The always excellent New Scientist has an article synthesizing much of the research into same-sex sexual behavior in animals and the possible evolutionary explanations. They spoke with University of California evolutionary biologists Marlene Zuk and Nathan Bailey, who recently published a paper examining same-sex behavior in various species. Zuk and Bailey note that same-sex sexual behavior in other animals can't necessarily be equated with sexual orientation in humans, researchers have come up with similar questions as to why certain animals have evolved to include members who expend energy on same-sex liaisons.

Evolutionary biologists have come up with various hypotheses for why same-sex behavior has evolved in various animals. In some cases, same-sex behavior has emerged as a result of specific adaptations, such as to foster social bonding, or because certain genes for same-sex attraction hold another survival benefit when only one copy is present. In some cases, though, the behavior is incidental, such as in certain fish that cannot easily tell male and female members apart.

Below, New Scientist charts several of the possible evolutionary explanations for same-sex sexual behavior in various species:

Bailey believes that exploring the evolution of sexual behavior will give us a better understanding of evolution, including the development of our own species:

"Given its persistence in species in many different animal groups, including humans, viewing it as an evolutionary force in its own right promises to provide a much richer understanding of the evolution of reproductive behaviour," Bailey says. He suggests we could make some fascinating comparisons. Might male-male copulation in species as diverse as flour beetles and dolphins have similar, even predictable, evolutionary consequences? More daringly, could understanding the evolutionary consequences of same-sex interactions in animals help us understand our own evolution?

Homosexual selection: The power of same-sex liaisons [New Scientist]

Muscle disease specialists at Ohio State University have been studying myostatin, the protein that regulates and curbs muscle growth. Their research found that a second protein, follistatin, can bind to myostatin, preventing myostatin from stopping muscle growth. They decided to test whether artificially introducing follistatin to the body would lead to an increase in strength and muscle mass. Using a common cold virus as a carrier, the researchers injected the follistatin gene into the thigh muscles of six macaque monkeys. The monkeys' thigh muscles grew an average of 15 percent as a result of the treatment, and one monkey experienced an incredible 78 percent increase in strength. The researchers reported in Science Translational Medicine that, after 15 months, the increases remained and that the monkeys experienced no visible side effects.

The researchers hope to start clinical trials on humans next year, with an eye toward helping people with degenerative muscular diseases. But for healthy individuals looking to increase their strength, the treatment would come at a cost: immunosuppressant drugs are a necessary component of the therapy.

Gene therapy may be used to treat muscular dystrophy [Times Online via Next Big Future via Reddit]

In a paper published in Forensic Science International, Dan Frumkin, a private forensics researcher, claims that fabricating DNA evidence has become so easy that "[a]ny biology undergraduate could perform this."

Frumkin outlines two methods for fabricating DNA evidence. The first requires access to a small sample of an individual's DNA, such as a hair or a bit of saliva. The size of the sample is then increased through a common technique known as DNA amplification. Then the hopeful framer takes blood from a different individual, centrifuges it to remove the DNA-carrying white blood cells, and leaves only the red blood cells, which contain no DNA. The person then adds the amplified DNA to the blood sample, creating a handy supply of blood that could be splashed onto a crime scene to implicate the chosen target.

The second method requires no actual sample of DNA, but a person's DNA profile, which may be stored in a law enforcement database. These profiles identify variations at 13 specific spots in an individual's genome. Frumkin claims that a scientist could keep a library of a cloned snippets of DNA representing the variants at the 13 spots (he estimates 425 samples would be needed in all), and he or she could mix the snippets to create a DNA sample matching anyone's genetic profile.

Frumkin says that, at the moment, there are ways to determine whether DNA evidence has been fabricated (and his own company, Nucleix, provides such tests), but it's a step forensic labs don't normally take. Although some respondents question whether criminals will actually use these techniques to throw suspicion off themselves and onto others, Tania Simoncelli, an American Civil Liberties Union science adviser, suggests that it's time for courts to reevaluate the reliability of DNA evidence:

"DNA is a lot easier to plant at a crime scene than fingerprints," she said. "We're creating a criminal justice system that is increasingly relying on this technology."

DNA Evidence Can Be Fabricated, Scientists Show [NY Times]

The research team at the Max Planck Institute for Evolutionary Anthology presented their findings last week at a human evolution conference. The researchers have compared the Neanderthal genome to that of modern humans of European and African descent. Because Neanderthals and modern humans coexisted in Europe, researchers have theorized that European genomes would have more similarities with the Neanderthal genome than would African genomes. However, European and African genomes have a similar number of differences from the Neanderthal genome, suggesting that modern humans in Europe outbred rather than assimilated the Neanderthals.

Earlier comparisons of mitochondrial similarly cast doubt on the Neanderthal interbreeding theory, but recent research has revealed that Neanderthals do not possess the very genes some researchers believed modern humans had received from Neanderthals. Neanderthals possess neither the microcephalin gene, linked to bulging brains in humans, nor humans’ increased fertility gene.

