Brief Guide to the Brain and Some of its Parts

The brain is the least known about organ in the human body -- much of it remains undiscovered territory.  It's vast intricacies, mysteries, and abilities fascinate me, so I thought I would share a bit. The human brain is what sets humans apart from other species; it allows humans to have the hyper awareness and cognitive ability that no other species does.  In addition, there are so many myths about the brain that have been proven to be false.  Check this out to be a true expert.

Something that isn't mentioned in this site is the myth that everyone is "left-brained" or "right-brained."  We use all of our brains! 

Now for a brief brain tutorial!

As Lucy, a fictional character, goes about her day, she uses many parts of her brain.  Let's find out what some of them do!  

Now, Lucy begins her day by opening her eyes to the sunlight coming through her window.  This sunlight -- along with everything else Lucy sees, is interpreted in her Occipital Lobe, which is connected to her eyes via the optic nerve.  

The next thing Lucy does is muster the strength to get out of bed, which she does via nerve impulses sent from her Motor Cortex.  

Lucy's Mom calls her down for breakfast.  How does Lucy hear her mother's yells?  Because her Auditory Cortex interprets them for her.  

How nice of it.  Before Lucy heads downstairs, she must decide what to wear.  She chooses the perfect outfit using the decision-making section of her Frontal Lobe, then heads downstairs.  Still coming from her Frontal Lobe, Lucy uses her self-control to refrain from pouring herself a bowl full of sugar cereal, and instead grabs a banana.  

Since Lucy is in High School, her brain isn't fully developed, so sometimes her judgement and self control aren't as regular as they will be once she reaches her early twenties.  She remembers a time years ago when she ate only sugar cereal for a week (this long-term memory was derived from her Hippocampus in the Limbic System of Lucy's inner brain).  

It's only about 7:30 a.m., and she's already used so much of her brain (much more than the parts mentioned here, to add).  Moral of this story: your brain is you!   Your brain controls your thoughts, memories, all five senses, and so much more.

A fun fact: A study done in Tel Aviv, Israel proved that male and female brains differ far less than once believed -- the brain essentially has no gender; it's much more of a spectrum than many have thought.

Fine and Dandy! (Dandelions 101)

Dandelions! We see them everywhere we go; why not learn a bit about them? Read on for some biology, history, and fun facts about the orange-yellow puff ball of a plant.

A bright and sunny dandelion in full bloom. Image from Wikipedia

Dandelions get their name from the French word for "lion's tooth," because of the serrated leaves on dandelions in full bloom (check out the image on the left). Dandelions, with the scientific name, Taraxacum officinale, have the longest flowering season of any plant -- the flowering season being only one stage of their unique, fascinating reproductive cycle. Dandelions reproduce via apomixis, the formation of seeds through asexual fertilization. After dandelions flower, they become gray puff-balls as they enter the seed-dispersal phase (the second image displays this stage). Each seed has a parachute-like quality, allowing the wind to blow them off of the weed's stem, and be planted all over (if your lawn has dandelions, chances are they're not just in one spot!).

Dandelions are just like any other plant, in that they use sunlight for energy to grow (this is called photosynthesis!) Sunlight absorption is key -- in fact, the greater the surface area of the dandelion leaves, the more sunlight they can absorb, and most often, the taller they get. This is particularly easy for humans to see/measure because dandelions are weeds, so by definition, they spread and grow at rapid speeds.

Unfortunately, in Montclair and in countless other grass-heavy locations, pesticide is used to kill dandelions because they grow in such large quantities on lawns. I say "unfortunately" because pesticides have been shown not only to be detrimental to the plants they are sprayed on (that's kind of the point in this case) and the animals that inhale them, but may be linked to many human diseases such as Alzheimers, ADHD, and even birth defects. Just something to think about.

An interesting fact to end this post: Dandelions were brought to North America by the early colonists, and were actually used as a healing herb because of their nutritious consistency. In fact, some herbalists consider the dandelion to be an effective treatment for liver disease, given its ability to clean the bloodstream and increase bile production -- the more you know!

In fact, just last night I had dandelion leaves in a salad last night -- they're a bit bitter but mixed with other greens added a fun and healthy flavor to my dinner!

A dandelion that has gone to seed. Image from Wikipedia.

Blowing dandelion seeds has universal appeal, unless you are someone who is obsessed with a perfectly manicured, green lawn. Can you see any adaptions when looking at the image above? I marvel at these perfect little reproductive parachutes.     

