covering called the tunica albuginea,
and an effective lubrication system
allows the slippage to occur without
pain or problems. Injury is rare, and
the main source of injury is in sports,
which is why it is recommended that
sport participants always use protective
equipment, such as a jockstrap or hard
cup, while playing.
Another reason for the existing
placement of the human male
reproductive system outside of the
body is that the
“… postpartum testicle is designed
to function at this lower temperature.
Failure of the testicles to descend into
the scrotum, called cryptorchidism,
causes an increased risk of malignancy
and other major health problems. The
process of testicle descent is also both
complex and poorly understood.” 16
Failure of the testicles to descend
following birth leads to progressive
abnormality in both the biochemistry
and physiology of the testis, often
causing infertility. 17
One example is that the abnormal
biochemistry caused by descent failure
interferes with many of the necessary
reproductive system developments.
Examples including the transformation
of neonatal gonocytes into type A
spermatogenesis, a step required to
produce viable sperm. 18 This is one
reason why failure of the testicles to
descend is a major reason for male
Evolution of the scrotum?
How the many complex male temp-
erature regulative system parts could
have evolved can only be speculated,
and not be based on observation and
science. 19 Consequently, evolutionists
must produce many just-so stories in
an attempt to explain their existence
and function. 20 In short, a literature
review found that “all of the current
hypotheses regarding the origin and
evolution of the scrotum” and external
testicles are seriously problematic.
Reasons include, assuming external
testicle evolution from lower life
forms with internal reproductive
organs is problematic because it is
“why the scrotum has been lost in
so many groups, that should be
explained”. 21 The authors even
speculate that the scrotum may have
evolved before mammals did
“… in concert with the evolution
of endothermy in the mammalian
lineage, and that the scrotum has been
lost in many groups because descent
in many respects is a costly process
that will be lost in mammal lineages
as soon as an alternative solution
to the problem of the temperature
sensitivity of spermatogenesis is
In conclusion, clear evidence
exists that year-round reproductive
cycles, plus the requirement that
human sperm must be kept close to
a constant temperature of 4˚C below
that of the core body temperature,
effectively explains the existing
design of testicles. Men who have
uncorrected non-descended testicles
are usually infertile and prone to
many other health problems, including
cancer. In short, the existing complex
design is required for many reasons,
including fertility and health reasons.
It is, therefore, clear that Hafer’s
poor design claim, along with those
of other evolutionists, is grossly
1. Rowe, C., The 10 Design Flaws in the Human
Body, Nautilus, 24 March 2016, p. 2.
2. Hafer, A., The Not-So-Intelligent Designer:
Why evolution explains the human body and
Intelligent Design does not, Cascade Books,
Eugene, OR, p. 5, 2016.
3. Hafer, A., No data required: why intelligent
design is not science, The American Biology
Teacher 77( 7):507–513, 2015; Hafer, ref. 2 p. 2.
4. Hafer, ref. 2, pp. 1–2.
5. Wechalekar, H., Setchell, B.P., Peirce, E.J.,
Ricci, M., Leigh, C., and Breed, W.G., Whole-body heat exposure induces membrane changes
in spermatozoa from the cauda epididymis of
laboratory mice, Asian J. Andrology 12( 4):
6. Setchell, B.P., The effects of heat on the testes
of mammals, Animal Reproduction 3( 2): 81–91,
7. Wechalekar et al., ref. 5, pp. 591–592.
8. Sodera, V., One Small Speck to Man—The
evolution myth, 2nd edn, Vija Sodera Productions,
pp. 109–110, 2009.
9. Chance, M.R.A., Reason for externalization
of the testis of mammals, J. Zoology 239( 4):
10. Hutson, J.M. and Clarke, M., Current
Management of the Undescended Testicle,
Seminars in Pediatric Surgery 16: 64–70, 2007;
11. Ahmad, G. Moinard, N., Esquerre-Lamare,
C., Mieusset, R., and Bujan, L., Mild induced
testicular and epididymal hyperthermia alters
sperm chromatin integrity in men, Fertility and
Sterility 97( 3):546–553, 2012.
12. Van Niekerk, E., Vas deferens—refuting ‘bad
design’ arguments, J. Creation 26( 3): 60–67,
13. Wechalekar, et al., ref. 5, p. 591.
14. Freeman, S., The evolution of the scrotum: a new
hypothesis, J. Theoretical Biology 145:429–445,
1990; p. 429.
15. Chen, Z., Toth, T., Godfrey-Bailey, L., Mercedat,
N., Schiff, I., and Hauser, R., Seasonal variation
and age-related changes in human semen
parameters, J. Andrology 24( 2):226–231, 2003.
16. Hutson and Clarke, ref. 10, p. 65.
17. Chung, E. and Brock, G., Cryptorchidism and
its impact on male fertility: a state of art review
of current literature, Canadian Urological
Association J. 5( 3):210–214, 2011.
18. Hutson and Clarke, ref. 10, p. 66.
19. Gallup, G.G., Finn, M.M., and Sammis, B., On
the origin of descended scrotal testicles: the
activation hypothesis, Evolutionary Psychology
7( 4):517–526, 2009; Freeman, S., The evolution
of the scrotum: a new hypothesis, J. Theoretical
Biology 145:429–445, 1990.
20. Heyns, C.F. and Hutson, J.M., Historical
review of theories on testicular descent, J.
Urology 153:754–767, 1995; Ivell, R., Lifestyle
impact and the biology of the human scrotum,
Reproductive Biology and Endocrinology
5( 15): 1–8, 2007.
21. Werdelin, L. and Nilsonne, A., The evolution of
the scrotum and testicular descent in mammals,
J. Theoretical Biology 196( 1): 61–72, 1999;
22. Werdelin and Nilsonne, ref. 21, p. 61.