Thread: Transitional species

I watched a video about a fish which became (the author theorized) transitional because this fish found that it could survive predation by swimming into shallow water where bigger fish could not follow. Presently, this fish grew apendages that assisted it to get even further out of the water and therefore escape more frequently. My question: Is there some recognition within the biology of the fish that "becomes aware" of this survival need of the fish and therefore supplies the means for better survival. I understand that mutation could provide these better equiped appendages to crawl out of the water but what is the signal for the organizm to know that it is this type of mutation that would help it survive?

... thanks

There is no signal along the line you are suggesting.

Evolution works by random changes. Some will help an organism to survive and reproduce, meaning those changes are more likely to be passed on. There is no awareness of the process, and no signal.

It is quite possible that the fishes that later became amphibious developed supporting limbs in order to hold their heads up near the surface, for more oxygen enriched water. If they lived in shallow and swampy waters, they could well need that to survive the low oxygen levels in those waters.

Not sure about "signaling" but intelligence, perhaps? I say this only because after making a public dibacle of myself getting a lung fish to immitate me by opening it's mouth, there was most certainly an inclination to believe the most ancient of fishes was aware of it's environment; a crazy woman who for some strange reason unknown thought this creature would "communicate" (have pictures to prove it)! Here is a link: Lungfish - Wikipedia, the free encyclopedia explaining it's peculiar adaptations including burrowing and utilizing oxygen via a primitive lung bladder. It just so happens this fish has the largest genome among vertebrates and is considered a "living fossil."

Most interesting is it's circulatory system comparative to that of a human fetus in vitro. Here is another link: Ductus arteriosus - Wikipedia, the free encyclopedia. explaining the shunting of blood when the lungs are filled with fluid and which closes at birth (the ductus arteriosus) becoming an "appendage" as well.

"because this fish found that it could survive predation by swimming into shallow water"

My guess is that theres more chances that the fish had a tendency to go into shallow water and happen to have survived (rather than finding out its safe). In addition, some behavior that end up being successful occur by the action of simple mechanisms rather than thought through reflection, like ants circling around an obstacle. If the fish stays idle vegetating while not perceiving a predator, and swooshes away when seeing a predator, it might end up more often staying longer where there's no predator(shallow water) and eventually exiting the predator rich zone, by the cumulative effect of this situation rather than thinking "hey that big fish is too big to go in shallow waters, so what I'm going to do is... so that... and then he wont...and therefore I will survive..."

No thought or awareness of any sort is involved. Just the inexorible mechanism of natural section. Only the fish that survive go on to reproduce. The inheritable characteristics that they have are passed on to the next generation. The inheritable characteristics of those who got eaten do not get passed on. The inheritable characteristis of those that escaped predation by going into shallow water but got stranded and could not get back into the water in time and so died, also do not get passed on.

Pretty much all species are transitional (including us) unless they go extinct.

We might be 'lucky' and do the shark or crocodile thing. But we'd need a Tardis or other time machine to go back and reset our development trajectory for that.

The whole primate group is just too adaptable as it's constituted for the last couple of millionish years.

But what's so wonderful about us as we are?
Speaking as a woman I've got a few suggestions (r e q u i r e m e n t s) for a better anatomical organisation. And I presume that any evolutionary descendants will be cleverer or tougher or maybe both! than we currently are, which would be a good thing.

Of course, future human 'evolution' is likely to be driven by human planning. Adelady's ideas of anatomical reorganisation may well happen, and within a couple hundred years, with human genetic modification.

I fear for our own future in this way. As i work in a university medical centre, i keep thinking about the implications of long term medical stimulation of society. In the past, mutations that would cause a deficienty would kill a person, rooting out the "bad" genes. But in this society, those "bad" genes are kept intact, they reproduce, and their offspring is likely as sick as they are. Which could result in another mutation, or a combination of bad genes, to worse genome then before.

How long can medicine save people, and at the long run, how advantageous are these treatments. There will be a time, when a person would need to ingest medicine constantly to survive. Which is great for pharmacies, but not for people..

Genetic modification will not be enough. In most cases, as more rare diseases will start affecting mankind. Hmm, what do you think about this?

