Robin Baker (biologist)

Last updated

Robin Baker
Dr Robin Baker 1998 West Didsbury.jpg
Born (1944-03-13) March 13, 1944 (age 79)
Education Marlborough Royal Free Grammar School
Alma mater University of Bristol (BSc, PhD)
Known for Sperm Wars
Scientific career
Fields Behavioural ecology
Sperm competition
Institutions University of Manchester
University of Newcastle
Doctoral advisor H. E. Hinton
Website www.robin-baker.com

Robin Baker (born 13 March 1944) is a British novelist, popular science writer, lecturer and broadcaster. [1] [2] A best-selling author in the field of sexual biology [3] his books have been translated into 27 different languages.[ citation needed ] These include the international bestseller Sperm Wars which was based on his own lab's original research on human sexuality. [4] His work and ideas on the evolution of human behaviour have been featured in many radio and television programmes around the world.[ citation needed ]

Contents

Education and early life

Born in Wiltshire, England in 1944, Robin Baker grew up in the small village of Manningford Bruce in the Vale of Pewsey. [5] Educated at Marlborough Royal Free Grammar School, where thirty years earlier the author William Golding had also been educated, he gained his Bachelor of Science degree in Zoology from the University of Bristol in 1965, followed by a PhD in 1969 supervised by H. E. Hinton. His thesis investigated the evolution of the migratory habit in butterflies and applied principles of behavioural ecology and evolutionary biology to the insect migration. [6] This work was subsequently published in the Philosophical Transactions of the Royal Society .[ citation needed ]

Career and research

Baker moved to the University of Newcastle in 1970 and from there to the University of Manchester in 1974 where he was first a lecturer, and in 1981 a Reader in Zoology in the School of Biological Sciences. In 1996 he left academic life to concentrate on his career in writing and broadcasting.

Although his early work was on evolutionary aspects of insect migration and territoriality, his interests broadened. With G.A. Parker and V.G.F. Smith in 1972, he proposed a theory for the evolution of anisogamy and two sexes [7] [8] and in 1979, with G.A. Parker he proposed the Unprofitable Prey Theory of the evolution of bird coloration. [8] In 1978 in his book The Evolutionary Ecology of Animal Migration [9] he wrote for the first time on the theme that permeated his work for the rest of his academic life: the application of the principles of evolutionary biology to the behaviour of humans. This led in the 1980s to controversial work on the role of magnetoreception in the navigation of humans, [10] and in the 1990s (with Mark Bellis) to a study of sperm competition in humans [4] and rats, including proposal of the kamikaze sperm hypothesis. Baker and Bellis' research into the evolutionary biology of infidelity, masturbation, sperm polymorphism, and sperm number in humans, as well as into the design and function of the human penis and cervix led to a number of scientific papers and an academic book: Human Sperm Competition: copulation, masturbation and infidelity. [11]

Noticing that sperm in a mixed sample tends to clump together—making it less mobile—and to have a high mortality rate, reproductive biologist Robin Baker, formerly of the University of Manchester, proposed about a decade ago[ when? ] that some mammals, including humans, manufacture "killer" sperm whose only function is to attack foreign spermatozoa, destroying themselves in the process.

To test this idea, reproductive biologist Harry Moore and evolutionary ecologist Tim Birkhead of the University of Sheffield mixed sperm samples from 15 men in various combinations and checked for how the cells moved, clumped together, or developed abnormal shapes. "These are very simple experiments, but we tried to mimic what goes on in the reproductive tract," Moore says. The team found no excess casualties from any particular donor or other evidence of warring sperm, they report in 7 December Proceedings of the Royal Society.[ citation needed ] "The kamikaze sperm hypothesis is probably not a mechanism in human sperm competition," says Birkhead.

The findings are "the nail in the coffin for the kamikaze hypothesis," says Michael Bedford, a reproductive biologist at Cornell University's Weill Medical Center in New York City. He says he had never given the idea much credence.   [12]

Publications

As well as being the author of around one hundred[ citation needed ] scientific papers and six academic books, Robin Baker is the author of four popular science books: Sperm Wars; [11] Baby Wars; [11] Sex in the Future; [11] and Fragile Science. [11] He has also written three novels: Primal; [11] Caballito; [13] and The Hitchhiker’s Child [11] which under the guise of being sexual whodunits continue the theme of the evolution of human sexual behaviour. [14] His first novel, Primal, [11] was likened [15] to both the TV series Lost and William Golding's Lord of the Flies . It describes a group of university students and staff stranded on a remote desert island occupied by feral chimpanzees. Bit by bit the people find themselves stripped of all the trappings of civilization until like the apes around them they have only their instincts to guide them.

