As part of the same quiz (another question I need help with here), I would like to find clarification for the following question:
“What is the oldest thing still alive on earth?” *
I sense this is going to be controversial, and in terms of the actual quiz I fear the quizmaster may have to discard this on marking due to it being too vague.
I’d like to find a definitive answer, so what say you? Is it…
[ul]
[li]Bristlecone pine trees in Canada / US? (Methuselah Tree)[/li][li]Some Coral Reef, somewhere? [/li][li]The flowering shrub called a “Creosote bush” in the Mojave Desert?[/li][li]The “King’s Holly” plant found in Tazmania?[/li][li]Something else altogether…[/li][/ul]
Difficult to say’ once you get away from organisms where there is some idea of persistence of identity, it all gets a bit blurry; many plants can reproduce by division - some (for example garlic, have abandoned sexual reproduction in favour of it).
If you take, say, a daffodil bulb and slice it in half vertically, both halves will survive and produce plants genetically identical to the one you started with - if we want to eliminate human intervention, just plant the bulb and it will naturally divide eventually. Which plant is the ‘original’? - both? neither? Possibly, but certainly not only one and not the other.
The same logical problem occurs even with organisms that do have persistent identity, because the components of which the organism is composed are often being replaced continually.
Without qualification, the quizmaster’s choice of correct answer is arbitrary.
I know I’ve heard - on here, I seem to think - that the largest living thing on the earth is some form of massive fungus, spreading over miles in America somewhere. So based on what people are saying here about the asexual reproduction of microbes, maybe that’s it. Fungi propagate by budding, which is asexual, as far as I can recall.
Actually, looking at the original question again, I see it is phrased as such:
**Which ** is the oldest thing still alive on Earth?
Does that change the question?
From another less quizzy perspective, what IS the oldest living plant with ‘persistence of identity’ throughout it’s existance?
The King’s Holly in Tazmania is said to be over 40,000 years old, but that is speculation or guessimate, surely.
The oldest plant with persistent identity is probably going to be Methuselah - a bristlecone pine tree in California’s White Mountains - believed to be nearly 5000 years old.
The creosote bushes and King’s Holly (along with any number of other organisms, including a really big patch of fungus in Oregon and a huge swathe of bushes somewhere in Siberia) are vegetatively-reproduced remnants of an organism that has been around for a long time - there may not be any traces of the original plant material remaining. Methuselah, OTOH, has the same trunk that it had 4.5 KYears ago. Like I said, unless the qualifiers are carefully defined, the choice of what represents the oldest organism is arbitrary. If you include the organisms that reproduce vegetatively, there’s no rational reason to exclude bacteria and algae, which have been around much longer.
A “clone” in the sense the term is used in botany and botanic ecology does not mean “Dolly the sheep is a separate individual created exclusively from a cell from her genetic mother” but rather “a vegetative growth that extends itself over a large area and is genetically identical in all its parts.” So it’s not a case of the elements of a given plant being the “clone,” in the Sunday supplement sense, of another plant, but rather that the plant is all of one piece biologically, even though spread over a large area; it has interconnected roots and such that make it a single individual entity reproducing vegetatively. By parallel, a “fairy ring” of mushrooms is a single “plant” (fungi are not plants, but allow me the popular usage) – you have individual sporing bodies emerging that look like separate entities, but they are part of a single underground vegetative body expanding in a circle from a given point, and growing sporing bodies – the actual fairy ring of mushrooms – at the edges of the circle. One such fungus in Michigan is enormous – something like 10,000 square miles in area – and extremely old, though probably not the record holder.
It’s in cases like this that one has to try to essay a definitition of “individuality” as applied to plants and such. Clearly two pine trees are separate plants – but is the same true of a clump of bamboo growing from the same rootstock? The crabgrass that reproduces vegetatively underground, where interconnected roots may link a hundred “plants,” in terms of what grows aboveground? If you count them as one plant, does taking a shovel and digging a trench across the middle of the rootstock constitute making two plants out of one? Is a piece of kelp, no part of which is over 20 years old, but which has been growing at one end and dying at the other for hundreds of years, less than 20 years old or several hundred?
The answer to the OP depends not so much on an actual factual statement as in the definitions you apply to not-so-obvious questions like these.
To further that one, if the two “plants” subsequently grow back together and splice together, have the two plants then become one again? What if two genetically distinct plants do so, or even two different species? I once saw a “tree” which had two different trunks fused together, apparently from related but different species (the leaves were similar, but the bark on the two trunks was completely different). Was that one tree or two?
The Great Vine at Hampton Court was planted in 1768. Not old compared with some of the living things cited in this thread, but it is definitely still the same, individual vine and its history is well-documented. It has always had its own greenhouse and still produces a good harvest of grapes each year, some of which are sold to the public.
There are such things as chimaerae in the plant world - commonly called ‘graft hybrids’ - Laburnocytisus Adamii - formed by grafting a Cytisus(broom) onto laburnum (or vice versa) - the tissues of the two plants mingle throughout the whole tree and some branches produce yellow flowers, others produce pink and yet others produce mottled bronzy ones. Not that this has anything to do with longevity.