The Brain and Movement

Not all living things have a brain. So, having a brain is not a necessary characteristic of life, but rather, a “luxury”. Most people associate having a brain with the ability to think, however, Dr. Daniel Wolpert believes this to be a misunderstanding in terms of the actual purpose of the brain. Dr. Wolpert suggests that the brain didn’t evolve under the premise of being able to think or feel, but rather, the brain evolved solely to control movement. Each section of the brain is based on the production or interpretation of movement in some form or another. Auditory; sensing the motion of sound waves through the atmosphere. Vision; sensing the motion of light in order to detect objects in our surroundings. Language; the physical motion of the mouth in order to create distinct sounds, and so on. The brain benefits many organisms by providing them with more control between the interactions with themselves and their environment, but is not a necessary component of survival and further reproduction.

A good example of Dr. Wolpert’s hypothesis can be found in the life cycle of the sea squirt. The sea squirt begins its adolescent stages of life by swimming around the ocean, looking for a suitable rock to call its home. Once the sea squirt finds an adequate location, it then permanently attaches itself to the rock. The sea squirt then begins to digest its own brain and nervous system for additional energy, since it no longer needs to move and has found its permanent residence. It then survives by filter-feeding the waters for nutrients, with the ocean currents doing the work of transporting the food to them.

What I find interesting about the sea squirt is its’ rudimentary instincts for survival. The sea squirt is born with a brain. It has the ability to sense and interact with the world around it; some people may even say it has a consciousness and is aware of its own being. With that being said, it then willingly gives up this luxury in order to ensure its own survival and further reproduction. This means that it essentially deletes its capability of controlling its own interactions with the world around it, and also sacrifices its awareness of its own being (assuming that consciousness is derived from the brain).

To me, this gives rise to a fascinating question; what’s the point of living if you do not have the capability of being aware that you even are? Well, the sea squirt does not answer this question, but rather, it emphasizes the primary foundations which guide the blueprint of all living things; survival and reproduction come first, everything else comes second.

Another piece of evidence supporting Dr. Wolpert’s hypothesis lies in the area of robotics and computers. In a way, computers have the ability to “think”, or make appropriate decisions, that surpass the thinking ability of any human. If you were to play a game of chess against a computer, the computer would win almost every time, for the computer can make the most appropriate decisions without mistake that would lead itself to victory based on programming. However, if you tell a robot to physically move a chest piece on the board, it cannot nearly do so as efficiently as a human can. The physical dexterity that is involved in moving a chess piece is where the human brain will beat the computer every time, for computers cannot simulate complex movements in a way that matches the performance that a brain provides. This emphasizes that the brain did not evolve around the ability to think, but rather, to perform and interpret movements in order to better interact with their environment.

Sexual Dimorphism in Non-Human Primates

By-Shannon Garnett

Everyone knows that humans are sexually dimorphic, in fact, we see it every single day; but have you ever thought about how other primates are sexually dimorphic? Are they sexually dimorphic in the same way? I did some research on chimpanzees, gorillas, orangutans, gibbons, old world moneys, new world moneys, tarsiers, and lemurs to answer this question and this is what I found.

Chimpanzees are mainly dimorphic in just size. The common female weighs between 57-100 pounds and the male weighs between 90-115 pounds.

http://michaelkeenan.net/images/gorilla_couple

Gorillas are highly sexually dimorphic. Males weigh about 350 pounds and females usually reach around 155 pounds. They also differ in their facial features. Males have a more a more protruding sagittal crests, brow line and canine teeth then females. Male silver-backed gorillas grow a sheet of white hairs on his backs and females do not.

Orangutans are also highly sexually dimorphic. Their faces are mostly hairless however, sometimes males develop hair on their face, giving them a moustache. Males also have fatty tissues on their face creating cheek flaps, which show their dominance. The males also make loud noises with throat pouches. Females grow to about 4 ft. 2 in and weigh around 100 lb., while adult males can reach 5 ft. 9 in and weigh over 260 lbs. with an armspan of about 6’6.

