Due to medical advances, people who would normally have died continue to live and reproduce - it is therefore my belief that as a race we have the most diverse gene pool compared to other animals
Now consider historical epidemics like flu, influenza and plagues that wiped out whole populations of ancient civilization
If we exempt current medical technology (and hygiene maybe?) and exposed ourselves to epidemics - would more of our population survive due to a more diverse gene pool?
Bonus Question: as in H. G. Wells ‘Time Machine’ when will our gene pool become so diverse that the human race forks off into different species?
Sorry, but your belief is factually wrong. Humans in fact have one of the lowest levels of genetic diversity of all the animals we know of. There is less genetic difference within the entire human species than there is between two tribes if chimps living 200 yards apart on opposite banks of a river. There is less diversity in our entire species than there is between wolves on opposite sides of a mountain range.
The only mammal species I know of with a less diverse gene pool than humans are all endangered.
[quote[Now consider historical epidemics like flu, influenza and plagues that wiped out whole populations of ancient civilization[/quote]
None of those diseases ever wiped out whole populations. Severely reduced them, sure, but not wiped them out.
More than what?
More than survived in the past? No, fewer would be survive.
More than other species would? That depends on what other species.
Currently being discussed in this thread.. The answer is " almost certainly never", barring interplanetary colonisation and subsequent tens of millions of years of physical isolation.
The reason for this is that the human population went through an extreme bottleneck event within the last few thousand years (I can’t find the figures right now). We are all descended from a small number of people, thought to be a few thousand. We came quite close to going extinct.
Most of the human genetic diversity that does exist resides in people of African descent.
Plus, using medicine to keep people alive is counterproductive to the OP premise. We are keep people alive who have weak or erratic immune systems. The entire history of human populations was that a significant number of children died within 5 years, usually from childhood diseases. Today, almost all survive thanks to cleanliness and antibiotics. One of the biggest issues with childhood is diseases like asthma, where it seems the immune system attacks the body.
I think the answer is the opposite. Diseases get weaker as they get older. The first bubonic plague killed (estimates vary) about 1/3 of europe. Subsequent waves were more of a nuisance than a disaster. The disease killed off those least able to fight it, and the disease agents survived and spread when they had a weaker effect on the host. The most lethal were burioed or burned before they could easily spread.
We see the same effectwith AIDS. People used to drop off within a year or so of infection. Now, we have a lot of people living decades with the infection. Which version of the disease do you think spreads to more victims?
Yeah, it’s not much time at all. But it was enough for us to go from ~.000002B to 7B worldwide!
I’m not sure how much the Toba link is scientific consensus at this point, or just one probable hypothesis. It gets popularize as established fact, but I don’t think we’re quite there yet.
Everyone is talking about how the Human gene pool isn’t diverse but I find that hard to believe. I read articles about it deteriorating in terms of quality but not diversity.
Take Sickle-cell anemia and how it protects against malaria - sickle-cell is the epitome of ‘bad genes’ that modern medicine can alleviate to some degree and allow carriers to promulgate.
I am just asking how the spread of negative genes can actually make our species more diverse and increase our inherent immunity to future epidemics - just like sickle cell and malaria go together.
I concede that it may be an arbitrary judgement but it is applicable to evolution in the context of natural selection.
Check this link about how “13 percent of the genes examined in the study showed evidence for negative selection, whereby harmful mutations are weeded out of the population. These included some genes implicated in hereditary diseases”
13% looks like a large figure but we have no comparative data to benchmark it on. What I want to know is if medical advances have mitigated negative selection and to what extent?
Lowering the impact of negative selection permits varied diversification - So as in the connection between Sickle Cell Anemia & Malaria would it boost our inherent immunity as a species against unknown future epidemics?
A lot of talk goes on about racial purity and good genes. Lots of dystopian stories are based on genetic policing and regulation
I am trying to find a positive perspective to retaining negative genes and all that rises to mind is the potential this diversity may have in immunity to incurable diseases. If anyone thinks of other positive arguments for retaining bad hereditary genes (as opposed to wiping them out) feel free to private message me
I know you’re new here, so you don’t have the perspective of all the threads we’ve had on this MB to address this topic. There is no difference between “medical advances” that help some live and the first human ancestor who made a stone tool that allowed his clan to butcher a carcass and eat it whereas the other clan without stone tools couldn’t do so. We are a tool making species. That is the niche we have perfected par excellence. Those tools involve things that allow individuals to survive who would not do so absent such tools. That is who we are. From the first flint knife to the most sophisticated laser. If you want to decry the latest medical advance as “degrading the genome”, you will need to do the same for every discovery from stone tools to fire to agriculture to the wheel to modern medicine.
This discussion got me to wondering just how often genetic makeup affects susceptibility to a particular disease. I understand that heart disease, diabetes, plague and sickle cell anemia (and for a few, HIV) would be included, but I have no idea how many others. Any thoughts?
That is very insightful, but not helpful. All you have done is expand the boundaries of my already complicated question when we need to be focusing on a specific factor. If you have any experience answering questions you would know that focusing and defining the scope as #2 poster (Blake) did is more important than introducing vague generalizations.
I think you have the correct approach to the problem SantaMan that would be the best place to start an enquiry and approach the subject matter
The Pleistocene covers a timeframe from 2.5M years ago up until the end of the last ice age (about 10,000 BC). That includes the entire span of the genus Homo (except for the last 12k years), so I’m not sure what you mean by that statement.
I already corrected Alka’s dates in an earlier post, if that is what you were referring to.
I meant to say that Pleistocene hominins had very low genetic variation as well, so a recent bottleneck doesn’t appear to be sufficient to explain our lack of genetic variation.
What definition of “hominin” are you using, and what data are you referring to?
“Hominin” can mean different things depending on the context. These days, you see Homininae meaning humans, chimps and gorillas and our ancestors back to the common one. Hominini means the same, except excluding gorillas.
