Prior to this year, the Ebola virus was an obscure pathogen that rarely grabbed a slice of attention. Now it’s front-page news. All over the globe, the overwhelming response to Ebola has been fear. But this virus’ lethality to humans also makes some people wonder about God’s goodness. How could a loving Creator, who is all-powerful and all-knowing, produce a world with pathogens that cause such pain and suffering? Fortunately, the RTB creation model can account for the Ebola virus and still maintain that God is good.
The Ebola virus is a member of the Filoviridae family. These viruses carry their genetic information in a single strand of negative-sense RNA. They also carry an RNA-dependent RNA polymerase, an enzyme responsible for synthesizing positive-sense and negative-sense viral RNA. The cell machinery then synthesizes the new viral proteins from the positive-sense RNA, leading to the assembly of new viral particles.
Ebola was first identified in 1976, during an outbreak in Zaire (now the Democratic Republic of the Congo). Despite this relatively recent discovery, Ebola does not seem to be a new virus. Researchers have identified filoviral gene sequences in the genomes of some vertebrates and based on phylogenetic analysis of these sequences, they estimate that vertebrates have been exposed to filoviruses since as far back as 40 million years ago. The presence of filoviral sequences in vertebrate DNA also implies that coinfection of filoviruses with retroviruses allows viral RNAs to integrate into the DNA of their hosts. It is important to point out that filoviruses and Bornaviruses were the only families of RNA viruses found integrated into the DNA of vertebrates.1
The reason for this integration is unclear. Research in the area of endogenous retroviruses indicates that the presence of these retroviruses in mammalian cells plays an essential role in placental development.2 It is then possible that the presence of filoviral sequences in vertebrates provides the natural hosts with important elements that could be crucial for their survival.
It is thought that fruit bats are the natural hosts of the Ebola virus. Humans become infected through contact with an infected animal, which could be a bat or an infected primate. Ebola then spreads from human to human through contact with blood or body fluids. Whereas mortality in humans is very high, bats and some other animals seem to develop an asymptomatic infection.
Recent studies on bats have revealed some interesting discoveries. Bats display unique biological features such as long life spans and a low rate of tumor development.3 Recent research has also shown that bats’ immune systems are in a more activated state than other mammals’.4 It is unknown whether exposure to the Ebola virus acts as a primer for the bat immune system to fight other pathogens, as well as tumor cells, or whether these viruses possess direct oncolytic behavior.
Bats are the only flying mammal and they are the second-most species-rich mammalian order. They play a very important role in ecosystems around the world, mainly through the consumption of insects. In a sense, bats act as agents of pest control. Filoviruses may then contribute to maintain the health of these animals, providing us with a more hospitable environment to live in (no mosquitoes!) and controlling agricultural pests that could devastate our food supply.
So, Ebola infection in humans can be understood as a break in the carefully balanced ecosystem involving microorganisms and natural hosts. The accidental encounters between Ebola and humans may result in tragic episodes of human death. However, we need to remember that viruses are part of Earth’s ecosystems and that they play a role in keeping our planet in an optimal state to allow for human life to be possible. Filoviruses may reflect another characteristic of careful design by God for the benefit of advanced life on Earth.
For more on the RTB model for the origin of human disease, see “Did God Create Flesh Eating Bacteria?”
- Vladimir A. Belyi, Arnold J. Levine, and Anna Marie Skalka, “Unexpected Inheritance: Multiple Integrations of Ancient Bornavirus and Ebolavirus/Marburgvirus Sequences in Vertebrate Genomes,” PLoS Pathogens 6 (July 2010): DOI:10.1371/journal.ppat.1001030.
- Christian Lavialle et al., “Paleovirology of ‘Syncytins,’ Retroviral Env Genes Exapted for a Role in Placentation,” Philosophical Transactions of the Royal Society B 368 (September 19, 2013): DOI:10.1098/rstb.2012.0507
- James W. Wynne and Lin-Fa Wang, “Bats and Viruses: Friend or Foe?,” PLoS Pathogens 9 (October 2013): DOI: 10.1371/journal.ppat.1003651.
- Guojie Zhang et al., “Comparative Analysis of Bat Genomes Provides Insight into the Evolution of Flight and Immunity,” Science 339 (January 25, 2013): 456–60.
By Dr. Francisco Delgado
Dr. Francisco Delgado received his medical doctorate from Universidad La Salle, Mexico in 1995. He completed a fellowship in infectious diseases at Vanderbilt University in 2002, and currently works as an infectious diseases consultant at Infectious Disease of Indiana in Indianapolis.