Gibbons do not display much of sexual dimorphism. Some males have dark patches on their fur to show that they are suitable for mating.

http://www.bbc.co.uk/nature/life/Toque_macaque

In the case of old world monkeys, males can be up to double the size of females.

There are four different types of new world monkeys and they all display different characteristics. The first type is cebinae monkeys (squirrel and capuchin monkeys). Male squirrel monkeys weigh between 750 and 1100 grams while females weigh from 500-750 grams. In capuchin monkeys, males tend to have a larger head and body proportions than females. Aotinae (night and titi monkeys) tend not to have any sexual dimorphism. Atelinate (howler and spider monkeys) are sexually dimorphic by size and they also have sexually dimorphic canines. In the case of pithecinae monkeys, females have shorter hair then males. Their hair color is different as well. Females have brownish-grey fur and white or pale brown stripes on their face whereas males, have blacker fur, with a reddish-white forehead, face, and neck.

Male and female tarsier monkeys are sexually dimorphic in size. Males usually weight close to 120-155 grams and females weigh about 110-130 grams.

In the case of lorises, males and females you can see bimaturism. They grow at the same rate but at different times, the same time at different rates or at mixed rates at different times.

Finally lemurs display sexual dimorphism only in color. Most male lemurs are one solid color and females have a white patch on their backs.

So as you can see, we are not the only primates who display sexual dimorphism. Primates are also not the only species whom display sexual dimorphism.

For more information on the topic check out these sites and sources:

http://anthro.palomar.edu/primate/prim_1.htm

Click to access Biology_of_Nonhuman_Primates2(PDF).pdf

Invasive species in New England.

By Andrew Wernik

Invasive species are non-native species that can quickly take over habitat. Due to lack of natural predators it can monopolize an area for space, food, sunlight and, water. Putting native species at risk. 

Alliaria petiolata is abiennial flowering plant of the mustard family. A native to Europe, central Asia and, Northern Africa. First introduced in North America in the mid 1800’s for culinary use. Due to lack of natural predators it has quickly spread in forest and wetlands. Plant should be pulled or cut to ground in spring.

Berberis thunbergii one of the widespread invasive plants in New England. First seen in Boston in the late 1800’s. It lives along field edges and in open forests. Southern New England has been hit hard by the plant. Dense areas of the plants prevents anything but Berberis thunbergii from growing. Pull out plants and/or seedlings.

Iris pseudacorusa native of Europe, first planted in the 1800’s to add color to  streams and ponds. A very widespread plant, it has been found in most of the United States and parts of Canada. It quickly takes over other native Iris species. Being the only wild yellow Iris it is easily distinguished from native species. Pull out the plants and roots.

Cynanchum rossicum is a flowering plant of the milkweed family. Native to Europe. Brought over for ornamental reasons in the late 1800’s. Taking over in grassland and endangering the native bird and insect life. Roots must be dug out before it goes to seed and destroyed.

Amorpha fruticosa is found in the wild in most of the United states. It was introduced in Europe for ornamental reasons and became invasive. Quickly and aggressively replacing native plants.

Sources:

http://www.newfs.org/protect/invasive-plants/massachusetts-invasive-plant-list.htmlhttp://www.nps.gov/plants/

Whiptail Lizard: All-Female Reproduction Without A Male

When most people think about reproduction it involves both a male and a female. Agreeably, in the animal kingdom the more common form of reproduction is sexual reproduction. However, we must not forget about the species that reproduce through asexual reproduction! This phenomenon is unique but existing. The most commonly known animal that reproduces unisexually is the whiptail lizard, or the “racerunner”, which is native to southwestern US and Mexico.

Teiidae is the family of these lizards, in which there are the parthenogenetic genera Cnemidophorus and Aspidoscelis, and the non-parthenogenetic Tupinambis. There are many different species of the whiptail lizard but I will be examining the parthenogenetic genus’s mentioned above.

