Trophic cascades are powerful indirect interactions that can control entire ecosystems.

In the early 1900s, when wolves roamed Yellowstone, young trees such as aspen and willow were abundant. In 30 years, after wolves were hunted out, the forest stopped regenerating. Reintroducing wolves into Yellowstone National Park after nearly 70 years of absence has been controversial. However, the effects have been utterly transformative to the Yellowstone ecosystem.

A trophic cascade recently has been reported among wolves, elk, and aspen on the northern winter range of Yellowstone National Park, Wyoming, USA.

What is a trophic cascade and how exactly do wolves change rivers?  What happens when a species that has been hunted to extinction is introduced to its happy hunting grounds after 70 years? Find out in this beautiful little film.

Could the impact of a species on an entire ecosystem  leads us to think differently about sustainable lines for solving the global climate crisis? 

The Future for Pregnancy and Child Birth - future reproductive technology

Since the early 1990s reproductive technology has been used to help women get pregnant. However, future technology may make it so that they don't actually have to be pregnant. There is a strong possibility that one day in the very near future babies will be conceived and grow in artificial wombs that are hooked up to a placenta machine. 

Scientists have been working on creating human sperm cells from embryonic tissue, as well as manufacturing eggs and even entire embryos. In 2001, researchers from Cornell University began growing sheets of endometrial tissue; when the sheets proved too thin to accommodate embryos, they were able to construct a freestanding uterus.

In 2008, scientists made a potential breakthrough in the treatment of serious disease by creating a human embryo with three separate parents (source BBC). The embryos were created using DNA from a man and two women in lab tests.The scientists took DNA from the mother and the father, but removed the parts that could foretell a condition like blindness or diabetes. That DNA was implanted into a donor egg which had been scraped of all genetic information except for the tiny bit that does control production of mitochondria, ensuring the fetus ended up with all the genes he or she needed, minus the disease-causing ones.

With advances in genetics research, people may soon preselect their children's physical and personality traits like they pick out options on a new car. So from this scenario, will children born without such genetic tinkering end up inferior to the ones born in the lab? For now, we're left with more questions than answers, but as we wonder at the possibilities, science keeps moving forward.

It may be possible for two gay men to have a baby together without the help of a surrogate, because eggs can be made from male cells. However, sperm requires a Y chromosome, leaving lesbian couples to rely on the help of male tissue.

The advances we discussed in this article aren't really right around the corner, but bioethicists are already deliberating and pondering over the implications of future reproductive technology. Are we simply ensuring that a child has the best possible start in life, or are we playing God? How old is too old to have a baby? Will men and/or women become superseded? Will the next generation be an army of clones? Who will be able to afford pregnancy and childbirth? And will a good old-fashioned way to lovemaking become the least popular way to have a baby? How far will reproductive technology go in the future? Will women one day be able to have children whenever and however they want? Will sex even be necessary? These are the questions that scientists are pondering. Read on to find out how the birds and the bees talk might go in the future.

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In the article 'Why sex could be history (Via Guardian) - author Aarathi Prasad in her book 'Like a Virgin' looks at the technologies that would take intercourse out of the reproductive equation, advances that could challenge everything we know about the relationship between men and women.  The book presents a portrait of the future in which sex is no longer necessary to reproduction and women can conceive using a combination of their own stem cells and an artificial Y chromosome to not only make eggs but also sperm.