Evolutionist, I need your help?

Question

I admit, I haven't studied evolution in depth. But I thought I had a pretty good understanding of it. Until the other day someone on this board said I didn't understand evolution because of a statement I made. The statement was something to the fact of for the theory of evolution to work, animals that eat plants would of had to evolved first before animals that eat other animals. This is the way I think of it, plants would have to evolve first, then plant eating animals, then meat eating animals. I know it is not that simple, but wouldn't that be the basic idea? And I am talking about macro-evolution, not micro.

Is my thinking flawed? If it is, can someone please shed some light on what I am missing?

I posted this on the biology section too, but I know a lot of Evolutionist are on R&S and this is actually where I was "corrected".

I'm not sure if adapting works in this case. I would consider that micro-evolution, within the same species. I'm talking about an animal that is like a Gazelle that eats plants...and Lions that eat Gazelles (and yes I know it is a bad example because they weren't around millions of years ago, and Lions eat other things besides Gazelle). But in this simple example, you couldn't have a Lion without a Gazelle...correct?

Well I'm glad I posted here too. The Biology section gave me some answers, but far more here.

I think the problem is I have always been more of a technology/physics mind set. I never liked biology and chemistry much, because everything was so much theory...and I viewed it as guess work. Give me some resistors and capacitors though, and I can build you a circuit and tell you exactly how it works and why it works. Maybe my mind is just not built to completly understand evolution theory because there seems to be a lot of jumps and guesses as to what may have happened. And I am all for that, but have a hard time accepting any of that as fact...good ideas, but still just ideas. I think I get into trouble because I want more than just a theory....I want to know what happened exactly, so when I ask a question like this and there is no exact answer, but someone tells me I'm wrong...I just don't get it. Thanks for all the good replies, I'm no biologist...so excuse the simple view.

Maybe saying for evolution to work is worded incorrectly.

How about if I said for evolution to bring us to where we are today?

Answer 1

Well as I'm sure you realise we have to be talking about unicellular organisms in all these cases. If not sub-cellular lifeforms like viruses - obviously chemotrophs or autotrophs will emerge first since a predator cannot appear if there is nothing for it to eat.

Presumably some larger than average cell found that rather than wait for energy from chemical processes or photosynthesis it could eat the tissue of animals that did this, which is a much quicker source of energy.

The answers relating to this are all really in the real of microbiology and abiogenesis which isn't really a part of evolution.

Some people like pointing out real or perceived flaws in understand just to make themselves feel better.

If you want to understand evolution here are some great sources but they won't teach you out about abiogenesis.

Books:
‘The Origin of Species’ by Charles Darwin
‘The Variety of Life’ by Colin Tudge
‘The Ancestor’s Tale’ by Richard Dawkins
‘Almost a Whale’ by Steven Jones
‘Evolution’ by Mark Ridley
‘Evolution: An Introduction’ by Stephen Stearns and Rolf Hoekstra

Web:
http://www.talkorigins.org/
http://en.wikipedia.org/wiki/Evolution
http://www.pbs.org/wgbh/evolution/
http://www.livescience.com/evolution/


This subject in particular? Let me find some.

http://en.wikipedia.org/wiki/Autotroph
http://zuserver2.star.ucl.ac.uk/~rhdt/diploma/lecture_4/
http://universe-review.ca/R10-23-plants.htm

**I agree with jonjon, and applaud your honest enquiry. It is a rare sight in this room. I'd be happy to help with any other misunderstandings you might have - like there being a difference between 'micro' and macro-evolution. No biologist uses the terms.**

For the record lions and gazelles were around a few million years ago. The kind of biological processes you're interested in were happening about 3000,000,000 years ago.

Answer 2

Evolutionary theory states that organisms react to a changing environment by adapting. Successful adaptations get transmitted to subsequent generations. The theory was formulated a century and a half ago, about a full century prior to the discovery of DNA and the need to explain how an adapted organism could possibly reprogram it’s own genetic material and deliver it to the next generation. Any reaction to environmental pressure can not be expected to extend to the DNA carried by the organism from it’s inception. Since the discovery of DNA, the theory has been modified to state that those organisms which were already more adapted to a given environment are more likely to reproduce, with no explanation for how they came to be more adapted in the first place, except for “mutation”.