 Cnemidophorus.

 Aspidoscelis.

‘The word parthenogenesis comes from the Greek παρθένος, parthenos, meaning “virgin”, and γένεσις, genesis, meaning “birth”.’ Parthenogenesis occurs naturally in nature, seen in about 80 different animals. Invertebrate species such as water fleas, scorpions, and some bees, have developed this behavior as well as vertebrate species including some fish, amphibians, reptiles, and very rarely in certain bird species.

In parthenogenesis, asexual reproduction is performed by two females laying amniotic eggs unfertilized by males that grow and develop into usually female young. Parthenogenetic offspring typically have the diploid chromosome number, having doubled the mother’s chromosomes, essentially being a genetic clone of their mother. Ovulation is enhanced through creating more eggs by female-female courtship rituals similar to behaviors displayed by closely related species that reproduce sexually. The lizard on the bottom has larger eggs while the top lizard has smaller eggs, switching off each mating season.

It is thought that this unique mating was forced on the whiptail lizard and other parthenogenetic species due to genetic isolation from the male. Some species such as the Komodo dragon or hammerhead shark do this as necessary, but the whiptail lizard doesn’t have such a choice. Genetic studies suggest that these unisexual species developed from two sexually reproducing lizards of closely related species. Usually when two different species mate and create a hybrid the offspring is sterile. However, the hybrid offspring had mutations needed for parthenogenesis. Recently, scientists created their own species of all-female, self-cloning lizards in a lab by making a hybrid between two existing species, therefore proving these unisexual lizards developed through hybridization.

Asexual reproduction “can have questionable genetic outcomes unless done right” but it has benefits too, says Baumann. “You’re greatly increasing the chances of populating a new habitat if it only takes one individual,” he says, citing the example of the brahminy blind snake, another parthenogenetic species. “If she has a way of reproducing without the help of a male, that’s an extreme advantage.”

Works Cited:

Harmon, Katherine. “No Sex Needed: All-Female Lizard Species Cross Their Chromosomes to Make Babies: Scientific American.” No Sex Needed: All-Female Lizard Species Cross Their Chromosomes to Make Babies. Scientific American, 21 Feb. 2010. Web. 05 Dec. 2012. <http://www.scientificamerican.com/article.cfm?id=asexual-lizards&gt;.

Keim, Brandon. “All-female Lizard Species Created in the Lab.” Ars Technica. N.p., 4 May 2011. Web. 05 Dec. 2012. <http://arstechnica.com/science/2011/05/all-female-lizard-species-created-in-the-lab/&gt;.

“Parthenogenetic.” BBC News. BBC, n.d. Web. 05 Dec. 2012. <http://www.bbc.co.uk/nature/adaptations/Parthenogenesis&gt;.

University of Iowa. “Value of sexual reproduction versus asexual reproduction.” ScienceDaily, 25 Jan. 2010. Web. 5 Dec. 2012.

The Resurgence of Wild Mammals in Massachusetts

By: Tim Phelon

Colonial Decline

Before European colonists arrived at Plymouth Rock, the area that would become Massachusetts was filled with unbroken hardwood forests and the multitude of mammals that inhabited them. The colonists soon started clearing large tracts of forest for timber and farmland. Many mammals were hunted and killed indiscriminately for fresh meat, furs, or to protect the settlers’ livestock. Within one hundred years many of the native mammal populations had been drastically reduced or even eliminated from many parts of the Northeast. This included moose, elk, cougars, black bears, wolves, beavers, martens, and wolverines. Moose, elk, black bears, martens, and beavers were hunted for food or for their furs, while wolves, cougars, and wolverines were considered to be a nuisance or a threat and were killed on sight.

 

A large bull moose in Massachusetts.

