More Than Biology: The Astonishing Design Behind Human Fever, Infant Senses, Bird Migration, and Leaf Patterns

Have you wondered why our temperature rises when we’re sick?Normally, body temperature is kept constant (around 36.5°C) and is regulated by the hypothalamus in the brain (which contains the body’s temperature control center – the brain’s “thermostat”). During illness, the immune system “recruits” millions of soldiers (macrophages) that kill the bacteria that have invaded the body. Besides their direct activity against foreign invaders, these macrophages also secrete proteins (interleukins) that can cross the blood–brain barrier and influence the hypothalamus to raise body temperature to a level at which certain bacteria and viruses can no longer survive or reproduce.

Fever itself is a response of the immune system in its battle against bacteria and viruses. The difference between 37°C and 38.5°C is critical, because many of the viruses and bacteria that cause familiar winter illnesses, such as the flu, cannot withstand this higher temperature. Even if they are not completely destroyed, their rate of reproduction drops in a warmer body. Therefore, when a fever appears, it is a sign that the body is reacting to bacteria and viruses and dealing with them.

Why do we shiver from cold when our temperature rises? Could it be a malfunction in the body’s systems?

The hypothalamus senses the current body temperature and compares it to the desired, preset temperature. If the current temperature in the body differs from the desired temperature, the hypothalamus tries to correct it. It sends nerve signals that cause us to sweat if we are too hot, or to shiver and warm the body if we are too cold. Sweating cools the body, while shivering warms it.

This is why we shiver with cold when our temperature rises. We may suffer from a high fever, sweat, and yet still feel cold, hide under blankets, and shiver (the shivering warms the body). A little while later, when the body temperature has risen to the new set point, the hypothalamus sends signals that the body temperature is now “normal.” At that stage, we no longer feel cold – that is the moment we throw off the blankets. After some time, the hypothalamus again changes the direction of temperature regulation and brings it back down to its usual value.

What feels like a “flaw” in the design is actually the natural way in which our body fights infection. Who designed such a wondrous mechanism?

How Is It That They Don’t See the Creator?

One phenomenon that fascinates me is how there are doctors and scientists who know the wonders of the human body and our amazing world in great depth – and yet do not return to faith. How can it be that there are doctors and scientists who even speak words of heresy at times?

Knowing that there is a Creator should be easy, because all of creation cries out, “There is a Creator to the world!” It is enough just to listen to the beating of our heart and understand that something far greater than us is at work. And yet, if everything is so clear, why are there so many people who don’t accept this simple truth? Why are there people who never pause to think, to contemplate this wondrous and incredible creation?

First, the constant chase after the vanities of this world leaves a person with no time or mental quiet for reflection. A person is busy with money, food, relationships, honor, productivity, achievement, and the race for success – he has no time to think! This world “hides” the truth from him.

Second, a person takes for granted the gifts that the Creator gives him in His kindness. A person grows up his entire life seeing, hearing, functioning, with a roof over his head and parents who care for his needs. He becomes accustomed to these blessings. This habit gives him the mistaken feeling that these good things are natural and inevitable – and therefore he does not understand that he must feel gratitude and thank the Creator.

Third, the failures a person experiences in life can lead him to be ungrateful to God. The difficulties that befall a non-believing person (which in truth come upon him justly and for his benefit) cause him to become angry, to complain against God, and to be ungrateful toward Him.

Finally, arrogance leads a person to believe that he is entitled to all these blessings, and that he owes no thanks or service to the Creator in return.

In light of all this, whenever we encounter scientists or doctors who make statements against religion, we should not lose heart and should not see their expertise as a “license” for a life of indulgence and denial. We must continue to look carefully at every aspect of creation and our lives, to see the wisdom and providence of the Creator, to thank Him for all the good He showers upon us, and to accept upon ourselves to serve the One who gives us life at every single moment.

Noise, Chaos, Shouting – Total Overload!

The baby is in its mother’s womb. The atmosphere is pleasant, food is always available, and there is no noise or commotion around. It’s like a vacation in a five-star hotel. But what happens from the moment of birth?

The baby may suddenly be bombarded with a million stimuli: seeing many people crowding around to welcome him, hearing shouting, crying, and loud voices, smelling unfamiliar smells, and dealing with the touch of people holding, hugging, and kissing him. Everything is new – and not necessarily pleasant.

Think how many new experiences the baby may need to process at once. All of his senses could be “switched on” at the same time! What will become of him? Is he truly able to absorb with all his senses and process all this information? How will he manage this sharp transition, which could frighten and confuse him? How will this fragile baby feel secure in this new world?

