Is the human hand evolved for punching?

By Lindsay Whitehurst

Jan 08 2013

http://www.sltrib.com/sltrib/news/55551424-78/carrier-fist-human-fists.html.csp

summary:

The fist could have shaped the evolution of the hand by giving early man an edge in combat.With long thumbs and shorter fingers and palms, humans are the only primates known to be able to form a fist. In a study published in the Journal of Experimental Biology, David Carrier and co-author Michael Morgan showed that the fist supports and protects the delicate bones, muscles and ligaments of the hand while still packing as much hitting power as an open palm. The study presents a controversial theory that the human hand may have developed for punching rather than solely to give people more manual dexterity after they descended from the trees. And while increased dexterity explains why the thumb became longer,current theories don’t fully explain why the fingers and palms also shortened. Natural selection favoring clenched fists could.

This article includes both evolution and natural selection and is thus connected to our unit.

Could Humans Have Evolved From Dolphins?

http://io9.com/5899331/humans-could-have-evolved-from-dolphins

Summary:
As the author delves into the question of human evolution, it is clear that he is aware of the very commonly accepted idea that humans and apes branched off from a common ancestor millions of years ago, thus forming two separate species. As he acknowledges this, he also pokes fun at the very thought that humans evolved from "aquatic apes", an idea used to explain the strange differences found between primates and humans. Many species at one point or another, when the going was rough on land, would find themselves taking refuge in the vastness of the oceans. The author argues that it is likely that humans in fact evolved partially in the oceans, as others had done, which would explain many peculiar human traits. Humans develop much less hair on the body compared to our primate relatives. Could this  in fact be an adaptation pointing to aquatic life for early human beings? The less hair, the more streamline the body. Another adaptation that has astounded scientists is the partial webbing between each individual finger and toe of a human. With this webbing, early humans could move more powerfully and swiftly through water. Lastly, the fact that new born humans can easily be taught to swim and will naturally hold their breath under water points to the idea of ancient child birth that took place in the water. The author uses these points to show that it is more likely that humans evolved partially on land and partially in the water, rather than completely from an aquatic ancestor, such as an "aquatic ape." He states that there is just not enough evidence that humans could have completely evolved from an aquatic species, clearly trying to put the misleading theory to rest. Many species have entered the waters to return a completely new species, adapted to its new environment. The author suggests that it is likely that at one point humans, having branched off from their primate cousins, spent time in or around water, explaining adaptations found in humans but not in primates. Having said this, the author explains that it is completely unlikely that humans branch off from aquatic mammals.

Connections:
This article directly connects to our unit on evolution as it discusses the ideas of differentiating theories behind human evolution. The author points out the importance of the relationship between environment and evolution, stating that the likeliness humans spent time in the ocean is very high, so the likeliness that some adaptations we see today would come from this time spent in the ocean is very high as well.    

Embryonic Sharks Freeze to Avoid Detection

Jane J. Lee

January 9, 2013

http://news.nationalgeographic.com/news/2013/130109-shark-embryo-freeze-predator-animals-science/

Summary:

Recent studies show that embryonic sharks may freeze like a possum when they detect danger nearby. Sharks have the ability, using pores called the ampullae of Lorenzini, to sense the electrical fields that every living organism gives off. Ryan Kempster, a student at the University of Western Australia, conducted a study using 11 brownbanded bamboo shark embryos. He then simulated a weak electrical field that would represent the predator and recorded the reactions of the sharks. All the sharks stopped moving once they detected the electrical field. Normally, they would beat their tails back and forth so seawater could enter the embryo. However, this generates an odor as well as small currents. However, the sharks became used to the  electrical field after the exact same signal was present again. 

Relevance:

When we talked about evolution in class, Darwin proposed the idea of natural selection and survival of the fittest. This trait of "playing possum" is a beneficial trait and would give sharks that have it an edge over the ones that do not. Therefore, the sharks the have it are more likely to survive and pass their genes on to offspring, which is the idea of natural selection. Additionally, the sharks adapt to the signals after they have felt it once. 

Jennifer Kay
December 6, 2012, from Yahoo! News
http://news.yahoo.com/gene-altered-mosquitoes-could-used-vs-dengue-101105808.html


summary:
In Key West, Florida, mosquito control officials are hoping to attempt a test release of genetically modified mosquitoes, to stop the spread of dengue fever in the area. Targeting the species Aedes aegypti specifically, as it can carry dengue fever, the scientists from the British company Oxitec caused the mosquitoes, all non-biting males, to carry a birth defect that would kill their offspring before maturing. Ideally, the males when released would mate with females, but then their offspring would all die due to the birth defect, and the population of Aedes aegypti in Key West would collapse in a few generations. This way, the control officials would not have to use pesticides. Supporters state that the local ecosystem would not be affected, as the species is not native and does not function as an important food source. However, others worry about unforeseen effects of the artificially inserted genes on humans or the ecosystem, and insist that the company at least spend more time testing the effectiveness of the measure before implementing it. As the company already has the green light from governments in other countries, a suggestion is that they wait to see whether the mosquitoes work as intended there before bringing them into Florida.

connection:
This article mainly connects to what we have learned about genetically modified organisms, which in this case are the mosquitoes. The article demonstrates some of the controversy caused by the release of GMOs into the ecosystem. Also, the article relates to gene insertion, as the genes causing the birth defect were inserted into the male mosquitoes by scientists.

New Obesity, Type 2 Diabetes Gene Identified

Catharine Paddock PhD, Medical News Today
10 January, 2013
Based on research published online Jan. 6 2013 in Nature Medicine
http://www.medicalnewstoday.com/articles/254817.php


Summary:
A team of researchers have found a gene that has an important role when involving insulin production as well as obesity, increasing the risk of developing type 2 diabetes and heart disease. Obesity is what occurs when the process that regulates food absorption and energy production "mess up", and the result is the excess storage of fat. Insulin resistance is a risk factor for type 2 because it is the less effective use of insulin (which regulates the amount of sugar in the body) compared to normal people.
From the study, the team found out from testing mice that if the gene TRIP-Br2 was "knocked out", then the mice would stop becoming obese and developing insulin resistance. The gene regulates the storage of fat and energy use. The team later on looked at the fat storage cells for these mice, they found that there was a high level of the conversion of fat into lipids to give the body energy. Based on the studies of other people, the researchers concluded that the gene could be a target for gene therapy for treating obesity and other similar conditions in humans.
This discovery of an "obesity gene" has followed those happening before, in 2010 and 2011. In 2010, researchers found there to be a variant of the FTO gene that causes Americans to gain weight and be a risk of obesity as well as the loss of brain tissue. This variant occurs in over one third of Americans. Then in 2011, researchers suggested that a gene called KLF 14 was linked to obesity, diabetes, and cholesterol. The researchers had found a "master regulator gene" that controlled be behavior of other genes existing inside of fat cells.

Connection:
This article relates to what we were learning in molecular genetics. In that unit, we learned about gene therapy, and we also learned how gene therapy can be very helpful for various diseases. This article is saying that this new gene was found out to have been affecting obesity and insulin production, so gene therapy in the future could target this gene as a solution to diabetes and similar problems. We also learned about adding and deleting genes/ sections. This relates to the article because the TRIP-Br2 gene in the mice were "knocked out" so that the study would be effective. There was also a small paragraph about diabetes (insulin production in bacteria), so this could prove to be an alternative to that.

Scientists Grow 56,000 Generations of E. coli to Study Evolution

Lee Dye

Published September 26, 2012 by ABCNews

http://abcnews.go.com/Technology/evolution-action-michigan-state-scientists-grow-coli-56000/story?id=17329160#.UOtwh2_7K5U

Summary

In 1988, Richard Lenski, a professor of microbiology and molecular genetics at Michigan State, began an experiment to study evolution. Because studying evolution requires many generations, scientists have to use organisms that reproduce quickly. So, for the past 25 years, Lenski and his team have been studying the bacteria E. coli. They have 12 populations of E. coli that create about 7 generations in 24 hours, and now have over 56,000 generations of E. coli. They take samples periodically and freeze them, providing a record of all the evolutionary changes from the beginning of the experiment.

E. coli has a special trait: they cannot eat citrate in the presence of oxygen. However, at about generation 33,000, the scientists noticed a large change. In one of the 12 populations, the E. coli began to eat the citrate and that population grew rapidly with the addition of the new nutrient. The scientists studied the frozen records in order to find the cause of the change by sequencing the genomes. They discovered that there were three mutations that occurred before the E. coli could finally eat the citrate. The first took place at about generation 31,000, but it still took two more mutations before the bacteria began to really consume the new nutrient. The E. coli had evolved to consume a food source that gave them an advantage over the other populations, as shown by their rapid growth. Previously, E. coli did not eat citrate. This change showed that complex traits can evolve quickly, and that species are always changing.

Connection

This article connects to our units on evolution, genetics, and heredity. The E. coli experiment showed how the bacteria evolved. They began to eat citrate, which is a trait different from other E. coli. Natural selection would have selected for the individuals with the mutation; they were more suited to the environment because they could take in more nutrients. Also, it connects to genetics because the change was caused by a beneficial mutation to the bacteria’s DNA. Lastly, it relates to heredity because the new trait was passed down to the offspring. 

Wrinkled Fingers are a Evolutionary Advantage

http://www.news.com.au/lifestyle/home-garden/why-do-fingers-wrinkle-in-water/story-fneuz5ql-1226550179190

Summary: Scientists are now researching the possibility that the fact that our fingers wrinkle up when they get wet could be an evolutionary advantage. Wrinkled fingers make it easier to pick up wet objects which could have allowed some humans to easily pick up food that was located in the water. They experimented with people who had submerged their hands in warm water for thirty minutes and those whose hands were completely dry. They found that wrinkly fingers did not help to pick up dry objects, wetter objects could be picked up much faster.

Connection: Our fingers wrinkling in water is an evolutionary change. It relates well to the evolution unit and easily shows how something seemly useless can be used in many different ways. Scientists have not mentioned where or when they think this evolution occurred but it has become a trait of all humans.

