Episode Transcript
[00:00:00] This program contains terminology describing the human reproductive system. Parental discretion is advised for younger listeners.
[00:00:20] Welcome to faith and science.
[00:00:23] Just the other day, I went to a lecture on the immune system, and it was really fascinating to learn some of the areas, again, of the complexity of the immune system, particularly the human immune system.
[00:00:48] And I was reminded, actually, I saw on my bookshelf, a book that I bought decades ago, was called the body at war by Professor John Dwyer, who was at that time professor of medicine at the University of New South Wales. And he was ranked as one of the world's most experienced clinical immunologists.
[00:01:17] And in particular, of course, the whole concept of, or the whole process of human conception, the beginning of human life, has a very, very interesting involvement with the immune system.
[00:01:40] And it's quite fascinating that a paper was published, or just a few years ago now, in the journal Science Immunology, back on the volume number two, issue 15, back on the 1 September 2017, and the article was titled An Immune clock of Human Pregnancy.
[00:02:11] And it was about the immunology immunological clock.
[00:02:17] And this was cutting edge edge research that was published back in 2017. And I remember there were a lot of articles published in the media about this discovery about the immune function as altered during pregnancy to actually protect the fetus from immunological attack by the mother's immune system.
[00:02:51] And the research that was done looking at this process and scientists trying to understand and get a handle on this process.
[00:03:05] And I find it fascinating that the maintenance and pregnancy relies on this finely tuned immune adaptions, which are precisely timed and in actual fact, reflect an immune clock of pregnancy during the pregnancy.
[00:03:28] And, of course, there's really complex biochemical components make up all these different reactions that are precisely timed to kick in at just the right time to preserve the little baby as it's growing in its mother's womb. And when I think about the fact that all these chemicals are encoded for the process to make these chemicals, the chemical reactions that release them at just the right time are all encoded for in the dna. And of course, the evolutionary story that we're told is that these processes all arose by random, blind emphasis on blind mutations or changes to the genetic code that somehow produced this system that works.
[00:04:28] And I think it becomes very obvious that random mutations aren't going to produce this complex biochemistry.
[00:04:39] When we look at human fertilization, which we're taught in school, is the union of the human egg and sperm, which occurs in the bend in the fallopian tube initially. And this union leads to the production of a fertilized egg, which is called as a goatee, and then it develops into the little baby. And so this all sounds fairly simple, the egg and the sperm meat thing. But when we drill down into this process, the biochemistry is extremely complex.
[00:05:21] So if we go to the next level, we can say, well, the process of fertilization involves a sperm fusing with an egg, and then the fertilization occurs.
[00:05:37] But when we look at this process and drill down again a little bit further, it becomes a little bit more processed. So upon encountering the egg, I remember reading, then there's an acrosome on the head of the sperm that produces enzymes, which allow it to burrow through the outer shell of the little egg, which is called the zona polusia of the egg. And the sperm plasma then fuses with the egg's plasma membrane, and their nuclei fuse together, triggering the sperm head to disconnect it from its flagellum. And that's the little propeller sort of system, the long trails that are out behind the sperm, like on other bacteria as well. And as the egg travels down the fallopian tube to reach the uterus, so that part of the sperm, the disconnect, the flagellum disconnects as the leg moves down the fallopian tube. And, okay, this all sounds very simple, but to make all this happens, there's a whole lot of biochemistry that is precisely timed and is controlled by chemical reactions and enzymes.
[00:07:11] So it's interesting that for the fertilization to occur, then the sperm have to swim towards the egg. And it's interesting that the sperm are attracted to progesterone, which is actually secreted from the cumulus cells that surround the little egg. And so again, when we drill down into this thing, we think, okay, we've got a little egg, but this little egg has special cells on the surface, the cumulus cells. And these cells, again, release progesterone, which again, we know as a hormone, female hormone. And also, though, the sperm have little sensors in them that detect the progesterone levels that are circulating there in the fluids in that part of the body. And they swim, they're programmed to swim towards the highest level or the more concentrated level. Now, in order to do that, of course, they have to direct themselves. And there's a whole logic system that controls the direction of their flagella so that they swim in that particular direction.
[00:08:48] And so the information that is received with regard to chemical gradients. And so there's a chemical gradient that is detected. And as a result of that, there has to be control of the directions of the flagella to swim in that direction.
[00:09:11] And this is quite a complex system. And I've talked in the past of the amazing motor system, for example, in the fagella of an E. Coli bacteria.
[00:09:25] But again, the sperm before it gets that has to be what is called capacitated.
