutionary theory (assuming macroevolution)? Are they really compatible, and if so in what way? What aspects of evolutionary theory make room for a creator and is there room for the theory of evolution in religion?

The Dating of Fossils

The age of fossils are critical for outlining evolution as with the age of fossils we are able to prove not only that the world has been around longer than the young earth creationists believe but also to plot the timeline of evolution and observe how and why animals evolved. As carbon dating as the generally accepted and most common way of defining the age of fossils seems more and more questionable with the nuclear bombs and testing that occurs around the world, what will be the next way to determine the age of fossils? If we are not able to determine the age of fossils, how will we continue to pursue the dream of following the footsteps of evolution? Will we even still be able to chase the proof of evolution? What will happen to the theory if we can't assign a definite time to each fossil we find? Would the whole theory just collapse without time reference?

Aim For the Weak Spot.

On page 141, Coyne explains how complex organs like the eye would have been created over the course of time by giving a series of examples with intermediary steps of said organ as can be found on animals today. But how could natural selection ever dictate that a blood vessel as crucial to the proper functioning of the body like the carotid artery would be placed so close to the surface of the skin, exposed and in great risk of being accidentally cut? This is just one example, another being the spinal column. It is illogical to think that such an important part of the nervous system would be surrounded by vertebrae and gelatinous discs that with one false move can sever the spinal cord and majorly disable a person. What other illogical body parts exist on humans that are either too vulnerable or exposed for natural selection to warrant their placements? On other animals? And how can evolution explain these simple vulnerabilities?

Is it Mathematically Possible?

Most Intelligent Design proponents base their theory on the idea of something being "irreducibly complex". A recent finding by scientists, according to Mr. Roys, proved that for a cell to survive, it needs a certain number of proteins (around 100), but the chances of molecular combinations occurring in such a way that all 100 proteins are created in the proper way at the proper time is around 1/10^40,000. Because any number lower than 1/10^150 is out of the realm of possibility, how can evolution be true when such clear-cut evidence is provided for an intelligent designer?

Evolutionary Pathways

In the section of Why Evolution is True titled "Can Selection Build Complexity?", Coyne delineates the many arguments in which ID proponents suggest that there is no evolutionary pathway that can construct certain traits, protein complexes, etc., and how there is often an answer if you think long enough. One of the most complex systems we have learned about so far is the immune system. What pathways could lead to having so many different antigen complement proteins and antibodies, able to be selected and proliferated as needed? What about the process of presenting an antigen on the cell surface? Perforin and the process of lysing antigen-presenting cells?

Retrodictions

On page 18, Coyne says that Darwinism can be supported be things he calls retrodictions. He defines them as "facts and data that aren't necessarily predicted by the theory of evolution but make sense only in light of the theory of evolution" (18). Coyne lists that some of the retrodictions that support evolution are patterns of species distribution, how organisms develop from embryos, and the existence of vestigial features. Define in your own words what a retrodiction is. Choose one from Coyne's list and provide examples of it. Why do these fit Coyne's definition of a retrodiction in support of evolution? Are there any other examples of retrodictions that support evolution that Coyne does not list?

Monday, April 12, 2010

The Pinky and The BRAIN

A huge part of the ID argument has to do with the human brain, and its amazing abilities. Humans are the only known organism to have "ideas." Ideas are a non-physical entity, so how is it possible that a physical organ can perceive them? Scientists and doctors can measure "brain-activity," but you can't measure "idea-formation." You can only infer that a certain amount of brain activity provides us with the ability of conscious thought.

Also, humans have the incredible ability of imagination. I can tell you to imagine a spherical chicken, and you can do it, but a dog cannot. It can be taught what a sphere is or a chicken, but it cannot combine the 2 concepts to imagine what a spherical chicken is.

What are some possible ideas that counteract this argument? Consider, can physical reactions between neurons really give rise to non-physical entities?

Don't Judge The Books By Their Covers

On page 159 Coyne further discusses about the theory of sexual selection. In the beginning paragraph, Coyne shows how the socially monogamous species do not actually exhibit the monogamous behavior. This is shown in many aspects of evolution where the initial physical appearance does not exhibit the matching behavior. What would be a reason for the contradiction or rather mismatching? Is there any examples, can be sexual selection or any other parts of evolution, that shows this mismatching? Explain.

Fossil Record

Coyne describes in detail Carbon-dating. What is the idea behind superposition of different isotopes? Does this produce the relative or actual age of rocks? (pg 23) What do opponents of evolution have to say about such radioactive decay evidence? (p 24)

Coyne claims that the fossil record is important for three main reasons (pg 53). Can you list other reasons that the fossil record is crucial to arguing for evolution (you may elaborate on Coyne’s three points)? It may help to name a few examples of species that support the assertion of the significance of the fossil record in the entire scope of evolution (gradual change within lineages, etc.)?

are psychological traits adaptations?