Bus-Size Sea Monster Found

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Brian Handwerk, National Geographic News

Published January 7, 2013

http://news.nationalgeographic.com/news/2013/01/130107-sea-monster-new-species-paleontology-science-nevada/?source=hp_dl2_news_sea_monster_discovered20130108

Summery:

A new type of sea monster was found in Nevada. It was evolved to eat prey it's own size. While this might not seem that special if you think about dragonflies and the like, this Triassic Monster was 28 ft long. That's about the size of a bus! It is called Thalattoarchon It was part of the ichthyosaur family, whose members look a lot like modern dolphins but are fish. The skeleton was found in 1998, but only the body was found. As the digging crew was leaving on the last day, they noticed the monster's teeth. After 10 or so years the crew came back to excavate the rest of the fossil. The skull that was found was massive and it was filled with large teeth. The teeth were found to be capable of tearing apart prey the size of the of itself. Sea predators capable of doing this today include orcas and great white sharks. Also, the discovery of Thalattoarchon shows how the earth is capable of recovering from mass extinctions. Since this creature existed only eight million years after the largest mass extinction in the history of the earth, the Permian extinction, it is possible to tell that the oceanic ecosystem became very stable in a very short time. The appearance of such a large predator can only mean that the ecosystem evolved enough to support four or five tropic levels. 

Connection:

This article connects to evolution. The Thalattoarchon must have evolved in such a way that it was able to support it's size. Perhaps it's powerful teeth and jaws let it hunt in the most efficient method as to use as little energy. It also connects to ecosystem stability, in the way that the appearance of Thalattoarchon, shows a stable ecosystem. Perhaps the reasons behind the stabilization of the Triassic ecosystem, if found, could help to rebuild our own damaged ecosystems.

Snakehead Fish Destroying Ecosytems in U.S.

R. Kayne
(No date of publication given)
http://www.wisegeek.com/what-is-a-snakehead-fish.htm

Summary: Recent studies show that a new species of fish introduced into America's ecosystems is dominating the food chain in the water (and sometimes on land) and rapidly increasing in population size. These fish are called snakeheads. Snakeheads look a lot like eels with a head that looks like a snake. These fish can also breath air and can live on land for a short period of time. Snakeheads are huge predators and eat small mammals and fish its size. It has been said that in Asia a snakehead even ate a human. These fish came from Africa and Asia and have been supposedly introduced to U.S. waters by being freed from food markets. Snakeheads are starting to dominate U.S. waters because they are extremly adaptable and reproduce rapidly. Also, snakeheads don't have any natural predators in the U.S. so the population easily grows. This invasive species threatens to wipe out other fish populations in the U.S. and needs to be controlled. Some forms of control include: fishing competitions to catch the most snakeheads and cooking contests involving the snakeheads.

Connection: Snakeheads are a perfect of an invasive species which has been released into the U.S. and has terrorized its surroundings creating an imbalance in the ecosystem. The snakeheads also relate to our talk of evolution because they adapt from generation to generation to survive in all different types of water in America. This species is like any other invasive species, perhaps Purple Loosestrife, which outcompetes other plants and increases in population rapidly.

Pets Vital to Human Evolution

Larry O'Hanlon 
Aug 10, 2010 
http://news.discovery.com/animals/pets-humans-evolution.html

Summary: A recent theory published by paleoanthropologist Pat Shipman of Penn State University suggests that animals play an important role in human evolution. Shipman thinks that the unique human habit of living with animals has made human evolved in terms of human tool-making and language. Living with pets since 2.6 million years ago switched human's diet from mostly vegetarian to rich in meat. According to Shipman, human make the evolution process faster by creating equipments to kill and hunt, which finally enabled human to compete with other top predators like wolves and tigers. Because managing and tracking animals requires technology and knowledge, language has evolved too. Meanwhile, there are also genetic mutations in animals because human bred for certain traits, like a cow that gives more milk. This evolution influence works for both human and the animals. Other paleoanthropologists has found this theory plausible.

Connection: This article connects to the evolution unit. It introduces a new theory about evolution and briefly talks about artificial selection. The article also gives an example of the beneficial influences of evolutions. Human select the dogs that have more genes for compassion to hunt with; on the other hand, human reproduce more offsprings, with dogs' help in hunting and securing their  homes. 

Human Blood Types Have Deep Evolutionary Roots

Rachel Ehrenberg
Oct 23, 2012
http://www.sciencenews.org/view/generic/id/345987/description/Human_blood_types_have_deep_evolutionary_roots

Summary:
According to new research led by Laure Ségural and colleagues (University of Chicago), A, B, and O types of the human blood have evolved at least 20 million years ago in the common ancestor of humans and other primates. The A, B, and O versions of the blood type gene differ slightly, and there exists two ideas about their evolution: first, the A version existed long ago, and the B and/or O types then popped up in several species, and second, all species inherited types A and B from a common ancestor. Ségural's team compared the DNA stretches of humans, chimpanzees, gorillas, bonobos, orangutans, and a few species of monkeys. In their comparison, they found that sections in the A version of human DNA more closely matched the A version of gibbons than the human B version, implying that the A and B groups existed more than 20 million years ago. A suspected reason why evolution favored different blood types is how people with different blood types are more or less susceptible to different pathogens. For example, type O people are more susceptible to cholera and plague, and type A people are more prone to smallpox and blood clots. This diversity could have offered protection over whatever diseases developed.

