(8.11.26) Hawaii Biology
The Fundamental Role of Water in Biological Chemistry
Water acts as the universal medium for life, providing an environment where materials can dissolve, recombine, and form new chemicals.
On early Earth, the raw ingredients of life constantly interacted and combined within water over millions of years to eventually lead to living organisms.
The "divide and conquer" approach of water facilitates the breakdown of chemical structures. For example, in table salt or sodium chloride (), water interacts with ions through its polar nature:
Negatively charged oxygen atoms surround the positive sodium ions ().
Positive hydrogen atoms surround the negative chlorine atoms ().
Because water remains in a liquid state under typical Earth surface conditions, molecules within it possess "degrees of freedom." This allows them to:
Move in different directions.
Flip, vibrate, stretch, and rotate.
Try novel combinations and form new chemical bonds.
Structural Function of Water in Plants
Water provides essential structural support to plants. A plant cell functions similarly to a water balloon.
Shape is maintained via the pressure of water pushing outward against the rigid cellulose cell wall. This internal pressure is referred to as turgidity.
When a plant is deprived of water, it loses its color and begins to sag or look "sad" before it eventually dies. This loss of structural integrity results in the plant becoming limp.
Geological Formation of the Hawaiian Islands
The Hawaiian archipelago is a 350-mile-long island chain located thousands of miles from the nearest land in the middle of the Pacific Ocean.
The islands were formed by a "hotspot," a point of weakness in the Earth's crust located more than three miles below the surface of the Pacific Ocean.
Over hundreds of thousands of years, lava piled up layer upon layer. The Big Island (Hawaii), measured from the seafloor, is taller than Mount Everest.
Kilauea is an extremely active volcano, producing enough lava daily to pave of two-lane highway.
This massive island chain forms a barrier to prevailing winds, creating distinct weather patterns such as the chilling, calmer air that stretches toward Asia.
Marine Ecosystems: Whales and Coral Reefs
Humpback whales travel approximately from the North Pacific/Alaska to Hawaii.
Hawaii serves as a safe haven for whales to breed and raise their young (pups) away from chief competitors.
Whales feed in Alaska during the summer to gain weight, then migrate to Hawaii to give birth to the offspring conceived the previous year. This indicates a long gestation period.
The waters around Hawaii are described as a "pelagic desert" because they are extremely low in nutrients. This lack of nutrients ensures the water remains clear.
Clear water is vital for coral reefs, which require sunlight for photosynthesis. If the ocean were rich in nutrients, algae would bloom and cloud the water, effectively starving the coral.
The unique underwater ecosystem in Hawaii has a high rate of endemism; a quarter of the fish species found there exist nowhere else on Earth.
Biological Classification: Native vs. Endemic
Native Species: Organisms that arrived in a location naturally (without human aid) but are also found in other geographical locations. An example is the Naupaka, a beach plant whose seeds float across the ocean.
Endemic Species: Organisms that arrived naturally but evolved over time into unique species found nowhere else on Earth.
Example: The Hawaiian Honeycreeper: These birds evolved from a single species (the rose finch) that arrived from Eurasia. They underwent adaptive radiation, developing specialized beaks for different food sources like nectar, seeds, or wood-boring insects.
Example: The Haleakala silver sword: A unique plant species.
Example: The Hawaiian Garden Eel: These eels disguise themselves as grass to catch prey.
The Physics of Hawaiian Waves and Surf Culture
Large Pacific swells are generated by powerful storms in Australia (to the South) and Alaska (to the North).
These swells travel across vast distances and collide with the steep underwater slopes of Hawaii.
Hawaiian lava (specifically "Ahoyhoy" or Pahoehoe), which is the hottest () and fastest-flowing type, cools rapidly when hitting the sea. This forms steep underwater ledges rather than gentle slopes.
When a swell hits these steep lava slopes, the water is pushed upward, creating massive waves.
Ancient Polynesians utilized dugout canoes to catch these waves to return to shore faster, eventually developing specialized boards for "He'e Nalu" (surfing).
Polynesian Discovery and Navigation
The Hawaiian Islands were initially uninhabited and undiscovered by humans.
Polynesians discovered the islands by following the migration of the Pacific golden plover (or "plumbers"). The birds flew from the South Pacific to the Arctic, pausing in Hawaii.
Because the Polynesians could not keep up with the birds' speed, they tracked them over generations (nearly 400 years). They would mark the spot where they lost sight of the birds using the stars and return to that same spot the following year.
A specific training site for navigators exists at Kaho'olawbe Bay, featuring a "navigator chair" (a rock) that points directly at the North Star.
Settlement of the islands by Polynesians occurred around 800 AD.
Agriculture and Resource Development
Early settlers brought essential items, such as the taro (Kalo) plant, as a carbohydrate source. Taro features a "breathing tube" that allows it to survive in flooded conditions.
Taro was pounded into a paste called poi, which resists spoilage for years.
While volcanic rock is tough, Hawaii receives over of rainwater daily. This water leaches phosphorus and other nutrients from the rock, funneling them into valley floors to support crops.
Hawaiiite: A super-hard rock found on Mauna Kea. It was formed years ago during an Ice Age (caused by a 2-degree shift in Earth's orbital tilt) when lava erupted under an ice cap and cooled instantly. Polynesians used this rock to make tools like axes, chisels, and spades, an advancement comparable to Europe's Bronze Age.
Ecological Succession and Volcanic Adaptations
Succession began as life moved onto barren lava landscapes. One of the first colonizing plants was the Ahilahua (or Ahi'ala Hua).
The Ahilahua tree can grow up to tall and does not require soil. Its roots have evolved to penetrate deep into the Earth to seek moisture.
Roots often reach into "lava tubes." These hollow tunnels are formed when Ahoyhoy lava cools on the surface but continues to flow underneath. When the flow stops, a hollow tube remains, featuring formations like "loxicles."
As pioneer species decay, they form the soil necessary for later waves of immigrants.
Insect Evolution: Over species of fruit fly evolved in Hawaii from a single pregnant female. Additionally, Hawaii is home to a unique carnivorous caterpillar (Eupithecia) that evolved from vegetarian ancestors.
Questions & Discussion
Question: Is the whole video on water?
Answer: It covers water's chemical role, but then shifts to the origin of the Hawaiian Islands, Polynesian navigation, and endemic biology.
Discussion on Ocean Salinity: The ocean is salty because rainwater flows across the land, collecting minerals and nutrients (salts), and carries them into the ocean, which acts as a catch-all basin.
Dialogue on Classroom Logistics: The safety contract is due by Friday. Students needs a pass or must sign the board to go to the bathroom. There was a discussion regarding a former teacher, Mr. Kim, and the transition to the new curriculum. Mentions were made of an "aura" to help with a stomachache.
Note on Whales: Whales do not eat while they are in Hawaii; they rely on stored fat from feeding in Alaska.
Etymology: "Molokai" (or modeled kai) is explained to mean "gathering of ocean waters," where "kai" refers to ocean water.