It is a scientific fact that all living things evolved from the simplest single cell bacteria. These are called cyano-bacteria or green algae. They were the first harvesters of sun energy using photosynthesis and making food for themselves. Thus the food comes from the Sun.
Slowly, the life diversified, especially after the introduction of oxygen into the atmosphere thanks to these green algae. Living beings evolved which cannot make their own food like plants but use the food prepared by the plants and burn it with oxygen.
Then Darwin came and after a massive study and observations in the Canary Islands announced that higher forms of living things evolve slowly from the lower forms. This is a consequence of struggle for survival and survival rate of the fittest or the species which are capable of modifying themselves according to the environment are the best. Humans are a mere speck in this diversity majority of which is staked by the bacteria.
From water to land and from crawling to walking on four limbs, human freed their forelimbs to use them as tools and also stand upright which helps in running away from danger, following the prey and gain the greater ability to watch up to far away distances to locate the danger as well as food. But we have to pay the price for this in the form of backaches, diseases and difficult child birth.
Natural selection continuously sifts the best from the individuals of each generation. But this sometimes occurs clumsily, as old parts and genes are co-opted for new roles. As a result, all species inhabit bodies imperfect for the lives they live. Our own bodies are worse off than most simply because of the many differences between the wilderness in which we evolved and the modern world in which we live. We feel the consequences every day. Here is the first.
Our cells are weird chimeras
Multicellular life started when two cells merged and fused into one. The hunter cell swallowed the prey cell and encapsulated it. Then the prey became the mitochondrion. This is the machinery which provides the cell energy and makes possible its survival. Most of the time, this ancient symbiosis proceeds amicably.
But every so often, our mitochondria and their surrounding cells fight. The result is diseases, such as mitochondrial myopathies (a range of muscle diseases) or Leigh’s disease (which affects the central nervous system).
Other handicaps shall be discussed in subsequent posts.