Connection:
This article connects to our unit on evolution as well as our unit on molecular genetics. It connects to evolution because the article discusses the evolution of blood types in humans; types A, B, and O evolved around 20 million years ago. It also connects to adaptation because different types may have had their benefits, which caused adaptation to maintain diversity. This article connects to molecular genetics because it uses the sequencing of DNA to find the similar blood type DNA sequences between humans, chimpanzees, monkeys, etc. 

Evolution in Action: Lizard Moving From Eggs to Live Birth

By Brian Handwerk, National Geographic
September 1, 2010
http://news.nationalgeographic.com/news/2010/09/100901-science-animals-evolution-australia-lizard-skink-live-birth-eggs/

Summary
This article provides an interesting insight into evolutionary changes in organisms as a consequence of adaptation. The Australian yellow-bellied, three-toed skink has provided the scientific community with a demonstration of how it adapts and evolves. The skinks that live in the warmer coastal lowlands of New South Wales lay eggs as their method of reproduction. However, majority of the same species of skinks that live in the cooler higher mountains, have abandoned egg-laying for live birth. Evolutionary records show that nearly a hundred reptile lineages have made the switch from laying eggs to giving live birth in the past but now only 20 percent of reptiles, specifically snakes and lizards, give birth to live young only. This a rare opportunity for scientists to study evolutionary changes in action and observe the skinks' transition of birthing methods. This can be done by studying the differences among populations that are in the different stages of this process and seeing the transition that follows it. A question that is raised in this evolutionary process is how the babies get nourishment before birth. In mammals, the fetus get their nourishment from the specialized placenta which is connected to the uterus so that they can take up oxygen and nutrients from the mother's blood. For eggs, the embryo gets nourishment from the yolk and calcium is absorbed from the shell. Organisms that use this mix of birthing styles, form the eggs but keep them inside the body until the last stages of the embryonic development. For this method, the shell formed is thin so that the embryo can breathe and it then reduces to a thin membrane in later stages. However, the shells are so thin that it is not an adequate source of calcium. These embryos get the calcium from the uterus.


Connection
This connects to climate change because laid eggs are more vulnerable to extreme weather and so skinks in cooler mountain climates find it easier to protect its young by keeping it inside their body for a longer time than the skinks that live in warmer climates. Another connection it makes to evolution is that we can observe how easy it is for skinks to switch from one birthing method to another because of the affect of climate change and possibly even predators. What makes this reptile's adaptation to giving live birth so successful is that in order to prevent the embryo from resulting in calcium defeciency, the skink's uterus secretes calcium that forms into the embryo. Scientists refer to this, as the early stages of the evolution of a placenta in reptiles.

The "Grave Robber" Identification of Fossil Remains solves a 121 year old 

Paleontological Enigma

MARSHALL GRANT

http://www.sciencedaily.com/releases/2012/11/121119151318.htm

       An international group of researchers have recently indentified and discovered more about the relationship of Necrolestes patagonesis which means "Grave Robber". The Grave Robber is an ancient ancestral mammal which lives most of its life buried underground like that of the mole. A controversial fossil mammal from South America held the key to a 121 year old mystery. The recent fossil discovery and comparative analysis of the skeletal structure allowed for the team of researchers to correctly date and place the 16 million-year old organism into the fossil record.

     How might this be important? The Grave Robber is interesting due to its structure of an upturned snout and large limb for digging out dirt. The find however unexpectantly dates the endpoint for the fossils evolutionary liniage by a sum of 45 million years. This means that families of mammals were able to survive the extinction event that ended the Age of Dinosaurs

    This amazing realization is another example of a species that lasted longer than expected called the Lazarus Effect. Much of what we knew of this organism was a mystery, but could be assumed as a mammal. Recent studies of the ear region led to another hypothesis to the Grave Robber being a marsupial. More studies on the cranial structure led to another finding that was on a completely unexpected branch of the evolutionary tree which was thought to die out 45 million years ago. The strange and varying anatomy of the creature leads scientists into classifying it into several groups of taxonomy  making it harder to narrow down evolutionary wise.

     Very similar was another organism called Cronopio, having similar homologous structures in and around the same time period. They believed it was the vast burrowing capabilities of the Grave Robber to survive any blast or impact made during the extinction event and allowed it to continually prosper.

     More teams are looking into the near future of exploring geological advantages and analyzing skeletal structure more to properly classify this mysterious organism that survived the extinction event.

Connection:
This connects to evolution and natural selections because a mammal like creature was able to adapt and function so that it could survive a mass extinction event and continue to prosper in an environment. It is interesting to see how the skeletal structures of the Grave Robber fits into many taxonomic groups and cannot be narrowed down after one study. The use of skull comparison like what we have done in class is useful to the classification and future study of this organism. To more study the fossil record and change the way mammals and creatures alike evolved from the extinction period and on is fascinating and connects to what we learn today.

