PLANTS ARE ALIEN CREATURES AND DOMINATE OUR PLANET
“Plants are what make the Earth the planet we know. Without them, our planet would very much resemble the images we have of Mars or Venus: a sterile ball of rock.” (Stefano Mancuso, The Nation of Plants).
“The rapid development as far as we can judge of all the higher plants within recent geological times is an abominable mystery.” (Charles Darwin).
No self-respecting botanist, even less so a zoologist, will ever admit that plants are utterly mystifying and may as well have come from Mars. But it is true.
Let me walk you through a thumbnail sketch of why this is true.
Firstly, guess what is the dominant life form on planet Earth? This figure says it all. Plants account for a staggering 80% the biomass of Earth with a far second being fungi and bacteria at 15%. Whales, lions, and you and me are in the rounding error of less than 1%. Put another way, planet Earth is essentially a plant planet. Everything else vanishes by comparison. This is one of the least appreciated and most jaw-dropping facts in biology.
Yet, to human beings, plants are alien in almost every conceivable way. Let me count the ways:
#1. Photon diets
Plants eat a diet of photons mostly from the sun which itself is made just of hydrogen and helium. The very vast majority of plants do not consume anything else. So the first and most prevalent atoms of the universe, hydrogen and helium generate massless bundles of energy that only plants have figured out how to harness to provide their every need. They did this by inventing photosynthesis and the chlorophyl molecule. In doing so, they also created an oxygenated planet some 2.4 billion years ago, which today supports the majority of life on Earth. These alone are accomplishments that far outshine any other organism on Earth.
#2. Feeding the planet
In the food chain, plants ultimately feed everything else: herbivores eat plants and carnivores eat herbivores. The energy converted from those photons by plants has passed down this chain to everything that eats somebody else, which is mostly everything except plants and some microorganisms.
#3. Plant intelligence
Because plants do not move like animals move, they have failed our standard tests for intelligence, the maze; and combined with lacking a nervous system or a brain, the general consensus is that plants are lacking intelligence. But plants perform fairly complex calculations, in order to store starch in varied light conditions, or to catch prey in the case of the Venus Flytrap. They calculate the most efficient arrangements for their leaves to catch photons, and adjust them as the sun moves in the sky. The relatively new subject of plant intelligence has rattled many cages, but the positive results are now uncontroversial.
#4. Ability to evolve
Plants and can learn, adapt, and evolve at rates comparable to creatures with brains. The ability to learn and adapt has been widely seen by zoologists as a hallmark of advanced life forms.
#5. Different time scales
The seeming inability to move has misled us to think that they are stationary, but time lapse of plants growing, or flowers opening and closing have shown that they simply operate on different time scales than humans. One these time scales they are very active creatures.
Plants have weirdly distributed and pluripotent bodies. What does that mean? Basically, a single twig of a plant can regenerate a new plant. Imagine breaking off a finger and growing a clone of yourself.
#7. Complex relationships
Plants form complex ecosystems and family associations, and this is facilitated by the underground fungal Mycorrhizal network that shares nutrients between various plants.
#8. Acute synchronicity over distance
If plants do not precisely time their breeding with other far distant plants, it will be a bust, and that species will quickly go extinct. So when the summer is later or early, hotter or colder, they all have to recalculate their breeding event, and reach the same exact conclusion.
#9. Diverse reproduction
Plants have extremely diverse reproductive strategies, more so than other species except fungi and bacteria. These strategies include apomixis, self-pollination, cross-fertilization, or reproduction by means of vegetative clones. In a large number of plants these comp,ex reproductive strategies have co-evolved with other species such as mammals, insects and birds in a variety of ingenious ways.
Plants actively communicate between themselves and with numerous other species by means of chemicals, sounds, and through the fungal root network.
Plants promiscuously form hybrids with other species at a surprising rate, and has had an important role in developing diversity during plant evolution. That diversity has been the core of their success.
Plants have been masters of co-evolving or enticing symbiotic relationships with numerous other species, including animal and insect pollinators, fungi and bacteria, and human beings to promote their success. One interpretation is that plants are exquisitely manipulative in serving their own ends. This is not a passive strategy but one that requires considerable awareness of other species.
#13. Longevity of the species
Consider this important fact. The average life of a species is 5 million years.
But some plants, like the horsetails have been around for 350 million years, and the Gingkos have been in existence for 250 million years. Far in excess of the average life of other species.
So despite being surrounded by these strange creatures, we have a very poor understanding of their true nature.
So we have established that plants are strange, maybe even very, very, strange creatures. And that they are the most successful creatures on Earth. How have they come to dominate our planet?
Their spectacular success of plants is the singular result of highly effective and diverse reproductive strategies. Period. Without a successful, diverse and robust reproductive strategy, and it is Game Over. Diversity of form and strategy provides plants with a toolbox of options to either enter new ecological niches or to survive catastrophic events.
When you combine diverse reproductive strategies with uncommon intelligence the result is spectacular; you have an organism that can figure out how to exploit numerous species in symbiotic collaborations to advance their success. Plant intelligence in this regard is very similar to that of viruses, bacteria and fungi who have also exploited the fellow members of their ecosystem in win-win partnerships.
