Survival of The Fittest in English Human Science by S Sinha books and stories PDF | Survival of The Fittest

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Survival of The Fittest

                                Story of Survival of The Fittest 

To survive in  this world one has to be fit . Every human being  is  born out of the meeting of a tiny sperm cell with an egg . Imagine some 36- 38 weeks back you were just a tiny sperm cell with a tiny head and tail racing with fellow millions alike and ultimately you won the race. So never underestimate yourself , you can do wonders .

The Struggle of Champion Sperm

Survival of the fittest - is the universal law. It’s a very real thing. 250 million sperms leave on a journey and only one makes it to the finish line – that has to be the toughest . It might seem trite dialogue .Being a sperm has to be the toughest job in the world. It has to compete with millions of others just like it, it has to swim at the fastest and hardest speeds upstream. A sperm has to counter hostile environments and above all else has to fight and defeat all fellows on its way into an egg.  Fast-swimming sperm can reach the egg in a half an hour, while others may take days. The sperm can live up to 48-72 hours. Only a few hundred will even come close to the egg because of the many natural barriers that exist in a woman's body.  

This journey is extremely tough. It’s a fascinating lesson into something that we all think we know that  when a sperm meets egg and  baby results but to understand all the finer details is a different matter. Its journey to meet the egg is no less than any wonder. The design is incredible and engaging. In short it can be described as below  -

From the moment sperm enters the vagina, it is under attack from the woman’s natural defense systems. Over 250 million sperm start the race to penetrate the egg, with only one surviving in the end. It is the ultimate story of survival of the fittest.

It takes approximately 70 days to produce sperm. In the average fertile man 1,000 sperm roll off the production line with every heartbeat. Although the journey sperm undertakes is only about 10 to 12 cm, it is truly remarkable. It is equivalent to a human swimming 30 miles.

Sperms are presented with hurdles and death at every turn, with only a few hundred getting as far as the Fallopian tube and only about one or two that ever get close enough to the egg to fertilize it.

Let us look at How 250 Millions sperms  begin race to egg but in the end only the fittest one won it - 

1. Sperm in  the making - sperm production  takes about 70 days . In  a typical fertile adult nearly 1000 sperm rollout with each heartbeat

2. Finishing touch- During next 2 weeks they get finishing touches such as tail modification while passing through a long winding tube which is known as  epididymis .

3.  Calm before the  storm - In the  epididymis sperms can remain healthy and still for many weeks in the human body. If ejaculation doesn't happen often the older sperms can destroy newer ones  leaving the epididymis .

4. Now  they're off - during ejaculation  sperms stored at the end of epididymis are propelled by muscular contractions through a tube vas deferens and then further  down .  An average  ejaculated  semen has 250 millions ( 25 Crores ) sperms.

5. The  survival of fittest - sperms must travel fast from vagina to cervix to survive. The only fastest , healthiest and also the luckiest ones can make it safely to the cervix. 99 % will die during their journey of race.

6.Where to go Left or Right - next how to get to the correct fallopian tube. Women have two  fallopian  tubes one for each ovary .But only one ovary releases an egg during the cycle .Sperms must race towards the correct ovary which has released the egg . Those choosing the wrong path are out of  the race.

7. Let me in   .. fallopian  tube entry is too small and acts like a valve allowing very few certain sperms in  . It’s just like they knock at the door and pray for entry into the fallopian tube .Those swimming erratically are left out. Those capable of entering will continue their journey further .

8. Safe haven - after ejaculation  , hardly 100 of 250 M get safely  in the  fallopian  tube .They stick to the inner walls of the tube waiting for release of egg.

9. Race Begins again - once sperms get signal that the egg is released they release themselves from walls and start racing further . After release from the walls they race towards the middle of the fallopian  tube in the direction of the ovary to find their target , the egg.

10. Almost there  - Woman’s egg is encircled by a cloud of cells called cumulus . Sperms must swim in their typical  style through the cloud to reach the egg’s  surface  

11. The Final hurdle - at this stage there are 1 or 2 sperms left  who have a chance to fertilize the egg. Now only 1 can reach inside .

12. Puncturing the egg  - on reaching the surface of the egg , enzymes on the head of the sperms burst which dissolves the outer membrane of the egg and the most powerful sperm enters into the egg .   

14. Doors  are locked - Once the sperm enters , chemical reactions  start in the egg hardening its membrane and stopping any further entry of sperm which might be on its way .

12. The End Result Conceptions - in the next few hours the tail of sperm is detached and  chromosomes in the head of sperm are released which line up with chromosomes of egg and it is fertilized , with their combination process of making a new baby starts in the womb . In due course various organs of the baby keep on growing in the womb till it’s ready for labor pain and delivery .

Post Fertilization Brief Story -

Nearly a week after conception , a hormone called  hcG (human chorionic gonadotropin ) can be found in mother’s blood .It is produced by cells that will become the Placenta . This hormone is easily detected in blood or urine tests . Some DIY  ( do it yourself) home tests can detect pregnancy on the next day of the missing period .

Baby’s growth - The fertilized egg attaches to the uterus  walls and cells keep dividing . Some cells become the Placenta While others become the embryo .Placenta attaches to the uterus walls and the baby's Umbilical cord arises from it . Heart starts beating during the 5th week . The brain , spinal cord , heart and other organs are in the making . Full term delivery usually happens anytime around 40 weeks .