Among the senses, the newborn enters the world with the senses of touch and taste functioning very well – the most crucial for him at this stage. Babies are born with a very developed sense of touch, especially in their fingertips and around the mouth. Touch is a basic survival need for them. The sense of taste is also developed, and they show a clear preference for sweetness, such as the lactose in breast milk. Lactose is extremely important: it provides energy for the rapidly growing body and brain, increases calcium absorption, and more.

In contrast, some senses are not at their peak at birth, but continue to develop later – for example, the visual system. The baby is born nearsighted; the world appears blurry, visual acuity is very poor, and mostly in grayish tones.

The baby enters this world without all of his senses fully mature and active at once. This is one of the Creator’s kindnesses – so that the baby will not be harmed or overwhelmed if all his senses were to operate at full capacity from the very beginning. In this way, he is able to make it through this sharp transition.

“Even the Stork in the Sky Knows Her Appointed Times” (Yirmiyahu 8:7)

Bird migration is a remarkable natural phenomenon. Birds move from place to place in a fixed yearly cycle and along set routes, to escape harsh climate conditions that don’t allow survival and to search for food.

Bird migration raises many questions: How do birds know when to begin their journey? How do they know where to migrate to? How do they navigate and find their way? How do they withstand harsh travel conditions and survive long-distance migration?

It is truly astonishing that a tiny bird weighing about 20 grams, with a brain weighing only about half a gram, is able to travel every year across migration routes thousands of kilometers long without losing its way, and to return along the same route to its place of origin.

Research has shown that birds possess an internal “clock” that senses changes in light and darkness. When days get shorter and nights longer, a change occurs in the hunger mechanism in their brains. As a result, the birds eat about 40% more than during other times of the year. They thereby build large fat reserves that provide them with energy for the long flight. After this “refueling,” the birds gather into flocks and depart.

Secondly, birds learn to recognize prominent landmarks along the route: rivers, lakes, mountains, sounds, and smells. Their bird’s-eye view and excellent visual memory help them navigate their way and repeat the same route every year. The celestial bodies also assist them: the sun’s position and height help them find direction and altitude, and at night the fixed stars help guide them.

Another tool that helps birds navigate is the Earth’s magnetic field. Powerful magnetic forces are concentrated at the poles and decrease as one moves away. The birds’ instincts allow them to sense changes in magnetic strength, and from this they locate north and south and determine their position along the migration path.

Researchers have also discovered that migratory birds have special biological adaptations suited to migration. Their wings are longer relative to their body size than those of similar, non-migrating species. The shape of their wings is also suited to the distance they must travel: in some species, the wingtips are pointed, a trait that increases speed and prevents waste of energy — critical for long-distance flight.

Despite the many studies on bird migration, many mysteries remain unsolved. Human intellect simply cannot fully grasp the immense wonder evoked by a small bird flying such vast distances.

Who Arranged the Leaves So Beautifully Around the Stem?

Almost all plants have leaves. They come in many forms: heart-shaped leaves, clover leaves, feather-like leaves, finger-like leaves, alternate leaves (one leaf from each node on the stem), opposite leaves (two leaves from each node), whorled leaves (more than two leaves from each node)… But they all share the same function: photosynthesis. Why, despite the same function, does each plant have differently shaped leaves?

When we look at the different shapes and arrangements of leaves on plants, we can see the adaptation between the structure of the leaf and the plant and its ability to absorb light efficiently. Even when the leaves appear to be arranged in a completely random pattern, this is not the case. Leaves are located along branches and stems in a defined and fixed arrangement that enables each leaf to fulfill its role and receive the amount of light it needs.

Every plant species has its own specific, fixed leaf arrangement called phyllotaxis – a botanical term describing the optimal arrangement of leaves around a stem for maximum absorption of solar energy.

In a wondrous way, the structure and arrangement of leaves – fixed and well-ordered along branches and stems – allow each leaf to perform its function and receive exactly the amount of light it needs. That light is essential for one of the most important processes in the living world: photosynthesis, at the end of which the oxygen we breathe is released.

The thin lines on leaves are the veins, which are tiny transport tubes that reach every part of the leaf. Just as blood flows through human arteries to nourish every part of our body, so plant sap flows through the leaf’s veins and nourishes it.

There are parallel veins – veins arranged side by side; arched veins – veins arranged in arch-like forms; and netted veins – veins arranged in a network.

Everything is beautiful, orderly, symmetrical, and clearly purposeful.
Who is the architect who designed and planned all this? Who is the skilled “plumber” who installed the plant’s transport pipes – its veins – in such a perfectly arranged way?