Jerry Coyne describes the evolution of the human brain as a physiological process that manifested itself as a change in skull and brain size. contemporary Evolutionary psychologists claim that selective pressures have also shaped the development of psychological traits such as memory, perception or language and that "

cognitive structure, like physiological structure, has been designed by natural selection to serve survival and reproduction". Based on what you know about natural selection, how is it that the concept of evolution may be reasonably applied to psychology? What situations may have selected for the development of emotions? Cognitive thinking, problem solving, social cooperation, altruism? How has this impacted our social structure, values, morals, beliefs etc. ? How can evolutionary psychology be applied to "survival of the fittest" in modern day society?

Resistance to drugs and poisons

Coyne says that "in 1941, [penicillin] could wipe out every strain of staph in the world. Now, seventy years later, more than 95 percent of staph strains are resistant to penicillin" (131). It is very evident that antibiotics are rapidly losing their effectiveness against bacterial infections. Scientists as of now have been able to produce new types of antibiotics that bacteria aren't resistant to, but they are rapidly running out of new kinds. Also, the use of bacteriophages to kill pathogenic bacteria is an area of extensive research to cure infections. What are some ways that scientists are trying to apply the use of bacteriophages to cure sicknesses, and what are other methods which biologists are researching to cure infections? Have there been any recent advances in the treatment of viral infections?

Technology - Good or Bad?

As great as modern advancements in medicine and technology seem to us over our lifetimes, (curing diseases, healing injuries, etc.) it seems that the great majority of them could prove to be detrimental to our species' survival in the long run. Antibiotics are creating more resistant pathogenic bacteria. Appendectomy's allow us to keep a feature in our digestive tract that has more potential harm than good. Is there any examples of modern technology that could benefit our species in the long run, whether already developed or in development? Are we creating a weaker human race, diminishing the chances of survival for the generations to come? What are other threats to the future survival to the human race?

Remember Thermodynamics?

An intelligent design argument is that the laws of nature tend to destroy rather than construct, and that this tendency toward entropy is too powerful say that evolution could be sustained long enough to be called macroevolution. Coyne says, "we easily accept that the Grand Canyon resulted from millions of years of slow, imperceptible carving by the Colorado River, even though we can't see the canyon getting deeper over our lifetime. But for some people this ability to extrapolate time for geological forces doesn't apply to evolution" (125). A logical (perhaps not infallably logical) reason for this would be the above. In fact, as stated on the cover of the AP Physics B textbook last year, delta-S-sub-universe>0, meaning the universe is always becoming more chaotic rather than more organized. How can one refute this in the case of evolution? Is there perhaps a solution related to thermodynamics? Any explanations as to how we can be at least fairly certain that the nature of nature is not so destructive as to prevent evolution would be welcome.

Young Earth Theory

On page 24, Coyne mentions the side of a group known as young earth creationists. This group attacks the reliability of carbon dating and other such radiometric methods used to determine the age of fossils. Coyne refutes the young earth creationist arguments about carbon dating that despite extreme temperatures and pressures exerted, the half life of an element remains unchanged. Continue to support Coyne's evidence concerning the reliability of age finding methods and relate how these ages can be used to support evolution, or provide some other evidence that young earth creationists use to support the young earth theory and analyze the possibility of these claims.

Sunday, April 11, 2010

The Extraterrestrial

One of the most fundamental ideas of creationism revolves around us being the only known intelligence in the universe (other than a presupposed creator). However, more and more in modern culture we see ideas of "alien salvation" (knowing) and similar concepts popping up. However, is it any more reasonable to believe that an extraterrestrial form of life exists when we have little nothing to suggest it is so?

And if yes, use your knowledge of evolutionary theory to explain why it would seem logical to believe that there are other intelligent forms of life.

Accepting Evolution

On page 221 Coyne tells us that even though people believe that the evidence for evolution is strong, they still don’t believe it. He says that for many people “evolution raises profound questions of purpose, morality and meaning.” Many creationists agree that the study of evolution will “spill over into the study of ethics, history and family life.” This idea may cause people to link things like genocide to evolution. In general, many people simply do not wish to believe in evolution because of moral or social worries.

What would you say to convince a hesitant person, who is trying to decide whether to believe in evolution or not? This person expresses the doubt stated above and needs an AP bio student to convince him/her otherwise. (Use 224-233)

evolutionary linguistics

On page 176, Coyne claims that "biological speciation resembles the speciation of two closely related languages". On a different note, what is the role of the speech function in human evolution? Elaborate on the coevolution of linguistics and of the brain/skull. How does the progression of human evolution demonstrate morphological modifications conducive to the development of sophisticated language? what are the selective advantages and how has language shaped the evolution of society and culture? Compare to the evolution of other primates. Be sure to consult outside sources.