Resurgence

Recently a few of these species have started to make a comeback. This gives biologists hope that other species will eventually return as well. The moose is one of the best examples of this recent comeback. Moose have been gradually moving south into their former range for years now. Local populations are steadily growing in many parts of Massachusetts and the surrounding states. Beavers have a similar story, at first a few returned on their own and then some were released in the 1930’s and now the population is strong statewide. Black bears were never completely exterminated from Massachusetts and they have bounced back very well. In the 1970’s the bear population was still fairly low, but now the population is up to about 3000 individuals. Wolves were essentially replaced by the coyotes that moved into the area in the 1950’s. Sightings of both wolves and cougars in Massachusetts still happen, although very few are ever confirmed. A wolf was killed in Franklin County in 2007 and cougar scat, but no cougar, was found near the Quabbin Reservoir in 1997. It is unknown if these were wild or escaped captive animals. Wolverines, martens, and elk were fairly rare before colonists arrived and they are the least likely to make a return to Massachusetts.

 

The 2 largest predators currently living in Massachusetts; the Eastern Coyote and the Black Bear.

Conservation Efforts

The biggest reason for this resurgence of mammals is habitat conservation. When colonists arrived and started farming the land, a very high percentage of the forests were removed. Thanks to the relocation of farming to the Midwest, many of the areas that were once agricultural fields were abandoned and the forest’s trees and plants were able to grow. Today, 62% of Massachusetts’ 10,555 square miles are forested. The second reason for this recovery is the institution of new hunting and trapping laws. It is no longer legal to take an unlimited number of any species at any time. Moose are illegal to hunt in Massachusetts and the other mammal species have well regulated hunting and trapping seasons. Large predators like the bear and coyote have benefited from the increase in the number of prey species, like the beaver, deer, and to a lesser extent the moose. The increase in forested land and biodiversity opens the door for the eventual return of other native predator and prey species.

The remnants of a farm’s stone wall in a now forested Massachusetts State Park.

References-

http://www.mass.gov/dfwele/dfw/wildlife/wildlife_home.htm

http://www.mass.gov/dcr/aboutDCR.htm

The Domestic Silver Fox

The Domestic Silver Fox by Emily Dauer

Foxes have long been branded as being cunning, mischievous, and manipulative characters in fables. But how would they fare if given characteristics such as friendly, happy, affectionate and loyal? Believe it or not these are some of the characteristics that arose from an experiment conducted by the late Dmitry Belyaev in Novosibirsk, Russia.

A geneticist in Stalinist Russia, Dmitry Belyaev sought to experiment how does domestication happen by selectively breeding the Russian Silver Fox. Prior to creating his fox farm facility Belyaev was under intense scrutiny for his strong beliefs in Darwinian genetics. This was due to the stigma surrounding genetics at the time. Trofim Lysenko was the director of Soviet Lenin All-Union Academy of Agricultural Sciences and advisor to Joseph Stalin. Lysenko was convinced that genetics was a bourgeoisie, fascist pseudo-science due to the adoption of genetics in fascist Germany and the implementation of eugenics. Lysenko was so adamant about genetics being disbanded from the sciences that, following the approval from Stalin, many Russian geneticists were executed. One of these scientists was Dmitry Belyaev’s own brother, Nikolay, who was exiled to a labor camp where he later died. Filled with fear for his life Dmitry Belyaev fled to Novosibirsk, Russia. A strong-minded Darwinian, Belyaev vowed to continue his research on genetics in secret.

Belyaev became the director of the Institute of Cytology and Genetics under the guise of researching fox fur in the attempt to create the finest and most profitable fur. Fur trading, a large Russian industry, was a successful cover. Belyaev and his team collected Russian Silver Foxes and did a simple aggressiveness test to determine which foxes would be allowed to breed and which would be sold for their fur. The Russian Silver Fox is the same species as the more common Red Fox, Vulpes vulpes, found here, in the United States. The test to determine aggressiveness was simple. Belyaev and his team would test on juvenile foxes by approaching a youngling in their cage. They would extend their arm as if to try and touch the pup. Usually, the feral fox puppies would cower in the corner of the cage and make a high-pitched bark signaling fear. These were the juveniles with more aggressiveness. But sometimes, about one in twenty, a juvenile fox would be born without the inclination to cower and bark. Some of the juvenile foxes seemed unfazed by the human’s presence. These would be the foxes that would begin the long line of artificial selection in Belyaev’s fox farm.