In Sperm Wars, Baker asserted the human cuckolding rate to be at 10% and that women frequently cheat to secure better genes for their offspring. This figure was later debunked, because studies which rely on a data set consisting of men who have requested paternity tests are strongly sample biased toward those who have a reason to have suspicions. [16] Men who have low paternity confidence and have chosen to challenge their paternity through laboratory testing are much less likely than men with high paternity confidence to be the fathers of their putative children. [16] A survey of 67 studies reporting nonpaternity suggests that for men with high paternity confidence rates of nonpaternity are (excluding studies of unknown methodology) typically 1.9%, substantially less than the typical rates of 10% or higher cited by many researchers. [17] "Media and popular scientific literature often claim that many alleged fathers are being cuckolded into raising children that biologically are not their own," said Maarten Larmuseau of KU Leuven in Belgium. "Surprisingly, the estimated rates within human populations are quite low--around 1 or 2 percent." "But reliable data on contemporary populations that have become available over the last decade, mainly as supplementary results of medical studies, don't support the notion that one in 10 people don't know who their "real" fathers are. The findings suggest that any potential advantage of cheating in order to have children that are perhaps better endowed is offset for the majority of women by the potential costs, the researchers say. Those costs likely include spousal aggression, divorce, or reduced paternal investment by the social partner or his relatives. The observed low cuckoldry rates in contemporary and past human populations challenge clearly the well-known idea that women routinely 'shop around' for good genes by engaging in extra-pair copulations to obtain genetic benefits for their children," Larmuseau said. [18]

Related Research Articles

<span class="mw-page-title-main">Sperm competition</span> Reproductive process

Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. However, multiple mates for a female means each individual male has decreased chances of producing offspring. Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase male's chance of reproductive success. Sperm competition results in a sexual conflict between males and females. Males have evolved several defensive tactics including: mate-guarding, mating plugs, and releasing toxic seminal substances to reduce female re-mating tendencies to cope with sperm competition. Offensive tactics of sperm competition involve direct interference by one male on the reproductive success of another male, for instance by physically removing another male's sperm prior to mating with a female. For an example, see Gryllus bimaculatus.

Professor Geoffrey Alan Parker FRS is an emeritus professor of biology at the University of Liverpool and the 2008 recipient of the Darwin Medal. Parker has been called “the professional’s professional”.

<span class="mw-page-title-main">Anisogamy</span> Sexual reproduction involving a large, female gamete and a small, male gamete

Anisogamy is a form of sexual reproduction that involves the union or fusion of two gametes that differ in size and/or form. The smaller gamete is male, a sperm cell, whereas the larger gamete is female, typically an egg cell. Anisogamy is predominant among multicellular organisms. In both plants and animals gamete size difference is the fundamental difference between females and males.

<span class="mw-page-title-main">Animal sexual behaviour</span> Sexual behavior of non-human animals

Animal sexual behaviour takes many different forms, including within the same species. Common mating or reproductively motivated systems include monogamy, polygyny, polyandry, polygamy and promiscuity. Other sexual behaviour may be reproductively motivated or non-reproductively motivated.

Sperm heteromorphism is the simultaneous production of two or more distinguishable types of sperm by a single male. The sperm types might differ in size, shape and/or chromosome complement. Sperm heteromorphism is also called sperm polymorphism or sperm dimorphism. Typically, only one sperm type is capable of fertilizing eggs. Fertile types have been called "eusperm" or "eupyrene sperm" and infertile types "parasperm" or "apyrene sperm".

Monogamous pairing in animals refers to the natural history of mating systems in which species pair bond to raise offspring. This is associated, usually implicitly, with sexual monogamy.

<span class="mw-page-title-main">Sexual conflict</span> Term in evolutionary biology

Sexual conflict or sexual antagonism occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly over the mode and frequency of mating, potentially leading to an evolutionary arms race between males and females. In one example, males may benefit from multiple matings, while multiple matings may harm or endanger females, due to the anatomical differences of that species. Sexual conflict underlies the evolutionary distinction between male and female.

<span class="mw-page-title-main">Reproductive synchrony</span>

Reproductive synchrony is a term used in evolutionary biology and behavioral ecology. Reproductive synchrony—sometimes termed "ovulatory synchrony"—may manifest itself as "breeding seasonality". Where females undergo regular menstruation, "menstrual synchrony" is another possible term.

