Earth Lessons

It feels strange to offer such a niche post when I’ve gone so long without saying anything (publicly) at all.   And yet.   I was so captivated by some lessons at a talk I went to recently, it seems a real shame not to find a way to share them.

With an eye toward helping us feel gratitude for our past to then yield a sense of responsibility for our future, a scientist covered some of the highlights of history on earth.

Did you know:

• The earth’s iron core gives us our atmosphere!   It creates a magnetic field that deflects particles from the sun that go zooming by that would otherwise sweeping away atmosphere.  
• Earth time is divided into eons.   Each eon is divided into eras.   The three most recent eras are:
  • Paleozoic – meaning old life
  • Mesozoic – meaning middle life
  • Cenozoic – meaning new life
• We’re in the Cenozoic right now.
• Five times in earth’s history have we seen more than 50% of life die out
  • at end of Paleozoic, 95% of ocean and 75% of land life was lost in great dying
  • at the end of the Mesozoic, an asteroid killed off many reptiles and birds  

• Some precursors to life being human-friendly:
  • Plants changed the atmosphere, pulling CO2 content way down.   At the same time the sun warmed things up.
  • In the Mesozoic, plants began to flower, seeds got bigger and richer
• Things that moved life toward a human body:
  • The emergence of jaws allowed chewing, which sped up digestion, which allowed for energy expensive brains.
    • It also allowed for facial expressions! Only mammals have this!
  • The earliest mammals had many predators and so were mostly nocturnal, causing an emphasis on development of hearing and smell.
    • There are still more nocturnal than diurnal animals!
  • The discovery of fire meant more calories could be absorbed from cooked food, supporting even bigger (calorie-expensive!) brains.

♣ Happy Human-ing!

While not writing publicly, I’ve still been… alive!     And occasionally communicating with people who subscribe.   And I’m pretty sure that sometime this year (2020), I’ll start publishing publicly again!