New research from the University of East Anglia shows that an evolutionary force known as 'sexual selection' can explain the persistence of sex as a dominant mechanism for reproducing offspring.

Biologists have long puzzled about how evolutionary selection, known for its ruthless requirement for efficiency, allows the existence of males -- when in so many species their only contribution to reproduction are spermatozoa.

But research published today in Nature shows that sexual selection -- when males compete and females choose over reproduction -- improves population health and protects against extinction, even in the face of genetic stress from high levels of inbreeding.

The findings help explain why sex persists as a dominant mechanism for reproducing offspring.

Lead researcher Prof Matt Gage, from UEA's School of Biological Sciences, said: "Sexual selection was Darwin's second great idea, explaining the evolution of a fascinating array of sights, sounds and smells that help in the struggle to reproduce -- sometimes at the expense of survival.

"Sexual selection operates when males compete for reproduction and females choose, and the existence of two different sexes encourages these processes. It ultimately dictates who gets to reproduce their genes into the next generation -- so it's a widespread and very powerful evolutionary force.

"Almost all multicellular species on earth reproduce using sex, but its existence isn't easy to explain because sex carries big burdens, the most obvious of which is that only half of your offspring -- daughters -- will actually produce offspring. Why should any species waste all that effort on sons?

"We wanted to understand how Darwinian selection can allow this widespread and seemingly wasteful reproductive system to persist, when a system where all individuals produce offspring without sex -- as in all-female asexual populations -- would be a far more effective route to reproduce greater numbers of offspring.

"Our research shows that competition among males for reproduction provides a really important benefit, because it improves the genetic health of populations. Sexual selection achieves this by acting as a filter to remove harmful genetic mutations, helping populations to flourish and avoid extinction in the long-term."

To uncover this role of sexual selection, the research team evolved Tribolium flour beetles over 10 years under controlled conditions in the laboratory, where the only difference between populations was the intensity of sexual selection during each adult reproductive stage.

The strength of sexual selection ranged from intense competition and choice where 90 males competed for reproduction with only 10 females, through to the complete absence of sexual selection, with only single males and females in monogamous pairings, where females got no choice and males experienced no competition.

After seven years of reproduction under these conditions, representing about 50 generations, the study exposed the underlying genetic health of the resulting populations. The team used experimental inbreeding to reveal the relative amount of deleterious mutations that lay hidden in each population.

They found that populations that had previously experienced strong sexual selection maintained higher fitness and were resilient to extinction in the face of inbreeding -- with some populations surviving even after 20 inbreeding generations where a brother was mated with a sister in each generation.

However populations that had experienced weak or non-existent sexual selection showed more rapid declines in health under inbreeding -- and all went extinct by the 10th generation.

Prof Gage said: "These results show that sexual selection is important for population health and persistence, because it helps to purge negative and maintain positive genetic variation in a population.

"To be good at out-competing rivals and attracting partners in the struggle to reproduce, an individual has to be good at most things, so sexual selection provides an important and effective filter to maintain and improve population genetic health.

"Our findings provide direct support for the idea that sex persists as a dominant mode of reproduction because it allows sexual selection to provide these important genetic benefits.

"In the absence of sex, populations accumulate deleterious mutations through a ratcheting effect where each new mutation takes a population closer to extinction. Sexual selection helps to remove those mutations, enabling populations to persist against the threat of extinction.

"Our monogamous treatment, for example, where there was no sexual selection for 50 generations, resulted in a lower level of population health and rapid extinction when populations were challenged by inbreeding. All the populations derived from monogamous histories became extinct after just eight generations.

"By contrast, populations derived from the same ancestors and identical apart from having the opportunity for male competition and female choice at each adult stage, maintained population health and avoided extinction, with some family lines still reproducing happily even after 20 generations of inbreeding."

This research was funded by the Natural Environment Research Council, the Leverhulme Trust and the University of East Anglia.

Cornwall's teenage pregnancy rate halved since 1998

CORNWALL'S under 18 conception rate has fallen by more than half since 1998, new statistics reveal.

Data released today by the Office for National Statistics shows the number of teenage pregnancies is now less than half the baseline set in 1998 when the National Teenage Pregnancy Strategy began.

The data released today shows Cornwall’s annual conception rate to be 18.2 conceptions per 1000 women aged five to 17, a whopping 54.3 per cent decrease from the 1998 baseline of 39.8 per 1000.

This means Cornwall has not only exceeded the national target of a 50 per cent reduction in pregnancy rates, but has also outperformed the average reduction achieved across England and Wales of 40 per cent.

