Embedded Files
By: Camila Ciochon
By: Camila Ciochon
Miami-Dade College
Miami-Dade College
Professor Larry Frolich
Professor Larry Frolich
Biodiversity Showcase
Biodiversity Showcase
Part One: History of Cannabaceae
Part One: History of Cannabaceae
Introduction
Introduction
Cannabaceae is a small family of flowering plants.
As now circumscribed the family includes about 170 species grouped in about 11 genera, including Cannabis (hemp, marijuana), Humulus (hops) and Celtis (hackberries). Celtis is by far the largest genus, containing about 100 species.
Cannabaceae is of the rose order (Rosales).
Members of the family are erect or climbing plants with petal-less flowers and dry, one-seeded fruits. Hemp (Cannabis) and hop (Humulus) are the only economically important species.
Importance...
Importance...
The cannabis plant has a long, intertwined history with humans; it was one of the most valuable plant resources for the endeavor of industrialization, providing medicine, clothing, industrial ropes, food, and more. In fact, most members of the Cannabaceae family provide reliable, industrial services.
Fossil History
Fossil History
Key evolutionary events in the history of Cannabaceae.
Key evolutionary events in the history of Cannabaceae.
- Grouping Cannabis, Humulus, and Celtis actually goes back 250 years.
- Print fossil of the extinct genus Dorofeevia (=Humularia) reveals that Cannabis lost a sibling perhaps 20 million years ago (mya).
- Cannabis print fossils are rare (n = 3 worldwide), making it difficult to determine when and where she evolved.
- A molecular clock analysis with chloroplast DNA (cpDNA) suggests Cannabis and Humulus diverged 27.8 mya.
- Microfossil (fossil pollen) data point to a center of origin in the northeastern Tibetan Plateau.
- Fossil pollen indicates that Cannabis dispersed to Europe by 1.8– 1.2 mya.
Taxonomy of the Cannabaceae
Taxonomy of the Cannabaceae
Species: Cannabis sativa, Cannabis indica,
Species: Cannabis sativa, Cannabis indica,
Cannabis ruderalis
Cannabis ruderalis
In some cases, these are all viewed as simply “Cannabis sativa”
Genus: Cannabis L.
Genus: Cannabis L.
Family: Cannabaceae
Family: Cannabaceae
Order: Rosales
Order: Rosales
Class: Magnoliopsida
Class: Magnoliopsida
Phylum: Tracheophyta
Phylum: Tracheophyta
Clade: Angiosperm (Flowering plant)
Clade: Angiosperm (Flowering plant)
Clade: Eudicots
Clade: Eudicots
Clade: Rosids
Clade: Rosids
Kingdom: Plantae
Kingdom: Plantae
Phylogenetic/Evolutionary trees
Phylogenetic/Evolutionary trees
Eukaryotes
Eukaryotes
Angiosperm
The Cannabaceae family is considered small for the plant world with a total of 11 genera (plural of genus). But these 11 genera are home to hundreds of subspecies. The genera classified under the Cannabaceae family are Aphananthe, Celtis, Trema, Cannabis, Gironniera, Humulus, Parasponia, and Pteroceltis.
Most leaves are simple and often oblique at the base. A few species have pinnatifid or palmately incised leaves (palmately lobed in Humulus, palmately compound in Cannabis).
Urticalean rosids
Urticalean rosids
Classification systems developed prior to the 1990s, such as those of Cronquist (1981) and Dahlgren (1989), typically recognized the order Urticales, which included the families Cannabaceae, Cecropiaceae, Celtidaceae, Moraceae, Ulmaceae and Urticaceae, as then circumscribed.
Molecular data from 1990s onward showed that these families were actually embedded within the order Rosales, so that from the first classification by the Angiosperm Phylogeny Group in 1998, they were placed in an expanded Rosales, forming a group which has been called "urticalean rosids".
Classification/Description
Classification/Description
The Cannabaceae consists of erect herbs, climbing vines, shrubs, and trees.
Leaves are arranged either alternate or opposite.
The leaves are simple and unlobed, palmately lobed, or palmately divided.
In some species, a stipule grows at the base of each leaf and persists through the growing season.
Flowers
Flowers
- The inflorescence is a branched array of flowers that grows from the point where the leaf attaches to the stem.
- Flowers are usually unisexual (they have either pollen-bearing or ovule-bearing parts, but usually not both).
- The flowers are small, actinomorphic (radially symmetrical) and typically 5-parted.
- There are no petals. In the ovule-bearing flowers, the 5 sepals are fused together and attach to the flower below the ovary (i.e., the ovary is superior).
- As an adaptation to this kind of pollination, the calyx is short and there is no corolla. Flowers are grouped to form cymes.
