Published on September 15th, 2012 | by David Marshall2
Episode 3: Amber and parasitism
In our first episode on the early origins of life, we discussed how without symbiosis or mutualism (the co-operation of organisms) life as we know it would not have evolved past its most basic levels. Within each Eukaryotic cell, mitochondria and/or chloroplasts are responsible for metabolism. However these organelles are actually endosymbionts and have their own DNA, this relationship is so mutually beneficial that their reproduction has become synchronised.
If the relationship benefits one organism, but has little effect on the other organism, this is termed commensalism. If an organism benefits at the cost of another organism, without benefiting the host, then this is parasitism. Parasites can cause a wide range of detrimental effects and can even be fatal to the host organism. Parasitism has a massive effect today on both our agriculture and healthcare industries, so for this reason understanding the evolution of parasites is massively important.
Upon first glance amber and parasitism may seem an odd coupling, but amber is one of the only windows through which we can see parasitism in the fossil record. Within this solidified tree resin, organisms become almost entirely isolated from outside conditions, this can cut out much of the normal taphonomic process, leaving them almost morphologically unaltered. Details can be preserved down to the cellular level, so even something as subtle and intricate as the parasite – host relationship can be observed.
Images courtesy of Dr George Poinar, OSU.