Today’s data release also brings Cornwall’s under 18 conception rate below 20 conceptions per 1000 for the first time and see’s Cornwall performing better than the South West average.

Cornwall Council remains committed to reducing the rate of under-18 conceptions and improving outcomes for young parents and their children through the Teenage Pregnancy Strategy and Action plan.

Teenage pregnancy is often associated with negative health outcomes for the mother and child and increased likelihood of them both living in long-term poverty.

In addition to this, many teenage conceptions are unintended.

Around half result in a termination, an avoidable burden for the young women affected.

Lex Gainsbury, who leads the Teenage Pregnancy Strategy at Cornwall Council said: “Today’s figures are fantastic news and are testament to the hard work of all our services and partners across Cornwall.

“It demonstrates that sustained effort from committed individuals at every level really makes a difference.

“We are over the moon to have achieved the national target but it is important that we do not become complacent and face the challenges ahead with the same vigour and enthusiasm as that which has got us this far.

“Evidence shows that the two factors that have the biggest impact on rates are access to young people friendly sexual health services and both formal and informal relationship and sex education, ensuring young people have the skills, knowledge and confidence to make positive choices about their sexual health now and in the future.

Boyfriend gets life for slaying of pregnant teen girlfriend

ANGLETON, Texas (AP) - An 18-year-old man faces life in prison after Southeast Texas jurors convicted him of killing his teenage girlfriend who was pregnant with twins.

Ryan Matthews was convicted of capital murder in the death of Arrijana Hill. Both Matthews and Hill were 16 when she was found dead last year in a pool of blood inside her family home in Pearland.

Prosecutors accused Matthews of killing Hill because he was worried children would ruin his future as an athlete.

Matthews admitted on the stand that he saw Hill the day of her death and that he threw away the shirt he was wearing that day.

He will be eligible for parole after 40 years.

Pearland is about 15 miles south of downtown Houston.

SOUTH AFRICA: Teenage pregnancy figures cause alarm

johannesburg, 6 March 2007 (IRIN) - Alarming figures released by a South African provincial education department indicate that schoolgirl pregnancies have doubled in the past year, despite a decade of spending on sex education and AIDS awareness. 

The number of pregnant schoolgirls jumped from 1,169 in 2005 to 2,336 in 2006 in Gauteng, the country's economic heartland and most populous province, according to statistics released in the provincial parliament. 

"South Africa has a huge teen pregnancy problem - one in three girls has had a baby by the age of 20," David Harrison, Chief Executive Officer of LoveLife, South Africa's largest youth-targeted HIV/AIDS campaign, told IRIN. 

In a country where HIV prevalence is 18.8 percent, the high level of teenage pregnancy has heightened concerns. According to the South African Medical Research Council (MRC), "The latest national survey into HIV prevalence recorded that 16 percent of pregnant women under the age of 20 tested HIV positive."

The problem is not equally serious in all parts of the country: on average, two to three girls fall pregnant in a typical school with 1,200 to 1,400 pupils. "But what is clear is that there are hotspots where things are horribly wrong," Harrison said. The Gauteng figures showed 71 percent of pupils pregnant at one school in Soweto, a huge township on the outskirts of Johannesburg. 

"Somehow there are schools where 60 to 70 percent of pupils were pregnant. There is no doubt that this is associated with things like gang activity, coercion and substance abuse," Harrison said, adding that according to a 2006 survey, 30 percent of girls in South Africa said "their first sexual experience was forced or under threat of force". 

But other factors are also driving the high teenage pregnancy rate in some areas. According to a recent MRC study, 'Blood Blockages and Scolding Nurses: Barriers to Adolescent Contraceptive Use in South Africa', "Nurses' attitudes were a major barrier to teenagers getting hold of contraception. The nurses were uncomfortable about providing teenagers with contraception, as they felt they should not be having sex. They responded to requests for contraception in a manner that was highly judgmental and unhelpful. The girls described it as 'harassment'". 

The study also found that social pressures often prevented young women from using contraception: "The girls felt they would only be accepted as women once they had proved their fertility - many mothers wanted their teenage daughters to become pregnant so they could have a baby at home again." 

Some observers have suggested that the child support grant provided by the state was an incentive to young girls to fall pregnant, but according to Harrison, "A recent survey of 1,500 girls aged between 15 and 24 indicated that only 2 percent cited the child-care grant as an incentive. About 25 percent just said they wanted to have a baby." Other influencing factors - accounting for 20 percent - were "social pressures and self-affirmation". 

