Research on the Obstacles of Medical Treatment to Human Evolution

Xiupu Zhao

Qingdao No. 39 Middle School, Shandong, China

Keywords: Medical Treatment, Gene Therapy, Normal Medical Treatment.

Abstract: It is relatively well-understood how natural selection took place in the distant past. But the study on how

natural selection act in the present is still ambiguous, Plus, humanity owns the unique skill that can cure

themselves effectively using external treatments, which might interfere the natural selection on current human.

Here, we quote the study on global heart disease, ancient insects gene therapy and high cholesterol to support

the idea that medical treatments would block the natural selection process of humanity. Plus, article also points

out the factors that make such block not thorough.

1 INTRODUCTION

Compared to other species, humanity evolved

extraordinarily quickly from the Dryopithecus. And

humans evolved even more rapidly since the

emergence of social organization. The difference

between human and other vertebrate are recognized

as owning the ability to use tools to fulfill their

purposes such as hunting, searching for food,

building the shelter. As ancient ape’s brain capacity

raised caused by the preference of natural selection

upon the smarter individual, the natural selection

have happened significantly on humans in ancient

times. (

Hawks 2012

)

Humanity had evolved in a macroscopical span,

and there is evidence pinpointing that humans have

been always keeping evolving and speed up the

process. To demonstrate, the DNA related to lactose

tolerance of ancient European people before last 6000

years did not exist in the population, but such DNA

sequence widely exists among European settlers

around 5000 B.C.E. (Wilde 2014) That is because

people in Europe in that range of time, human were

used to obtaining food by hunting, fishing and

gathering fruits and nuts. As long as settlers start

operating agriculture, and drinking milk produced

from livestock, people’s diet changed. Then, the

people who owned the gene that allowed them to

absorb more nutrients and to tolerate intaking more

amounts of milk are more likely to survive, and pass

their gene to the next generation. Thus, the gene of

lactose tolerance widely appeared in the population.

Plus, research done by Henry C. Harpending’s team

shows that selection has accelerated greatly during

the last 40,000 years, and more than 1800 genes

speeded up. They assumed that this phenomenon is

matched with human’s settled life and increasing

population. (

Qin 2009

)

But as for the rapid improvement of medical care,

which mainly took place from the second industrial

revolution, it made humanity became the first species

that can use effective external treatments to improve

their health level. For the doubt whether this

difference will interfere with the process of natural

selection, some scientists had offered their theory.

According to Steve Jones, a genetics scientist, and

professor at London university, address that the effect

of natural selections had been decreased by 70%

compared to hundreds of years ago for our humanity,

because the number of elder fathers (procreate at an

age after 35) decline, which means less possibility for

spermatocyte’s gene to mutate. Then the genetic

diversity of offspring will be limited, which will slow

down the evolving process. Jones also addressed that

in the past there would be less than half of the total

number of kids could live longer than 20 years old,

but now in the western country, 98% of kids could

live longer than 21 years old. (

Wilde, Timpson,

Kirsanow, Kaiser, Kayser, Unterländer, Hollfelder,

Potekhina, Schier, Thomas, Burger 2014

)

Here, we divide the entire medical treatments into

two main categories, the normal treatment and gene

therapies. The standard is that the normal treatments

refer to the medical treatments that cure disease by

using medicine, operations, radiation or other

methods without modifying patients’ genetic

Zhao, X.

Research on the Obstacles of Medical Treatment to Human Evolution.

DOI: 10.5220/0011290700003444

In Proceedings of the 2nd Conference on Artiﬁcial Intelligence and Healthcare (CAIH 2021), pages 219-224

ISBN: 978-989-758-594-4

219

material. And gene therapy Refers to the introduction

of exogenous normal genes into target cells to correct

or compensate for diseases caused by defects and

abnormal genes to achieve the purpose of treatment.