[00:09:40] I'll come back to that in a second. But it's interesting that the progesterone binds to what they call a cat sperm receptor on the sperm membrane. So again, these are other specialized membranes that have specialized structures that are all encoded for in the DNA. And remember, according to the evolutionary theory, all these structures arose by random mutations in a code. And the code is represented by. Is made up of four chemical compounds that we represent by the letters act and g, which is a language. Just like we write the word apple, a PL E that writes the word for an apple. But a plea doesn't look anything like an apple. It's just code and the same the DNA code.
[00:10:34] And so just imagine how many times a two year old would have to type on a typewriter just to write the word apple. If you needed the word apple to be typed, just imagine how long it would take him. And eventually he would probably do it. We can work out the probability, but it's quite a long time. Well, the same thing refers to blind mutations, which are far more complex than the word apple. The genetic code to make these compounds, such as the catsper receptor on the sperm. And this is where the theory of evolution really breaks down. It can't explain this amazing complexity. So again, the progesterone binds the catspur receptor on the sperm membrane and increases intracellular calcium levels, which then increase hyperactivity of motility. So it increases the sort of power or revis, you might say, on the little sperm, fagilla. The sperm then continue to swim towards the higher concentrations of progesterone, effectively guiding it to the egg. And so again, though, the sperm, at the beginning of the process, the sperm itself undergoes changes.
[00:11:59] So it's because interesting that freshly ejaculated sperm is unable to pour or very poorly able to fertilize an egg. The sperm itself must first undergo what's called capacitation in the female reproductive tract. And it's interesting that the uterus aids the steps of capacitation by secreting sterile binding albumin, lipoproteins and protolytic and glycosytic enzymes.
[00:12:33] One of those is hesparin. So these compounds and enzymes again increase the motility of the sperm and also what they call hypopolarizes the membrane, which prepares it for what they call the acrosome reaction, which is a change that occurs in the head of the sperm to enable it to release the enzymes so that it can get through the egg's tough membrane, or egg coat, which surrounds the egg.
[00:13:16] And so the capacitation of the sperm, as it's called, as it comes into this process. So you can see there's an interaction between compounds in the female and compounds from the male that actually prepare the sperm so that it can fertilize the egg. And the capacitation reactions have two effects.
[00:13:42] They actually destabilize the sperm head membrane, which allows it then to penetrate the outer layer of the egg. And it produces chemical changes in the tail that allow greater mobility of the sperm.
[00:14:02] And these changes are again facilitated by the removal of long or compounds that we call sterols, such as cholesterol, and also bound seminal glycoprotein. So these are protein sugar compounds, and the result is a more fluid membrane with an increased permeability to the calcium ion.
[00:14:34] And as I was talking about earlier, that influx of calciumide produces increased intracellular, what they call camp levels, or cyclic adenosine monophosphate. That's the chemical name. And this is a particular chemical signaling compound. It's called a second messenger, which produces cellular signaling within cells. And so these compounds that are called second messengers, they trigger physiological changes at the cellular level and such as proliferation, differentiation, all sorts of different compounds. And it's interesting that Dr. Earl Wilbur Sutherland, he discovered second messenger cells and won the Nobel Prize in 1971, the Nobel Prize in Physiology and Medicine.
[00:15:41] And so again, these specialized compounds are all encoded for in the DNA.
[00:15:50] And again, according to evolutionary theory, the chemistry, the biochemistry to produce these compounds arose by blind random mutations in the code, massive changes in the code, but all worked, all worked to produce these changes, because without these changes, fertilization isn't going to happen. No new life is going to form from the union of the male and female gamete cells.
[00:16:21] And the hyperactivation, which coincides with the onset of capacitation and is a result of the increased calcium levels, has a synergistic effect with another compound called adenosine that increases another compound called adenyl cyclose activity in the sperm.
[00:16:46] The reason I'm talking about these chemical names is that these are all chemical compounds, specific chemical compounds that have to be produced or the whole system doesn't work. It's extremely complex.
[00:17:04] And as I mentioned that paper in 2017, and I noticed there was another paper published in 2020. Also that where scientists are still working on trying to understand the complexity of fertilization because as we know, there are so large number of couples today are finding it difficult to conceive and have a baby. And so in order for medicine to be able to help these people, they're trying to understand better the system. So what we can see is that the reason why one of the problems with conceiving is that so many things can go wrong. And one of these things, if it does go wrong, then conception doesn't occur.
[00:17:59] And yet the evolutionary theory talks about how all this amazing, extremely complex biochemistry evolved by random chances of random chance mutations. And yet if something doesn't work, it doesn't work. There's no new life, so there's no process available for even natural selection because nothing's going to happen. And to me, this is just powerful evidence for amazing creator that put together this amazing system that allows us to reproduce.