The evolution of bipedalism

on page 194-207, Jerry Coyne addresses the divergence of Homo sapiens from apes. The discovery of Lucy told scientists that "our upright posture evolved before our big brain" and "went against conventional wisdom that larger brains evolved first" (202). What anatomical modifications were necessary for bipedalism to evolve and why is it that modern apes are not physically able to walk upright? How did Johanson's discovery provide evidence that bipedalism evolved before our big brain? What might be the reason that bipedalism evolved first and what selective pressures/potential advantages may have caused such change? Finally, elaborate on the effects of bipedalism on human evolution - cultural ramifications, predation and foraging, migration and geographic distribution.


Foes to Friends

The human relationship with animals has been one of radical change. What started as a predator-prey relationship (with the humans often as prey) has dynamically evolved as now animals are studied by humans, even thought of as material comforts in some case. Obviously humans have gotten smarter over the decades but, over time, what do you believe the evolutionary complications of such a quick radical shift in the power dynamic? Also do you think that there will be further change in these relationships such as Mr. Erdmann suggested (with the use of natural selection to cause peaceful coexsistance of bacteria and humans)?

Creationism Weakness

Throughout out the book, Coyne lists many different points that creationists have brought up when refuting the theory of evolution. He also, after stating them, provides evidence for why their argument is not true. Do you feel that he adequately shut down all of the creationists points? Are there any other arguments that creationists have against evolution that he may have missed? If so, what are they and is there any evolutionary evidence that proves it to be wrong? With all of the evidence against the creationist theory, why are there still so many people attached to it?

Feedback and Complexity

When we think of evolution, we are usually thinking of physical traits. Coyne uses examples such as fins, wings, fur color, etc. However, it took much more complexity to create the diversity of life that we see today. When Coyne discusses complexity, it almost comes off as a five page rant about Intelligent Design (starting on 136). His chief examples are blood clotting and the eye. He shows simpler structures such as ancient proteins and eye spots. The concept is that these organs gradually evolved into their complex forms.
We have learned that it takes more than an organ's shape to make it function properly. There is a whole network of proteins, hormones, tropic hormones, pH and salinity balances at work. My question is this:

How does feedback allow for complex organs and systems to function in our own bodies? When is there a selective advantage for positive feedback, and when is there an advantage for negative feedback? Why does this difference exist?

Saturday, April 10, 2010

Chemical Evolution

Conye doesn't seem to mention much about chemical evolution (the theory of how chemicals gathered into living things) in his book, yet this is a major creationist argument: there is too low of a probability for chemical evolution to occur. How do evolution proponents refute the claim of creationist, or, if you're a creationist, then what are the main arguments against evolution proponents? Use examples and outside sources to support your claims.

Bad/Odd Design

Coyne cites “bad design” as an argument against creationism. Vestigial organs are one example of bad design like our appendix. Coyne also gives examples of odd design that shouldn’t be created by an intelligent designer. One example of this is the flatfish; as opposed to other fish, the flatfish swims on its side and has deformed features. (82)

Find an example(s) of bad design in organisms, like in the flatfish, and describe the functions of traits/structures and give a possible evolutionary basis for that trait. Explain why bad design is evidence of evolution and also write why creationists are so keen to avoid the topic of bad design.

"It's just a theory!"

On page 15, Coyne defends the idea against evolution from the claim "Evolution is just a theory." He defends against this by stating that, in science, a theory is more than a speculation but rather is a well thought out group of hypothesis and observations meant to explain things in the real world. Another point he brings up is that a scientific theory must be testable and make verifiable predictions. For both of these defenses, Coyne uses the atomic theory. In this way, support the theory of evolution by presenting hypothesis' made by evolutionists and also the verification of these hypothesis' through evidence such as fossil records, vestigial traits, dead genes. Also, explain why that if there is such seemingly overwhelming evidence supporting it, it is still called just a theory and not a fact.

Friday, April 9, 2010

Destroying Life's History?

According to Jerry Coyne, ecosystems are incredibly vulnerable. As he addresses, “island ecosystems… are fragile things, easily ravaged by foreign invaders who can destroy habitats and species,” (110). The worst, as he adds, are humans themselves. We’ve seen the destruction of the rainforests for trees and land, as well as land in our own towns destroyed to make homes and buildings. As Coyne continues, “each species represents millions of years of evolution and, once gone, can never be brought back” (110). What lengths are humans going to to protect ecosystems and preserve their habitants? Also how are we restoring habitats that might have been damaged by humans? Coyne’s also brings up the point that we bring over organisms into different habitats that the environment isn’t adapted too. Give an example of an animal that has invaded a foreign habitat and the results of its invasion. If possible, explain how humans are trying to fix the problem and restore balance to that environment.