In this article, we will comprehensively analyze

two types of medical treatments, and using the data

from UN and some global long-lasting study to

support the idea that medical treatments hindrance the

evolution of human being. And here, we will also

point out that medical treatments will not stop the

people, due to different rational affluence level and

the disability to some particular diseases. (

British

scientist declare that human evolution 2008

)

2 THE INTERFERE OF NORMAL

MEDICAL TREATMENTS ON

HUMANITY EVOLUTION

2.1 Normal Medical Care Hindering

Humanity’s Evolution

During the whole history of the evolutionary process

for humanity (started from Dryopithecus), it is known

that ancient human beings would use spittle to cleans

their wound, which is just like other animals did. And

later, they would use the cloth to cover the wound to

stop bleeding. Nevertheless, this advance still is not

effective, patients still would die from infections or

left Sequelae. Based on that, we can figure out that

whether people own a stronger body or better

physical conditions was still determined to survive in

their circumstance, in other words: avoid being

eliminated. And this principle was dominant until the

second industrial revolution, which made a

significant change in medical care. (

QIAO 2011

)

After experience the secondary industrial

evolution, Health care had unprecedented innovation

compared to the past. People are more concentrated

on finding the methods to cure patients by science and

effective medicine, and doing the operation on

patients to clean up the wound. The disinfect method

provided by Louis Pasteur lowered the probability of

getting infected while experiencing injure, surgeon,

and giving birth. For the medical treatments, they

help people to survive when they suffer from physical

injure both spontaneous and induced by external

factors. Based on that, the weaker in the aspect for the

physical condition would not be eliminated.

(

Besenbacher, Hvilsom, Marques-Bonet, Mailund,

Schierup 2019

)

The rapid decline in mortality of infants took

place in current society can perfectly demonstrate this

case. Infants with hereditary spontaneous heart

disease before the great development of medicine

were very likely to die before the age of 18, and their

genes are not likely to be delivered, so they are been

eliminated. But for now, the death rate of people

owning spontaneous heart disease who will survive

from it is much lower in the past. According to the

research on the systematic analysis for the global

burden of congenital heart disease from 1990 to 2017,

congenital heart disease caused 261247 deaths (95%

uncertainty interval 216567–308 159) globally in

2017, a 34·5% decline from 1990, with 180 624

deaths (146825–214178) being among infants (aged

<1 year). Congenital heart disease mortality rates

declined with increasing Socio-demographic Index

(SDI). (

Hawks, Wang, Cochran, Harpending,

Moyzis 2007

)

Figure 1: Mortality of congenital heart disease in children

under 1 year of age, 1990–2017.

2.2 The Incompleteness of the

Hindrances Due to the Normal

Medical Treatments

Based on the above case, we can also infer another

important point: The hindrance due to the normal

medical treatments is existing, but cannot totally

block the selection. Because first: many diseases that

due to the mutate happened to patients’ genes or some

genetic disease, is difficult to be cured by the normal

treatments, which like hemophilia, red-green

colorblindness, rheumatism and thalassemia. Those

genetic diseases are hard to be cured by taking

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medicine or using normal medical treatments. In such

cases, those diseases would permanently become the

barriers for patients to live a normal life, and which

can affect bearing children. (

GBD 2017 Congenital

Heart Disease Collaborators, Global, regional, and

national burden of congenital heart disease, 2020

)

Then, individuals with those particular genetic

diseases that are hard to be controlled by normal

treatments are likely to be eliminated, which means

that natural selection is still operating. Second:

people’s reproductive rate would be interfered with

more or less if they owning the genetic diseases, even

though their genetic diseases have gotten control for

the level of trials. This can be proved by long-lasting

research done by the team of Sean G. Byars. They

estimate the total cholesterol of different and their

reproductive success in their lifetime, both male and

female residents. (

Byars, Ewbank, Govindaraju,

Stearns 2010

)

Figure 2: The effect of total cholesterol upon the

reproductive during lifetime.

They found out that there is a linear relationship

between two factors, and it is slightly negative, which

shows that the cohorts with higher total cholesterol

tended to own less reproductive success time during

their lifetime. And this will then reduce the frequency

of genes of high cholesterol (

Wilde, Timpson,

Kirsanow, Kaiser, Kayser, Unterländer, Hollfelder,

Potekhina, Schier, Thomas, Burger 2014

However, this can apparently only be viewed in a

huge population, which means the individual can

hardly feel this tiny difference, and would not likely

to take drugs to increase their fertility success rate.

