How do orchids know what bees look like?

[RJSquirrel]

how do orchids know color and scent of pheromones?
do they know after millions of years of evolution the difference in a bumble bee and a wasp?
how do they know how to protect themselves from destructive forces of nature?
how do they know that they attract insects with the faces in their cups?

how do they know?

[snappyguy]

They don't "know." Evolution is a process of random gene recombinations and mutations. Only the good ones survive on into the next generation. Over time beneficial traits supplant less desireable ones. No thought, no planning, just constrained randomness.

[Ray]

Yep - natural selection.

The plants carrying flowers more attractive to the pollinators are the ones that propagated most, the ones that didn't would eventually die out.

[Discus]

You need to turn the question around a bit.

The bees and wasps know what bees and wasps look like and want (to the point that some Ophrys orchids are apparently more attractive to males than the actual females of the corresponding insect) - and the orchids that happen to most look like that, or have the most attractive scent/colour/shape/nectar/etc. "win" by being pollinated the most (because they attract the most potential pollinators), having the most offspring, passing on their genes to the next generation. Because there will be variation in the next generation, the selection process happens over and over again, and over time, the allele/gene frequency tends towards the most effective one. There may be a better way of "designing" a flower from scratch, but orchids "make do" with what they have - it might be sub-optimal, but it works well enough - and that is all that evolution, survival and natural selection "care" about.

Think of it a little bit like a human hybridiser picking the best of a cross, and doing that over and over again, scrapping the ones that don't fit the bill and propagating the ones that do, over and over again.

[BobInBonita]

Might be random, but frequently not a solitary thing in my mind.

I think many species co-evolve to the benefit of the whole system. When a moth with a long proboscis was predicted based on the morphology of an orchid (years before the moth was discovered), we had just touched on the logic of nature.

Don't want to sound all new-agey or anything, but I think as we learn more and more, we'll discover many inter-relationships between things that really make it all work.

It's easy to see the benefit to the orchid, when it looks and smells like a particularly hot and needy wasp, but the benefit to the wasp is more elusive. It is probably detrimental to be tricked, so there must be some deeper benefit that we just don't understand yet - otherwise female wasps would have randomly evolved their appearance or scent to reduce competition from orchids. It may be a couple of steps removed, but there is probably a future "ah-hah" moment when we start to discover the hidden relationships and benefits.

[dendro photo]

i feel the flowers came first and everything else morphed to use them

[Connie Star]

Originally Posted by dendro photo

i feel the flowers came first and everything else morphed to use them

This is THE classic question- which came first, the chicken or the egg?

[Hedge]

Well, plants did evolve before animals, but I'm not sure that evolution to flowering from spore production was before or after insects first appeared, and thus, like BobinBonita, I think they must have co-evolved

[camille1585]

Originally Posted by dendro photo

i feel the flowers came first and everything else morphed to use them

I don't think anything came first, they co-evolved to have the relationship they have today. Natural selection favored the the bee looking/smelling plants since they were more likely to be pollinated.

[Discus]

Originally Posted by Hedge

Well, plants did evolve before animals, but I'm not sure that evolution to flowering from spore production was before or after insects first appeared, and thus, like BobinBonita, I think they must have co-evolved

Flowering plants (Angiosperms) only came about around 140MYA I think. Insects are quite a bit older than this.

As with anything that has ended up co-evolving - like many insects and flowering plants - the chicken/egg situation is very prevalent!