Did Life on Earth Originate from Outer Space?

A couple of weeks ago, we learned about the origin of life on earth both through watching an educannon video and a video in class. We learned that the earth was formed 4.5 billion years ago and that the origin of life could be traced through molecular evidence, geological evidence, and chemistry evidence.

According geological evidence, life most likely began 3.5 - 3.8 billion years, traceable through absolute and relative dating. Chemically, Miller and Urey performed an experiment to simulate the conditions of early earth, adding early atmospheric gases and an electrical charge equivalent to lightning, forming amino acids. Molecular evidence shows that the tree of life branched from a universal common ancestor that most likely had DNA, RNA intermediates, proteins, ATP, a lipid membrane, and cell division since every other form of life uses these today.

The most currently accepted idea is that life came from non-life or chemistry in shallow pools of water with the elements H, O, C, and N. However, the earth melting repeatedly due to collisions with meteorites would have wiped out any form of life developing immediately. Therefore, some scientists are suggesting that some chunks of earth flew into space after collision, containing the newly formed primitive chemistry, which could have survived the trip into space and back home through the same meteorite landing back on earth.

This idea of life coming from earth into space, surviving in space, and coming back to earth in meteorites blew me away. I was dumb struck to think that life could survive in space. This lead me to think that if life could survive in space, could life on earth have originated in space entirely and come to earth only by chance that a meteorite with life land on earth?

I researched this topic further and found that scientists from Cornell University have found that some amino acids and sugars exist inside of meteorites using the Alma Observatory in Chile (O’Callaghan 2014). Not only that, but they also discovered the presence of carbon 27,000 light years away, suggesting the possibility that life came from outer space (O’Callaghan 2014). In addition, they found hints of the molecule isopropyl cyanide (a complex molecule common in life-essential molecules) in the form of emitted radio waves from a giant gas cloud near the center of the Milky Way (O’Callaghan 2014). This means that the building blocks of life may have originated somewhere else in space and could have been brought to earth via meteorites. Their research has me questioning that if life did originate from space (I’m not solidifying that this is how life rose about on earth) and come to earth in meteorites, what is to say that these meteorites did not carry life to other planets as well? Could the same basic organic chemistry that evolved into life as we know it today be present on other planets?

Work Cited:

O'Callaghan, J. (2014, September 29). Did life on Earth come from outer space?

Discovery of carbon 27,000 light-years away suggests building blocks came from

elsewhere in the Milky Way. Retrieved October 29, 2014.

Coevolution: Planalto Hermit Humming Bird and Ornithophilous flower

Throughout the continuous evolution of new species over time, coevolution has been a mechanism for multiple species to selectively put pressure on each other, thereby affecting each other’s evolution. It has influenced the evolution of host species to stay resistant to parasites by reproducing sexually, which allows a higher chance of immunity. The parasite is pressured to evolve in response to have a better chance at infecting the host. This cycle continues as demonstrated in the Red Queen’s hypothesis (Cronk & Ojeda 2008).

Additionally, the Planalto hermit humming bird (Phaethornis pretrei) has coevolved a mutually beneficial relationship with the ornithophilous flower (Beloperone californica) (Faria & Araujo, 2008). The flowers itself are “characterized by having brightly colored (e.g. red or yellow) odorless flowers, tubular and evenly curved corollas, diurnal anthesis and sucrose-rich nectar” (Faria & Araujo, 2008). The plants have morphologically co-adapted these traits overtime with the hummingbird. Specifically, the flowers’ long and tubular shape appeals to hummingbirds because the bird’s bills are oriented similarly, allowing them to easily probe these flowers as opposed to other flowers (Cronk & Ojeda 2008). Over time, the plant species are selectively pressured to evolve flowers that are more tubular in shape, so that the hummingbirds will prefer to pollinate their flowers instead of other plants. In turn, the hummingbird species morphologically co-adapt a more similar shaped beak to fit smoothly into the flowers in order to get nectar. The plants have also evolved to produce a higher volume of nectar with a higher sugar production than other plants that are pollinated by insects to meet the birds’ energy requirements (Cronk & Ojeda 2008). The co-evolution patterns go as far as the plants’ flowers’ colors evolving to suit the humming bird specie’s vision. Birds prefer red pigmentation in flowers because they have a good sense of color discrimination and spectral sensitivity at the red end of the visual spectrum (Faria & Araujo, 2008). Therefore, the hummingbird has selectively pressured the plant species to evolve more red-toned flowers over the course of many generations., which encourages the hummingbird to take pollen from their flowers to reproduce instead of other plants. The convolutions have gone as far as the blooming times of the flower to coincide with hummingbird breeding seasons (Faria & Araujo, 2008).

Work Cited:

Cronk, Q., & Ojeda, I. (2008, March 7). Bird-pollinated flowers in an evolutionary and

molecular context. Retrieved October 19, 2014.

Faria, R., & Araujo, A. (2009, August 31). Flowering phenology and pollination of

ornithophilous species in two habitats of Serra da Bodoquena, Mato Grosso do
Sul, Brazil. Retrieved October 19, 2014.