Fruit
Fruit
- In some genera, the fruit is subtended by a bract that, in some species, is large enough to conceal the flowers and fruits (such as "hops").
- The fruit is an achene or a drupe.
Dioecious reproduction
Dioecious reproduction
- Cannabaceae are often dioecious (distinct male and female plants).
- In the dioecious plants the masculine inflorescences are long and look like panicles, while the feminine are shorter and bear less flowers. The pistil is made of two connate carpels, the usually superior ovary is unilocular; there is no fixed number of stamens.
Diversity within Cannabaceae
Diversity within Cannabaceae
- DNA evidence has shown that all are related, and certainly humulus (hops) and cannabis share obvious similarities with regard to floral structure.
- Both contain terpenoids, accounting for their similar fragrance, but humulus is a bine (climbing plant) and cannabis is herbaceous. Rather than vine because, unlike vines, they have stiff downward facing hairs that provide stability and allow them to climb.
- Other similarities between members of the Cannabaceae family include stipule-bearing leaves (in cannabis, the stipules are the two tiny shoots at the base of each leaf), and cystoliths, or enlarged leaf cells containing crystals of calcium carbonate.
- A pair of stipules is considered part of the anatomy of the leaf of a typical flowering plant, generally to refer to any small leaves or leaf-parts, notably prophylls.
Lozanella Greenm.
Lozanella Greenm.
Pteroceltis Maxim.
Pteroceltis Maxim.
Cannabis L.
Cannabis L.
Also known as Hemp.
Three species: Cannabis sativa, Cannabis indica, Cannabis ruderalis
Humulus L.
Humulus L.
Also known as Hops.
Used by breweries to preserve and flavor beer
Aphananthe Planch.
Aphananthe Planch.
Evergreen trees
Celtis L.
Celtis L.
Hackberries or nettle trees
Gironniera Gaudich.
Gironniera Gaudich.
Deciduous trees
Chaetachme Planch.
Chaetachme Planch.
https://sensiseeds.com/en/blog/the-cannabis-family-tree-an-introduction-to-phylogenetics/
Plant Use
Plant Use
- Carbon dating has revealed that these plants may have been used for ritual/medicinal purposes in Xinjiang, China as early as 494 B.C.[9]
- Hop (Humulus lupulus) has been the predominant bittering agent of beer for hundreds of years. The flowers' resins are responsible for beer's bitterness and their ability to extend shelf life due to some anti-microbial qualities. The young shoots are used as vegetable.
- Some plants in the genus Cannabis are cultivated as hemp for the production of fiber, as a source of cheap oil, for their nutritious seeds, or their edible leaves. Others are cultivated for medical or recreational use as marijuana.
- Several selectively bred "strains" have been produced for both higher and lower yields of THC, other cannabanoids, as well as terpenes with desired flavors or aromas, such as blueberry, strawberry, or even citrus.
Part Two: Evolutionary Process in Cannabaceae
Part Two: Evolutionary Process in Cannabaceae
Variability in Cannabis
Variability in Cannabis
Genetic Variation
Genetic Variation
Cannabaceae is an economically important family that includes ten genera and ca. 117 accepted species.
Cannabis (also known as marijuana) is a psychoactive plant that contains more than 500 components, of which 104 cannabinoids have presently been identified.
Two of these have been the subject of scientific investigation into their pharmacological properties: Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). Cannabis potency is primarily evaluated according to a sample's THC concentration. This is the primary psychoactive cannabinoid in cannabis. The adverse effects after acute or regular cannabis use are in direct relation to THC concentrations in the product.
Cannabis has 20 different chromosomes (for reference, humans have 46) with potentially hundreds of different genes existing on each one.
Cannabis plants have female and male plants.
Just like human beings, marijuana receives an individual chromosome from a single mother and a single father (cannabis has both male and female plants).
The female is the one that has the highest THC level.
It is more complicated for growers to breed dioecious plants because they have to be pollinated (both male and female).
The seeds that are generated from the cross pollination makes genetics more variable than if seeds were generated by self pollination.
Lafaye, Genevieve et al. “Cannabis, cannabinoids, and health.” Dialogues in clinical neuroscience vol. 19,3 (2017): 309-316. www.ncbi.nlm.nih.gov/pmc/articles/PMC5741114/
s12864-018-4494-3.pdf
Phenotypic Variation
Phenotypic Variation
When these chromosomes combine, a unique arrangement of expressed and non-expressed genes is formed.
This is why – even in a crop that’s been pollinated by a single male plant with known genetics – you can get offspring that possess wildly different phenotypes and Cannabinoid profiles.