Belyaev and his team bred the most docile foxes in order to create the most docile young. Each pup born in the farm was evaluated for aggressiveness and only a percentage of pups born were allowed to breed and create the forthcoming generation. Belyaev’s research on breeding out aggressiveness in foxes also had a parallel study, one in which bred for aggressiveness. They would not only select the friendliest foxes for breeding, but also the most aggressive. The foxes that were caught in-between were sold for their fur.

After only four generations, lasting from 1959 to 1964 foxes that had been bred for being nice began to show signs of domestication like wagging their tail when a human came close to them. By 1970 the foxes were loyal to humans and followed them like a dog would. They would even jump into the arms of the scientists at the facility and lick their faces. The team continued their research until an astounding new byproduct of their artificial selection presented itself in 1980. The foxes that were being bred for niceness were becoming physically different. Their ears started to flop, their tail’s curled, their teeth became smaller, their bones became smaller, and most observable- their coats changed. Foxes began to appear with white, orange, and even spotted coats. These results were not initially expected and created a huge outpour of evidence supporting how the domestication of other animals, such as the dog from the wolf, can create such variety in physical appearance. This extreme change in physical appearance as well as personality had occurred in a little over a decade. Ten years! Dogs have evolved from wolves over thousands of years and Dmitry Belyaev had created a domesticated fox in ten years.

So on one side of the fox farm there were affectionate, happy, tail-wagging, face-licking foxes that whimpered for attention when humans walked past. On the other side of the fox farm were the aggressive foxes. Belyaev’s team bred just as many generations of the aggressive foxes. These foxes grew to have extreme anger at even the sight of a human. They would become wild, snarl, bark, and attempt to bite at the human through their cage. These foxes did not have the type of juvenile traits attributed to the nice foxes.

Beylaev and his team used artificial selection to breed for nice foxes and ended up creating foxes that are basically trapped in their juvenile phase. The adrenal glands in these foxes are severely slow and undeveloped resulting in the inability to transmit neurochemicals that trigger ear development, skin pigmentation, and other physical traits that would otherwise allow the fox to develop into a feral adult. Many theorize the same delay in development or a permanent juvenile phase is what has created the common domestic dog.

The Institute of Cytology and Genetics’s fox farm has fallen under extreme financial difficulties since the demise of the Soviet Union. A majority of their funding comes from selling their domesticated foxes as pets to interested buyers all over the world. A fox can run you upwards of eight thousand dollars. These foxes still consume raw meat and require an outdoor enclosure as their permanent residence. So, are foxes the new pet craze? Many satisfied fox owners seem to think so.

 

References:

http://www.domesticfox.com

http://www.hum.utah.edu/~bbenham/2510%20Spring%2009/Behavior%20Genetics/Farm-Fox%20Experiment.pdf 

http://www.radiolab.org/2009/oct/19/new-nice/

http://ngm.nationalgeographic.com/2011/03/taming-wild-animals/ratliff-text/2

http://redhotrussia.com/domestic-foxes-novosibirsk/

The Effects of Invasive Plants on Native Ecosystems

Written by Nicole Giles, Westfield State University, Environmental Science, November 2012

Humans have gradually introduced new plant species into ecosystems without understanding the repercussions for their actions.  We have a tendency to buy plants based on our landscaping needs, whether it be a flower or known for its vine and erosion control.  Unfortunately, some companies import plants from other countries and sell them based on their physical properties. These ‘new’ species are quick to adapt to their new environment, with no natural predators and can be disease resistant. According to the Massachusetts Division of Fisheries and Wildlife, these plant species are categorized as an invasive plant and if left unchecked, these organisms can quickly crowd native species and kill everything that is not suited to compete.