These extraordinary plant strategies have enabled them to survive the devastating meteorite impact that wiped out all of the dinosaurs, and 75% of oceanic animals. Half of plant species went extinct after the meteorite, part from two years of dust blocked sunlight, part from tsunamis and violent earthquakes and geological activity. The 50% of plants that did survive were better adapted for extreme conditions, as well as seeds capable of being dormant until conditions improved.
Diversity is the result of successful breeding. The diverse reproductive systems of plants allow them to weather out environmental change most effectively, by shifting the bell curve to species with more successful strategies in those challenging conditions.
Successful breeding strategies have made plants the dominant life form on this planet. The gynoecium of a plant is at the heart of its survival and success. The gynoecium is a collection of the parts of the flower that contain the equivalent of a womb, responsible for accepting the male pollen to make seeds and fruit. The stigma of the flower is the plant equivalent of the human vagina and the anther is the human penis equivalent. But the sexual structures of plants are merely the means to deliver the fresh mix of genes that code these diverse phenotypes, and it is this thread of germplasm stretching from the past into the future which is how plants have won the game of life.
There are commonly four distinct whorls of flower parts: (1) an outer calyx consisting of sepals; within it lies (2) the corolla, consisting of petals; (3) the androecium, or group of stamens; and in the centre is (4) the gynoecium, consisting of the pistils.
Why should the reproductive structures of flowering plants (angiosperms) exhibit greater variety than those of any other group of organisms? Diversification in form and function of flowers is associated with an equally impressive variety of mating strategies and sexual systems. Patterns of mating in plants can be both complex and highly promiscuous in comparison with many animal groups. Male and female gametes are deployed in a wide array of spatial and temporal options at the flower, inflorescence, plant and population level resulting in diverse sexual systems composed of different combinations of hermaphroditic, female and male plants.
Plant biomass is dominated by terrestrial plants, specifically vascular plants, with only a minor contribution from bryophytes (e.g. mosses) and of all marine plant biomass.
Plants Are the World’s Dominant Life-Form. Flora make up the majority of Earth’s biomass, followed by bacteria. Plants (primarily those on land) account for 80 percent of the total biomass, with bacteria across all ecosystems a distant second at 15 percent.
Source of great circle figure.
Plants Are the World’s Dominant Life-Form. Flora make up the majority of Earth’s biomass, followed by bacteria. The results show that plants (primarily those on land) account for 80 percent of the total biomass, with bacteria across all ecosystems a distant second at 15 percent.
There are about 391,000 species of vascular plants currently known to science, of which about 369,000 species (or 94 percent) are flowering plants.
Animals are consumers and they all depend on plants for survival. Some eat plants directly, while others eat animals that eat the plants.
The Venus flytrap can count to two and five in order to trap and then digest its prey.
Arabidopsis thaliana in effect performs division to control starch use at night
Plants Are Strange and Wondrous Beings.
Gynoecium (/ɡaɪˈniːsi.əm, dʒɪˈniːʃi.əm/; from Ancient Greek γυνή (gunḗ) ‘woman, female’, and οἶκος (oîkos) ‘house’) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) pistils and is typically surrounded by the pollen-producing reproductive organs, the stamens, collectively called the androecium. The gynoecium is often referred to as the “female” portion of the flower, although rather than directly producing female gametes (i.e. egg cells), the gynoecium produces megaspores, each of which develops into a female gametophyte which then produces egg cells.
The gynoecium is often referred to as female because it gives rise to female (egg-producing) gametophytes; however, strictly speaking sporophytes do not have a sex, only gametophytes do.
Unlike most animals, plants grow new organs after embryogenesis, including new roots, leaves, and flowers. In the flowering plants, the gynoecium develops in the central region of the flower as a carpel or in groups of fused carpels. After fertilization, the gynoecium develops into a fruit that provides protection and nutrition for the developing seeds, and often aids in their dispersal. The gynoecium has several specialized tissues. The tissues of the gynoecium develop from genetic and hormonal interactions along three-major axes. These tissue arise from meristems that produce cells that differentiation into the different tissues that produce the parts of the gynoecium including the pistil, carpels, ovary, and ovals; the carpel margin meristem (arising from the carpel primordium) produces the ovules, ovary septum, and the transmitting track, and plays a role in fusing the apical margins of carpels.
If a flower has both androecium and gynoecium present in it, they are known as bisexual flower. They are also called as perfect flowers. Bisexual flowers contain both pistils and stamens in the same flower. Hence, bisexual flowers are called androgynous or hermaphrodite flowers as well.
In bisexual plants, both cross pollination and self pollination can occur due to the presence of both the reproductive organs in the same flower itself. During self pollination, the stigma of the plant is pollinated by pollen grains of a genetically identical flower. Hence, genetically identical offspring are produced by self pollination. It occurs in three ways: autogamy, cleistogamy and geitonogamy. The pollination within the same flower is known as autogamy. The pollination between different flowers on the same plant is known as Geitonogamy. Cleistogamy is pollination of the flower before its opening.