Evolution Revised

Coyne's book is focused on explaining and proving what has been the accepted theory of evolution for more than a 100 years. Yet recent research has uncovered a kind of second genetic code in the form of epigenetics. Epigenetics, while not an actual genetic code, codes for the expression of genes in DNA. The interesting part of Epigenetics is that your epigenome can be altered within in a time span as short as one generation. In your opinion is the theory of evolution altered when viewed in the context of this new "genetic code"? Is it possible that we must write a new revised version of the evolutionary theory as more research is done in this area, or does the discovery of epigenetics simply clarify the workings of the body and either not effect or strengthen the argument of evolution?

¡Viva la Evolución!

On pages 125-128, Coyne addresses artificial selection in the form of plant and animal breeding. He explains that all modern domestic dogs are most likely a descendant of the Eurasian gray wolf, and through breeding humans have created 150 breeds that are recognized by the American Kennel Club.

Give another example of an animal or plant that humans have transformed for their own needs or desires. Do you think that through breeding humans are meddling with natural selection and disrupting the evolutionary process or is this just another factor influencing evolution. Explain and provide strong support for your opinion.

Morphological v. Molecular

This year we learned about two kinds of phylogenetic trees. Originally scientists based the organization of this tree on morphological and developmental data. However, new molecular data such as DNA sequences have provided another source of information in order to determine common ancestry. What similarities or agreements exist between morphological and molecular trees? How are they different?

Coyne brings up the point that certain groups of organisms are considered to be separate species even though they look exactly alike. For example, the group of fruit flies, Drosophila, is recognized as nine separate species due to differences in where they live and who they bite. Conversely, there are groups like humans that look very different, yet still have the ability to successfully mate together and are considered the same species. This brings up the question on whether or not "designation of species is an arbitrary exercise" or not (171). Therefore, what advantages are there to organizing the species into phylogenetic trees even through there are obvious inconsistencies and debates within the system?

Non-Evolution

We are always talking about how animals evolved, and showing examples that explain how they could have evolved. Is there any animals that did not evolve that we know of? Would this prove the evolutionary theory wrong? If these animals are not evolving, are there any signs that they possibly are? Bring in sources that help answer your thoughts.

Thursday, April 8, 2010

Islands

Coyne classifies two types of islands, continental islands and oceanic islands (page 100) Evolution uses these two types of islands to point out that the oceanic islands that are missing similar types of species so if a creator had made all the animals everywhere than this wouldn't be the case. Coyne then goes on to explain that this is an example of the "blend of chance and lawfulness" (page 109) of evolution when distributing life on earth. First, define the two types of islands. Then find examples of species that are found on main lands and continental islands but not on oceanic islands. Explain how oceanic islands can be considered to always have been separated hence why evolution of certain species did not occur there when the well established principle of pangea is accepted as truth. If all of the land was once together than wouldn't evolution occur similarly on all of the land that broke off? Not just some of it? Doesn't calling evolution a blend of chance and lawfulness give support to Creationism? If evolution is one large part chance that we do not explain in a scientific way then isn't there a gap open for divine intervention? How is it chance that the birds migrated to the Galapagos islands, they must have had a scientific reason for leaving where they came from in the first place and another reason to stay on the island therefore how is that chance at all? Use examples in your explanation. 

Our brain vs Evolution

Humans are the smartest creatures on this planet. With our brain being able to perceive everything that goes on in our day. It is the largest for our size and most complex. We say that we are descendent's from a common ancestor to chimps, but if our brain evolved shouldn't we see the chimps being pretty intelligent as well? The brain should have evolved over time, so that means that certain processes should be present in the chimps, but they are not able to do many of the things that our brain is physically capable of. How is it possible that our brain could have appeared from nothing?

One Becoming Two

In the chapter The Origin of Species, Coyne describes how the majority of species that form the diversity of the biosphere we live in. The predominant pro-evolution theory is that different species were caused by a single population being separated geographically and evolving in a different manner from its distanced kin until a point where if the two populations were reintroduced, they would be unable to reproduce with each other and therefore recombine their genes. However, can we really expect that of the millions (and perhaps billions depending on the classification system) of species in the world that they all were separated by a landmass forming across the sea or a mountain chain rising amidst a forest? Granted that the earth has been around for a long time and that the planet has changed a lot since life first inhabited it but what other possible ways could a population evolve separately from another population of the same species to the point where it can no longer share genes and becomes a different species? Dr. Coyne also gives the example of flowers adapting to different pollinators and therefore not being able to recombine their genes so obviously this one is exempt.

Wednesday, April 7, 2010

Lamarckian (Vestigial) Evolutionary Theory

At the very beginning of the book, Coyne establishes the basis of modern evolutionary theory (Coyne 1-19). On the other hand, Jean-Baptiste Lamarck, one of the “evolutionist biologists” prior to Darwin, proposed his own theory of evolution that has been overwritten with Darwin’s theory. First, describe the two key parts that make up Lamarckian evolution. Then, compare and contrast how these two parts relate to the six parts that compose the modern theory of evolution as described by Coyne. Predict why these two parts could have been more acceptable in a historical context over Darwin’s theory of evolution immediately after the publication of The Origin of Species.Finally, using examples from Why Evolution is True and outside research, briefly describe how either part or both parts of Lamarckian evolution can be disproven using this information.