Neither theory explains the source of the adaptations, that is, the reprogramming of the DNA. Even without any conviction that life and the universe that harbors it are the products of design, the reprogramming conundrum persists, especially when considering the macro evolution of a bird from a reptile. This transformation is way beyond the “bad leg becoming a good wing in a single generation” problem, as it also must account for lighter bones, enhanced balance, dramatically improved visual acuity, 3-D navigation, and a host of other improvements, all in a single generation. “Mutation” is inadequate to explain this.

Fortunately, the vegetarian vs. carnivore question is far simpler. Microbes absorb proteins and other materials from other microbes, often to the detriment of the microbes absorbed from. In other words, bacteria eat other bacteria. IF more advanced organisms evolved along the way, some would be plants, some would be those who eat plants (herbivores), and some would be those that eat any other organism (omnivores). Omnivores may eventually learn that meat has a higher protein density and become carnivores. Few carnivores are strictly meat eaters. Most will eat vegetation in a pinch.
So, if these life forms evolved, their evolutionary pathways would have been parallel. In fact, at the level of bacteria and very small multi cellular organisms, carnivores and omnivores may well have preceded true plants.

Answer 3

I can't imagine why you think that herbivores would need to exist before carnivores in order for evolution to work. You'd have to explain your thinking because that one's lost on me. At bottom, plants and animals existed as different bacterial cells. They have different cell structures which distinguishes plants from animals but get this: we're all related. It's all just DNA. Some "plant" cells ate other plant cells, some animal cells at animal cells, and some ate each of the other. Or took energy some other way. There is no "order" to evolution. It's about adaptation.

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"Herbivorous" microbes evolve into herbivorous fish, "carnivorous" microbes evolve into carnivorous fish, they evolve in parallel from the earliest organisms up to the present day. No evolutionist would argue that lions just sprang into being when gazelles evolved. Each evolved very, very slowly from earlier forms. And sometimes organisms changed their diets, if the food available in their environment changed.

What you call guesswork is established by observable data, an enormous fossil record, and induction (remember that?). There is no such thing as micro- and macro-evolution - evolution happens at the DNA level. YOU are an intermediate species. Wiki "Ring species" and tell us whether or not that's micro or macro. These are species that exist today and we can genetically map their relationships. New species break off from existing chains constantly - just too slowly to be observed.

Answer 4

You seem to understand the basics. Things started out simple and over time it became more complex. - this is know as 'common decent'.

However - plants may be less complex organisms than antelope, but it does not mean that the one came before the other. Evolution is not a ladder - (with each evolution the organism becomes more complex), but rather a tree. One stem (the common organism) that brances out (different types of species).

No evolutionary scientist questions whether evolution occurs and has occurred. The actual scientific debate is over HOW evolution occurs, not whether it occurs.

What you do not seem to understand is the diferrence between fact and theory.

Facts are the world’s data. Theories are structures of ideas that explain and interpret facts.

Facts don’t go away when scientists debate rival theories to explain them. Einstein’s theory of gravitation replaced Newton’s in the 21st century, but apples didn’t suspend themselves in midair, pending the outcome. And humans evolved from ape-like ancestors whether they did so by Darwin’s proposed mechanism or by some other yet to be discovered.

Moreover, “fact” doesn’t mean “absolute certainty”. In science “fact” can only mean “confirmed to such a degree that it would be perverse to withhold provisional consent.”

Evolutionists have been very clear about this distinction of fact and theory from the very beginning, if only because it has always been acknowledged how far we are from completely understanding the mechanisms (theory) by which evolution (fact) occurred. Darwin continually emphasized the difference between his two great and separate accomplishments: establishing the fact of evolution, and proposing a theory — natural selection — to explain the mechanism of evolution.

Answer 5

I, too applaud your genuine curiosity (I've answered many dozens of "I really want to understand it" questions, when clearly, they didn't).

I just wanted to give a couple of resources:

http://www.newscientist.com/channel/life/evolution

New Scientist is a UK science news magazine. Some of the links on the page I gave require subscribing to the mad to read, but others are free to all.

http://evolution.berkeley.edu/

U.C. Berkeley's portal to evolution.

No, the basic idea you expressed wasn't flawed, as you're getting from most of the answers -- though it is an oversimplification. Clearly the first life won't be a carnivourous animal. In fact, animals didn't exist for most of life's existence on the planet, as the First Pollution of plants pumping free O2 into the air is what allowed animals to develop.

Yes, there IS a lot of guesswork about many details in the story, though there are guesses and there are guesses, and there are multiple lines of reasoning and evidence behind the guesses that are eventually accepted as what most likely happened.