QUESTIONS IN THE COMMENT SECTION...............THIS IS COOL

First Fossil Bird With Teeth Specialized for Tough Diet

Benjamin Stern
1/7/13
http://www.sciencedaily.com/releases/2013/01/130107082602.htm

Summary: Darwin's finches showed clear adaptation by beak type, reflecting different food sources.  Birds that live in modern times have beaks to chew up their food, but a new fossil has recently been discovered that possesses  specialized teeth to manipulate its food, suggesting it had a durophagous diet, which means that the species was capable of eating prey with tough exoskeletons.  This is a new type of diversity within birds previously unknown by researchers.  The species of birds, called Sulcavis Geeorum lived roughly 125 million years ago near China, meaning it lived in the Cretaceous period among dinosaurs.  This species likely evolved from early dinosaurs, but later died out.  It is unclear why this relatively advanced species of birds died out, but it likely had to do with changes in food sources.  No other birds possessed any dental ornamentations, yet this species had many; preserved ridges, stritations, and serrated edges.

Connection: This clearly connects to evolution, the bird species evolved complex traits to adapt to better survive.  Their adaptations, specialized teeth, enabled them to eat animals they wouldn't normally be able to chew.  More specifically, this is an example of evolution extremely similar to Darwin's finches.  Both involved populations of birds that evolved to be able to eat specific foods.

Milk of Human Kindness Also Found in Bonobos

Sindya N. Bhanoo
January 7, 2013
http://www.nytimes.com/2013/01/08/science/the-unexpected-altruism-of-bonobos.html?ref=science&_r=0


Summary: Evolutionary anthropologists Brian Hare and Jingzhai Tan from Duke University have been researching the behavior of Bonobos. Their observations suggest that they may have found the origin of altruism in human, the behavior of an animal that benefits others of its kind but not itself. In one experiment, bonobos were given food and then given the chance to release a stranger or group mate from other rooms. The bonobos shared the food with the strangers they released. This trait is not shown in chimpanzees who are the closest relatives to humans. This evidence creates a new scenario in which chimps, human, and bonobos had a common ancestor with this trait.





Connection: This article connects to our current unit on evolution. Just like how we did the online activity to find the closest relative to the whale through anatomy and molecular biology, these evolutionary anthropologists are using the same type of methods but finding similarities based on the behavior of these different species. Just like how we found the closest ancestor of the whale by finding homologous structures between the whale and other organisms, the same sort of method is being applied to the bonobos. Because they express altruism like humans, but the chimpanzees do not, Tan and Hare concluded that humans chimpanzees, and bonobos share a common ancestor.

Plants in California

California is one of the most diverse places on earth in terms of plant species.Many plants which would have gone extinct elsewhere, thrive in the climate of California. Over 5,500 plant species live in California and over 40% are endemic or occur nowhere else on earth. Previously it was believed that a high speciation rate, or the rate at which new species evolve from old species.This assumption was derived from the high amount of relatively young species in California. When a new species evolves, the species from which it evolved usually dies. Professor Kathleen Kay of University of California-Santa Cruz and Lesley Lancaster of Lund University in Sweden made evolutionary trees of 16 different plant evolution using DNA sequencing. With this data they can accurately estimate the extinction and speciation rates of the certain plants. They speculate that the high diversity is based on the perfect and varying conditions, which allow plants to not become extinct. The study differs with another famous study in the 1970's entitled "Origin and relationships of the California flora." Another cause of speculation is that the climate is like the Mediterranean and it is one of the few non-tropical regions to never be glaciated over or become a desert. 

This connects to Evolution in several ways.The researchers used cladograms to make evolutionary trees, they also used dna sequencing which has to do with molecular genetics. They used fossil records to piece together the evolutionary tree. Also natural selection plays into my article because normally when a new plant species evolves from an old plant species, the old specie becomes extinct, however this is not the case in california.

Are Humans Still Evolving?

Jack Foster P3

Darwin published his book The Origin of Species in 1859 and ever since then it has been a well accepted fact that natural selection of animals causes certain species to evolve and adapt based on their environment. Many people know and understand this but are humans exempt from evolving? Have in a way beaten the system where are mortality rate has skyrocketed so high that even those with non ideal genes can still survive and live despite not being able to many centuries ago? Although in short the answer is yes we are still changing one example is how many years ago almost all humans would be lactose intolerant after infancy. Now a days it is the opposite being that the majority of people can digest lactose. Many populations used dairy farming as a main source of nutrients so over time people have apapted and changed due to their environment. Also many medical and technological advances have let us saved the lives of those that would've been deemed lost in the past. This trumps natural selection and lets everyone get a fair share of life rather than just the most fit. Although this doesn't completely cancel out natural selection as many dominant traits that are deadly can destroy a population because it i s very likely that it will be passed on but those who are homozygous recessive will still be able to thrive. Many have come to believe that humans will not adapt based on how the world changes but rather how we change the world. There are no other species exactly like humans that have the power to change the earth as we know it. This could either lead to our own demise or give us hope to change ourselves for the better in future years.