Extra-pair copulation (EPC) is a mating behaviour in monogamous species. Monogamy is the practice of having only one sexual partner at any one time, forming a long-term bond and combining efforts to raise offspring together; mating outside this pairing is extra-pair copulation. Across the animal kingdom, extra-pair copulation is common in monogamous species, and only a very few pair-bonded species are thought to be exclusively sexually monogamous. EPC in the animal kingdom has mostly been studied in birds and mammals. Possible benefits of EPC can be investigated within non-human species, such as birds.

<i>Sperm Wars</i>

Sperm Wars is a popular science book by evolutionary biologist Robin Baker about sperm competition. Originally published in English in 1996, it has since appeared in 25 languages and in 2006 a 10th anniversary edition was published in the United States.

<span class="mw-page-title-main">Cuckold</span> Husband of an adulterous wife

A cuckold is the husband of an adulterous wife; the wife of an adulterous husband is a cuckquean. In biology, a cuckold is a male who unwittingly invests parental effort in juveniles who are not genetically his offspring. A husband who is aware of and tolerates his wife's infidelity is sometimes called a wittol or wittold.

Bateman's principle, in evolutionary biology, is that in most species, variability in reproductive success is greater in males than in females. It was first proposed by Angus John Bateman (1919–1996), an English geneticist. Bateman suggested that, since males are capable of producing millions of sperm cells with little effort, while females invest much higher levels of energy in order to nurture a relatively small number of eggs, the female plays a significantly larger role in their offspring's reproductive success. Bateman's paradigm thus views females as the limiting factor of parental investment, over which males will compete in order to copulate successfully.

<span class="mw-page-title-main">Female sperm storage</span>

Female sperm storage is a biological process and often a type of sexual selection in which sperm cells transferred to a female during mating are temporarily retained within a specific part of the reproductive tract before the oocyte, or egg, is fertilized. This process takes place in some species of animals, but not in humans. The site of storage is variable among different animal taxa and ranges from structures that appear to function solely for sperm retention, such as insect spermatheca and bird sperm storage tubules, to more general regions of the reproductive tract enriched with receptors to which sperm associate before fertilization, such as the caudal portion of the cow oviduct containing sperm-associating annexins. Female sperm storage is an integral stage in the reproductive process for many animals with internal fertilization. It has several documented biological functions including:

Sexual antagonistic co-evolution is the relationship between males and females where sexual morphology changes over time to counteract the opposite's sex traits to achieve the maximum reproductive success. This has been compared to an arms race between sexes. In many cases, male mating behavior is detrimental to the female's fitness. For example, when insects reproduce by means of traumatic insemination, it is very disadvantageous to the female's health. During mating, males will try to inseminate as many females as possible, however, the more times a female's abdomen is punctured, the less likely she is to survive. Females that possess traits to avoid multiple matings will be more likely to survive, resulting in a change in morphology. In males, genitalia is relatively simple and more likely to vary among generations compared to female genitalia. This results in a new trait that females have to avoid in order to survive.

Timothy Robert Birkhead is a British ornithologist. He has been Professor of Behaviour and Evolution at the University of Sheffield since 1976.

<span class="mw-page-title-main">Sexual selection in birds</span>

Sexual selection in birds concerns how birds have evolved a variety of mating behaviors, with the peacock tail being perhaps the most famous example of sexual selection and the Fisherian runaway. Commonly occurring sexual dimorphisms such as size and color differences are energetically costly attributes that signal competitive breeding situations. Many types of avian sexual selection have been identified; intersexual selection, also known as female choice; and intrasexual competition, where individuals of the more abundant sex compete with each other for the privilege to mate. Sexually selected traits often evolve to become more pronounced in competitive breeding situations until the trait begins to limit the individual's fitness. Conflicts between an individual fitness and signaling adaptations ensure that sexually selected ornaments such as plumage coloration and courtship behavior are "honest" traits. Signals must be costly to ensure that only good-quality individuals can present these exaggerated sexual ornaments and behaviors.

<span class="mw-page-title-main">Sexual selection in amphibians</span> Choice of and competition for mates

Sexual selection in amphibians involves sexual selection processes in amphibians, including frogs, salamanders and newts. Prolonged breeders, the majority of frog species, have breeding seasons at regular intervals where male-male competition occurs with males arriving at the waters edge first in large number and producing a wide range of vocalizations, with variations in depth of calls the speed of calls and other complex behaviours to attract mates. The fittest males will have the deepest croaks and the best territories, with females making their mate choices at least partly based on the males depth of croaking. This has led to sexual dimorphism, with females being larger than males in 90% of species, males in 10% and males fighting for groups of females.

