Adam's Curse
Encyclopedia
Adam's Curse: A Future Without Men (also known as Adam's Curse: A Story of Sex, Genetics, and the Extinction of Men) is a 2003 book by Oxford University human genetics
professor Bryan Sykes
expounding his hypothesis that with the declining sperm count in men and the continual atrophy of the Y chromosome
, within 5,000 generations (approximately 125,000 years) the male of the human species will become extinct.
Sykes believes one of the options for the survival of humanity is unisex reproduction by females: female eggs fertilised by the nuclear X chromosome
s of another female and implanted using in vitro fertilisation
methods. He also introduces the possibility of moving the SRY
and associated genes responsible for maleness and male fertility to another chromosome, which he refers to as "the Adonis chromosome", engendering fertile males with an XX karyotype
.
A further point of contention is that declining sperm counts have been linked to industrialisation, with environmental toxification as the presumed mechanism. If this is indeed the cause, then there is no reason to believe that a solution to the pollution problem won't also lead to a return to historical levels of male fertility.
More recent research (discussed at the end of the book) has shown that the Y-chromosome is capable of self-repair. In any case, it is impossible to assure that Y chromosomes won't evolve in any other way than self-repairing or extinction.
It can be noted that the Dunnart
has a Y chromosome that has shrunk to only 4 genes, the smallest of any mammal, with no apparent ill effect.
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
professor Bryan Sykes
Bryan Sykes
Bryan Sykes is a former Professor of Human Genetics at the University of Oxford and a current Fellow of Wolfson College.Sykes published the first report on retrieving DNA from ancient bone...
expounding his hypothesis that with the declining sperm count in men and the continual atrophy of the Y chromosome
Y chromosome
The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...
, within 5,000 generations (approximately 125,000 years) the male of the human species will become extinct.
Sykes believes one of the options for the survival of humanity is unisex reproduction by females: female eggs fertilised by the nuclear X chromosome
X chromosome
The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
s of another female and implanted using in vitro fertilisation
In vitro fertilisation
In vitro fertilisation is a process by which egg cells are fertilised by sperm outside the body: in vitro. IVF is a major treatment in infertility when other methods of assisted reproductive technology have failed...
methods. He also introduces the possibility of moving the SRY
SRY
SRY is a sex-determining gene on the Y chromosome in the therians .This intronless gene encodes a transcription factor that is a member of the SOX gene family of DNA-binding proteins...
and associated genes responsible for maleness and male fertility to another chromosome, which he refers to as "the Adonis chromosome", engendering fertile males with an XX karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
.
Opposing view
The Y chromosome may wither to the absolute minimum needed to sustain reproduction, but no more, because a chromosome that won't breed won't be carried to its descendants - therefore, only functioning Y chromosomes will be passed on to future generations, and obviously no infertile men will transmit any Y chromosomes causers of infertility. Female infertility is also strangely forgotten in the work.A further point of contention is that declining sperm counts have been linked to industrialisation, with environmental toxification as the presumed mechanism. If this is indeed the cause, then there is no reason to believe that a solution to the pollution problem won't also lead to a return to historical levels of male fertility.
More recent research (discussed at the end of the book) has shown that the Y-chromosome is capable of self-repair. In any case, it is impossible to assure that Y chromosomes won't evolve in any other way than self-repairing or extinction.
It can be noted that the Dunnart
Dunnart
Dunnarts are furry narrow-footed marsupials the size of a mouse, members of the genus Sminthopsis. They are mainly insectivorous. A male dunnart's Y chromosome has only 4 genes, making it the smallest known mammalian Y chromosome....
has a Y chromosome that has shrunk to only 4 genes, the smallest of any mammal, with no apparent ill effect.
External links
- Review of Adam's Curse from The Daily TelegraphThe Daily TelegraphThe Daily Telegraph is a daily morning broadsheet newspaper distributed throughout the United Kingdom and internationally. The newspaper was founded by Arthur B...