Bootle, Olly. "Are Humans Still Evolving by Darwin's Natural Selection?" BBC News. BBC, 03 Jan. 2012. Web. 09 Jan. 2013.
http://www.bbc.co.uk/news/science-environment-12535647

What Mice Can Tell Us About Obesity and Genetics

Alexandra Sifferlin, TIME
Published on January 9, 2013
http://healthland.time.com/2013/01/09/what-mice-can-tell-us-about-obesity-and-genetics/

Summary
For more than two years, researchers at UCLA have observed and monitored weight gain among lab mice. The effects of high-fat and high-sugar diets on them has shown that risks of obesity are affected by genes. The scientists have identified 11 genetic regions affecting obesity and fat acquisition from the diet, several of which are similar to human genes that have also been linked to obesity. During the study, the mice were put on a normal diet for 8 weeks, then consumed a high-fat or high-sugar diet for another 8 weeks. The build up of fat varied widely among the mice, ranging from 0%-600% increase in body fat over the 16 weeks. The amount of fat gained was connected with changes in the mices' gene activity. About 80% of body fat was found to likely be regulated by genes, suggesting that DNA directed the energy needed for processing food, or their metabolism, and that the amount of food the mice ate was not as much of a factor. The study suggests that the amount of physical activity the mice get and how they metabolize food has a greater impact. This may be true for humans as well. Previous studies have estimated that 50%-90% of obesity is inherited in genes, but these have not been fully identified yet. It is also possible that genes may not be directly responsible for obesity, but are set off in the presence of environmental factors such as stress. Studying the different ways that DNA impacts weight can lead to better ways of fighting obesity, which is an increasing problem in the world today. The scientists are planning to further test the genes they identified in the mice in various lab environments to gain a better understanding of how they influence body fat and behavioral responses like appetite.

Connection
This article connects to the heredity and genetics units. It connects to heredity because certain genes in the mice, their genotype, affect their body fat and metabolism, their phenotype. These obesity affecting genes can be passed on to offspring, which is what causes them to exhibit certain rates of body fat gain. Also, the article connects to genetics because DNA is what causes certain genes to exhibit certain traits. However, human genes may influence obesity only in the presence of certain environmental factors such as stress, which is an example of gene regulation.

How a Fish Climbs a Waterfalls

Christine Dell'Amore, National Geographic News
Published on January 7, 2013
http://news.nationalgeographic.com/news/2013/01/130107-freshwater-fish-weird-animals-science-evolution/

Summary
       The Nopili goby has the ability to complete the great feat of climbing up waterfalls; the fish, only an inch long, can make its way up a hundred feet along the rocks. Due to the freshwater environment of the fish, the organism must move upstream during a disturbance in the environment.
       Richard Blob, an evolutionary biologist as Clemson University, and his students traveled to the fish's Hawaiian habitat. After the laborious process of catching one of these fish, the scientist filmed the fish climbing and the fish feeding on algae-covered glass. After analyzing the videos, the group found that the movements in both were overall the same. This means that at some time in the past, the organism had undergone exaptation, an evolutionary result where the structure or behavior of a species is also used for a completely different process. It is unknown which of the two came first.

Relevance
       The article relates to our study of evolution because the Nopili goby evolved to use the suckers along its body and mouth to climb. Natural selection chose the fish who were able to climb, while the others would die during a change in the environment. These changes in environment are often caused by storms or other random natural disasters, which are examples of genetic drift.

A Genetic Defect in Sex Cells May Predispose to Childhood Leukemia

Published December 17, 2012
Medical Xpress
http://medicalxpress.com/news/2012-12-genetic-defect-sex-cells-predispose.html  
(no author given)

Summary
Researchers have discovered that it is possible for a predisposition to acute lymphoblastic leukemia (ALL) to be inherited. This occurs when one of the parent’s PRDM9 gene mutates in the gamete that a child arises from. About half the patients with ALL have this inherited mutation. However, not everyone with the gene gets ALL. It only gives a head start on the mutations needed to develop this cancer, so even children without the inherited mutation can still develop this cancer.

Connection
This article relates to the study of inherited mutations. We learned that mutations could only be passed down if they are present in gametes, not somatic cells. In this case, the mutation is in a gamete, so it can be inherited. Additionally, this connects to our study of cancer. We learned that cancer cannot be inherited, but mutations that lead to cancer can be if the mutation is in a gamete. It normally occurs when there are mutations to the tumor-suppressor genes and growth factors because then cells divides too fast and the tumor-suppressor genes don’t limit their growth. So, if only one mutated cell is inherited, it can lead to cancer but only if other mutations accumulate. It just has a head start on the accumulations. The PRDM9 mutated gene only leads to ALL with further mutations.

