Malevolent Design News - How Female African Monarch Butterflies Find a Mate Despite Most Males Being Killed By A Parasite

Malevolent Design News

How Female African Monarch Butterflies Find a Mate Despite Most Males Being Killed By A Parasite

African monarch's, Danaus chrysippus

Female butterflies breed despite male shortage - News

African monarch butterflies, Danaus chrysippus

arian.suresh - Flickr

Talk about pointlessness!

It seems creationism’s malevolent designer has gone to all the trouble of designing a parasite to kill most males of the African monarch butterfly, only to have the females find a way to mate with the few remaining males. So, either killing the males was just gratuitous cruelty, or the supposed designer, who also designed the females, didn't know what they were capable of.

That's if you've fallen for the childish notion of species being designed by a magic invisible skyman who allegedly knows everything and has limitless powers, that is.

If not, like to most normal adults, it should be obvious that this is the sort of thing a mindless natural process with no plan and no consciousness would produce. The parasite in question is a bacterium of the Spiroplasma genus, a genus which infects insects and often forms endosymbiotic relationships with them:

Spiroplasma is a genus of bacteria that is commonly found in insects, particularly in their hemolymph, salivary glands, and reproductive organs. Some species of Spiroplasma are known to form endosymbiotic relationships with their hosts and have been shown to play a role in the reproductive success, development, and even behavior of their insect hosts.

One well-known example of such an endosymbiotic relationship is between Spiroplasma and the African Monarch butterfly (Danaus chrysippus). Research has shown that Spiroplasma infection in this butterfly species can result in male-killing, where infected male larvae die before reaching adulthood, leaving a higher proportion of female butterflies in the population. This is thought to increase the reproductive success of female butterflies, as they face less competition for resources and mates.

Additionally, Spiroplasma infection has been shown to affect the coloration and pattern of African Monarch butterfly wings, with infected individuals exhibiting a higher degree of melanization and altered wing patterns. These changes in wing coloration and pattern are thought to affect the behavior and mating success of the infected butterflies.

References:

1. Hurst, G. D. D., Jiggins, F. M., & Pomiankowski, A. (2003). Evolutionary implications of symbiotic bacteria for host sex determination. Journal of evolutionary biology, 16(2), 175-182.
2. Hornett, E. A., Charlat, S., Duplouy, A., Davies, N., Roderick, G. K., Wedell, N., & Hurst, G. D. (2006). Evolution of male-killer suppression in a natural population. PLoS biology, 4(9), e283.
3. Oliver, K. M., & Russell, J. A. (2011). Moran, N. A. & Hunter, M. S. (2005). Costs and benefits of a superinfection of facultative symbionts in aphids. Proceedings of the Royal Society B: Biological Sciences, 272(1561), 2187-2192.
4. Balenger, S. L., & Oberhauser, K. S. (2005). Effects of parasitic infection and melanization on wing morphogenesis in Danaus plexippus (Lepidoptera: Nymphalidae). Journal of insect physiology, 51(2), 191-200.

ChatGPT. (18 Apr 2023). Tell me about the endosymbiont, Spiroplasma and African Monarch butterflies, with references, please. [Response to a user question].
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This is an extreme example of what competition between sexes can produce. The female genes benefit from fewer males in the competition for resources and, so long as enough males survive to produce the next generation, there will be an evolutionary balance between virulence/infectivity and female reproductive success.

But, as some recent research shows, there has also been selection pressure on the females to find the few survivors of the symbiont's genocide. The work was carried out by scientists from the universities of Exeter, Rwanda and Edinburgh, and the Dian Fossey Gorilla Fund, who published their findings, open access in the journal Ecology & Evolution. The University of Exeter news release explains their work:

Female African monarch butterflies have no trouble finding a mate – even when a parasite kills most of the males, new research shows.

Some females carry a parasite called Spiroplasma that kills all their male offspring, meaning highly infected populations have very few males.

But the new study – by the universities of Exeter, Rwanda and Edinburgh, and the Dian Fossey Gorilla Fund – found females mated about 1.5 times on average, regardless of how many males were around.

The male proportion dropped below 10% in some cases, but it appears the remaining hard-working males managed to breed with most of the available females.

10-20% of females remained unmated, only slightly higher than the expected average in a population with plenty of males (5-10%).

It was an inspiring and powerful experience working along with an international team of experts and advancing our knowledge of monarchs, which will shape my future career path towards research-based conservation,

Vincent Rutagarama, first author
University of Rwanda.

It seems that monarch butterflies are very good at finding each other and mating.

The proportion of males in butterfly populations fluctuates through the year, but we found consistent evidence of female breeding success all year round.

We hope the monarch butterfly could become a symbol of conservation across Africa. Monarchs live in savanna habitats. When there is rain, they thrive. When there is no rain, there are no butterflies, no cattle and no food for humans. The future of the monarch butterfly is tied to that of the continent, and humanity must tackle the climate and environment crisis to secure that future.

Professor Richard ffrench-Constant
Centre for Ecology and Conservation
Exeter University, Penryn Campus in Cornwall, UK

Dr Ian Gordon, of the University of Rwanda, said this breeding success might explain how the male-killing parasite can be successfully transmitted in a population where males are rare.

The irony is that if the entire population was infected, monarch butterflies – also known as African queens – would produce no more princes, and the parasite would die out along with the butterflies.

Further research is now needed, to find out why some monarch butterflies remain uninfected, and therefore able to produce healthy male offspring. Future research could also explain why the male-killing parasite is currently confined to a sub-section of the East African ‘contact zone’ (where prevailing winds converge, bringing flying insects together).

Dr Ian Gordon, co-author
Department of Biology
College of Science and Technology
University of Rwanda, Kigali, Rwanda

Professor ffrench-Constant said other butterfly species have evolved resistance to parasites like Spiroplasma, so monarchs – which are very numerous and widespread – are unlikely to be at risk.

However, several years of severe drought in East Africa have caused a food crisis for humans and damaged biodiversity and ecosystems.

In butterflies and moths, successful breeding involves the transfer of a “spermatophore” from the male to the female. Spermatophores remain detectable after breeding.

In this study, carried out at one site in Rwanda and another in Kenya, male-female ratios were regularly counted, and 10 randomly selected females were dissected each month to count spermatophores.

The Creationist fallback position in situations such as this, where the observable fact make no sense as the work of an intelligent designer, is, "It is not for mankind to try to work out the thinking of an omniscient god, and anyway because he [sic] is defined as all-loving, there must be a good reason, if only we could understand it with our limited intellect". However, although that probably accurately reflects the limited intellect of creationists, it doesn't take a supernatural genius to work out that killing most of the males of a species for no discernible benefit is not the work of either an intelligent, or a compassionate designer, but is best explained as the result of mindless, unplanned natural selection, with its lack of a plan and no regard for the suffering its 'designs' produce.

However, for reasons not far removed from political and/or financial gain, creationist cult leaders would prefer their dupes to think of their putative designer as malevolent and/or incompetent rather than have folk accepting the overwhelming evidence for evolution.

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