I wonder if creationists ever puzzle over the fact that science never produces any evidence supporting their dogmas and superstitions; instead, science repeatedly finds evidence the flatly contradicts them. It takes a special form of delusion and self-deception to dismiss all that contrary evidence and stick with an evidence-free notion.
Just such a creation-refuting piece of science has just been published in the journal Nature Plants. It concerns the evolution of the parasitic plants, the Balanophora and in particular, the discovery that during their evolution they lost 38% of their genome.
Despite the fact that many parasites have undergone a genome reduction during their evolution to a parasitic life-style, creationist dogma dictates that mutations and loss of genes are always deleterious, or 'devolutionary' (©Michael J Behe) a nonsensical term which tries to relate biology to the biblical myth of 'The Fall' because Behe has now abandoned the futile attempt to prove that evolution isn't a natural process in which no gods or supernatural entities are involved.
Parasitism is also a refutation of the childish notion of intelligent [sic] design, especially by a supposedly omni-benevolent designer, because no intelligent designer would design the inevitable arms race that characterises a parasite-host relationship, unless that designer was both malevolent and extremely stupid.
First, a little about the Balanophora:
Tell me about the parasitic plans, the Balanophora, their evolution, life cycle and modus operandum.Reserchers at the State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China, together with Dr. Sean Graham of the Department of Botany, University of British Columbia, Vancouver, BC, Canada, discovered is that, in addition to an unprecedented loss of genes, Balanophora have evolved unique structure for attaching to and extracting nutrients from their host plants which involved inducing the host to contribute to the structure.
Balanophora is a genus of parasitic plants that belong to the family Balanophoraceae. These unique and fascinating plants are found in tropical and subtropical regions around the world. They have evolved some remarkable adaptations to their parasitic lifestyle, which sets them apart from most other plants. Here's some information about Balanophora, including their evolution, life cycle, and modus operandi:
Evolution:
Balanophora plants have a long evolutionary history dating back to the Late Cretaceous period, making them some of the most primitive and ancient angiosperms (flowering plants). They are believed to have evolved from a mycoheterotrophic ancestor, which means they likely had a mutualistic relationship with mycorrhizal fungi before becoming fully parasitic.
Morphology:
Balanophora plants exhibit unique and unusual morphological features. They lack leaves, chlorophyll, and typical roots, as they have adapted to a parasitic lifestyle. Instead, they consist of fleshy, underground or semi-underground stems, often resembling tubers or rhizomes. These stems are typically small and unbranched.
Life Cycle:
Balanophora plants have a complex life cycle that involves a dependence on both their host plants and mycorrhizal fungi. Here's an overview of their life cycle:
- Seed Germination: Balanophora plants start their life cycle as tiny seeds. When these seeds germinate, they rely on mycorrhizal fungi in the soil to establish a connection with potential host plants.
- Attachment and Tapping: Once connected to a host plant's root system through the mycorrhizal fungi, Balanophora plants tap into the host's vascular system. They extract water, nutrients, and carbohydrates from the host, effectively becoming parasites.
- Growth and Reproduction: Balanophora plants grow and produce reproductive structures, which are often unique and distinctive in appearance. These structures can vary among species but usually consist of densely packed flowers that emerge above the ground.
- Pollination: Balanophora flowers are typically unisexual, with male and female flowers on separate plants. In some cases, insects or other animals may play a role in pollination.
- Seed Production: Once pollinated, female Balanophora flowers produce seeds. These seeds fall to the ground and may wait in the soil until they encounter the right conditions for germination, including the presence of suitable host plants and mycorrhizal fungi.
Modus Operandi:
Balanophora plants are obligate parasites, meaning they cannot complete their life cycle without a host plant and mycorrhizal fungi. They rely on their hosts for water, nutrients, and carbohydrates. The specific host plants they parasitize can vary depending on the Balanophora species.
Balanophora plants have evolved specific adaptations to survive in their parasitic lifestyle, including reduced photosynthetic capabilities and the development of specialized structures for tapping into their host's vascular system.