Parasites

In ecology, one of the more fascinating topics is symbiotic relationships. 3 types of symbiotic relationships exist: mutualism, commentialism, and parasitism (1). Mutualistic symbiosis is a type where 2 organism may coexist to better each other's chances of survival, so natural selection would proliferate this type of relationship. For example, the stinging ant/hollow tree relationship Coyne discusses on page 121 is mutualistic. A commentialistic relationship is one where both organisms coexist, but neither receives any benefit (sometimes very little benefit) or harm this existence. The last type of relationship is parasitic; this means that one organism is harmed, while the other benefits. Usually, a parasitic relationship ends with the host organism dying, taking the parasite along with it.

How would killing of the parasite's host be beneficial to the parasite, if it will die as well? Would it not seem logical that genes would be selected that stop the parasite from growing too large or too harmful, to maximize its own life span, and thus its reproductive success?

1: Campbell, P. 1202-1203

Gametes and Evolution in Humans

As we all know, males have sperm and females have eggs. Males have lots of sperm and females have only a couple eggs (156). Why is it that males create so much sperm, while women only have a couple eggs? What is the evolutionary significance? Could it be possible that males are suppose to have multiple partners if they produce so much sperm, and could this be a break for evolution stating that we are suppose to produce as many children as possible? If not, why is it that males create so much because isn't it a waste of energy?

Lucy in the Sky with Diamonds

Creationists vary on how conservative they adhere to the seven (technically six) days of creation as described in the bible. Some creationists believe in microevolution but not macroevolution while Coyne states that "liberal creationists admit that some species could have evolved from others, (but) all creationists draw the line at humans" (193). What seems to be the major barrier in the debate of evolution versus intelligent design is how Homo sapiens came to be so incredibly different from other animals, both physically and mentally. It was a scientific milestone when Johanson discovered "Lucy", a Australopithecus afarensis, in 1974 (200). This nearly complete fossil lived 3.2 million years ago and helped close the gap between modern humans and the missing link between humans and chimpanzees. In which ways did the anatomy of Lucy help close this gap? Explain how Lucy specifically showed how human anatomy is physically traceable to other species. In what other humanoid fossil discoveries helped close the mental gap?

An ever evolving struggle

In Coyne’s harrowing tale of the Asian giant hornet he describes a specific prey adaptation of the Japanese bee in order to combat the hornet upon an invasion of their hive (112). He also gives one other example of a predator/parasite-prey evolutionary relationship with the example of a roundworm infecting an ant in Central America but this point for evolution is rather scarcely covered with examples. What other examples are there of complex and specific predator (or parasite) to prey relationships where the predator is well adapted to hunt its prey and the prey has evolved specific defenses as a reaction to these recurrent attacks? Also is it not also true that, in time, predators would begin to adapt to the strategies used by their prey to fight them off? Provide another example for this case where the predator is adapting alongside its prey.

Divergent Selection

On pages 175-176, Coyne describes what he calls divergent selection, based on geographic barriers in flowering plants, hummingbirds, and bees. He suggests that in one isolated region containing more hummingbirds than bees, flowers may evolve to become better suited to pollination by hummingbirds than bees- and the other way around in a region characterized by more bees. Then he speculates, that over time, should these two types of flowers that have evolved distinctly from one another suddenly be placed in the same location, the geographic barrier having disappeared, and the area containing equal amounts of bees and hummingbirds, then these flowers would each have their own type of pollinator and would not cross pollinate as a result, for they are now two different species. How difficult is it to maintain the ability to mix genes with closely related species (defining species by the definition given on page 172) or at least with those species derived from a common ancestor? Why would different species adapt their reproductive organs to become better suited for their own species rather than a wider range of potential mates? Wouldn't it be to the advantage of the flower placed back in the location described above to be able to be pollinated by both bees and hummingbirds? To what extent would it not? Why don't we see greater potential to mix genes and reproduce across species if sex has evolved as a means for genetic diversity?

Birds Galore

THIS PROMPT IS WRITTEN BY GRACE KAPOV!!!!!!!

On pages 39-47, Coyne talks about how birds evolved from reptiles. He explains reptiles began to have asymmetrical feathers to aid in flight and opposable big toes for perching. Why would these changes be beneficial for the reptiles' survival? From this evolutionary break, birds have evolved into a variety of different species due to the demands of their respective environments. According to www.birdlist.org, there are at lease 10,031 species of birds on the planet! Choose a specie of bird and explain in detail how it has evolved from its distant ancestor to fit its environment. Are there any ways in which this specie of bird does not fit its environment? Explain.

Revenge of the Ignored!

