Harold's avatar
  • Last visit: July 7th, 2016
  • Joined: May 30th, 2009
  • Flag as…

Harold’s profile

Harold’s story

I am a lecturer in health sciences at Charles Sturt University in New South Wales, Australia. I have almost finished a PhD in assessment of Work Integrated Learning. I am a recent ex-Christian, trying to work out what I believe. I have been married to the best woman in the world for 28 years, and have two adult sons of whom I am very proud.

Topics (5) see all

Login to see what topics you have in common with Harold

Greatest questions see all

Login to send a message to Harold.

Recent messages for Harold

mollydrew's avatar mollydrew said

Regarding your answer:
Thank you I respect your honesty

October 7th, 2010

Theby's avatar Theby said

Regarding your answer:
Harold, I am VERY glad you are only an occasional visitor to fluther.

April 7th, 2010

Fyrius's avatar Fyrius said

Hello again. :)

I’m glad you’ve given it thought, and glad you’re asking questions about it.
And don’t worry, the answers indeed weren’t in there. :P

“How did the cells that life originated from come from nothing?”
Technically speaking this is outside the scope of the model of evolution; if there were no answer to this, that wouldn’t be an objection to that model. Evolution is concerned with what happened to life from the first protozoons to all the diversity we see today.
Scientists have found answers to this question, though, from a whole different field of biology – abiogenesis. In a nutshell, if my tenuous understanding of this field is close enough to being right, the answer is that the first life forms were so simple they could have arisen through chemical reactions in a “primordial soup”. (I don’t know much about this, though – see the wiki page for details, if you want.)
The famous Miller-Urey experiment gave this explanation serious credibility by simulating the atmosphere and sending a spark of lightning through it, which caused amino acids to form – the building blocks of all life.
(And obviously the first life forms didn’t come literally from nothing, but from non-organic chemicals.)

“How does survival of the fittest explain the less complex becoming more complex?”
If I compare genetic variation to a million monkeys with computer keyboards, and if I compare natural selection to a computer program that compares everything the monkeys peck out to the text of Hamlet and saves only the input that corresponds to words that are in the play, does that help you understand how such a thing can lead to complexity?
This is not an ideal example, since natural selection does not have a frame of reference that life should resemble, but it should serve to explain the basic mechanism.
Genetic variation generates great amounts of random data, and natural selection separates the wheat from the chaff. That’s how those two factors, working together, can create huge complexity out of utter simplicity if you let them at it long enough.

Ragingloli posted this video and this one, that let you watch first-hand how this sort of mechanism works, with a computer program simulating both genetic variability and natural selection filtering its results.

Does that answer your questions?

June 5th, 2009

Fyrius's avatar Fyrius said

Good evening. I’m here to bother you with a huge PM of what I consider to be information you really need to learn about. :)

Let me start this PM with the positive and friendly message that I commend you for not losing your temper in the face of so much criticism. I also commend you for valuing open-mindedness and avoiding bigotry, as you write in your mini-bio.

I’ll have to continue this PM in a somewhat more ambivalent way.
On the one hand you belong to a group of people who make me very sad. I’m not talking about Christians, or even religious people, but in this case about people who have a fundamentally wrong impression of the theory of evolution.
On the other hand, you have shown open-mindedness, which gives me hope that you’re just not that knowledgeable about this, and not the kind of person to ignore compelling evidence and sound arguments that are handed to you on a silver platter. So I’m just going to do the latter, and see what happens next. :)
Forgive me if I tell you things you already know. I have gotten used to the fact that ninety-nine times out of a hundred, people who deny evolution with conviction don’t know the first things about it.

You’ve expressed the idea that evolution is mathematically “improbable, if not impossible.” I presume that makes you one of those who think evolution relies on “blind chance.” This is completely wrong.
Evolution, as presently understood, relies on natural selection, which is a systematic filtering of what works from what does not work.

In a nutshell, it’s like this.
The properties of a life form are coded in its DNA, which is passed on to its offspring. This is a well established fact. It follows from this that animals who succeed in reproducing succeed in passing on their DNA, which means that DNA that makes animals successful at reproducing will have a greater chance of continuing to exist. The DNA of animals that fail to reproduce is lost forever when the animal dies.
To give a simplistic example, DNA that codes for, say, particularly strong muscles will make strong animals that fight better, escape more predators, catch more prey and attract more mates by flashing their huge manly biceps. Thus they live long enough and are attractive enough to get to reproduce, and so their strong-muscles-genes continue to exist. Meanwhile, animals without this strong muscle gene will have a lot more trouble at all of these things, and their DNA will have a much smaller chance to be passed on.

That’s how the filter works. Then of course we need the strong muscle gene to come from somewhere. There’s still some discussion about the details, but the gist is that when reproducing, the DNA changes subtly.
This is rather obvious; offspring will always be a little different from their parents. The differences won’t be as large as a next generation suddenly having eyes, which would be very improbable indeed, but much more subtle.
Over millions of years, the tiny changes that the filter lets through will pile up and lead to drastic changes when compared with the ancestors of so many aeons ago.

I hope that gets your impression of improbability out of the way. Evolution is in fact quite inevitable.

As a side note, I’d like to leave the theory of evolution and turn to the fact of evolution: common descent.
It has been extensively proven that all life derives from one common ancestor, in complicated phylogenic family trees that have been worked out in admirable detail. Anatomical comparisons, genetic comparisons and the fossil record all independently point to the exact same complicated family tree of all life.

Furthermore, evolution at work is in fact attested and well documented. The most well-known example is of viruses that evolve resistance to antibiotics.

This is why there are no biologists left who doubt that evolution really happened. There is still much debate on how the details work, but ever since Darwin published his famous book, On the Origin of Species, natural selection is widely considered the only realistic way to explain the diversity of life.

June 2nd, 2009