Humans - Emergence

What a piece of work is man?

Let's give Patrick Stewart a chance here.  
My partiality to Gielgud or Olivier is showing

Cells don't exist alone. They exist in an ecosystem that contains food and other cells like themselves - the biosphere.  Bacteria seem aware of each other and respond to certain group behavior thresholds, for example.

Once prokaryotic cells existed for a couple of billion years, they modified our planet, its atmosphere and the soup of the oceans, laying the foundation for the development of the larger eukaryotic cells with internal organelles and nuclei to carry DNA.

Comb Jellies - beautiful in their simplicity, with a nervous system but no brain.
[Like some people we know?]

Eventually some cells operated in a group and individual cells took on a division of functions - functions like digestion, locomotion, sensitivity to light, etc. It is highly likely that microbial life is widespread in the universe, but for the conditions to lead to eukaryotic cells and multicellular life takes a longer time. The container or bubble in which it is developing must have long safe periods on a stable planet in a quiet corner of some galaxy.

And then for multicell life to develop into modern larger and more complex organisms only  begins afer a few billion years of foundation building. What we think of as larger animals only really began about 500 million years ago. And the achievement of more advanced intelligence like mammals began about 65 million years ago and humans about 2 to 4  million years ago.

mya = million years ago

A lot of things have to go right for this to happen. My estimate is that microbes may be common and develop quickly on a cosmic time scale, but creatures like us may be rare, very rare and take a minimum of billions of years of a chain of low probability events to happen.

Could the dinosaurs have become as advanced as us? It all means what you mean by advanced. The dinosaurs dominated the Earth for 130 million years, and yet they are gone. We have only been here for two million years or about a hundred thousand for modern man and 10,000 years for society. Given our current behavior, we may not be here much longer.

Although we think intelligence is valuable because we have it [or at least a little], it may not be important on some other scales. 

What is evolutionary success? - The number of individuals? - Their total size or biomass? Their endurance or longevity as individuals or species? 

Viruses have no smarts at all, but obviously vastly outnumber us. The total weight of insects on this planets easily outweighs all the mammals and certainly the humans. Cockroaches were here long before we got here [and may still be here when we are gone, if we don't get our act together.]


Lucy & Ardi - our great . . . great … great grandmothers:
Lucy lived over 2 mya [million years ago] 
But Ardi lived 4 mya.

There’s more ahead, inclduing something suprising and unforseen :
We really have found the missing link, Ardipethicus.
Ardi is very human like and yet her feet still show grapsing ability. Ths leads many to think that our walking upright developed before our big brains.

What makes the difference? Walking upright on two legs? Leaving our hands the freedom to develop manipulation? And where did our brains come from ?

What comes after bipedalism? How about thinking. !!
Oddly, it seems that feet came before brains. 
But let’s move on to brains:


Next >>> Thinking

© Gareth Harris 2019                                      Email:                  See also: