Planet Earth - The Ectasian Period - Caution contains first record of sexual reproduction

The Ectasian period that dated from 1,400 to 1,200 million years ago is the second of three periods that make up the Mesoproterozoic Era. So why the picture above - read on and you'll find out why.

The term Ectasian comes from the Greek word for "Extension" and relates to the continuing expansion of the continents by the progression of sedimentary and volcanic deposits that continue, during this period, to cover the craton (the older and more stable part of the craton). This extension helped to form the basis of the  supercontinent Rodinia, which lasted from 1,100 million years to 780 million years ago, through the break up of the previous supercontinent, Columbia, and through accretion. A mountain range building event, known as the Grenville orogeny, that ran from the Labrador coast to Mexico on the North American continent was also formed over a series of events; it should be noted that part of Scotland has evidence of this orogeny.

It should be noted that this period is potentially the first recorded time that sexual reproduction had been recorded. A form of red algae (Bangiomorpha pubescens - a form of eukaryote) left its microfilaments as a fossil in the Hunting Formation on Somerset Island in Canada and is dated around 1,200 million years old. The microfilaments are evidence for complex multicellularity - multicellular organisms contain cells that perform specialised functions. Sexual reproduction has to solve the problem of generating an organism from germ cells (a biological cell that produces gametes of a sexually reproducing organism and a gamete is a cell that joins with another cell during fertilisation).

Previously asexual reproduction, the direct copying of cells without the fusion of gametes into an organism, meant that multicellularity could not exist. So, therefore, it stands to reason that both multicellularity and sexual reproduction and fossilised records of the former are all geological markers within our history of both Whatlington and Vinehall Street 

There is an interesting article about the chemical properties of early life that can be found here.

Next time - The Stenian Period