Throughout his book, Jerry Coyne provides evidence of evolution in bacteria, plants, and animals, but largely, if not completely, leaves out evidence of evolution in archaeans, protists, and fungi. Archaeans may even be the best example for natural selection, living in several different types of environments that are lethal to almost any other organism on the face of the planet. What kind of evidence for natural selection occurs in archaeans? In fungi? Protists? Why might Jerry Coyne have seemingly ignored these three kingdoms, considering that they are both so well-adapted to the environments in which they live? How might these kingdoms be utilized in an argument for evolution?

Unnecessary adaptations?

The Tardigrade (or water bear) is a microscopic animal typically between 1.5 and .1mm. Despite their small size water bears are some of the most durable animals. They are able to live at temperatures as low as -273 degrees Celsius (thats 1 Kelvin almost absolute zero) and as high as 151 degrees Celsius (a 1000 times more radiation than humans can handle). Additionally water bears have survived 10 days in the space before coming back to earth and laying eggs hatching normal offspring making them the only known animals to have survived in a vacuum. Though impressive these adaptations do not seem to serve a practical purpose. There are no environments on earth that are found to be near absolute zero or comparable to space, so why do you think these adaptations evolved? More importantly how do you think these adaptations came about? What sort of conditions could lead to such extreme survival skills?

Why Do Fish Still Exist?

Coyne frequently references organisms evolving to better their chances of survival. A prime example of this is the evolution of fish into reptiles and reptiles into mammals, but if environmental stress variables forced water-based species to evolve to a more land-based life, why do fish even exist anymore? Wouldn't they have all evolved and followed a similar path of evolution as their reptilian relatives? In addition, reptiles coexist with fish in many areas where environmental stress variables once forced fish to evolve into reptiles to survive. If, going by the definition of evolution, a species' inability to evolve will lead to its death, then why is it that fish managed to survive stress variables in the same location that some of them actually evolved into reptiles?

Tuesday, April 6, 2010

Sensory-Bias Model

The sensory-bias model, as Coyne outlines on pages 166-167, suggests that sexual dimorphisms evolved as a result of biases in the female nervous system – whether it be like the theoretical example that he shared with the mutant male's red coloration on his breast stimulating the female's visual preference for red color, or simply, a stimulation of the nervous system as a result of more extravagant displays. Consider why these preferences are so nonspecific; why might it be 'better' to recognize the red coloration rather than a certain chemical secretion? And to what extent do these animals have to recognize and 'appreciate' different behaviors or physical adaptations (such as shiny fur or long mating calls)? Why might females have adaptations to be able to process these different adaptations on males? Why spend more energy, for instance, developing eye spots to visually choose males if that's their only purpose? Is it worth it?

What About the Females? (Sexual Selection)

Coyne states, in passing, while offering examples about male competition and sexual selection, that “Females, who don't have to fight, are presumably close to their optimal weight for reproduction” (150). It is shown that “direct competition between males” and “female choosiness” (148) are apparent among organisms, and a key to sexual selection. As a result, it is arguable that males would tend to change more than females in order to increase their fitness and opportunity to produce offspring. Coyne already addresses the issue of the tradeoffs between adaptations benefitting survival and those aiding in reproduction in males; though there are many seemingly energy intensive/wasteful traits that males have to “win over the females”, they tend not to become so elaborate that these adaptations would result in the death of the organism before they even have a chance to pass of their genes to their offspring. However, in females, this becomes more of a question; since they tend not to have to fight for males, and do the choosing of their potential male mates, how is it that the females are able to adapt to become more suitable for reproduction? It would seem as if the males would tend to undergo selection “faster” than females do. Also, how far does this go? A deer's antlers can only get so large; with males having the largest, most robust antlers winning more jousting contests and impregnating more females. With this type of selection, wouldn't it be reasonable to presume that the deer's antlers would approach a certain maximum size (consider the tradeoff with survival and reproduction – at some point, the antlers would hinder their ability to survive). Speculate as to what happens in this situation.

Allo + polyploidy = Allopolyploidy

Jerry Coyne describes allopolyploid speciation as speciation that occurs due to the “hybridization of two different species that live in the same area” (Coyne 186). It occurs in plant species with regularity, producing a new species that contains the added number of chromosomes of the parents that produced it. It also happens in animal species; however, it occurs far more rarely. What do plants have that animals don’t that allow them to develop allopolyploid species? If an animal were to develop allopolyploidally, how could it develop a new species, being that no other examples of the allopolyploid animal would be able to mate with the original organism? Since plants develop allopolyploidally relatively often, what might the reasons be that plants with thousands of chromosomes don’t exist, given that one allopolyploid species could mate with another?

Bacteria: A Gift to Science or a Curse?