I fear for our own future in this way. As i work in a university medical centre, i keep thinking about the implications of long term medical stimulation of society. In the past, mutations that would cause a deficienty would kill a person, rooting out the "bad" genes. But in this society, those "bad" genes are kept intact, they reproduce, and their offspring is likely as sick as they are. Which could result in another mutation, or a combination of bad genes, to worse genome then before.

On the other hand, parents are rooting out some of those bad genes with abortions. Parent's ability to do this will continue to improve unless our false sense of ethics gets in the way. Modern technology has also removed many of the barriers to natural selection--such as new born head size. I can imagine a future archaeologist seeing us as a transitional species between some former walking primate and himself--a big brained, huge birth weight, genius species which depends on caesarean sections for birth.

Originally Posted by Zwolver

Genetic modification will not be enough. In most cases, as more rare diseases will start affecting mankind. Hmm, what do you think about this?

I think you are being pessimistic and underestimating human ingenuity.

My own prediction is that, in 100 years, defective genes will no longer be a problem. It will be pure routine to remove them before an IVF-like form of reproduction. Within 200 years, the human genome will have been improved out of sight. The new human will, by our current standards, be a super-human.

If I am wrong, and you have waited long enough to be sure, then you have my permission to come and berate me for the error.

in 100 years, defective genes will no longer be a problem

In a hundred years? 3 generations? Just how many defective genes do you think there are? I'd be very pleased if they got rid of Charcot Marie Tooth disease, my own particular problem. But I'd never put it ahead of cystic fibrosis or those breast cancer genes and the other dozens of degenerative, fatal conditions.

And CMT is a good example of the problems such projects face. It's often the subject of theses in genetics because it's well understood, in general, but very variable in its structure and its physiological effects in various family lines.

We may eventually get rid of such conditions, but it'll take a good bit more than a century. I'd much rather we focused on getting rid of transmissible diseases that are exclusive to humans. We're almost there with polio. It'll take at least 50, if not a hundred years to get rid of measles.

Still too pessimistic, Adelady.

New Scientist claims the sum total of all knowledge will double within 40 years. Within another 50, what then?

Knowledge is power. Knowledge gives us the power to do wonderful things, and genetics is one field where knowledge is growing even faster.

Yeah, I would say 100 years is enough. More than enough.

genetics is one field where knowledge is growing even faster.

The knowledge is growing. But the money needed to do ethical research into how best to apply that knowledge is not unlimited.

I'm really happy to see the latest research results on identifying genes within breast cancer tumours that will, within a decade or so, show significant changes in successful treatments - for those who have access to them. I also see that it may take as long if not longer to modify or eliminate the genes in women that lead to heightened risk for breast cancer. And they've not yet identified all of those. And there goes 20 or more of your 100 years.

I'll be really pleased if you're right. My feeling is that progress will be seriously uneven. The more we find out, and the more we can do, the more we'll find out what we don't yet know and can't yet do. But knocking cystic fibrosis out of the game would be a wonderful achievement all on its own.

Originally Posted by Lynx_Fox

On the other hand, parents are rooting out some of those bad genes with abortions. Parent's ability to do this will continue to improve unless our false sense of ethics gets in the way. Modern technology has also removed many of the barriers to natural selection--such as new born head size. I can imagine a future archaeologist seeing us as a transitional species between some former walking primate and himself--a big brained, huge birth weight, genius species which depends on caesarean sections for birth.

Isn't that eugenics?

Eugenics is the "applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population", usually referring to the manipulation of human populations.

On the other hand, parents are rooting out some of those bad genes with abortions.

There are other ways. The approach of the affected communities with Tay-Sachs disease is exemplary. Population-based genetic screening for reprodu... [Eur J Pediatr. 2000] - PubMed - NCBI

The group knows it is susceptible to the condition and how it is transmitted and expressed. People who wish to marry are counselled and advised whether they are putting their offspring at risk. Many couples decide to not marry each other rather than go childless.

My not be so successful where individuals are not brought up in a community that knows it has such a problem. But it's worth trying in some further similar defined circumstances.

Originally Posted by skeptic

If I am wrong, and you have waited long enough to be sure, then you have my permission to come and berate me for the error.