Fortunately, thanks to the combination of science and history we can come up with some pretty accurate guesses.
cannabis genetics and phenotypes on earth appeared somewhere in Asia — probably in the modern day Hindu Kush mountains.
It is uncertain how he would have cataloged the new Indian and Asian cannabis cultivars had he been aware of them during his era. Comparative analyses between the Indian and the European hemp varieties, based on size, shape, leaf structure, and psychoactive effects, inspired Jean-Baptiste Lamark to classify the Indian cultivars as a separate species, Cannabis indica (Lamarck, 1811). The Soviet botanist Janischevsky revisited the polytypic (multi-species) view when he recognized that local Russian plants did not fit the characteristics of C. sativa or C. indica, but fell within the Cannabistaxa
Natural Selection
Natural Selection
How might natural selection act on variability?
How might natural selection act on variability?
As humans started domesticating cannabis, human-mediated selection following the principles of Mendelian genetics significantly impacted the future of the plant.
This process is as simple as crossing red with white roses to get pink ones – but represents a huge shift in the ability to customize plant characteristics for human use.
Breeders began creating hybrids of cultivars to achieve different plant height, form, and color.
And, as humans began to migrate, so did the cannabis plant, with different cannabis seeds carried throughout the world.
Cannabis began to grow in new regions and natural selection again came into play as the traits that allowed it to thrive in difficult environments were selected for in subsequent generations.
Cannabis history began long before humans.
During it’s evolutionary pattern the plant adapted both to human desire and climate changes in an effort to colonize as much land as possible.
Wild forms of Cannabis, Humulus and Vitis have little resembling what we see today in commercial productions, due mainly, human influences.
Species Concepts
Species Concepts
how are species determined
It can be difficult to obtain an accurate record of the evolution of a plant species.
It can be difficult to obtain an accurate record of the evolution of a plant species.
Cannabis plants do not possess bony skeletons, which are often the sole remnant of an ancient animal species, and are comprised of vegetative matter that decomposes rapidly.
Despite this, traces left behind in fossils and soil can yield valuable clues.
At the time of writing, there were well over 1,000 marijuana strains available. This includes strains from famous families such as Kush and Diesel, but it does NOT mean that there are thousands of cannabis species.
Although the number of species within the marijuana family is often disputed, there are three recognized ones:
- Cannabis Sativa
- Cannabis Indica
- Cannabis Ruderalis
Technically, cannabis is a dioecious flowering herb that offers a single harvest each year.
However, in the modern era, advanced growing techniques and auto-flowering strains mean growers can enjoy several harvests each year.
Further down the evolutionary road, cannabis science pioneers like Raphael Mechoulam began to dig a little deeper into the cannabis plant and discovered its astonishing array of cannabinoids.
Plant breeders accordingly began selecting for the genes that produced varying levels of the most popular cannabinoids – THC and CBD – which is how consumers are able to purchase products with specific percentages of certain cannabis compounds today.
And these changes in cannabis composition have occurred very rapidly
Dr. Holloway in regard to cannabis genetics. said that by understanding cannabis exists as a single species, we recognize the fact that a “universe of genetic diversity” exists and that we can’t accurately identify the effects or appearance (or even the cannabinoid profile) of a particular cultivar based on strain name alone.
She suggests that all marijuana genetics should belong to the single species Cannabis sativa L, and that the “relationships between different cultivars” should be based solely on genotype.
Ecology and Evolutionary Innovation
Ecology and Evolutionary Innovation
Ecological relationships between cannabis and the environment
There are many hypotheses as to what function THC has for the plant.
It is a secondary metabolite, meaning it does not serve a direct role in the growth, development, or reproduction.
It is produced from glandular trichomes that can be found in the greatest abundance on the female flowers.
Research indicates that THC plays a multifaceted role in protecting the plant from fungi and microbial infection as well as deterring herbivory.
Recently it has been found that THC has high UV-B absorption properties, leading some to believe it may also protect the plant from sun exposure.
Once confined to central Asia, cannabis has been distributed by humans to all four corners of the globe.
Different cannabis species have developed due to human selection for industrial, nutritional or medicinal traits.
Cannabis has become a stronger, more diverse, more adaptive and more widely-cultivated plant as a result of it’s relationship with us.
Marijuana & Coevolution
Marijuana & Coevolution
Darwin was the first to describe the term ‘coevolution,’ but it wasn’t until 1964 when Peter Raven and Paul Ehrlich released their paper entitled “Butterflies and plants: A study in coevolution,” that the phrase became well known.
Darwin was the first to describe the term ‘coevolution,’ but it wasn’t until 1964 when Peter Raven and Paul Ehrlich released their paper entitled “Butterflies and plants: A study in coevolution,” that the phrase became well known.
