Synthisophy 527 

Lesson 3:  Chapter 2  - Evolution and Human Evolution 

 

Watch the video: http://www.synthisophy.com/2-human-evolution.html

...which only discusses human evolution, summarize and expand upon this in front of the class. Scroll down to the evolution chart at the bottom of the page, discuss that…..

Then you will go back in time to address Evolution of life from the beginning.

Atomic – atoms – show periodic table of elements

Molecular – atoms bind together to form molecules – show examples

Biochemical – molecules interact in chemical reactions – show examples

Organelles – part of a cell where chemical reactions take place – show examples

Cell – all this taking place in a single cell – show examples

Organs – group of cells functioning within a unit for a purpose – shows examples

The whole living organism


















Let’s keep this in mind and look at evolution of life on earth

 

Look at periodic table, look at carbon, the living atom, and other important elements in living organisms: Oxygen and Nitrogen to a large extent, with many of the other elements like chlorine, sodium, potassium, calcium and many others…

 

Life first emerged on the earth about 4 and 3.5 billion years ago, when certain molecules had developed that somehow reacted with each other to form a living thing that could reproduce itself.  Exactly what happened and how this happened is not known, but at some point in time it must have happened, because there is life on the planet and we are talking about it right now. These organisms developed into single celled organisms, now called prokaryotes, the simplest form of life are bacteria and archaea (R key ah), which can live in extreme environments (in terms of temperature, salt content and/or pH), and are thought to be the closest to the first living cells that emerged 3.5 billion years ago:































The next step in evolution was the appearance of single celled eukaryotes 2.7 billion years ago.  These cells have a well defined nucleus, mitochondria and other organelles, an organelle being an “organ” with a particular purpose inside the cell.  Notice above that prokaryotes do not have a nucleus or organelles. Also note that mitochondria in eukaryotes contain different DNA then the nucleus of the cell, so what most likely happened here was a eukaryotic cell absorbed a prokaryotic cell that then became a critical part of that cell – the mitochondria – mitochondria provide chemical energy for the cell. Examples of single celled eukaryotes are protozoa, and species of algae that are single celled.


Algae structure and function


























The DNA is like the architectural blueprint of the cell, it code

The DNA is like the architectural blueprint of the cell, it codes the information from which the cell creates itself, and how it functions and reproduces itself, the difference being, a blueprint has all the information to construct something, but the blueprint does construct or reproduce itself – a cell and a living organism does.

Multicellular eukaryotic organisms appeared on the planet about 1 billion years ago.  That’s when somehow single celled eukaryotic organisms figured out a way to be more productive, and more reproductive, if they merged together forming a multicellular organism.  Examples of eukaryotic organisms are brown, red, and green algae, fungus, plants and animals.



















 

Let’s follow the evolution of eukaryotic organisms from their start 1 billion years ago.

Six hundred million years ago simple multicellular organisms (simple from our perspective, but the most complex at the time) similar to jellyfish and worms split evolutionarily into what would become two different groups of animals, vertebrates and invertebrates, as in fish/amphibians/reptiles/mammals and insects/spiders/crab/shrimp, etc…

The appearance of fish in the evolutionary record started about 500 million years ago primarily in the oceans of the earth.


            Haikouichthys






               Coelacanth