Magnolia Leaves: Why are they so weird?

After taking a year of AP Biology, we have been acclimated to apply what we see around us to everything that we have learned in class. In a biology scavenger hunt that Ms. Eckert made for us, she asked us to find a non-native plant whose leaves are used to make wreaths. Our group immediately went for the Blue Spruce Tree, thinking that the leaves would be like pine leaves, but as it turns out the Blue Spruce was not what she was looking for. Although the Blue Spruce is both non-native and used to make wreaths, the answer Ms. Eckert was looking for was the magnolia tree. Surprised, we decided to go take a closer look at the tree. When examining the leaves, we found that the underside was fuzzy and soft. Immediately our first question was: what kind of evolutionary advantage would these strange adaptations have for the plant? (of course)

Our own amphitheater is home to dozens of plant species, one of which is the fascinating magnolia tree. You might know the magnolia tree as a tree that sprouts beautiful flowers in the springtime, (which it does), but to us, they are a lot more than just pretty plants, they are a product of millions of years of intricate evolution. The top of magnolia leaves have a waxy coating that makes them resistant to damage from salt and air pollution. On the underside, leaves have yellow-brown pubescence, which is soft, short, erect trichomes (hairs). See the image below to compare the top and underside of the magnolia leaf.

While many plants have trichomes, the concentration of trichomes on the magnolia leaf that make its underside fuzzy is unique. We wondered what evolutionary advantage this adaptation might provide for the magnolia plant. Creating and maintaining such a large number of trichomes takes a lot of energy and resources from the plant that could be used for other necessary life functions, so why would natural selection favor plants that invested so much of their energy into this? The trichomes must serve an important function that makes the amount of energy used up by their maintenance worthwhile for the plant. The function of trichomes on plants in general can be to reflect excess light and provide shade for the plant, to reduce water loss, and to defend against insects by forming a barrier or secreting sticky fluids and toxic compounds.

Magnolia leaves have an abundance of trichomes on the underside, but none on the tops. This leads us to hypothesize that trichomes on magnolia leaves may be used more for the purpose of reducing water loss from the plant through transpiration, the process by which a plant loses water by evaporation. This evaporation occurs through the stomata, pores in the epidermis of the leaf located on the underside, just as the trichomes are. Stomata on a magnolia leaf are surrounded by trichomes which can trap moisture from some of the water evaporating. The unique structure of magnolia leaves then causes the plant to require less water input to maintain homeostasis and carry out life functions.

As our fellow classmates walk across the bridge at graduation, they will be able to see the magnolia trees from their beautiful flowers to their intriguing textured leaves. If you happen to stumble upon a magnolia tree, take a closer look! Maybe you’ll uncover something yourself.

This is a picture of a Magnolia wreath, which are becoming very popular for the holidays.

This is a magnolia tree from the amphitheater. Here, you are able to see the glossy surface on top of the leaf and the fuzzy trichomes on the underside of the leaf (and Sammy admiring it :) )

Samantha Rego and Leela Rangachar

More Than You Ever Wanted to Know About Grass

I sat in the grass in Rand Park. Whatever would I write my blog post about? What was important enough to demand a full post on the MHS Biology Blog? The grass had recently been cut (after months of overgrowing) and I was inspired by it's freshly chopped smell.

This is a pretty familiar sight, right? Grass is so common in our everyday lives. Go grass.

Grass covers over 20% of the earth’s land surface. It’s everywhere. And as it turns out, grass has a semi-interesting history.

Here’s how it goes:

Grass began to evolve in South America and Africa 60 million years ago, as is evidenced by the pollen fossils found from around that time. Grasses are classified by their unique pod shapes and their age of maturation - far earlier than other plants of the time. Soon after, the grasses evolved the ability to thrive in dry and open areas. This began their takeover of the earth.

Soon, grasses covered the plains of the world. (Soon being a relative term, I’m talking in terms of 10s of millions of years). Animals evolved to eat the grass - the ancestors of cows, sheep, zebras and the like. Grasses outputted a different form of carbon gas that was easily digestable by the animals -- but not humans. Don't worry though, soon, own ancestors began to creep onto the grass-covered plains, intrigued by the food source the herbivores themselves might provide.

Of course, there was one problem. ¡Predators! Grass had not evolved to be incredibly tall, and those crossing the grasslands were at risk of being attacked by the ancestors of lions and other big cats. Only some could survive in these conditions. Only the bipedal ones, who could run much faster through the plains. Early humans thus evolved their current stance.