In summary, Balanophora plants are intriguing examples of parasitic plants with a complex life cycle that involves a strong dependence on both host plants and mycorrhizal fungi. Their unique morphology and adaptations make them a subject of scientific interest and curiosity among plant enthusiasts.
What do you know about the structures with which they attach to their host plants?
Balanophora plants have specialized structures that allow them to attach to and tap into their host plants' vascular systems. These structures are essential for their parasitic lifestyle and nutrient acquisition. The specific structures can vary among Balanophora species, but they generally include the following:
- Haustoria: Haustoria are modified, root-like structures that Balanophora plants develop to penetrate and attach to the host plant's roots or underground stem structures. These haustoria are adapted for parasitism and are responsible for the transfer of water, nutrients, and carbohydrates from the host plant to the Balanophora.
- Rhizomes: Balanophora species often have underground or semi-underground stems known as rhizomes. These rhizomes can grow and spread within the host plant's root system, enabling the parasite to establish a more extensive connection with the host.
- Adventitious Roots: Some Balanophora species may produce adventitious roots from their stems. These roots can grow into the host plant's tissues, allowing for a more direct connection and nutrient exchange.
- Mycoheterotrophic Associations: In addition to their own structural adaptations, Balanophora plants form mutualistic relationships with mycorrhizal fungi. These fungi play a crucial role in facilitating the connection between Balanophora and their host plants. The mycorrhizal fungi extend the reach of the Balanophora's haustoria, increasing their ability to tap into the host's vascular system.
These structures collectively enable Balanophora plants to anchor themselves to their host plants and access the water, nutrients, and carbohydrates they need for survival. It's important to note that the specific adaptations can vary among Balanophora species and may be influenced by the type of host plant they parasitize. These parasitic plants have evolved over time to become highly specialized for their unique mode of existence.
As the University of British Columbia news release explains:
Balanophora shed one third of its genes as it evolved into a streamlined parasitic plant—an extreme degree of genome shrinkage even among parasites—according to new research in Nature Plants. Along the way this subtropical plant developed the ability to induce the host plant to grow into the parasite’s own flesh—forming chimeric organs that mix host and parasite tissues.Sadly, the team's paper in Nature Plants is behind an expensive paywall, so only the abstract is available:
If you happen to come across plants of the Balanophoraceae family in a corner of a forest, you might easily mistake them for fungi growing around tree roots. Their mushroom-like structures are actually inflorescences, composed of minute flowers.
But unlike some other parasitic plants that extend an haustorium into host tissue to steal nutrients, Balanophora induces the vascular system of their host plant to grow into a tuber, forming a unique underground organ with mixed host-parasite tissue. This chimeric tuber is the interface where Balanophora steals nutrients from its host plant. The study revealed Sapinia and Balanophora have lost 38% and 28% of their genomes respectively, while evolving to become holoparasitic—record shrinkages for flowering plants.
But how these subtropical extreme parasitic plants evolved into their current form piqued the interest of Dr. Xiaoli Chen, a scientist with BGI Research and lead author of a new study published this week in Nature Plants.
The study revealed Sapinia and Balanophora have lost 38% and 28% of their genomes respectively, while evolving to become holoparasitic—record shrinkages for flowering plants.Dr. Chen and colleagues—including University of British Columbia botanist Dr. Sean Graham—compared the genomes of Balanophora and Sapinia, another extreme parasitic plant in the family Rafflesiaceae that has a very different vegetative body.
The researchers found a near-total loss of genes associated with photosynthesis in both Balanophora and Sapinia, as would be expected with the loss of photosynthetic capability.The extent of similar, but independent gene losses observed in Balanophora and Sapinia is striking. It points to a very strong convergence in the genetic evolution of holoparasitic lineages, despite their outwardly distinct life histories and appearances, and despite their having evolved from different groups of photosynthetic plants.