The team is planning to publish a rough draft of the Neanderthal nuclear genome, and hopes that a closer study of the genome will reveal more about the Neanderthal history. They believe, for example, that further analysis of the available genome will reveal whether Neanderthal practiced polygyny, with fewer males breeding with proportionally more females. But the study is hampered by the poor quality and small sample of available genetic samples, and the researchers say it will be another year or two before an adequate sequencing is complete.

[New Scientist]

The volunteers are all participating in the Personal Genome Project, a Harvard study, which as we’ve mentioned before, is attempting to create a database of 100,000 human genomes. Although other services collect genomes as well, PGP has come to public attention for taking personal information in lieu of payment:

In exchange for the decoding of their DNA, participants agree to make it available to all — along with photographs, their disease histories, allergies, medications, ethnic backgrounds and a trove of other traits, called phenotypes, from food preferences to television viewing habits.

So what has prompted these volunteers to make so much of their personal lives publically available? Each possesses, in PGP head George Church’s estimation, the equivalent of at least a master’s degree in genetics, and many have an academic and/or financial interest in furthering genetic research:

• George Church, PhD, Professor of Genetics at Harvard Medical School, Professor of Health Sciences & Technology at Harvard and MIT, and head of PGP.
• Esther Dyson, technology entrepreneur and commentator, philanthropist, and future space tourist.
• Misha Angrist, PhD, Science Editor at the Duke University Institute for Genome Sciences & Policy and author of The Genome Revolution: DNA, Health and Society.
• Keith Batchelder, MD, founder and CEO of Genomic Healthcare Strategies.
• Rosalynn Gill, PhD, founder and Chief Science Officer of Sciona.
• John Halamka, MD, MS, Chief Information Officer of the CareGroup Health System and Chief Information Officer and Dean for Technology at Harvard Medical School.
• Stanley Lapidus, Chairman and CEO of Helicos BioSciences Corp.
• Kirk Maxey, MD, manages the Donor Sibling Registry and the Cayman Biomedical Research Institute.
• James Sherley, MD, PhD, Senior Scientist at the Boston Biomedical Research Institute.
• Steven Pinker, PhD, Johnstone Family Professor of Psychology at Harvard University.

While the “PGP 10” understand the benefits and consequences of posting this sort of information online, some fear that those who follow their lead won’t be so savvy:

“I’m concerned that this could make it seem easy and cool to put your information out there when there is still a lot of stigma associated with certain genetic traits,” said Kathy Hudson, director of the Genetics and Public Policy Center at Johns Hopkins University. “There will be new uses of this data that people can’t anticipate — and they can’t do anything to get it back.”

But some have already been lured in by PGP’s promise of a free genetic screening, which could tell them if they are predisposed toward certain diseases. In the latest issue of GQ, University of Illinois professor Richard Powers shares his own journey through PGP’s gene mapping process, including his decision to join the genetic database and what the geneticists found.

[Personal Genome Project]
Taking a Peek at the Experts’ Genetic Secrets [NY Times]
The Book of Me [GQ]

Says Rubin:

With the data that we are generating from plant genomes we can home in on relevant agronomic traits such as rapid growth, drought resistance, and pest tolerance, as well as those that define the basic building blocks of the plants cell wall—cellulose, hemicellulose and lignin. Biofuels researchers are able to take this information and design strategies to optimize the plants themselves as biofuels feedstocks—altering, for example, branching habit, stem thickness, and cell wall chemistry resulting in plants that are less rigid and more easily broken down

Rubin recommends the Clostridia species of fungus could be spliced into trees to make them self-fermenting. In the past, he has suggested splicing termite gut genes into trees so that they would essentially digest themselves and make biofuel processing easier.

I can't wait for a self-digesting apple so that I don't have to squash the things up to make my applesauce. I wouldn't mind eating a little bit of termite genome for that.

Genomics of Plant-Based Biofuels [via DOE JGI]

Church has good reasons for wanting piles of genomic data. As a Bloomberg article on the project says:

By matching genetic data from each person with his or her health history, Church would build a database that would link DNA variations and disease for scientists and drugmakers, the first step in deciding on treatments that can block the mutations or adjust how they work within the body.

Church also said he'll explore other human traits under genetic control. Participants will give facial and body measurements, tell researchers what time they get up in the morning, and detail other behaviors, he said.

Church has already partially sequenced genomes from 10 people, and the jump to 100,000 is under review by a Harvard ethics panel. The project ``only stops when we stop learning things,'' Church said.

We should note: there's no evidence of wrongdoing here, and Google has never explicitly said "we want to organize genetic information." True, they are major investors in the personal genomics company 23andMe, but we have every reason to believe that Big brother "don't be evil" Google will play it straight, keeping any information they have access to safe and anonymous.

But still you've got to wonder, does Google want direct access to DNA information? And if so, why?

Source: Bloomberg via SciGuy

Graphic: Personal Genome Project (Church's outfit)