Evolution has shown us many types of unique traits that help organisms to better survive in their environment. One such exotic creature, which has rapid adaption, is the common cockroach. Though it is hated by many, it is one of the arthropod ever to survive in any given conditions. This paper will be discussing about this hypothesis, which cockroaches have evolved to reduce their life span to almost 1-2 years. This is done to make them fast maturing and thus accelerating the evolution process. A studies conducted has proven that Escherichia coli can evolve to digest citrate within 68000 generations. Also recent antibiotics have become less futile towards these microbes. Thus our cockroach here needs to runs faster in the evolutionary race in order for the survival of its species. Being around unfit environment this natural stress is competed with short life span, thus making roaches early maturing to give rise to new and fit progeny to better adapt to the environment. If this hypothesis is true, then cockroaches are walking medicines which could help humanity to compete with antibiotic resistant bacteria.
Significance of cockroach
Studies have shown that cockroaches are a hub of antibiotics. It was found that roaches have antibiotics secreting from their heads. Scientists have extracted the brain as well as the neural tissue from the roach and have found molecules in the roaches’ head that could kill Staphylococcus aureus and Escherichia coli (1). Also it was also proven that cockroaches have di-phase immune system. The study conducted has shown that, there are two types of immune responses, the first response is non-specific and the second one is more specific. The experiment was conducted with P.aeruginosa which roaches shown significant protection (2). P.aeruginosa is one of the leading causes of infections in humans, which in some cases can lead to death.
It was also exciting to find out that the milk of cockroaches has essential antibodies which can be used in therapeutics. A species known as, Diploptera punctuate was tested and has found essential amino acids. It suggests that the cockroach could become the next super food (3).
We all know we came from the pre-existing bacteria, which ultimately led to complex structures. But has evolution stopped? No. Still bacteria evolve and has adapted to certain antibiotics. A recent article published suggests that bacteria can give rise to 2 million within just few hours, under right conditions (4). This is a major problem, not only for us but also for the cockroaches. Another article suggests that Escherichia coli was able to digest citrate after exposing it for 68000 generations(5,6), so think how fast it will adapt to anything in 2 million? So how does a cockroach cope up with this evolutionary race?
Cockroaches belong to a group of species known as Blattodea, which link cockroaches, termites and even mantises (7).Scientists around the world believe that the first Blattodea came about around 300mya. This could mean that, the first cockroach came about before the splitting of the continents (From the super continent Pangea) (8, 9). The fossil record suggests that the first ancestor of today’s roaches came about came about in late 245mya, and the ancestor of the common roaches around 140mya. There almost 4000 species of cockroaches within this short period of time. So it can evolve much faster to cope with the race of bacterial evolution.
A dilemma that led to the hypothesis
Though cockroaches have high immunity and radio resistance, the average life is between 1-2 years. How can such a creature with such massive adaptations were able to live up to only this long? Then evolution answered everything. The cockroaches have adapted to shorten their life span so they can grow and mature faster. This helps in the exponential growth rate in the cockroach populations. As new generations occur within this short span of time, new variation is added to the cockroach gene pool. A female roach lays an ootheca which has about 50 eggs in it (10). Also it is seen that the first arthropod came around 400 million years ago (mya), about 100my before the first Blattodea, also the first cockroach came in around 140mya. From that time onwards, cockroach species have diversified so much that we have around 4500 species. So it all add up to this:
1) The bacteria evolves faster
2) Being an unhygienic organism, cockroaches are more prone to these bacterial infections
3) Hence they are also in need to adapt faster.
4) Evolution can only occur in successive generations, thus cockroaches must also reproduce at large scale
4) Large scale reproduction can lead to early maturation, resulting in early senescence.
If my hypothesis is true, then cockroaches can deal with the antibiotic crisis around the world. With faster adapting microbes, we could get faster and upgraded antibiotics to meet the demand.
2) Department of Biological Sciences, University of Cincinnati, Ohio 45221.
4) https://www.livestrong.com › … › Digestive Conditions › Food Poisoning
5) Article | Published: 18 October 2017Benjamin H. Good, Michael J. McDonald, Jeffrey E. Barrick, Richard E. Lenski & Michael M. Desai.Nature.com
7) “ITIS Standard Report Page: Blattodea”. www.itis.gov. Retrieved 10 May 2018.
8) Ruth Schuster is Senior Editor at the Haaretz-TheMarker English Edition.
9) Molecular Biology and Evolution by Dr. Thomas Bourguignon