![]() ![]() We’re not just looking at the venoms of sexually mature males. This could be critical for improving existing anti-venoms, and for designing evidence-based treatment strategies for bite victims. The new genetic sequences we discovered will enable a better understanding of what funnel web spider venom does to the human body. Now armed with a stronger understanding of how delta-hexatoxins evolved, we want to put that knowledge to use. So the venom of females is thought to remain potent only against insects their entire lives.įemale funnel webs stay in their burrows, so are less likely to be eaten by predators. Unluckily for humans, who are vertebrate animals, we copped it in the process.įemale funnel webs stay safely in their burrows and let the males come to them. ![]() We found over time, the venom of adult males evolved to be potent to vertebrate predators. We examined the genetic sequences of all delta-hexatoxins in funnel web venom. When funnel-web spiders evolved millions of years ago, toxins in its venom mainly targeted their natural prey: insects such as cockroaches and flies. Should I kill spiders in my home? An entomologist explains why not to These can include reptiles (such as lizards or geckos), marsupials (such as antechinus and dunnarts), mammals (such as rats) and birds. This puts male funnel web spiders in the path of vertebrate predators. When males sexually mature, they leave the safety of their burrow and wander considerable distances to find a female. Our data revealed how natural selection triggered a change in the venom of adult male funnel webs. The genes responsible for this success are preserved and carry on to the next generations, driving the process of evolution It all comes down to natural selection – the process where organisms best adapted to their environment survive and procreate. Having this extra data helped us paint a much clearer picture of the venom’s story. Our analysis increased the number of known delta-hexatoxins to 22, from the venom of ten funnel-web species. Although 35 species of Australian funnel-web spiders were officially recognised, only nine delta-hexatoxins from four species had previously been identified. We set out to solve this mystery, using molecular analysis of the venom. Venom from a male funnel web spider can kill vertebrates, including humans. This suggested the venom played a defensive role. However we did know most funnel web bites in humans occur during the spiders’ summer mating season, when the male spiders rarely feed. Scientists were also perplexed as to why male funnel webs appeared to have much deadlier venom than females, and caused most human deaths. Scientists have long been puzzled by why these toxins are so deadly to humans, when we and other primates have never been funnel web prey or predator. In severe cases the venom can cause muscles to go into spasm, blood pressure to drop dangerously, coma and organ failure, and ultimately death – sometimes within a few hours.ĭon't like spiders? Here are 10 reasons to change your mind This toxin can kill humans by attacking the nervous system, keeping nerves “turned on” and firing over and over again. However all 13 recorded deaths occurred before anti-venom was introduced in 1981.įunnel web venom is lethal because it contains a type of neurotoxin called “delta-hexatoxin”. As an animal matures and its activities change, so too can its venom.Īustralian funnel webs are among a small group of spiders whose venom can kill humans. Shutterstock Why so deadly?Ībout 15% of all animals use venom for reasons such as to kill or immobilise prey, self-defence or to gain advantage over competitors, such as during breeding season. Funnel webs are among Australia’s most feared spiders. ![]()
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