Creationist dupes will confidently tell you that genetic information can only be created with the intervention of a magic, supernatural creator because, so they claim, information theory says, no new information can arise because it's somehow analogous to the creation of energy which the First Law of Thermodynamics says can't be created.
Press them to explain why they think information is analogous to energy and they'll break off the conversation and run, usually with departing abuse or smug condescension.
They will also confidently tell you that all mutations are deleterious, so evolution is either impossible, or 'devolutionary' [sic] (© Michael J Behe).
So, show them examples of increase in genetic information being part of the explanation for evolution in some taxons because the real world has no difficulty duplicating all or part of a genome then letting natural selection select for advantageous mutations in the duplicated genes, and they'll go into denial mode or pretend to be too stupid to understand.
These examples abound in nature and most species will have remnants of gene duplication in their genome. An example of the role it played in the evolution of a highly diverse class of mollusks, the marine gastropods, many of which are venomous.
Tell me all about the venomous marine gastropods.In common with many venomous species, the venom of these gastropods is often a complex mixture of toxins that have different effects on their prey. These are usually the result of evolutionary arms races in which the prey evolves immunity so the predator either has to find a new prey species or modify its venom to overcome the immunity. Often, immunity is achieved by small changes in cell receptor site proteins that the venom attaches to, so, to accommodate this, while retaining its ability to prey on non-immune species, the evolutionary change often involves gene duplication and mutations to produce a toxin which again binds to the modified cell receptor proteins.
Venomous marine gastropods, often referred to as venomous cone snails or cone shells, are a group of predatory sea snails known for their potent venom and unique hunting methods. These gastropods belong to the family Conidae within the larger class Gastropoda, which includes a wide variety of snails, slugs, and sea snails. Here is some detailed information about venomous marine gastropods:It's important to note that cone snails are not the only venomous marine gastropods, but they are one of the most well-known and studied groups within this category. As with any wildlife, it's crucial to exercise caution and avoid handling or disturbing these creatures in their natural habitat to minimize the risk of envenomation.
- Classification: Venomous marine gastropods belong to the family Conidae, which is part of the superfamily Conoidea. They are characterized by their cone-shaped shells, from which they derive their common name.
- Habitat: These snails are primarily found in warm, tropical marine environments. They are commonly found in coral reefs, rocky coastlines, and shallow waters.
- Physical Characteristics:
- Shell: Their shells are typically conical, elongated, and have a variety of intricate patterns and colors. These shells can range from a few centimeters to around 15 centimeters in length.
- Radula: Like other gastropods, cone snails have a specialized feeding organ called a radula, which they use to grasp and manipulate their prey.
- Diet: Venomous marine gastropods are carnivorous and feed primarily on other marine organisms. Their diet mainly consists of fish, worms, and other gastropods.
- Venom and Predatory Behavior:
- Venom: What sets cone snails apart from other gastropods is their potent venom. They have a specialized tooth called a radular tooth that is modified to deliver venom to immobilize or kill their prey.
- Hunting: When hunting, cone snails use a harpoon-like structure called a radular tooth, which is loaded with venom. They extend this harpoon and strike their prey, injecting the venom. The venom paralyzes or kills the prey, which is then consumed.
- Venom Components: The venom of cone snails contains a complex mixture of toxins, which can include neurotoxins, cytotoxins, and other bioactive compounds. Some of these toxins are extremely potent and can affect the nervous system of their prey.
- Medical Research: Despite their potential danger to humans, cone snail venom has garnered significant interest in medical research. Some of the compounds found in their venom have been studied for their potential use in pain management and the treatment of neurological disorders.
- Human Interaction: While cone snails are not typically aggressive towards humans, they can be dangerous if handled or stepped on. Some species have venom that is potent enough to cause paralysis or death in humans, although fatal encounters are rare.
- Conservation: Some species of cone snails are threatened by habitat destruction, overharvesting for the shell trade, and pollution. Conservation efforts are in place to protect these unique marine creatures.
This phenomenon is also seen in venomous snakes.
These evolutionary arms races are, of course, completely inconsistent with the notion of intelligent design, since any designer of them would be in competition with itself, treating every solution to a problem as a new problem to be solved. It takes a creationist to believe that is something an intelligent designer would do.
Now, a team of researchers led by Sarah Farhat of the Institut Systématique Evolution Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France have revealed how the hyperdiverse class of venomous marine gastropods, commonly known as cone shells, evolved by just such a process of gene duplication, including whole genome duplication, to give the estimated 1,000 species of cone snails.
They have published their findings, open access, in the journal Molecular Biology and Evolution:
AbstractOnly by remaining stoically ignorant of the facts, can creationists continue to believe that no new genetic information can arise naturally. There is nothing unnatural about gene duplication or the environmental selectors that favour advantageous mutations in those duplicated genes, while quickly eliminating any deleterious mutations. As ever, the information in the genome is determined by the environment with the environment determining what is useful and what isn't. A mutation which confers immunity on a prey species is obviously advantageous to the prey species, whilst a mutation which overcomes the immunity in the prey species is obviously advantageous to the predator.
The diversity of venomous organisms and the toxins they produce have been increasingly investigated, but taxonomic bias remains important. Neogastropods, a group of marine predators representing almost 22% of the known gastropod diversity, evolved a wide range of feeding strategies, including the production of toxins to subdue their prey. However, whether the diversity of these compounds is at the origin of the hyperdiversification of the group and how genome evolution may correlate with both the compounds and species diversities remain understudied. Among the available gastropods genomes, only eight, with uneven quality assemblies, belong to neogastropods. Here, we generated chromosome-level assemblies of two species belonging to the Tonnoidea and Muricoidea superfamilies (Monoplex corrugatus and Stramonita haemastoma). The two obtained high-quality genomes had 3 and 2.2 Gb, respectively, and 92–89% of the total assembly conformed 35 pseudochromosomes in each species. Through the analysis of syntenic blocks, Hox gene cluster duplication, and synonymous substitutions distribution pattern, we inferred the occurrence of a whole genome duplication event in both genomes. As these species are known to release venom, toxins were annotated in both genomes, but few of them were found in homologous chromosomes. A comparison of the expression of ohnolog genes (using transcriptomes from osphradium and salivary glands in S. haemastoma), where both copies were differentially expressed, showed that most of them had similar expression profiles. The high quality of these genomes makes them valuable reference in their respective taxa, facilitating the identification of genome-level processes at the origin of their evolutionary success.
Farhat, Sarah; Modica, Maria Vittoria; Puillandre, Nicolas
Whole Genome Duplication and Gene Evolution in the Hyperdiverse Venomous Gastropods
Molecular Biology and Evolution 40(8) msad171; DOI:10.1093/molbev/msad171
Copyright: © 2023 The authors.
Published by Oxford University Press for the Society for Molecular Biology and Evolution. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
There is no external 'gold standard' by which mutations can be measured outside the context of the environment in which they occur.
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