Based on that, the frequency of related genes would

gradually decline. Thus, normal medical treatments

cannot totally block the selection process. (

UN Inter-

agency Group for Child Mortality Estimation, data

for infant mortality rate for each country.

)

Besides, the differences in local regional

economic level also makes normal medical

treatments can’t stop evolution of humans. To be

more specific, the hindrance caused by the medical

treatments is in proportionality with the local health

care, which can be reflected by the level of affluence.

For the people who live in a prosperous area, once

any individuals got the illness, they will timely take

medical care, and the medical treatments will cover

up the original undesirable trials quickly and

efficiently through accurate diagnosis and effective

pharmacy medicine or surgery. Then the hindrance

would be dramatic, because, among them, those

inheritable traits can’t be eliminated, and be delivered

to the next generation. For the people who live in a

poor area, they cannot receive and get appropriate,

normative medical care. In such a case, only the

stronger individuals that resist those diseases, or the

individual without those disease-cause genes can

survive, which means the selection process is still

operating dramatically. (

Tvedte, Logsdon, Forbes

2019

) This can be proved by the statistical data from

the UN Inter-agency Group for Child Mortality

Estimation (Figure 4). It can be easily analyzed that

the more developed an area is, the smaller rate for

infant mortality, and also the smaller rate for child

mortality aging under five. For the poor area, they

own a higher rate for infant mortality and child

mortality aging under five. Consequently, the

individual with harmful variance will be eliminated

relatively quickly in the poor area. For the prosperous

area, the individual’s harmful variance will be more

likely to be reserved because of the medical care

making block to the natural selection to eliminate the

weaker.

2.3 Summary

The hindrance of natural selection due to the normal

treatments exists. However, the hindrance is limited,

which can be seen when individuals own some

particular and severe genetic diseases or

chromosomes mutates, the natural selection that

happened on them could still be dramatic. And the

hindrance caused by medical treatment will in

proportional to the local health care, which can be

reflected by the level of affluence.

Research on the Obstacles of Medical Treatment to Human Evolution

221

Table 2: Infants mortality rate (death per thousand live infants) from 1990 to 2019 for World Bank Low Income Economies

and World Bank Upper-Middle Income Economies.

Geographic area :Sex Time period Observation Value Reference Date Interval

WBLI/WBUMI _T: Total Jun-90 109.463446509862/42.7815011606326 1990.5 1

WBLI/WBUMI _T: Total Jun-95 100.922626747199/37.0132344311526 1995.5 1

WBLI/WBUMI _T: Total Jun-00 88.6047895128807/29.908538620655 2000.5 1

WBLI/WBUMI _T: Total Jun-05 73.8161550778262/22.6922795024222 2005.5 1

WBLI/WBUMI _T: Total Jun-10 62.4996950995103/17.052156472951 2010.5 1

WBLI/WBUMI _T: Total Jun-15 53.4542695157647/13.3918464099905 2015.5 1

WBLI/WBUMI _T: Total Jun-19 47.9118341480216/11.3477289544356 2019.5 1

WBLI refers to the World Bank Low Income Economies; WBUML refers to the World Bank Upper-Middle Income Economies;

Observation value refers to the infant mortality per one thousand of live infants.

3 THE INTERFERE OF GENE

THERAPY TREATMENTS ON

HUMANITY

EVOLUTION

3.1 The Further Hindrance to the

Natural Selection of Human Being

Due to Gene Therapy

Heritance and mutation are two ingredients for

species evolution. And neither of them should be

absent. In another word, only when both of them are

satisfied, species evolutions are keeping processing.

When one species never mutates, then the genetic

sequence of such a creature will never change, and its

gene will remain the same without any evolution.

However, this would never occur under the current

circumstance, because all species’ genetic material

would mutate with a very low probability. When the

mutation process of one species is blocked, assume

the mutate rate follows the normal, the mutate can’t

always be delivered or can’t be delivered. This will

cause the evolution speed of such species to slow

down. Phasmatodea is one of the species that some of

its genetic sequences cannot be delivered.