[00:18:38] There's so much more.
[00:18:40] The tripeptide, which is called the fertilization promoting peptide FPP, is again essential for controlling capacitation. So this is another compound, another that a protein or peptide, the FPP, is produced in the prostate gland as a component of seminal fluid. And when the fpp comes in contact with the little sperm as it's mixed, because the seminal fluid, of course, comes from the prostate gland, the spermazoa themselves come from the testes. They're mixed during the process of ejaculation. And when the sperm and the seminal fluid mix, now the high levels of active FPP prevent the capacitation. But after ejaculation, the concentration of FPP drops in the female reproductive tract, and that allows then the acrosome reaction to occur. So here we see again in the male reproductive system, we have these special fertilization promoting peptides, FPP produced as part.
[00:19:58] So the acrosome reaction is the reaction that occurs in the head of the sperm, the acrosome. So this is a little sort of like a little hollow dome part that is at the head of the sperm. And this reaction begins to occur as the sperm approaches the egg. So this acrosomes, it's like a little membrane that covers a little cavity at the tip of the sperm, the spermazoon. And as the sperm approaches the outer shell of the egg, the membrane surrounding this acrosome, or the head of the sperm, fuses with the plasma membrane of the sperm's head and exposes the contents of this little acrosome, this little cavity at the top. And the contents include surface antigens which enable binding to the egg's shell membrane, and then a number of enzymes that are responsible for breaking through or helping to dissolve the egg's tough coating, which then allows fertilization to occur. Now, the sperm actually binds through another structure called the corona radiata, which are a layer of follicle cells on the outside of the little egg. So again, these are more specialized cells that all have to be programmed according to the dna code.
[00:21:44] But there's more. The corona radiator send out chemicals that attract the sperm in the fallopian tube. And we talked about that earlier. There's all these particular glycoproteins that surround the little egg there.
[00:22:05] When the little sperma spermisoin is about to pierce the yolk of the little egg, the or plasm is drawn out into a conical elevation called the cone of attraction, or receptive cone. And once the spermizunus entered, a peripheral portion of the egg yolk changes into a membrane called the prevotelline membrane, which prevents the passage then of additional spermisoa. So once the first sperm has got in, these changes also occur that prevent usually, and we know you can have paternal twins can sometimes occur, but that's the mechanism that prevents more sperm from fertilizing the egg once that occurs.
[00:23:05] And again, for me, the emphasis is here. This is amazing biochemistry.
[00:23:13] All these specific structures, all these different types of cell membranes, they're different types of biological structures that have to be assembled and put together. There are chemical reactions that are occurring that produce the different enzymes and other compounds and peptides and proteins and all this sort of thing. They all have to be encoded for in this code, which is a massive code. And we know in humans, with 4 billion letters or thereabouts in our code, there's so much complexity. And this is just in the fertilization of an egg so that we can reproduce. And it's slightly different in different other animals, too, and different other species.
[00:24:05] In many species, the sperm doesn't require capacitation. It's available to convertilize an egg immediately.
[00:24:15] And rats have a slightly different system to humans as well. For example, a lot of work is done studying on the reproductive system as looking at rats. But again, there's slight changes and differences in the biochemistry, but it all works. And the bottom line is it's extremely complex.
[00:24:39] There's so much more that we can talk about in terms of amazing biochemical compounds that are in sperm. And as I mentioned at the start of this talk here, the recent paper that was just published in 2017 about the fine tuning of the immune system, because the seminal fluid that carries the sperm from the male has quite powerful antioxidant, or, sorry, antiinflammatory characteristics which help then suppress the immune system in the female so that the female's immune system doesn't destroy the sperm. There's this really delicate balance that occurs. And as was reading, sorry, in the lecture that I heard just the other day is as the little fertilized egg then has moved into the uterus area. I think it's about six days later again. It's carrying foreign proteins from the sperm from the male, which would normally be attacked by the immune system there. But there's a special covering that is developed that protects it from the immune system, from being destroyed in the immune system, and allows it to bind successfully to the wall of the uterus.
[00:26:35] The complexity and the timing, and of course, this article was published in Science Immunology was looking at the amazing timing of all the processes that occur so that everything just works at just the right time. To me, this is such powerful evidence for an amazing creator God designer. And the whole purpose of these programs is to encourage you in your own personal lives to get to know that creator God and we can learn about him in the Bible, which is, there's so much evidence that the account, the biblical account, was inspired revelation from the creator God himself.
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[00:27:31] If we want to relisten to these programs, remember us. Google three abnastralia.org au click on the radio and the listen buttons for faith and science. I'm Dr. John Ashton. Have a great day.
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