<span class="mw-page-title-main">Polyandry in animals</span> Class of mating system in non-human species

In behavioral ecology, polyandry is a class of mating system where one female mates with several males in a breeding season. Polyandry is often compared to the polygyny system based on the cost and benefits incurred by members of each sex. Polygyny is where one male mates with several females in a breeding season . A common example of polyandrous mating can be found in the field cricket of the invertebrate order Orthoptera. Polyandrous behavior is also prominent in many other insect species, including the red flour beetle and the species of spider Stegodyphus lineatus. Polyandry also occurs in some primates such as marmosets, mammal groups, the marsupial genus' Antechinus and bandicoots, around 1% of all bird species, such as jacanas and dunnocks, insects such as honeybees, and fish such as pipefish.

<span class="mw-page-title-main">Extended female sexuality</span>

Extended female sexuality is where the female of a species mates despite being infertile. In most species, the female only engages in copulation when she is fertile. However, extended sexuality has been documented in old world primates, pair bonded birds and some insects. Extended sexuality is most prominent in human females who exhibit no change in copulation rate across the ovarian cycle.

<span class="mw-page-title-main">Human sperm competition</span> Form of sexual selection

Sperm competition is a form of post-copulatory sexual selection whereby male sperm simultaneously physically compete to fertilize a single ovum. Sperm competition occurs between sperm from two or more rival males when they make an attempt to fertilize a female within a sufficiently short period of time. This results primarily as a consequence of polyandrous mating systems, or due to extra-pair copulations of females, which increases the chance of cuckoldry, in which the male mate raises a child that is not genetically related to him. Sperm competition among males has resulted in numerous physiological and psychological adaptations, including the relative size of testes, the size of the sperm midpiece, prudent sperm allocation, and behaviors relating to sexual coercion, however this is not without consequences: the production of large amounts of sperm is costly and therefore, researchers have predicted that males will produce larger amounts of semen when there is a perceived or known increase in sperm competition risk.

References

  1. ↑ Bellis, Mark A.; Baker, R. Robin (1990). "Do females promote sperm competition? Data for humans". Animal Behaviour. 40 (5): 997–999. doi:10.1016/S0003-3472(05)81008-5. ISSN   0003-3472. S2CID   53147779.
  2. ↑ Baker, R.Robin; Bellis, Mark A. (1993). "Human sperm competition: ejaculate adjustment by males and the function of masturbation". Animal Behaviour. 46 (5): 861–885. doi:10.1006/anbe.1993.1271. ISSN   0003-3472. S2CID   53201940.
  3. ↑ New Scientist, 18 May 96, p. 52
  4. 1 2 Channel 4, 60-minute TV Documentary. Women – The inside story, first broadcast 1996
  5. ↑ Where are they now? Wiltshire Gazette and Herald, 14 December 1978
  6. ↑ The Times Newspaper, Science Report, 9 April 1968
  7. ↑ Parker, G.A.; Baker, R.R.; Smith, V.G.F. (1972). "The origin and evolution of gamete dimorphism and the male-female phenomenon". Journal of Theoretical Biology. 36 (3): 529–553. Bibcode:1972JThBi..36..529P. doi:10.1016/0022-5193(72)90007-0. ISSN   0022-5193. PMID   5080448.
  8. 1 2 Krebs, J.R. & Davies, N.B. (1993) An Introduction to Behavioural Ecology, 3rd Ed., Blackwell, p. 176 [ ISBN missing ]
  9. ↑ Book Review: Animals on the Move, New Scientist, 9 November 1978
  10. ↑ BBC 30-minute TV Documentary: Naturewatch, first broadcast October 1982
  11. 1 2 3 4 5 6 7 8 [ ISBN missing ]
  12. ↑ Hagmann, Michael (10 December 1999). "No Evidence for Sperm Wars". AAAS. Retrieved 17 May 2020.
  13. ↑ Baker, Robin (11 December 2012). Caballito. eBook Partnership. ISBN   978-84-695-6501-8.
  14. ↑ Sexual whodunits and evolutionary psychology: the shaping of three novels. Evolutionary Psychology 11(1): 243-247
  15. ↑ News of the World, Book Review (25 July 2009)
  16. 1 2 "The paternity myth: the rarity of cuckoldry". Discover Magazine. Retrieved 17 May 2020.
  17. ↑ Anderson, Kermyt G. (1 June 2006). "How Well Does Paternity Confidence Match Actual Paternity? Evidence from Worldwide Nonpaternity Rates". Current Anthropology. 47 (3): 513–520. doi:10.1086/504167. ISSN   0011-3204. S2CID   56318457.
  18. ↑ "Cuckolded fathers rare in human populations". sciencedaily.com. Retrieved 18 May 2020.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.