Heat-Resistant Corals Provide Clues to Climate Change Survival

Daniel J. Barshis, ScienceDaily
Published on January 7, 2013
http://www.sciencedaily.com/releases/2013/01/130108091820.htm

Summary

Climate change poses a major threat to coral reefs around the globe. Over half of the world's coral has been killed by rising temperatures and factors related to human disturbance. However, some coral individuals have a mutation(s) that allows them to survive at higher water temperatures. Scientists have experimented on coral to find out how they survive in the wild at temperatures as high as 32°C (90°F). Researched analyzed coral animals' gene expression at varying water temperatures up to 35°C (95°F). The results showed that in the heat-resistant individuals, the 60 genes responsible for managing heat stress had been activated even before the coral was exposed to heat. Patterns such as these are allowing scientists to find out which individuals are most likely to survive climate change, which is instrumental to protecting them.

Relevance

This article employs genetics and evolution. It relates to our unit on genetics because the coral underwent a genetic mutation that permanently turned on the heat-stress genes. This was likely caused by a mutation in the repressor protein of the operon(s) that deals with the heat-stress gene, so it could not bind and prevent RNA polymerase from attaching. In terms of natural selection, the coral best suited to climate change (those with the heat-resistant mutation) will be most likely to survive. In addition, the heat resistance is an adaptation because it makes the coral better suited to warmer environments as ocean temperatures rise.

In Analysis of Skulls, Following the Path From T. Rex to Falcon

James Gorman, NY Times
31 May, 2012
http://www.nytimes.com/2012/06/05/science/skull-analysis-charts-the-changes-from-dinosaurs-to-birds.html?ref=evolution

Summary

Most people would know, or even have heard that birds were evolved from Dinosaurs, but the amount of change between the two species still calls for new research. A recent study focuses on the comparison of size and shape of skulls. Skulls in birds are proven to not change in shape, only size, as a result of evolutionary changes. This in result looks like the skull of a baby dinosaur. This shows that as birds evolved, their growth patterns changed so they wouldn't change their skull shape from its juvenile version. Dinosaurs obviously didn't have this trait because they were the ones that were changed due to this mutation. The dinosaur's juvenile skulls resemble those of matured birds.
Scientists say that the dinosaurs that gave rise to birds may have had feathers but didn't fly and didn't resemble any modern day birds. The characteristics of birds like being able to spot things from thousands of feet and swooping down to catch it are obviously far from running around on the land. This is obviously a very dramatic evolutionary change which causes many scientists to still ponder the fact today.

Connection

This article relates to our studies in class because it deals with the idea of evolution and how species change. It talks about how dinosaurs evolved into birds. Because of the mutations in genes, another thing we studied in class, that allow skulls to mature have shown that adult bird skulls resemble baby dinosaur skulls. This article also talks about comparing skulls and bones to determine what they are related to, the article talking about birds and dinosaurs. We have been learning about that in class as well. This article, I believe, ties in really well to our studies in biology.

DNA of 100,000 People to be Mapped for NHS

Peter Walker, The Guardian

December 10 2012

http://www.guardian.co.uk/science/2012/dec/10/1000000-peoples-dna-mapped?INTCMP=SRCH

Summary:

Over the next three to five years, up to 100,000 people with cancer or certain rare diseases will volunteer to have DNA their mapped. This is the start of a public health initiative by the UK government. They hope that it will improve treatment and prevention of cancer. Genetic analysis is an essential part of some medical treatments. Sir John Bell, professor of medical sciences at Oxford University and the government's adviser on genetics, said that the UK hoped to lead the world in the practical applications of DNA mapping. He believes that DNA mapping can allow scientists to deliver medicines and understand cancer and other diseases more precisely.

The first complete map of the human genome was finished in 2003.  The endeavor took more than 10 years to complete, at a price of 750 million pounds. However, since then, the cost of genome sequencing has been decreasing, making it more possible for scientists to use.

A target of this investigation will be cancer. DNA analysis can detect genetic susceptibility to certain rare cancers, but through genetic mapping, scientists hope to understand the development of cancer.

Relevance:

This article connects to our unit on Genetics and DNA technology because it relates to real uses of DNA mapping, an example of DNA technology. It illustrates how scientists apply the same ideas we discussed in class about DNA technology to learn about cancer and other rare diseases. The article concerns the DNA mapping of many patients to find treatments to these diseases.

Odd, Ancient Bird Had Sharp Teeth

By Tia Ghose
Published January 7, 2013
http://news.discovery.com/animals/odd-ancient-bird-had-sharp-teeth-130107.html

Summary:  A fossil skeleton of a bird called Sulcavis geeorum was found in China.  This bird lived 125 million years ago and had strange teeth.  Scientists think that the bird used its teeth to eat hard shelled insects, crabs, or snails.  Birds no longer have teeth, however they do carry the genes for teeth.  Some believe that birds evolved to having beaks because they are lighter and therefore easier to fly with.  This toothed bird looks very similar to the modern-day songbird, the only difference being that songbirds do not have teeth.  A lot of fossils have been found from the time period of the toothed bird over the past 15 years.  Scientists hopefully will continue to find more so they can get more information about the Sulcavis geeorum. 