Dr. Xiaoli Chen, co-first author
State Key Laboratory of Agricultural Genomics,
BGI Research, Shenzhen, China
But the study also revealed a loss of genes involved in other key biological processes—root development, nitrogen absorption, and regulation of flowering development. The parasites have shed or compacted a large fraction of the gene families normally found in green plants—the large sets of duplicated gene plants that tend to perform related biological functions. This supports the idea that the parasites retain only those genes or gene copies that are essential.
Most astonishingly, genes related to the synthesis of a major plant hormone, abscisic acid (ABA), which is responsible for plant stress responses and signaling, have been lost in parallel in Balanophora and Sapinia. Despite this, the researchers still recorded accumulation of the ABA hormone in flowering stems of Balanophora, and found that genes involved in the response to ABA signaling are still retained in the parasites.
Dr. Huan Liu, a researcher at BGI Research, emphasized the significance of the study in the context of 10KP—a project to sequence the genomes of 10,000 plant species.
The study of parasitic plants deepens our understanding of dramatic genomic alterations and the complex interactions between parasitic plants and their hosts. The genomic data provides valuable insights into the evolution and genetic mechanisms behind the dependency of parasitic plants on their hosts, and how they manipulate host plants to survive.
Dr Huan Liu, co-corresponding author
State Key Laboratory of Agricultural Genomics
BGI Research, Shenzhen, ChinaThe majority of the lost genes in Balanophora are probably related to functions essential in green plants, which have become functionally unnecessary in the parasites. That said, there are probably instances where the gene loss was actually beneficial, rather than reflecting a simple loss of function. The loss of their entire ABA biosynthesis pathway may be a good example. It may help them to maintain physiological synchronization with the host plants. This needs to be tested in the future.
,” said Dr. Sean W. Graham, co-corresponding author
Department of Botany
University of British Columbia, Vancouver, BC, Canada
AbstractTo recap then, what we have here is:
Parasitic plants have evolved to be subtly or severely dependent on host plants to complete their life cycle. To provide new insights into the biology of parasitic plants in general, we assembled genomes for members of the sandalwood order Santalales, including a stem hemiparasite (Scurrula) and two highly modified root holoparasites (Balanophora) that possess chimaeric host–parasite tubers. Comprehensive genome comparisons reveal that hemiparasitic Scurrula has experienced a relatively minor degree of gene loss compared with autotrophic plants, consistent with its moderate degree of parasitism. Nonetheless, patterns of gene loss appear to be substantially divergent across distantly related lineages of hemiparasites. In contrast, Balanophora has experienced substantial gene loss for the same sets of genes as an independently evolved holoparasite lineage, the endoparasitic Sapria (Malpighiales), and the two holoparasite lineages experienced convergent contraction of large gene families through loss of paralogues. This unprecedented convergence supports the idea that despite their extreme and strikingly divergent life histories and morphology, the evolution of these and other holoparasitic lineages can be shaped by highly predictable modes of genome reduction. We observe substantial evidence of relaxed selection in retained genes for both hemi- and holoparasitic species. Transcriptome data also document unusual and novel interactions between Balanophora and host plants at the host–parasite tuber interface tissues, with evidence of mRNA exchange, substantial and active hormone exchange and immune responses in parasite and host.
Chen, X., Fang, D., Xu, Y. et al.
Balanophora genomes display massively convergent evolution with other extreme holoparasites and provide novel insights into parasite–host interactions. Nat. Plants (2023). https://doi.org/10.1038/s41477-023-01517-7
© 2023 Springer Nature Ltd.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
- An example of evolution by a loss of genetic information - something that creationist frauds tell their dupes is impossible.
- An example of parasitism and an arms race which no sane omnibenevolent designer would come up with.
- An example of the massive complexity of a system, simply to reproduce a plant, when simpler examples exist allegedly by the same designer. This is the antithesis of good, intelligent design but a characteristic of a mindless, utilitarian natural process with no plan and no ultimate objective.
- An example of how the expert researchers relied on the Theory of Evolution to explain their results, with no hint of abandoning it, or it not being fit for purpose.
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