Bacteria have the ability to adapt to new environments relatively rapidly because adaptations occur over many generations, but some bacteria replicate as often as every 20 minutes. As a result, within just a few days, bacteria can go through hundreds, if not thousands, of generations. This makes them prime candidates to undergo lab simulated evolution to help us get a better understanding of evolution and survival. On page 128, Coyne describes how bacteria can quickly adapt to simple hazardous environments. Quite surprisingly, he also goes on to show how they can adapt to more complex situations in the example of Barry Hall's experiment with E. coli and lactose. Explain Dr. Hall's experiment and why it is so significant in the debate of evolution versus intelligent design. Provide another example of a species which was introduced into a similar situation and modified its current genes to survive. However, this rapid adaptation to bacteria has costly effects such as their rapid immunization to antibiotics. Expand Coyne's statement of simple adaptations of bacteria in labs to explain how bacteria become immune. Give an example of a bacteria that, through adaptations, has become immune. Does the benefit of medicine outweigh the threat of evolving a more deadly bacteria?

Man's origin

Many people scrutinize the idea that humans evolved from ancestors of apes. On pages 193-194 Coyne speaks of several scientists who were timid to share their findings with the world and contradict the social norm. Explain the evidence that gave these men, like Charles Darwin, the confidence to provoke the world. Explain how closely humans are related to apes, physical traits, behavior, etc. Predict what factors may have caused the ancestors of man and ape to evolve into humans. What different factors would have caused that ancestor to evolve into the present day ape?

Why [Recreational] Sex?

Sex is a very costly process for females. On page 157, Jerry Coyne explains that while the male investment in sex is cheap, "for females it costs much more: the production of large, nutrient rich eggs and often a huge expenditure of energy and time". Thus, females are often very picky about choosing a mate. However, in some organisms, this is not the case. Among bonobos and dolphins for example, sex is a very common occurrence, engaging in 'intimate relations' very frequently. Dolphins become sexually active even before they become sexually mature, and bonobo sexual behavior has no regard for gender or age. How could this sort of behavior have evolved among these organisms? How can females afford to take the risk of investing in so many potential offspring?

Has Evolution Reversed?

When I hear or read the term evolution I immediately connect it with a song by a rather unheard of Punk-Rock band called NOFX, the song is titled “The Idiots Are Taking Over” (Lyrics: http://www.lyricsondemand.com/n/nofxlyrics/idiotsaretakingoverlyrics.html and please excuse the expletives) but the song itself deals with the political ramifications of a possible reversal of evolution in human populations, the band argues that since the Industrial Revolution the fittest of our species have no longer been the only survivors and not only that but the unfit are producing more offspring and further propagating their “worse” genes. Their argument brings up a good question: Has humanity come to a point where natural selection no longer applies, where random mutations that cause lower fitness in a human actually get spread throughout the gene pool? Support your answer, and if so: What will the potential effects be on humanity as a species in the future?

The Perfect Design

Animals seem to be amazingly designed in order to fit their needs. Jerry Coyne on page 118-119 explains the elaborate design of the woodpecker. The woodpecker hammers its head into trees creating holes at “a speed that can crumble your car”. With such a force the bird should be hurting itself, but because its skull is “specially shaped with extra bone” and how it’s “beak rests on a cushion of cartilage” it is able to collect food unfazed. What are other examples of animals with complex design? How do their adaptations help them survive in their environment? Explain how early naturalists used complex design to support their argument. How do evolutionists refute their claim?

Monday, April 5, 2010

Cultural (R)evolution

During the course of human evolution, there have been two types of evolution that have gone on: physical evolution, which is the topic most discussed in Why Evolution is True, but also cultural evolution. On page 215, Coyne talks about “gene-culture coëvolution”, which is to say that our culture is influencing the way that our genes propagate themselves. Generally, gene-culture coëvolution results from sexual selection, such as the princess who chooses a certain body type for her mate, setting a fashion for everyone else. Is it possible that, due to differing views of beauty, and supposing that humans continue to evolve, separate cultures may evolve independently? If that were to happen long enough for speciation to occur, what might the ramifications be on international and interpersonal relations? In addition, humans have developed genocide and war. Is war a possible deëvolution mechanism, due to the fact that the healthiest and strongest physical specimens are sent to die? If so, why doesn’t culture evolve for the same purpose as physical characteristics, to produce an organism with the highest likelihood of reproduction? If not, why not?

Do Atavisms have a Purpose?

Coyne discusses atavisms, which is "an anomaly that looks like the reappearance of an ancestral trait" (64-55). He continues by providing examples, such as the legs of whales. Why do you think atavisms occur? Is it because of genetics, evolutionary pressure, or for some other reason? Provide an example of such an occurrence that has been cited or studied that supports your reasoning for why atavisms occur. Also, do you think that atavisms can be evidence of devolution? Provide examples, if any exist, and explain how they apply. Finally, consider atavisms in the context of the mechanism of evolution: natural selection. Is it selectively advantageous for organisms to be able to have atavisms and why?