Invasive Plant Introduction

Invasive plants reproduce rapidly with the help of wind, water, and local wildlife for dispersal their seeds to other areas for easy colonization (Somers 5). For example, birds will eat the fruit from the plants and disperse the seeds in flight.  People can act as dispersal mechanisms as well, spreading seeds on shoes and clothing, and by also introducing contaminated fill or mulch into areas during construction (Somers 5). It is the law in Massachusetts to wash boats before and after they are put into bodies of water, to help prevent the spread of invasive aquatic plants such Eurasian Water Milfoil.

Affects on Ecosystems

 Phragmites australis also known as the Common Reed is an invasive species typically found in wetland areas. Introduced to the Atlantic coast during the late 1800s, this invasive can generate extensive damage in the areas in which it is growing (Blossey). Due to its extensive root system and structure, Phragmities alters the function of the wet ecosystem by changing the nutrient and hydrologic cycles of the soils (Blossey). Dense patches of Phragmities discourage native biodiversity because it is not the habitat of choice for native waterfowl and migratory birds; these birds prefer native short grass habitats (Blossey).  Control programs such as the one in Primebrook National Wildlife Refuge in Delaware saw a recovery in bird communities after chemically controlling the invasive plant (Blossey).

Phragmities

Japanese Knotweed or Fallopia japonica is another example of an invasive species that is very difficult and expensive to control. Making its first challenging appearance in the United Kingdom, Knotweed quickly grows into dense thickets that crowds out native plants and are of no use to wildlife (Shaw). This invasive can also grow to great heights, shading out native plants thus reducing ecosystem biodiversity (Shaw). Flooding facilitates dispersal of Knotweed by spreading seeds and stems downstream which rejuvenate in spring months (Shaw). Removal efforts for this plant are extensive and may further inhibit the soil and native plants (Shaw).

Japanese Knotweed

Kudzu, a native plant to Asia, is a climbing semi woody vine found in Southern United States (DCNR). When Kudzu invades an area, it covers native vegetation with a blanket of leaves and prevents the natives from getting sunlight for photosynthesis (DCNR). Kudzu can also uproot entire trees and shrubs using its weight as an advantage (DCNR). Kudzu roots can grow to 7 or more inches in diameter and 6 feet or more in length, weighing 400 pounds (DCNR). This invasive is abundant throughout the southeastern United States but is being seen in Pennsylvania (DCNR).

Kudzu

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References

Blossey, B., et al. “Common Reed.” .” Ecology and Management of Invasive Plants Program. Cornell University: 2008. Web. 24 Nov. 2012. <http://www.invasiveplants.net/monitor/9CommonReed.aspx&gt;.

“Boat Massachusetts: Your Guild to Boating Laws and Responsibilities.” Massachusetts Environmental Police. 2010. Print.

Britton, Kerry., et al. “Kudzu.” Ecology and Management of Invasive Plants Program. Cornell University: 2008. Web. 24 Nov. 2012. <http://www.invasiveplants.net/monitor/25Kudzu.aspx&gt;.

“Kudzu.” DCNR Invasive Exotic Plant Tutorial for Natural Land Managers. Plant Conservation Alliance. 24 Nov. 2012. < http://www.dcnr.state.pa.us/forestry/invasivetutorial/kudzu.htm&gt;.

Shaw, R. H., et al. “Japanese Knotweed.” Ecology and Management of Invasive Plants Program. Cornell University: 2008. Web. 24 Nov. 2012. <http://www.invasiveplants.net/monitor/12Knotweed.aspx&gt;.

Somers, Paul. “Guide to Invasive Plants in Massachusetts.” Massachusetts Division of Fisheries and Wildlife. 2006. Print.