And, yes, its frustrating to not really know all the answers to all the questions, but that's the nature of the beast. We don't have the whole story, we've only recently begun to piece it together, it's a HUGE and complex story, and most of the evidence has been destroyed (that is, only a tiny proportion of living things leave fossils, for example).

But as time goes on, they find more and more pieces, and develop more ways of reexamining evidence.

Answer 6

The problem with your thesis is that you're jumping into the story at a point billions of years after evolution started working. Today's clear distinction between herbivores and carnivores, and their respective foods, has emerged out of a far more complicated ecology that developed over that incredibly long period.

To try to analyse the order of this development becomes very confusing. Remember that for billions of years, all life on earth was single-celled. Such creatures, although they can be amazingly sophisticated, are necessarily simpler than the enormous multi-celled lifeforms we encounter routinely today.

The earliest cells probably ate raw chemicals, but eating each other is always more efficient. Some single-cells 'invented' chlorophyll, and derived much of their sustenance from photosynthesis. Such critters would in some cases later go on to form the plant kingdom. Others stayed as algae and strange beasts like Euglena, which is essentially both a plant and an animal.

Many single-celled 'predators' are in the habit of eating pretty much anything they bump into. If they live in an algae-rich area they'll gobble them up like big green potatoes. But to describe such unicellular organisms as 'herbivores' is stretching a point..

So the current arrangement - of some animals eating plants, and others, animals - arose immensely slowly out of a system where such labels don't really apply.

Large multicelled animals like cows and leopards are hugely specialised in their eating habits: cow food is so hard to digest that cows are just stomachs on legs. Pure carnivores can dispense with all the complex digestion system, and develop the features that help them to catch their meat.

Once an animal has set off (genetically) in a particular direction in its food requirements, it's not possible for them to change quickly. Even omnivores are actually far from universal eaters: if you want to be able to digest grass or leaves, you have to have such a huge stomach that predation becomes impractical.

So to get back to your basic idea of 'plants developing before herbivores' - this issue was really swamped by another development: the early Earth had no oxygen, and no animals except unicellular anaerobes could develop until the first algae and simple plants had produced enough O2 for true animals to breathe.

You can get a better look at the sort of 'which came first' event you seem to be interested in by considering flowers:

Before plants 'invented' flowers, most pollination was done pine-tree-style: dump your pollen on the wind and hope for the best. When the first insects evolved, some of them started eating all that pollen, and as they moved from plant to plant they accidentally pollinated the plant with their spilled crumbs.

Plants that developed extra insect-attracting features - small patches of sugar solution, say - benefited from increased insect traffic and better pollination. As usual, evolution tried everything, and when it hit on a good trick - like insect-visible petals to show where the pollen and sugar was - the insects responded, and both parties benefited.

The result of millions of years of this is the fabulous flowers we see today, and the specialised pollinators that visit them - including birds, the descendants of the dinosaurs!

Sorry if this is confused, but it's a huge subject.

CD

Answer 7

I applaud what actually seems like a genuine desire to learn about evolution. Based on my understanding - and I admit I'm not a biologist - evolution doesn't have anything directly to do with whether an animal is a carnivore or an herbivore. It's certainly not the case that plants have to evolve first, then herbivores, then carnivores, as if it's "something in the food." Of course, maybe I'm just misunderstanding this question.

Answer 8

I do believe herbivores existed before carnivores/omnivores.

I don't think that if it didn't happen that way, that evolution wouldn't "work," that's just how it turned out because of the way things evolved.

I hope you get a more in-depth answer in the Biology section.

P.S. Don't use the term "evolutionist"--that's a term coined by dishonest people who try to make it sound like evolution is a religion or ideology, in an attempt to put it on equal ground with creationism (when it obviously isn't).

Answer 9

Professor Adjineri is erroneous back. (he's extremely a guy!) you do no longer would desire to have a scientific clarification for something until now you ought to use it. If it works, you ought to use it. The birds did no longer have a concept of flight, yet they flew. women human beings did no longer understand what made cleansing soap do what it does (many nevertheless do no longer), yet they have been given their outfits sparkling besides. this is the version between a discovery and an invention. Darwin got here across what the animals and flora were doing by using time. He did no longer invent the phenomenon, he purely defined it in a fashion that made greater experience than people who wrote until now, which includes Lamarck.

Answer 10

Try put "adaption" into the equation and you have your answer.