Look at how the sun shines on it. So majestic. And with such a rich history. 

So it turns out grass and us go way back. Nowadays it’s pretty comfortable to lie on and decorates the ground here in Rand Park, and I think we take it for granted. So here's a quick thank you: Thanks Grass!

Mysterious Wisteria

If I could go back in time to last September or October and tell my past self that the most difficult thing I would have to do in AP Biology in the second half of May was find and identify a bine in the amphitheater, my past self would have laughed in my face.  However, during a scavenger hunt only two of the thirteen students in our class could identify and name the Wisteria, a climbing bine, in our very own amphitheater.  So what is a bine? The autocorrect on my computer doesn’t even think that “bine” is a real word.  A bine is a climbing plant that climbs by its shoots growing in a helix around a support whereas a vine uses climbing tendrils or suckers to grow and climb.

The wisteria in amphitheater 

Wisteria are woody climbing bines, most of which are native to Asia and some of which are native to America. The American wisteria is recommended as an alternative to Asian wisteria which are classified as an invasive species in the United States.  An invasive species is a non native species to a specific area which tends to have negative effects on the other species of the area.  Invasive species can cause damage to the environment, human economy, or human health.  Van Vleck Gardens is home to two invasive Wisteria species, Japanese wisteria (Wisteria floribunda) and Chinese wisteria (Wisteria sinensis)

It sure looks pretty

So why would Van Vleck allow something to grow in the amphitheater that's so dangerous to the native organisms? These species of wisteria can tear off gutters, bend iron railings, strangle trees, and smother entire woods and hillsides.  Without proper care, these suckers could take over the world (*this might be a slight exaggeration*).  In all honesty, I'm not sure why wisteria is grown in Van Vleck other than for the aesthetic of the beautiful, fragrant flowers.

So, if you're like me in September and couldn't care less about some purple plant, if these nasty bines start growing in your yard, you might want to start worrying.

Pillbugs vs. Sowbugs. . .Which Do You Prefer?

Ms. Eckert's classroom is the home of many organisms.  There is Savannah (our leopard gecko), Clem (our albino axolotl), our many pillbugs as well as sowbugs, and many tiny microorganisms that we cannot see!  In the beginning of the year, there was a lab conducted by our biology class to observe the behavior of the species Armadillidium, commonly referred to as pillbugs.  The purpose was to evaluate what types of environments the pillbugs preferred to reside in.

Drawing copyright © 1997 R. Brusca.

Pillbugs are classified in the order of Isopoda which include crustaceans that range in various shapes and sizes.  Isopods are commonly mistaken as insects due to the fact that they are small and live in the ground, however, they are terrestrial crustaceans.  As in most crustaceans, the isopod body is divided into three distinct regions of the head (cephalon), thorax, and abdomen (pleon).  The first segment of the thorax is fused to the head.  There are usually seven free segments called pereonites of the thorax that make up the pereon.  They also have compound eyes, two pairs of antennae, and four sets of jaws.  Isopods also are found in marine and terrestrial habitats as well, but most of these creatures live in water.  Common marine crustaceans include lobster, crab, krill, shrimp, and barnacles.  Crustaceans respirate through gills that are located where the legs attached to the thorax. 

Before actually starting the experiment, the biology class compared the differences between two terrestrial crustaceans, pillbugs to sowbugs.  Pillbugs and Sowbugs are recognized by their wingless, slate­ grey colored, round­-back, bodies that have segments which resemble armored plates.  Their oval bodies are convex above but flat underneath.  They also have seven pairs of legs and two pairs of antennae, although one pair is barely visible.  Sowbugs, the species Porcellionidae, are typically larger than pillbugs and also have two tail-like appendages that jet out at the rear end of the body.  Since pillbugs do not have these appendages, it allows them to roll up into a tight ball when disturbed - hence the name "rolly-polies."

 Can you identify which ones are sowbugs and which ones are pillbugs?

Pillbugs and sowbugs are found in moist environments, commonly outdoors.  Occasionally, they will end up in buildings but have no fear if you find them in your house!  They may be found in large numbers but these bugs do not bite, sting, or transmit diseases.  Indoor environments are often too dry so the pillbugs and sowbugs will die soon after coming inside.  Both species play a role in the cycling of nutrients as they feed mainly on decaying organic matter.  They can only thrive in environments of high moisture such as damp areas under objects.  Around buildings and playgrounds are common areas to find them.  Do you remember digging in the ground when you were younger and finding rolly-pollies in the soil? I hope that I wasn't the only kid who did that.

I personally like pillbugs and because they are a lot calmer than sowbugs.  When I let a pillbug walk across my hand, it takes its time to crawl and I get a chance to see its physical characteristics.  I also think its really cool that pillbugs can curl up into balls - c'mon they even got a good name for themselves!  Sowbugs are a bit bigger and more aggressive when traveling.  They like to move quickly and are more frantic.  When I placed a sowbug in my hand, it kept trying to run away and eventually just fell off my hand. 

Here is one of the class's pillbugs! (left: curled up, right: crawling)

Now let me show you a sowbug (left: crawling OFF my hand, right: back in its habitat)

So although pillbugs and sowbugs are pretty similar. . .which do you prefer?

Living Walls: The Innovative Solution That's Saving African Lions in Northern Tanzania

Maasai school children, staff at the Noloholo Environmental Center, and students from National Geographic, myself included, stand in front of a finished Living Wall which we constructed. Picture by Cameron Zegers.

The African Lion (Panthera Leo) has roamed the vast continent since ancient historic times. Throughout the rich history of Africa, they have been mythologized and idolized for their incredible strength and courage. Two thousand years ago, over a million lions inhabited our Earth. By 1940, their population had dropped to an estimated 450,000. Today, a mere 20,000 remain. How has this species, once worshiped for their incredible power and endurance, been reduced so significantly in a matter of years? Humans may be to blame, but not all hope is lost for the African Lion.

Lionesses in the Ngorongoro Crater feast on a wildebeest.

            As human populations skyrocket on the African Continent and worldwide, more and more land is devoted to satisfying their needs. In Eastern Africa, the seemingly endless savannahs are nearing their carrying capacity far sooner than anticipated. Wildlife habitats are being depleted at alarming rates, leading to a rapid decline in primary consumers such as zebras, giraffes, wildebeests, and impalas. The food chain has been ruptured, and consequently, the lion population is dwindling. In the Maasai Steppe, a rural region that is home to the second largest concentration of wildlife in Northern Tanzania, the semi-pastoralist Maasai tribe must compete with wildlife populations in order to allow their livestock to graze.  Take away their pastures, and their entire livelihood is lost. Take away lion habitats, and they will soon become extinct. To further complicate this issue, lions will often prey on Maasai livestock, costing families thousands of dollars. Maasai tribes will often retaliate by killing the lions with spears and poison. Many young Maasai warriors will poison animal carcasses and leave them out for lions to feast on. This is especially dangerous because it has the potential to wipe out anywhere from a single lion to an entire pride. This complex issue has created a situation in which everyone loses and nobody wins. Fortunately, Doctor Laly Lichtenfeld of the National Geographic Big Cats initiative has a solution.

A Maasai warrior leads his livestock to pasture.

            Dr. Lichtenfeld has spent over 20 years on the ground in Northeastern Africa, tracing and studying lion populations in the region. She now resides in rural Tanzania, where she worked with her husband to establish the Noloholo Environmental Center for research as well as community programs. She has fostered a close relationship with nearby Maasai communities, and has worked with them to solve the conundrum of lion predation on livestock. And thus, the Living Wall was born. Living Walls are fences constructed with chain link and local acacia trees as fence posts. As the trees grow, their thorny branches add height to the fence, preventing lions from leaping over them.  Using the acacia as fence posts also eliminates the cost of purchasing and transporting posts hundreds of miles to the Maasai Steppe. The Living Walls cost about $500 each and last for a minimum of 20 years. 

12 year old Mwanaidi Bakari helps me to affix the chain link to an acacia tree post.

These fences have so far been 100% effective in preventing attacks on livestock and keeping both lions and livestock safe. The Noloholo Environmental Center comes together with the Maasai community to install these fences around livestock enclosures. Together, they are preventing the deaths of approximately 75 lions each year, a number that will only increase as more fences are installed. With each new Living Wall, another village sleeps soundly at night, with the assurance that their livestock are safe. With each new Living Wall, a few more lions are saved from premature death. African Lions have certainly not seen their final days on the Maasai Steppe. 

Five Maasai Junior Elders, in their traditional attire.

            

For more information on the Living Wall project, watch Dr. Lichtenfeld's TEDx talk here.