From Seed to Fork – Greg Morter

Greg’s talk was fascinating although very big numbers we are not used to dealing with.

 

 

 

In a nutshell:
Life in the sea evolved to live on land (about 700 million years ago)
Plants had to evolve to live on land before animals could
Early plants were similar to today’s liverworts and club mosses relying on water for survival
It took about 400 million years for plants to evolve sufficiently to live happily on land and produce seeds leading to the first herbivores
Humans diverge from their closest relatives about 6 million years ago
Agriculture only dates back about 15000 years

A bit more detail:

Plants emerged from the sea about 700 million years ago and the problems they had to solve in order to survive on land were:

  • nutrition (in the sea they just absorbed this direct from the water)
  • drying out
  • gravity
  • reproduction (done in the sea by releasing male and female spores into the water)

To overcome these problems early plants had to develop:

  • waxy cuticles to reduce water loss
  • stomata to breath whilst reducing water loss
  • rhizome (early roots)
  • vascular systems to transport fluids around the plant

It wasn’t until plants evolved to produce seeds (about 300 million years ago) that the first herbivores emerged. The first seed producing plants were Ginkgo & Monkey Puzzle trees (both primitive conifers). It was about this time also (Carboniferous era 359-299million years ago) that our coal supplies were laid down in tropical forests (all still close to water), dragonflies had up to 1m wing spans and millipedes up to 2m long.

130 million years ago, conifers got marginalised as flowering plants started to emerge, the earliest of which include Magnolias. This is a significant point of evolution since most of the plants we eat are flowering / seed bearing plants. Bees, butterflies & ants emerged at this time also therefore solving the pollination issues.

Early plants protected themselves from grazing animals by producing:

  • spines
  • toxins (e.g. caffeine in coffee, cannabis, quinine)
  • nut shells

70 million years ago grasses evolved however it takes several million years for grassland became more dominant. Man has built his civilization on grasses.  Humans diverge from their closest relatives about 6 million years ago.

15000 years ago agriculture emerged (from the former hunter gathering)

Greg described ‘Agriculture as evolution going backwards’. For example:

  • Plants protect themselves by being ‘bitter’ whilst man selects less bitter plants.
  • Man selects plants that do not shed their seed easily / over a period of time
  • Man wants plants that germinate easily whereas plants tend to have complicated germination requirements to help protect them from germinating at the wrong time of year
  • Man selects for large seeds (as big as possible where as a plant is best producing the smallest seeds possible)

It has been discovered that ancient civilizations tended to be less healthy after the shift from hunter / gathering life styles to agriculture. On average the former diet contains approximately 360 species whilst the later only 10 species.

Greg also runs ‘universe walks’, 2 day walks ‘walking the story of the universe’

http://universewalk.co.uk/

A summary of the evolution of plants over the last 450million years and how we have adapted them in the last 100 years since the agricultural revolution. I found a link online which lists the evolution of life on Earth which will save me millions of years of typing and less risk of errors on my part:

https://www.newscientist.com/article/dn17453-timeline-the-evolution-of-life/