reply to posts by Johnze
Nice one, nophun. Yes, of course, we evolved tastebuds to help us work out what's good to eat and what isn't. But that doesn't really answer
Why does an orange taste good to Johnze? Because it evolved to taste that way. It didn't evolve that way with Johnze in mind, though; it had its own
selfish reasons. It wanted to taste good to birds and arboreal mammals. That is what fruits exist for: to be eaten by birds and
swing-through-the-trees-type beasts like Johnze's ancestors and mine. That gorgeous orange globe was 'designed' to catch the eye; that juicy, tasty
pulp was 'designed' to be devoured. Why? Only so that a few hard, bitter seeds would be eaten along with the pulp, pass through the eater's gut
undigested, and be excreted somewhere along with a dollop of fine organic fertilizer. Because that is how orange trees have baby orange trees.
Of course, Johnze's folks and mine did evolve digestive systems that could extract the appropriate nutrients from an orange, and tastebuds that found
things like oranges tasty, so you're partly right as far as that goes.
Adolescent couch potatoes often notice that it's difficult to have any sex if you spend your whole life rooted to the spot. Couch potatoes can do
something about that because they (usually) have legs, but plants are pretty much stuck. Some, like grasses, trust to the wind to blow their genetic
material far and wide, hoping some of it sticks to an attractive member of the opposite sex and makes more grass, but it's just as likely to end up
on a car windscreen or inside a hay-fever sufferer's sinuses. A bit wasteful, a bit message-in-a-bottle. So what many plants do is recruit things
with wings and legs to have their sex for them, and carry their offspring too.
Excepting the insects, we are the most diligent of those recruits. Many species of plant no longer rely on any other creature but man to do their sex
and childbearing for them: from cabbages to courgettes, oranges to okra, rice to red beans, a vast number of plants have evolved to use human beings
as their sole reproductive aids.
Of course, that's not the whole story. Many of these plants have their present-day form because of careful breeding - artificial rather than natural
selection. The original oranges were green and quite bitter; the original corn, teosinte, is something you wouldn't even think of as food. So it's a
process of co-evolution; we help them make themselves attractive to us, helping to ensure our reproductive success as well as theirs in the process.
But the plants probably started it, back in the Cretaceous, when angiosperms first evolved with their flowers and fruit. There were, of course, no
humans around back then.
Did you ever think that your true purpose in life might be to help an orange tree have babies?
reply to posts by filosophia
Originally posted by filosophia
Usually when I ask questions about evolution, first my intelligence gets insulted, and then my question is not really answered. I appreciate the
desire to answer questions we may have.
I'm sorry to hear that, filosophia, and - hoping my answer to Johnze above was to the point and didn't insult your intelligence - I'm happy to have
a go at your questions. Phlynx didn't answer them too well, I'm afraid; Phlynx, maybe you should be asking the questions, not offering to answer
filosophia: if there are transitional fossils, what did humans evolve from?
To answer your question correctly
: ultimately, modern humans evolved from the common ancestor of all life - the evolution of life is a vast,
branching tree that grows from a single seed, the first living, replicating proto-organism.
But this answer, though correct, isn't really what you're looking for, is it? You want to know when a creature that was an ape gave birth to a
creature that was, maybe not a man, but something with a touch of humanity in it. Well, that would be the common ancestor of chimpanzees and humans or
one of its descendants. We have never dug up a fossil of that common ancestor, so we don't have a name for or a classification for it, but we are
sure it existed.
How can we be sure, if we haven't found the body?
To understand how, we have to recognize first that evolution is a continuous process. Even humans are still evolving - lactose tolerance in adults,
for example, evolved in the last few thousand years. Now, since every living thing is subject to evolution, it follows that all species
'transitional'. Any animal that dies and gets fossilized is a 'transitional fossil'. There are no other kinds. All fossils are transitional
But not every organism that dies gets fossilized. Actually, hardly any do - it's a rare occurrence. And of the very few dead organisms that do turn
into fossils, fewer still are dug up, identified and classified. So the fossil record is spotty: like dots on graph paper, and spaced pretty widely
apart as that. We can draw the line between them that shows how the evolution of a present-day species must have progressed, but we certainly don't
have fossils for every point on the line.
On the line connecting humans to our ape ancestors, there are many, many missing points - what people who think of evolution as a chain instead of a
tree call 'missing links'. One of them is the all-important point where the line of hominid evolution forked, with one fork leading to us and the
other to modern chimpanzees. No fossil of the common ancestor of both species has yet been found. However, we can compare our DNA with chimps' (and
other animals, too) and show that there must
have been a common ancestor and it must have lived 5-7 million years ago.
Another important missing point on the long, long line of human evolution is the common ancestor of apes and monkeys. And there are plenty of other
'missing links' like this. Even so, we can trace the evolution of primates back 65 million years, all the way back to the end of the Cretaceous.
Evolution of the great apes
If there are so many missing points, how can we be sure there's a line at all? Now there's a question. Sadly, it is not one that can be answered in
a few paragraphs on a popular internet forum. You need to interest yourself in evolution, and thence in palaeontology and evolutionary biology, to
anwer that one. Though Phlynx is welcome to try
We evolved from the common ancestor of chimps and people (but not of other hominids, like gorillas or orang-utans). Not directly, of course - there
were several other species in between. The ape-chimp ancestor evolved from the common ancestor of hominids (but not other apes). The common ancestor
of hominids evolved from the common ancestor of apes (but not of monkeys). Apes and monkeys evolved from the common ancestor of primates (but not,
say, of badgers and wolves). Then we go back to the common ancestor of mammals, the common ancestor of land animals, the common ancestor of
vertebrates and so on, all the way back to the beginning. If you want to take that trip in detail, read The Ancestor's Tale
by Richard Dawkins
(who, by the way, is a professional biologist and only a hobby atheist, though he takes his hobbies seriously). It's an easy read, and fun.
if humans evolved from monkeys, why are there still monkeys? (this would make more sense if humans evolved from a now non-existent species like
As you can see above, that is just what happened. Perhaps it would be better to ask, 'if we evolved from fish, why are there still fish?' The reason
is, of course, that the aquatic environment still exists and can sustain life. Some fish stayed in the water and did well for themselves. Some
ventured out onto dry land and found a new world of opportunity waiting for them. Later on, the competition on land began to hot up and new species
evolved from mutation and natural selection to exploit ever more specific niches.
The real question you're asking is, 'why is there such a variety of life on Earth?' The answer is that Earth presents many different opportunities
for different kinds of life to prosper - one species' meat being another species' poison. Evolution does not mean supercession unless the parent and
daughter species are both competing for the same resources within the same geographical range.
What, in your opinion, is a practical purpose of evolution? Other than simply the curiosity of finding out where we came from, is there any
scientific discoveries that evolution is giving to society?
Ah, an opinion question. An easy one, then.
Evolution is a force of nature, not a human invention. It has no purpose, unless you believe there is a God behind nature, who created the world for a
But I suppose you mean to ask what is the purpose of studying
evolution. I give you Michael Faraday's reply to a similar, but not identical
question: 'Of what use is a newborn child?' Thank you for your kind attention.