Convergent Evolution

On page 92, Coyne states that convergent evolution explains why different types of animals have simular forms in different places; "Convergent evolution demonstrates three parts of evolutionary theory working together: common ancestry, speciation, and natural selection" (94). Explain how these elements support why fundamentally different animals on different continents are so similar. Try to use specific examples. How does continental drift contribute to convergent evolution? How would evolution be different if we never had a separation of continents?

Genes and Evolution

Mr. Coyne states that the genes of a chimp compared to us humans are about a 1.5 percent difference. This sounds that we are very closely related to chimps, but later Coyne saids that these differences could completely alter a protein sequence (210-211). This would show that the sequences are hugely different. Could this be one flaw in how he presents his case for evolution? If our gene codes are different, how can we be descendants of these species? Every creature has a set amount of genes that separates it from another creature. What boundaries must be met in order to recognize that species are different from one another?

Continental Biogeography: Before and After

Coyne tells the story of the Norwegian explorer Roald Amundsen who froze to death with his party in 1919 after “their unsuccessful attempt to be the first at the South Pole” (99). He continues to compliment their recognition of the Glossopteris fossils they found. In addition, Coyne provides a map of the supercontinent that shaped the world during the Permian period (98). First, describe how the theory of biogeography applies to evolution in the context of continents. Then, explain how the example of the Glossopteris fossils supports this theory. Predict why evolutionary pressures affected the Glossopteris fossils more than they did to other animals that currently live in Antarctica. Finally, consider the modern African continent, which is slowly being pulled away from Europe and Asia due to plate tectonics; predict the region of Africa this will most strongly affect evolution in and how?

What's the deal with sex?

Many organisms reproduce by means of sex. They find a companion, or the opposite sex, and mate. However, there are also female organisms that can reproduce "parthenogenetically" (155). This means that the female just produces eggs that can fully develop without being fertilized. Parthenogenetic reproduction is much less energy intensive because there is no need to find a mate and would also cause to a decreased need of ornate (and possibly detrimental) physical characteristics in sexual dimorphism. And females would be able to produce twice as many parthenogenetic offspring because all would be female and able to reproduce alone. But we know that sex is the most common means of reproduction. Why is this? If parthenogenetic reproduction costs less energy, why don't parthenogenetic organisms outcompete sexually reproducing organisms? A rise in parthenogenetic reproduction would make males obsolete. What would happen if this happens?

Natural Selection and Individual Fitness

As Coyne describes on pages 121-122, when invading lions displace resident males of a pride, they slaughter all the unweaned cubs so that the females will come back into estrus (since they are not nursing the cubs anymore, they will be ready to conceive again). By the theory of evolution, as Coyne has outlined throughout the book, this act benefits the fitness of the individual, by increasing the invading lions' reproductive output, though at the expense of the species as a whole, thus increasing the likelihood of extinction. For this 'gene causing infanticide' to have been acted upon by natural selection, it must first have resulted from a random, genetic mutation. Speculate as to why this gene causing infanticide may have been selected to recur throughout the population of lions, taking into consideration any issues of resources and energy on the part of the females in nursing their cubs, as well as the advantages for the lions' mode of development; in other words, how much do lions nurse their young, and what limitations or burden does this place on the female lions in their inability to conceive while nursing their unweaned cubs? Why would it not be feasible for female lions to have had natural selection act upon them to shut off the gene that prevents them from going into heat while nursing? (Perhaps it is not in the interest of the invading males individual fitness to allow the old cubs to live, but it might increase the fitness of the females to do so.)

Humans: More than just social apes?

Homo sapiens, like all other modern species, make up a branch of the evolutionary tree that can goes back to the first living organism to exist. However, humans stand apart from all other species; human intelligence allows for social achievements. This is a major argument of the intelligent design proponents. Propose some ideas on how human social behavior is selectively adaptive. On page 225, Coyne points out that we are simply "evolved mammals, (therefore) there will be nothing to prevent us from acting like beasts". He goes on to relate this to the incident at Columbine. Explain some modern human behavior and current theories on where the behavior comes from such as "The Selfish Gene" and "The Cooperative Gene" (226). In which ways can modern human behavior be traced back to the basic behaviors we discussed in Chapter 51 of Campbell? And are these behaviors even genetically based adaptations or something else that have arisen in recent history?

Remnants and Creationism

Vestigal traits are discussed starting on page 56 and explained as a trait that "no longer performs the function for which it evolved" (page 58). The example of an ostrich is given because it does not use its wings to fly however it does use them to balance when running and as a warning to enemies. Therefore how is it decided that the wings are a vestigal trait of the ostrich since they are indeed performing a function? How is it decided that the wings did not evolve to help balance the ostrich instead of flying? What are the criteria for a vestigal trait? What are the criteria to classify a trait as an atavism?Then discuss how creationism discards vestigal traits as support for evolution.