Phasmatodea owns a unique reproduction method,

we called them clonal or hemiclonal reproduction.

However, hemiclonal reproduction is more usual. In

clonal reproduction, sperm only play a role in

activating the embryo. During hemiclonal

reproduction, the oocyte just sweeps away the

paternal genes and then integrates with the sperm.

The most typical species with hemiclonal

reproduction is Phasmatodea. In such case, the

meiosis will not occur in the formation of the egg cell.

And then the genetic recombination would not occur

as well, which will greatly lower the mutation rate.

This would cause less variability for their genes,

which makes their genes stable for millions of years.

So it is obvious that either of them is blocked, the

evolution speed would slow down. Gene therapy can

fix the original undesirable gene, and replace it with

the new and external gene that controls the correct

trials, which means the delivery of the mutation is

blocked. In such situation, nature could not eliminate

the weaker, because once a harmful genes carrier

came out, they can be detected and fixed, then the trial

would be modified as well, and then hardly do weaker

exist. Then, the evolution is apparently blocked by

analogizing. (

Ye, Chang, Lin, Sun, Yu, Kan 2009

)

With the import of gene therapy, many diseases

can be further and radically cure, such as hemophilia,

red-green colorblindness, rheumatism and

thalassemia. According to the report published on

PNAS, the innovation of reprogramming somatic

cells to induced pluripotent stem cells provides a

possible new approach to treat β-thalassemia and

other genetic diseases such as sickle cell anemia.

They Induced pluripotent stem (iPS) cells that are

made from these patients' somatic cells, and the

mutation in the β-globin gene is corrected by gene

targeting, and the cells differentiated into

hematopoietic cells to be returned to the patient.

Based on the dramatic effect of genetic therapy, it

raises the possibility of using iPS cells to treat

patients with homozygous β-thalassemia. A similar

strategy of treatment may also be applied to sickle

cell anemia, as has been demonstrated in a mouse

model (20). Somatic cells such as skin cells can be

cultured from the patients and reprogrammed into iPS

cells. The mutation in the β-globin gene in β-

thalassemia or sickle cell anemia can be corrected in

the cultured fibroblasts or following their

reprogramming into iPS cells by the gene targeting

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method. The iPS cells can then be differentiated into

hematopoietic cells for the treatment of the patients.

As the cells are the patient's own, immune rejection

is avoided (Ye, Chang, Lin, Sun, Yu, and Kan 2009).

Also, parents can get a gene test for their fetus if there

are any possible genetic diseases. In such way,

parents can fix their disease-causing genes. With the

effective treatments to diseases, humanity who

receive the gene therapy will all then converge in

aspect for physical condition. And after conducting

those treatments, their physical condition will no

longer be the barrier to get a higher social status due

to the combination of normal treatments and gene

therapy, which means they would own the equal

opportunity to live well. Thus, natural selection is

being further blocked in aspect for better cure effect.

(

Wipfler, Letsch, Frandsen, Kapli, Mayer, Bartel,

Buckley, Donath, Edgerly-Rooks, Fujita, Liu,

Machida, Mashimo, Misof, Niehuis, Peters,

Petersen, Podsiadlowski, Schütte, Shimizu,

Uchifune, Wilbrandt, Yan, Zhou, Simon 2019

)

3.2 The Incompleteness of the

Hindrance Due to the Gene

Therapy

Likewise, the hindrance due to gene therapy would

also be incomplete, it can be reflected that some

genetic diseases like Polygenic, which would make

the treating process very sophisticated and evenly

impossible to be eradicated.

In addition, the hindrance caused by the medical

treatments is in proportionality with the local

affluence level, which can be reflected by the level of

affluence. Residents in the rich area are more likely

to afford the expense of gene therapy, and the

hindrance will be strong. For the poor area, people

can’t afford such expense of gene therapy, and the

natural selection preference would be still significant.