Many plants have complete flowers with both female and male parts, others only have female or male parts, and still, other plants have flowers on the same plant that are a mix of female and male flowers. Some plants even include all three types of flowers, where some flowers are the only female, some are only male and some are both female and male.
Note: Unisexual flowers are also known as incomplete flowers, containing either female or male reproductive organs in the flower. That means, the male reproductive structure or the androecium, and gynoecium – the female reproductive structure, are found in separate flowers.
Plants have complex lifecycles involving alternation of generations. One generation, the sporophyte, gives rise to the next generation, the gametophyte asexually via spores. Spores may be identical isospores or come in different sizes (microspores and megaspores), but strictly speaking, spores and sporophytes are neither male nor female because they do not produce gametes. The alternate generation, the gametophyte, produces gametes, eggs and/or sperm. A gametophyte can be monoicous (bisexual), producing both eggs and sperm, or dioicous (unisexual), either female (producing eggs) or male (producing sperm).
The sporophyte of a flowering plant is often described using sexual terms (e.g. “female” or “male”) based on the sexuality of the gametophyte it gives rise to. For example, a sporophyte that produces spores that give rise only to male gametophytes may be described as “male”, even though the sporophyte itself is asexual, producing only spores. Similarly, flowers produced by the sporophyte may be described as “unisexual” or “bisexual”, meaning that they give rise to either one sex of gametophyte or both sexes of the gametophyte.
Flowers vary enormously in their structure (morphology).
Plants have evolved an incredible diversity of strategies to optimize their sexual reproduction. The physical distance between plant male and female organs varies from hermaphroditism to biparental reproduction. The investment of resources in different sexes is also extremely diverse. For example, male gamete dispersal can be wholly aspecific, relying on the mass production of pollen to saturate the environment and maximize the chances to encounter the maximum of receptive females through wind dispersal. On the contrary, it can be explicitly mediated by a single pollinator or targeted to a single female receiver via pollen dispersal units such as pollinia. Plants have also evolved pseudo-sexual strategies such as apomixis or self-fertilization to ensure reproductive success when pollen vectors or compatible mates are scarce. The type of reproductive strategies employed are, nevertheless, believed to have profound consequences on the evolution of populations by influencing the nature and strength of the selective forces driving genome and phenotypic evolution (e.g., sexual selection or sexual conflict) while at the same time, also, conditioning the population genetic parameters that determine the efficacy of natural selection. As a result, these strategies also impact macroevolutionary processes, including the rates of speciation and extinction.
Although historically thought of as rare, interspecific mating is increasingly recognized as an important evolutionary process. Hybridization can generate increased genetic and morphological variation and has been tied to increased diversification and other biological phenomena such as geographic range expansion and the success of invasive species.
The asteroid impact that wiped out most of the dinosaurs 66 million years ago sparked two years of darkness caused by the soot from raging wildfires that filled the sky and blocked the sun, and which enveloped many parts of the Earth in darkness for up to two years.
The asteroid crash caused what we call the Cretaceous-Palaeogene or K-Pg mass extinction. This killed species around the world. The shockwaves, earthquakes and tsunamis would have killed many plants. Forest fires may have burnt large areas.
Three-quarters of the animals in the ocean and all of the dinosaurs apart from birds died in this mass extinction.
Around half of all plant species went extinct after the asteroid hit Earth.
Compared to animals, plants have an advantage in surviving mass extinctions. Plant seeds can remain dormant for many years in the soil. After the K-Pg mass extinction conditions were not right for plant growth, but plants could wait as seeds in a dormant state until things improve. This probably explains why plants did not suffer as much as animal groups in the extinction.
The Botany of Desire, Michael Pollan
The Revolutionary Genius of Plants: A New Understanding of Plant Intelligence and Behavior.
Despite not having brains or central nervous systems, plants perceive their surroundings with an even greater sensitivity than animals. They efficiently explore and react promptly to potentially damaging external events thanks to their cooperative, shared systems; without any central command centers, they are able to remember prior catastrophic events and to actively adapt to new ones.
STEFANO MANCUSO, THE NATION OF PLANTS
Plants are what make the Earth the planet we know. Without them, our planet would very much resemble the images we have of Mars or Venus: a sterile ball of rock.
The Gingko biloba is probably more than 250 million years old, the Equiseta (horsetails or puzzle grass) were already widespread 350 million years ago. One fern, the Osmundastrum cinnamomeum, has been found in fossil rocks from 70 million years ago. In general, it is estimated that the average life of a species, whether animal or vegetable, runs to 5 million years.
Charles Darwin considered plants to be the most extraordinary living things he had ever encountered.
Darwin coined the phrase, abominable mystery, in 1879. In a letter to his closest friend, botanist and explorer Dr Joseph Hooker, he wrote: “The rapid development as far as we can judge of all the higher plants within recent geological times is an abominable mystery.”
In the fossil record they appear very suddenly in the Cretaceous, dated at about 100 million years ago, and there’s nothing that looks like an angiosperm before them and then they suddenly appear and in considerable diversity.
New light shed on Charles Darwin’s ‘abominable mystery’ https://www.bbc.co.uk/news/