Hassan Lorgat, coordinator of the South African chapter of the Global Campaign for Education (GCE), said it was important to understand the causes of these "disappointing figures", and stressed the need for more research. "There are no studies about the role of males in the problem," he commented. 

Education is fundamental 

The MRC study recommended "sex education at school before the age of 14, when young people become sexually active". 

This should include "information for teenagers about avoiding sexually transmitted diseases, providing detailed information about contraception and its side effects; better management and training for nurses, so they can deal sympathetically with teenagers requiring contraception and provide the necessary information and education campaigns that take away the stigma of teenage sexuality, so that girls are not afraid to ask for contraception". 

LoveLife's Harrison stressed the role of schools in curbing adolescent pregnancy: "Schoolgoing is protective. [Teenagers] not at school are more likely to fall pregnant than those at school; surveys show girls are 1.7 times more likely to use condoms when in school." 

He said there was a need to determine whether teen pregnancies in Gauteng schools were "really spiraling out of control or whether the higher figures represented improvements in reporting, or [there was] less stigma associated with disclosing a pregnancy". 

Keeping children in school was essential, Harrison said. "We need to do a better job in anticipating school leaving - that's when they [schoolgirls] become hugely vulnerable." 

Sierra Leone News: As TIDEA launches report … 34% pregnancies are teenage girls

The Executive Director of Tricia Initiatives for the Development and Empowerment of Adolescent Girls and Youths (TIDEA) Patricia Bah yesterday revealed that, recent data shows that 42% of girls have a child or are pregnant by age 18years, 26% of women aged 15-19 have already given birth, while 34% of all pregnancies occur amongst teenage girls.

This alarming statistics was revealed at the official launch of an assessment report of teenage and adolescent pregnancy, in the wake of the Ebola epidemic, at the Buxton Methodist Memorial Hall, on Charles Street in Freetown.

Further making her presentation, Madam Bah explained that the findings of the report reveal that the Ebola crisis has greatly affected adolescent and teenage pregnancy programming in Sierra Leone, and that there was an increase in adolescent and teenage pregnancy during the Ebola crisis.

She said analysis from key informants showed that key drivers of adolescent and teenage pregnancy were due to poverty, anti-social behaviours, and inattentive parenting.

Madam Bah called on all present, especially women advocate to continue to urge government to enforce laws, poor attitudes towards contraception, and the reduction in reproductive health services for pregnancy prevention.

During the assessment, she said that quality data control and analysis, helped field staff to overcome some of the many challenges, especially at rural level and an alarming figure of over 30,000 teenage and adolescent pregnancies were reported in the 44 health facilities across the Country for 2014.

The Executive Director disclosed that 58% of the pregnancies occurred during the Ebola crisis, and the overall teenage and adolescent pregnancies increased by 27% nationwide.

In almost all of the districts, Madam Bah noted that statistics show that the views among participants in the assessment were that teenage pregnancy has worsened during the Ebola crisis.

Despite this, there were isolated cases where people suggested that the Ebola situation has brought down teenage pregnancy.

Madam Bah explained that in the assessment, a family support unit officer (FSU) in Kono was of the view that teenage pregnancy has come down in the district as a result of the restriction of movement of people.

She noted that apart from the Western Area, Kenema, and Kailahun, teenage and adolescent pregnancy has not shown patterns that are significantly different from the period before the Ebola outbreak.

Launching the assessment report, the President of the West African College of Nurses (WACN), Amelia Gabba, commended the management of TIDEA for their initiative and commitment to carry out the assessment, which revealed that much more needs to be done to reduce teenage and adolescent pregnancy, nationwide.

She said TIDEA has chosen the right time to launch the report and go into action, which is in line with Government’s National Strategy on Teenage Pregnancy Reduction, which has a pillar on Gender Equality and Women’s Empowerment.

Madam Gabba, who is also a nursing sister of long years, called on government and other health partners to collaborate with TIDEA, as it is through effective collaboration, teenage and adolescent girls will be able to achieve their full potential.

Concluding the WACN President appealed that the Ebola disease should not make room for more girls to become pregnant.

As she put it “Let girls be girls, not mothers”.

By Ade Campbell

UK tops league of teenage pregnancy

Britain still has the highest rate of teenage pregnancy in Western Europe despite being one of the world's biggest users of contraceptives.

The figures, which emerged yesterday in a large- scale international study, appeared to explode claims by the sex education lobby that the UK's sky-high teenage birth rate is down to ignorance.

It showed that four out of five females between the ages of 15 and 44 in Britain - 80 per cent -use some form of contraception.