Thus, the block effeck due to medical treatments can

also not be thorough.

3.3 Summary

Gene therapy blocks natural selection more deeply.

Because gene therapy's trials of inheritable. Likewise,

the hindrance can also be incomplete due to the

disability to inheritate diseases like Polygenic, and

the differences in health care levels.

4 CONCLUSIONS

Medical treatments will block the natural selection

both for normal treatment and gene therapy.

However, this hindrance caused by both normal

treatments and gene therapy will not be thorough due

to the realistic objective factors. Plus, both of the

hindrances for two kinds of treatments are in

proportionality with the prosperity level.

REFERENCES

B. Wipfler, H. Letsch, P. B. Frandsen, P. Kapli, C. Mayer, D.

Bartel, T. R. Buckley, A. Donath, J. S. Edgerly-Rooks,

M. Fujita, S. Liu, R. Machida, Y. Mashimo, B. Misof, O.

Niehuis, R. S. Peters, M. Petersen, L. Podsiadlowski, K.

Schütte, S. Shimizu, T. Uchifune, J. Wilbrandt, E. Yan,

X. Zhou, S. Simon, Evolutionary history of

Polyneoptera and its implications for our understanding

of early winged insects, PNAS, February 19, 116, 3024-

3029 (2019).

British scientist declare that human evolution had stopped.

www.chinadaily.com 2008 10 08

E. S. Tvedte, J. M. Logsdon Jr., A. A. Forbes, Sex loss in

insects: causes of asexuality and consequences for

genomes, Current Opinion in Insect Science, February,

Volume 31, Pages 77-83 (2019).

GBD 2017 Congenital Heart Disease Collaborators, Global,

regional, and national burden of congenital heart

disease, 1990–2017: a systematic analysis for the Global

Burden of Disease Study 2017, The Lancet Child &

Adolescent Health, March, Volume 4, Issue 3, Pages

185-200 (2020).

J. Hawks, E. T. Wang, G. M. Cochran, H. C. Harpending, R.

K. Moyzis, Recent acceleration of human adaptive

evolution, PNAS, December 26, 104, 20753-20758

(2007).

John Hawks, Longer time scale for human evolution, PNAS,

September 25, 109, 15531-15532 (2012).

L. Ye, J. C. Chang, C. Lin, X. Sun, J. Yu, Y. W. Kan, Induced

pluripotent stem cells offer new approach to therapy in

thalassemia and sickle cell anemia and option in prenatal

diagnosis in genetic diseases, PNAS, June 16, 106 9826-

9830 (2009).

QIAO Yu-cheng, Evolution and Degeneration: The

Evolvement of Human Physique and Its Cause Analysis

—From the Perspective of Physical Anthropology,

SPORT SCIENCE, Vol.31, No .6 (2011).

Qin S i-he, The Exploration of the Momentum for the

Evolvement of Vertebrate into Human Being, Medicine

and Philosophy (Humanist ic &Social Medicine

Edition), Vol.30, Total No.394 (2009).

S. Besenbacher, C. Hvilsom, T. Marques-Bonet, T. Mailund,

M. H. Schierup, Direct estimation of mutations in great

apes reconciles phylogenetic dating, Nature Ecology &

Evolution page Feb, 286-292 (2019).

Research on the Obstacles of Medical Treatment to Human Evolution

223

S. G. Byars, D. Ewbank, D. R. Govindaraju, S. C. Stearns,

Natural selection in a contemporary human population,

PNAS, January 26,107 (suppl 1) 1787-1792 (2010).

S. Wilde, A. Timpson, K. Kirsanow, E. Kaiser, M. Kayser,

M. Unterländer, N. Hollfelder, I. D. Potekhina, W.

Schier, M. G. Thomas, J. Burger, Direct evidence for

positive selection of skin, hair, and eye pigmentation in

Europeans during the last 5,000 years, PNAS, April 1,

111, 4832-4837 (2014).

UN Inter-agency Group for Child Mortality Estimation, data

for infant mortality rate for each country.

CAIH 2021 - Conference on Artiﬁcial Intelligence and Healthcare

224