Funny to say this though.. Hehe, in 200 years i have the permission to.. "Quote your error", thanks, i'll write it in my agenda. But hey, in 200 years the world we know it will definitely look very different, but still similar.

I think, with the ethics shifting as they are now, that it would be unethical to genetically alter and change the rich class, while leaving the poor class in the mutating pools of our own filth. This would cause a "War" as even predicted by Gene Roddenberry. After this war, it would be back to square one, and noone would be able to selectively alter their genome. While those who can't pay for it, won't get the chance to do this. Though why stop at diseases. Why not make your son look like the president of the united states, or George Clooney. Where is the edge of reason, where will the genetic alterations stop?

Though i believe cybernetics will be used more often, and because these parts do not transfer from father to son, it would be the more "ethical" thing to do.

But in 200 years, you can quote me if i'm wrong as well. So, i'm looking forward to that conversation.

Zwolver

On the business of rich vs poor.

Yes, that will happen. But it will be temporary. Two points.

1. All new technologies begin expensive, but drop in price over time. When the technology to 'genetically improve' our offspring is new, it will be confined to the rich. But within a couple decades, the cost will drop and everyone can benefit.

2. One of the new developments over the next few decades will be an explosion in capability of robotics. Volkswagon already has, as a prototype, a car that can temporarily drive itself, even across a city. http://www.engadget.com/2011/06/24/v...riving-to-the/
Within a much shorter time than the 100 and 200 years we discussed, there will be sophisticated robots able to carry out all the genetic modifications we need, at very low cost.

Handsfree driving, does not compare to handsfree genetic manipulation.

- There is Ethics involved here.
- There are variables where we can't even think of right now.
- The financial standards are involved here.
- Also, everyone can drive, a child can drive, some drunks can even drive, also handicapts etc. There are very few people of inner knowledge of the genetic defects of A gene, let alone all genes. It will not become cheaper, due to the ethics thing.
- If you genetically engineer your child, is it really still YOUR child?
- Does the undiversifying effect of everyone with a genetic illness getting the same exact gene, not scream for disease?

Originally Posted by skeptic

Within a much shorter time than the 100 and 200 years we discussed, there will be sophisticated robots able to carry out all the genetic modifications we need, at very low cost.

Zwolver's concern, perhaps, is whether or not those robots, or ourdecendants, will be able to distinguish between the modifications we need and those that we want.

Zwolver

If history teaches us anything, it teaches us that ethics are a variable.
In the 1960's, artificial insemination of humans was an absolute "no-no". It could not be done for the strongest possible ethical reasons. Guess what? It is now an everyday event.

When IVF was invented, a whole bunch of 'busy-body' ethicists got together and said "this cannot be done!" Guess what?

So you think that genetic modification of humans is unthinkably unethical? Guess what? Look ahead 100 years and see what our descendents think.

On the other hand, at one time eugenics was generally thought to be a Jolly Good Idea. Now it can't be mentioned in polite society.

We can't really know what the future ethical (or technical) limits will be on genetic modification of humans.

There will be limits. The one that parents want a child that's theirs, and the natural way. A perfect looking, diseaseless child looks great, but it is not your legacy, it's not the continuation of your own genes. Like we feel, every breath we take, we would not be spreading mankind, we would be spreading technology.

Zwolver

A perfect, disease-less child would take the modification of very few genes. You would end up with a child that was still something like 99.9% of its parents genes.

After all, when we reproduce, we end up with a child that is only 50% ours, genetically. To lose another 0.1% in order to get a disease free child is a small price.

The 0,1% is what differs you from me. From person to person. So that's why it's relevant. If we all incorporate the same genetic code for our otherwise sick genes, then the next mass extinction will kill everyone, because there would not be any variation. Many proteins slightly differ because they work better on a lower oxygen, or a higher oxygen level. Just changing it to THIS oxygen level will halt every evolution we still have at this moment (diversification). I would say, there is no better way then the natural way. Letting people die because of genetic defects is the price to pay, but our survival is the result.

Originally Posted by Zwolver

then the next mass extinction will kill everyone,.

Yeah, I sometimes wonder if that's why they call them mass extinctions. You know, like the clue is in the name.