This compares to 76 per cent in the U.S., 75 per cent in France and 59 per cent in Japan.

Britain, nevertheless, has a sky-high level of teenage pregnancies, with 2.9 out of every 100 girls aged between 15 and 19 giving birth every year.

In France, where there is less contraceptive use, only 0.9 of every 100 girls aged 15 to 19 have babies, according to the survey.

The level in Germany is 1.1 per hundred girls while in Japan it is only 0.4 per hundred.

The findings suggest the huge growth in single parenthood in the UK in recent years - much of it a result of teenage pregnancy - has little to do with a lack of knowledge of sex and contraception among young people.

Recent research projects have contradicted the long-standing claim of the sex education lobby that more information and better distribution of contraceptives is needed, pointing away from ignorance as the cause of pregnancy among young girls.

Yesterday's report from the U.S. pressure group Population Action International surveyed health and reproduction statistics in developed countries and those in the Third World.

Alongside Britain the countries with the highest rate of contraceptive use are China, and, surprisingly for two Catholic nations, Spain and Italy.

The findings bear out research last year at Southampton University which found that teenage girls in Britain have a sophisticated knowledge of contraception.

For example, seven out of ten knew the morning-after pill was effective after more than 24 hours.

A report last month from Prince Charles's charity the Prince's Trust said teenage single girls on sink estates admire their peers who have given birth and often seek to copy their status and acquire the free flat they think having a baby usually brings.

The Family Planning Association insisted yesterday, however: 'Contraceptive use and teenage pregnancy are really two different issues and it doesn't help to lump them together.'

British rates of teenage pregnancy remain well behind those of the U.S. One in 20 girls there has babies each year compared to one in 34 in this country.

Last year more than 48,000 babies were born to teenage mothers in Britain.

They cost the taxpayer an estimated £125million in income support alone every year, apart from other costs such as assistance with rent and council tax.

The easy availability of contraception led to steep falls in the teenage birth rate across Europe in the early Seventies.

But while other countries continued to achieve dramatic falls Britain's has not changed since

According to a 1999 report by the Social Exclusion Unit the lack of education in sex and relationships was considered the main cause.

But the survey suggests the Prince's Trust may have been more accurate in its assumption that the attraction of financial benefits may be more to blame

Teen Pregnancies Have Hit an All-Time Low....

But teens still aren’t opting for the most effective forms of birth control

The United States has one of the highest rate of teen pregnancies in the developed world, with up to seven times the rate of pregnancy of countries like Swit

zerland. But in recent years, that rate has been falling. Now, new data released from the CDC shows that in the U.S. teen pregnancies have hit an all-time low, falling from 61.8 births per 1,000 teens in 1991 to 26.5 births per 1,000 teens in 2013.

The data has some big implications for both the government and young women. The CDC estimates that the United States spends approximately $9.4 billion each year on teen moms, and studies have shown that teen moms face everything from poverty to domestic violence.

But the CDC’s report also shows that though 90 percent of teens are using contraception, most aren’t using the most effective types of birth control. Officials say that Long-Acting Reversible Contraception (LARC) like IUDs and implants, which can prevent pregnancy from three to 10 years, are only being used by a handful of teens. The two main methods of birth control used by teens—birth control pills and condoms—fail more often and are forgotten more frequently, meaning they’re a less effective option for sexually active teenagers.

But though use of LARC is on the rise (teens seeking birth control opted for LARC seven percent of the time in 2013, up from just one percent in 2005), there are plenty of barriers to its use. Not many teens know much about it, and many think it’s only for older women. (For many years, doctors only recommended IUDs to women who were done with child-bearing.) And when teens seek LARC at clinics, they can be stymied by high costs, uninformed clinicians and those who mistakenly believe that IUDs and implants are unsafe or inappropriate for teen use.

That needs to change, says Hal Lawrence, CEO and executive vice president of the American Congress of Obstetricians and Gynecologists. “Long-acting reversible contraceptive methods—including intrauterine devices and implants—are the most effective forms of reversible contraception available and are safe for use by almost all reproductive-age women.” In a statement, Lawrence noted that long-acting contraception options are just as safe in adolescents in adults…but though the recent reduction in pregnancy rates is “encouraging,” the medical profession must continue to play a role in reducing teen pregnancy.

So where’s the highest concentration of teens who choose contraception like IUDs? In Colorado, where tens of thousands of IUDs were provided to low-income women due to a private grant, the rate of IUD use in teens who seek contraception is the highest in the nation at 25.8 percent. That’s compared to just 0.7 percent of teens who seek birth control in Mississippi.