My last post was about how I had difficulty in the language used to describe evolution (https://confessionsofayec.wordpress.com/2011/06/20/the-language-of-evolutionists/).
This post is about items in nature that caused me the same issues.
There are some amazing things that happen in nature and sometimes they seem to defy any sense of logic. Trying to imagine how they could happen through chance mutation sends my head in a spin. Yet, somehow they did.
Balanites wilsoniana and the Elephant
Its not too much of a stretch to imagine and suggest that elephants eating fruit from trees, moving on and then eventually excreting the seeds of said fruit several miles away assists with the dispersal of those fruit trees. In fact there are several fruits that benefit from elephants this way and its been estimated that the African savannah elephants disperse a third of the fruit seeds that get germinated. This makes elephants extremely important to the ecology of the areas they roam. One can only image what the impact of their severely depleted numbers will have.
The Balanites wilsoniana are a bit more special though. These are large fruits, with large seeds and rely utterly on the elephant for dispersal. What’s more, the tough outer covering gets partially digested in the elephants gut and the result is the seeds germinate better having passed through. The same seems to be true of the Sclerocarva caffra. This goes beyond the elephant merely assisting in the dispersal of the seeds and makes the two species of fruit dependant on being eaten by elephants for the seeds to get the best chance of germinating and producing a new fruit tree. See http://www.sciencedirect.com/science/article/pii/S1146609X11000154#sec5 and http://chapmanresearch.mcgill.ca/Pdf/46_Balanites.pdf
Why would evolution do that? Surely evolution seeks to make life easier and better; constraining a seed to such a specific germination requirement seems rather limiting.
Cardiochiles nigriceps parasitic wasp and the broad-leaved helleborine orchid
The parasitic wasp in question in quite well known, it paralyses a caterpillar and lays its eggs inside the body. The caterpillar is kept alive but immobile while the eggs incubate and hatch. On hating the caterpillar became the first meal for the grubs of the next generation of parasitic wasp.
What is more impressive is that the wasp knows where to find the caterpillars because of the scent given off by the plant leaves when they are eaten. Damaged leaves give off a scent, anyone who has mowed a lawn will know well the scent of freshly cut grass. All across the plant world, leaves give off scents when they are damaged.
The wasp is able to tell the difference between the scent from a damaged plant and the scent of a plant being eaten by the Heliothis virescen caterpillar, its preferred victim. Yes, the plant gives off a different scent when its being eaten by this caterpillar, well it could be any caterpillar I guess. The wasp knows this scent and comes in for its nasty business.
Rather than the plant specifically calling to the wasp for help, its far more likely that the wasp has learnt to recognise this specific scent as the indicator of the presence of its victim.
See http://depot.knaw.nl/56/1/13583.pdf.
So far, all reasonable from an evolutionary perspective, though its precisely the sort of thing I’d have brought up previously as something that can’t happen by mistake; especially the wasp laying its eggs in a caterpillar bit.
However, this is where we go a little surreal.
The broad-leaved helleborine orchid gives of the same scent, or at least one that’s close enough, that attracts the wasp. The wasp finds no caterpillar, but it gets a good mouthful of sweet nectar and helps the orchid along with its pollination in the process.
How utterly wonderfully bizzar! I love it!
The wonders of Chance
I am sure I could find many more examples if I tried a bit harder, but these two will have to suffice as I think they serve to make my point well enough.
They are exactly the sort of thing that would have had me crying out “See! Evolution could not possibly be true for things like this to exist. The chances of it happening by accident are just too small.”
The thing is, odd things and coincidences happen by chance all the time and when you have the meandering randomness that is evolution, then there will be some strange and hard to explain things that happen simply as a by product of that.
Oddities spread throughout nature are not at all evidence against evolution, quite the opposite. Yet, when I was in the mindset of not accepting evolution, this was exactly the sort of thing that set me back.
Related articles
- A Friendly Reminder from the Wikipedia Page on Parasitoid Wasps (slog.thestranger.com)
- Elephant extinction (bbc.co.uk)
- Coming soon to a garden near you …. (vegplugs.wordpress.com)