Science, Art, Litt, Science based Art & Science Communication

What baby reflexes tell about our evolution

As part of my science communication exercises, recently I have shown these two pictures to a few mothers and fathers and asked them to tell me what these pictures tell them about babies

And these are some of the replies of mothers:

1. Giving confidence to the baby that we are there for you.

2. Checking whether all motor functions are doing well or not (this was given by my sister)

3. Care, Securedness, confidence ......

Very interesting is that, a small baby also knows to take care of him/her self (they hold onto our body, clothes whatever they can hold and make themselves secure). Only we feel that we are there to take care of them.

Every creation in this Universe comes with a system and mechanism to take care of themselves.

4. Once let go you have a bigger scope of bringing out unknown capabilities

5. Let loose and a larger scope opens up. Till the baby's hands are held he is closed, tight, more comfort zone and once that is let loose and he is dropped automatically .... the hands dont drop off he balances them.

Surprisingly, fathers didn't give replies at all! They weren't sure. Some tried to search using google but their efforts turned futile because unless and until you use specific words, you won't get any information about them!

Finally I gave them this information:

I am amazed at the motherly instincts taking precedence while answering the questions I asked. Well done mothers. You are all very good mothers, when emotions are taken into account. Loved reading/listening to your adorable replies.

But, there is an unseen world too. The scientific world that knows more about babies than mothers and fathers do. Let me show you that world too.

Heard about evolution?

Evolution doesn't stop. Ever.

It just goes into hiatus until the need to change a characteristic emerges. When a heritable characteristic is no longer a viable trait for the survival of that species, it is thrown to the back of the pile. It's still there, but is forgotten as the brain develops.

But you can still see those traits in babies .

The Moro reflex ( the first picture above) is one such thing.

The Moro reflex is an infantile reflex that develops between 28 and 32 weeks of gestation and disappears at 3–6 months of age. It is a response to a sudden loss of support and involves three distinct components:
spreading out the arms (abduction), pulling the arms in (adduction), and crying
The primary significance of the Moro reflex is in evaluating integration of the central nervous system

[S ( my sister), your reply was close ( I am sure you observed doctors doing the motor skill tests on N, N and then on Y - I am sure I rubbed off some of my qualities on you ) ; absence or asymmetry of either abduction or adduction by 2 to 3 months age can be regarded as abnormal; absence during the neonatal period may warrant assessment for the possibility of developmental complications such as birth injury or interference with brain formation. Asymmetry of the Moro reflex is especially useful to note, as it is almost always a feature of root, plexus, or nerve disease].

The Moro reflex occurs when a baby suddenly loses support and feels like it's falling. The baby involuntarily spreads its arms out, clenches, and brings the arms back in. Then finishes it off with the loudest cry possible.

Once the baby is done crying, take its hand and run your finger across its palm. What happens?

The Palmar Grasp Reflex, the second picture above. The palmar grasp reflex allows a newborn to clench an object when pressure and touch are applied to the palm. The first readily recognizable fine motor skill that is crucial to normal development is unfisting.

It is theorized that the grasping reflex evolved as it is essential to survival in species, usually primates, where the young are carried in the fur. The infant's ability to grasp onto a mother's fur allows the mother to keep the infant with her while foraging for food or moving from one place to another. This is beneficial to the mother because she does not lose function of her limbs or mouth

These reflexes are an echo of our evolutionary past. We are all primates. Human and chimp DNA diverged between 5 and 7 million years ago and there is only a 1.23% difference between chimp DNA and modern human DNA. As evolution takes its course and our brains develop, our DNA changes as well.

Most primates live on the canopy most of their lives. Their young are instinctively able to hang to their mother’s fur and eventually on to the trees. The Moro reflex is an evolutionary response that enables the baby to either regain hold or alert the mother that they have fallen off. The palmar grasp reflex works to enable primates to move around in the canopy e.g. jump from one tree to another and not fall off regularly, or even hold on while doing other activities like sleeping or eating. It's not the baby that does this, but the brain. In humans however, development of the frontal lobe (responsible for voluntary responses) suppresses these reflexes and is instinctively forgotten overtime.

Another example :

When you soak your hands in water, your nervous system sends a message to your blood vessels to shrink. Your body responds by sending blood away from the area, and the loss of blood volume makes your vessels thinner. The skin folds in over them, and this causes wrinkles.

It's not the temperature of the water, nor is it the nature of your skin. This reflex is caused by the nervous system, not the brain, and occurs when your skin is exposed to water over a prolonged period of time. But why just your palms and not your entire face? Because when you’re a primate cruising around the canopy on a wet day, wet palms would not help your grip.

That’s right. Evolution literally wrinkles your palm and fingertips to create treads (very much like tire treads) to channel water away from your fingertips and palm and maintain your grip on branches.

What baby reflexes tell about our evolution

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