Connection:  This article connects to our study of evolution.  This specie of birds has evolved from having teeth to beaks.  This is partly because birds eat different things now but also because beaks are easier to fly with.  Birds have adapted to their surroundings.  There are now different things for them to eat and they have different predators and organisms living around them.  This specie was able to change through natural selection.  The birds with the beaks and no teeth were better suited to their environment and were able to survive and reproduce. This article also relates to genetics.  Birds may not show the trait of teeth but they do carry the gene for them.      

Giant Galapagos tortoise species may not be extinct

Jack Billings
http://usatoday30.usatoday.com/news/world/environment/story/2012-01-06/galapagos-turtles-extinct/52467768/1
Published: Monday January 9, 2012
Source: USA Today
Author: Elizabeth Weise

Summary:
When Darwin visited the Galapagos islands in 1835, one of the animals that helped him develop his theory of evolution was the tortoise. One species he described was the Chelonoidis elephantopus which lived on Floreana Island and was thought to have gone extinct within 10 years of Darwin’s expedition due to whalers who hunted them for food. Recently, researchers did DNA testing on 1,600 tortoises on Isabela Island, and found 84 which were direct offspring of the Chelonoidis elephantopus among the Chelonoidis becki natives. They did DNA testing on the shells of tortoises in museums (where the only known Chelonoidis elephantopus were) to confirm that the 84 tortoises were in fact descendants of the Chelonoidis elephantopus. Because the length of these giant tortoises lives, these individuals could be the grand kids or even direct offspring of some the the tortoises Darwin saw on his expedition. This discovery wasn't made until now because Isabela Island was never settled by humans for its lack of fresh water and because of the difficulty of getting blood samples from these 400 pound tortoises. No pure-bred Chelonoidis elephantopus tortoises were found, but scientists plant to create a breeding program to back-cross the hybrids to make a population closer to full-blooded Floreanas that could be used to repopulate Floreana Island.

Relevance:
This connects to our units on heredity, molecular genetics, and the evolution of life. The article relates to heredity because it discusses selectively breeding the tortoises to obtain the pure-bred forms of the Chelonoidis elephantopus tortoises (which have bred with the native Isabela Island species). It relates to molecular genetics because the researchers had to use DNA testing to determine what species were on Isabela Island. It relates to evolution because (much like Darwin’s finches) these tortoises probably have a common ancestor from which they have adapted to their new, isolated environments. These isolated environments have cause them to evolve through genetic drift and natural selection. Gene flow is also shown when the two species of tortoises cross-breed on Isabela Island.

Studying Seemingly Immortal Lichens, in a Place for the Dead

Hillary Rosner, NY Times

December 31^st 2012

http://www.nytimes.com/2013/01/01/science/studying-seemingly-immortal-lichens-in-a-place-for-the-dead.html?pagewanted=1&_r=0&ref=science

Summary:

Aging, also known as senescence, has previously been thought to be a fundamental tenet of cellular biology. Cells were believed to be incapable of immortality, as over time, cells will accrue numerous mutations, eventually leading to death. However, this may not hold true for certain organisms. Dr. Anne Pringle studies lichens (algae and fungus living in a symbiotic relationship) in a New England cemetery, measuring and analyzing the lichens every fall. Over time, she has been studying whether lichens can die of age. Like many other fungi, with yeast as an exception, lichens can grow and live for incredibly long periods of time without showing signs of deterioration, leading researchers to believe that they, in fact, do not senesce. However, it is important to note that despite the fact that these fungi do not age, they can die; as Dr. Pringle says, “A bus can still run over them,” but they can only be killed by lack of resources or external forces. This has lead researchers to wonder why this trait has not appeared in other organisms, such as humans, as it appears to be clearly selected for. But, in reality, the human males who produce more babies, and thus are more biologically fit, are predisposed to prostate cancer, causing prostate cancer, and as a result, mortality, instead of “immortality” would be spread to the next generation. Yet, fungi are unique in that as they age, they are actually less likely to die, which gives a possible indication that even in fungi, “immortality” may not selected for, perhaps instead we happen to see only the longer living (fungi can live for 1000’s of years), but perhaps less fertile fungi. However, research is being done in fungi, as well as, the bristlecone pine tree and the wandering albatross, both of which may also avoid senescence, to determine the specific genes responsible for this “immortality” for possible use in human medication.

Relevance:

This article is extremely relevant to many of the topics we are discussing in Biology this term. First of all, this is relevant to our current unit of evolution, as the article discusses whether “immortal” individuals of species are more biologically fit and how this trait may have become common in some organisms but not others. It also relates to our molecular genetics and biotechnology unit in that researchers are attempting to isolate the genes for “immortality and use them in human medication, maybe creating transgenic humans or other organisms.

Quarter 2 Biomedia Due Dates

Due Dates and Topics for Quarter 2
Due Dates:
- Post Media, Summary, and Relevance by 1/10.
- Questions of Classmates made in comments by 1/18. THIS LINK may help.
- FOR EXTRA Credit: Answers to Questions posted in comments by 1/21.
The topics for term 1 are Heredity, Genetics, and Evolution.