8. How did life evolve?
Although this is a question we will never be able to definitively answer (unless Number 18 becomes possible), I think we will one day be able to demonstrate practical ways in which life can evolve from non-life. In 1953, Miller and Urey demonstrated the formation of essential amino acids by simply electrocuting boiled methane, ammonia, hydrogen, and water — compounds believed to be abundant on the early Earth. Since then, many researchers have uncovered many specific conditions that can result in the formation of compounds necessary for life as we know it, including the formation of nucleic acids.
It is very conceivable that in the near future, scientists may demonstrate the formation of self-assembling, replicating molecules in such an experiment. Perhaps they will then show how these replicating molecules can acquire membranes, like the phospholipid bilayers of our own cells (which are already known to be self-assembling). A wide variety of theories exist concerning the abiotic origins of life, too many to debate here, and I think that we may in our own lifetimes find practical methods that our own molecular ancestors might have used to become life.
9. What is the exact evolutionary lineage of all life on Earth?
As above, historical events are by definition inherently unknowable, from a definitive standpoint. However, as the fossil record continues to accumulate, and more importantly, as more and more genomes are sequenced, we will be able to compare the specific DNA codes of all life on Earth (or as much as we want) to calculate the ultimate Tree of Life on Earth.
There will always be holes, and specific areas of fuzziness in the data. Many organisms have been show to transfer genetic material between species, largely due to things like retroviruses and bacteria, which can muddy our understanding of specific lineages. Nonetheless, we will eventually construct a tree of evolution that comes close to outlining the entire history of natural selection on Earth.
10. Can we engineer our own evolution?
The trajectory of current molecular and developmental biology places us squarely in line to eventually understand the contributions of all genes within human development and physiology. We are already at the point where embryos can be screened for genetic defects, such as Trisomy 21 (Down Syndrome), before being implanted into a woman’s uterus.
Our tools for genetic manipulation are improving, though we are still far from using gene therapy as a routine treatment. It seems likely that we will one day be faced with the opportunity to engineer our own evolution. The current state of civilization seems to suggest that at least a macro level, humans are not experiencing selective pressure to evolve, other than negative selection against disease.
However, we may one day be able to direct the course of our own evolution. We would need the currently unimaginable computing power necessary to simulate potential genetic changes, and superb genetic tools. Perhaps with enough knowledge of developmental biology, physiology, anatomy, and with the necessary computing power and tools, we could make our species happier, adapted to undersea life, more intelligent, free of disorder and disease, or any number of things we can imagine for our species.
Of course, there are enough moral and societal issues with this possibility to fill a Wikipedia. Then again, who knows what kind of world humans will live in many generations from now.
11. What are the costs and benefits to specific changes in the brain?
An interesting issue has been brought up by the fields of clinical psychology and cognitive psychology, and it is the issue of the cost/benefit of deficits or enhancements in the brain. Many have speculated that a growing list of artists, geniuses, and creative thinkers from our history have been autistic, or at least have had personalities in the autistic spectrum.
In addition, creativity has been positively linked with bipolar disorder (formerly known as manic depression). The study of neuroscience and neuropsychology will likely discover some interesting links between gaining certain abilities or traits, while displaying deficits of others. We have all heard of the rare “savants”. If we do get to the point of self-directed evolution or even personal enhancement with drugs, it may be interesting to define the interplay between these different traits in the human psyche.
12. How does a single cell turn itself into a thinking, breathing organism?
How does a fertilized egg regulate its own genes and control the timing and three dimensional growth of cells to form tissues and organs? The field of developmental biology is currently in an explosion of data. What at first seemed only insanely complex, now seems near-infinitely more so with the discovery of the roles of things such asmicroRNAs, epigenetics, and maternal contribution on development, on top of the role of protein-coding genes.
It seems like it will take centuries for us to parse out the different factors, interactors, and processes involved in the construction of an organism. However, time is something we’re not concerned with here. Assuming all remains right with the world, science will almost definitely explain exactly how a sperm and an egg can come together to create someone like you.
13. Is there a maximum human life span?
The human body did not evolve to be particularly long-lived. As we age, our somatic telomeres shorten (which degrades genes at the end of a chromosome). We accumulate mutations, oxidative damage, and cellular debris, and we develop diseases. How many of these things can we overcome?
As of this moment, there is only one proven method of extending life spans in mammals:caloric restriction. Eat less, live longer — at least on a population level. It remains to be seen how long we can extend the human life. Even if we can extend it further, we will have to address issues of quality of life as well. Nevertheless, I have much optimism that science could extend the human life dramatically, given the time and knowledge.
14. Can we save our planet?
How much power can we wield over mother earth? Will we learn to alter climate? Will we learn to utilize renewable energy? Can we cure hunger? To me, it seems that we may always remain as ants when compared to the larger forces of this planet. I cannot foresee large scale engineered climate change and weather control. Then again, who could have conceived of gene therapy two hundred years ago? I think that science has already provided at least rudimentary answers to both renewable energy and hunger. The main issues with these seem now to be cultural and economic, which I don’t want to get into here.
Bioengineering is almost assured to produce a new revolution in energy production. I predict that we will soon have microbes producing ethanol or other hydrocarbon fuels from cellulosic material. We already have solar technology. And bioengineering is also in the beginning stages of creating more nutritious foods that are easier to grow. These will have negative effects and issues of their own (such as the loss of biodiversity and increased susceptibility to sudden disease), but these are issues that I believe we can overcome.
15. Can humans survive on other planets?
Scientists have already discovered over 300 extrasolar planets (planets around other stars). Right now, our technology is limited to inferring planets by the wobble their gravity induces on nearby bodies, so most of the discovered planets are enormous Jupiter-like planets.
However, mounting evidence suggests that earth-like planets orbiting “habitable” zones, which are areas of proper temperature ranges, may be much more common than initially suggested. Thus, I think it’s easily conceivable that with new detection technologies, we may discover watery earth-like worlds in our own lifetime, or our children’s. Now can we get there?