Coevolution is when two different living species influence each other and help one another survive and adapt.
Coevolution is when two different living species influence each other and help one another survive and adapt.
There’s a distinct possibility that coevolution happens between humans and marijuana.
There’s a distinct possibility that coevolution happens between humans and marijuana.
At one time, weed was confined to Central Asia, but with human assistance, it spread all over the world.
At one time, weed was confined to Central Asia, but with human assistance, it spread all over the world.
Human selection for nutritional, medicinal, or industrial traits has resulted in a huge array of new cannabis species, and weed has become stronger, more adaptive, and more diverse because of its relationship with humans.
Human selection for nutritional, medicinal, or industrial traits has resulted in a huge array of new cannabis species, and weed has become stronger, more adaptive, and more diverse because of its relationship with humans.
All in all, it goes without saying that we have benefited enormously from cannabis.
All in all, it goes without saying that we have benefited enormously from cannabis.
Take this into consideration: it is widely known that hemp seeds (which come from cannabis) are extremely healthy and nutritious for humans.
Take this into consideration: it is widely known that hemp seeds (which come from cannabis) are extremely healthy and nutritious for humans.
So is it a coincidence that cannabis has evolved into a plant that produces seeds which just so happen to produce essential fatty acids in almost the precise ratio that we required!?
So is it a coincidence that cannabis has evolved into a plant that produces seeds which just so happen to produce essential fatty acids in almost the precise ratio that we required!?
Moreover, marijuana is capable of dozens of medicinal uses, and even its ‘high’ can prove a boon to creativity. Some of the best art, music, and writing we’ve ever produced as a species owes its existence to weed!
Moreover, marijuana is capable of dozens of medicinal uses, and even its ‘high’ can prove a boon to creativity. Some of the best art, music, and writing we’ve ever produced as a species owes its existence to weed!
Marijuana & Coevolution
Marijuana & Coevolution
Darwin was the first to describe the term ‘coevolution,’ but it wasn’t until 1964 when Peter Raven and Paul Ehrlich released their paper entitled “Butterflies and plants: A study in coevolution,” that the phrase became well known.
Darwin was the first to describe the term ‘coevolution,’ but it wasn’t until 1964 when Peter Raven and Paul Ehrlich released their paper entitled “Butterflies and plants: A study in coevolution,” that the phrase became well known.
Coevolution is when two different living species influence each other and help one another survive and adapt.
Coevolution is when two different living species influence each other and help one another survive and adapt.
There’s a distinct possibility that coevolution happens between humans and marijuana.
There’s a distinct possibility that coevolution happens between humans and marijuana.
At one time, weed was confined to Central Asia, but with human assistance, it spread all over the world.
At one time, weed was confined to Central Asia, but with human assistance, it spread all over the world.
Human selection for nutritional, medicinal, or industrial traits has resulted in a huge array of new cannabis species, and weed has become stronger, more adaptive, and more diverse because of its relationship with humans.
Human selection for nutritional, medicinal, or industrial traits has resulted in a huge array of new cannabis species, and weed has become stronger, more adaptive, and more diverse because of its relationship with humans.
All in all, it goes without saying that we have benefited enormously from cannabis.
All in all, it goes without saying that we have benefited enormously from cannabis.
Take this into consideration: it is widely known that hemp seeds (which come from cannabis) are extremely healthy and nutritious for humans.
Take this into consideration: it is widely known that hemp seeds (which come from cannabis) are extremely healthy and nutritious for humans.
So is it a coincidence that cannabis has evolved into a plant that produces seeds which just so happen to produce essential fatty acids in almost the precise ratio that we required!?
So is it a coincidence that cannabis has evolved into a plant that produces seeds which just so happen to produce essential fatty acids in almost the precise ratio that we required!?
Moreover, marijuana is capable of dozens of medicinal uses, and even its ‘high’ can prove a boon to creativity. Some of the best art, music, and writing we’ve ever produced as a species owes its existence to weed!
Moreover, marijuana is capable of dozens of medicinal uses, and even its ‘high’ can prove a boon to creativity. Some of the best art, music, and writing we’ve ever produced as a species owes its existence to weed!
Final Thoughts on the Biological Evolution of Marijuana
Ancient civilizations referred to marijuana as the ‘tree of life,’ which should tell you everything you need to know about this remarkable plant.
It seems incredible to think that a plant with such a rich history, and one that has obviously coevolved with humans, is banned in all but one country in the world.
Meanwhile, we destroy our bodies and minds with so-called ‘legal’ pharmaceuticals.
We need our coevolutionary partner, and it needs us!
TheMarijuanaGrowersGuide.pdfGoogle Sites
Report abuse