News for you, Zwolver.
Genetic variation covers all 100% of our genes. Not just 0.1%.

Yes i know. But we don't differ 100% from another by basepairs, just the 0,1%.

Zwolver

Genetic modifications, as will occur in the future, will not target the 0.1% that show you and I are different. They will be practised on the entire 100% - any and every one that is defective, or can be improved. Individuals will still be different, both in the 0.1% that demonstrates clear cut individuality, and in the other 99.9% that are largely common to all humans.

Besides which, once humans expand our geographic distribution beyond our solar system, there will rapidly develop numerous sub populations, all of which are modified to adapt to slightly different environments.

Humans will never reach a place outside this solar system. (at least not with the understanding of technology we have, or will recently have) I can't see a way for it to happen. So these sub populations will not form.

We have already begun, ad we have the ISS in Earth orbit.
The big step forward will be large and permanent space habitats, probably rotating for gravity. The first will probably be only decades away. From there, permanent populations in space is only a matter of time. One such habitat in space can build a second, using material already in solar orbit. Remember that, by then, robots will be widespread and highly sophisticated - ideal for operations in vacuum.

If we look ahead, 500 to 1000 years, there will probably be a large number of such space habitats. All that is needed is a population that is massively disgruntled (taxes, politics etc), which will build onto the habitat a massive ion drive engine and start accelerating towards Alpha Centauri.

Ion drive engines have little propulsion power, it would take months for it to reach any kind of speeds. This would make the travel uneconomical, stasis would be required, or the use of drones on trade, so it would never be further away then mars, and so we won't reach other solar systems. It is even unknown if our propulsion will work to far away from the sun. We would need more then the simple kinetic energy from an ion drive. We would need to bend space around our vessle, simulate 0 mass, and then we can easily reach any speed.

But i can't see that happening, and in 1000 years, going on it at this rate, all human life on earth will be extinct.

Zwolver

Ion drive engines have all the power you need. What they lack is acceleration. So if your vessel is capable of reaching 10% of light speed, it may take 10 years to accelerate to that, and another 10 to decelerate. At that rate, you will take 55 years to reach Alpha Centauri.

So what?
55 years may be a small percentage of the lifespan of the new human who lives 500 to 1000 years from now. He/she will live in a large ark ship with luxuries unforeseen by anyone living today.

Why do you think 10% of light speed is feasible?

Originally Posted by skeptic

Zwolver

Ion drive engines have all the power you need. What they lack is acceleration. So if your vessel is capable of reaching 10% of light speed, it may take 10 years to accelerate to that, and another 10 to decelerate. At that rate, you will take 55 years to reach Alpha Centauri.

So what?
55 years may be a small percentage of the lifespan of the new human who lives 500 to 1000 years from now. He/she will live in a large ark ship with luxuries unforeseen by anyone living today.

I wasn't talking about taking humans there, but i will never be a commercial thing, it will be a once in a lifetime thing, where mainly scientists and pionneers would ever dream of going. Though humans may reach Alpha Centauri (i doubt it will be habitable), but never colonise it. As commercial shipping will never exist.

The 55 years you say it takes, is for the outside world. Inside the ship it will be more like taking a 35 year trip. As of speed slows the flow of time.

Though, i hope i am wrong about this.

Harold

I have no such personal theory.

However, there was an article in SciAm about 12 years ago written by a couple of NASA scientists about interstellar travel. They made the statement that travel at 10% to 20% of light speed should be possible in 500 to 1000 years. They might be wrong, but they are rocket scientists and I am not.

Originally Posted by Harold14370

Why do you think 10% of light speed is feasible?

Given our present level of scientific/technological knowledge it would be difficult, if not impossible, for anyone to respond with an answer that would clearly show such a development to be a likely future outcome.
On the other hand it would be an arrogant and unscientific to attempt to impose arbitrary limits, on the increase of such knowledge, into the medium-term and distant future.

Originally Posted by Harold14370

Why do you think 10% of light speed is feasible?

As skeptic says, experts in the field believe it to be feasible. Your question implies you think this is unrealistic. If this is so, what is your reason for that viewpoint?