The 3 species that break genetics

Perhaps you have encountered one of these plants while walking during a hike in North America.

Perhaps it was the exquisite, melodious blossoms that captured your attention.

However, these vividly-colored flowers possess a scientific mystery.

Despite the apparent variations in their blossoms when observed closely, all of them belong to the same species, but with some distinctions.

And that is the dilemma.

They disrupt the fundamental concept of what constitutes a species.

These inconspicuous alpine blossoms are challenging scientists' comprehension of genetics to its limits.

All of these blooms belong to the Penstemon genus, commonly known as Beardtongues.

The purple flowers belong to the species known as the New Mexico Beardtongue and the Upright Blue Beardtongue, whilst the red flowers are simply referred to as Beardtongues.

Moreover, these organisms are not just connected, they are classified as a species complex, which means they are two or more species that are extremely similar to the point that they may nearly be considered as a single species.

As a brief refresher, a species is typically defined as a collection of creatures that are capable of reproducing with each other in their natural environment, but are unable to reproduce with similar organisms from a different group or species.

While individuals within a species may bear a resemblance to each other, it is not a must.

The distinguishing feature of these beardtongues is their specialized adaptation to match their respective pollinators.

The New Mexico and Upright Beardtongues possess broad, purplish-blue blossoms that are highly attractive to insects such as bees. Bees, with their exceptional ability to perceive blue-to-ultraviolet light, are drawn to these flowers as they provide a convenient landing spot for gathering nectar.

Contrarily, the red Beardtongues mostly rely on hummingbirds for pollination. Hummingbirds are attracted to red colors and do not require a landing surface as they are capable of hovering. They extract abundant amounts of nectar located deep within the flower's bell.

Due to the lack of cross-pollination between hummingbirds and bees, red flower pollen seldom reaches blue blooms, and vice versa.

That causes the species to become separated.

However, this does not imply that they are incapable of reproducing with each other.

Regardless of our standards, genes can still be transferred across species that have recently diverged.

However, the manner in which this is occurring in beardtongues is peculiar.

Extremely peculiar.

In order to comprehend the reason behind this, it is necessary to go into the concept of the law of independent assortment.

This can be traced back to Mendel, the renowned botanist who conducted experiments on pea plants.

Typically, the various variations of a gene, known as alleles, will be segregated into reproductive cells separately from the alleles of other genes.

If gene A and gene B are located on distinct chromosomes, then two chromosomes will undergo independent segregation.

Indeed, if they are distantly separated on the same chromosome, such an event can also occur, as chromosomes have a propensity for aligning and exchanging segments during the formation of reproductive cells.

This implies that the genes responsible for hair color are unlikely to have an impact on the genes associated with another characteristic, such as height.

In addition to independent assortment, it is also recognized that certain genes are not completely independent from one other.

They are actually transmitted or inherited together.

These genes are considered to be genetically related.

Typically, in such cases, the genes are in close physical proximity to one another on the same chromosome.

Consider the following analogy: When you are driving a car, you do not anticipate that the other vehicles will arrive at the same destination as you.

Each of them is moving autonomously.

However, it is likely that when you are on a bus, a few of the fellow passengers will disembark at the same stop as you.

Regarding flowers, it is possible to possess genes that are closely related to one another in terms of shape, color, or size, and these genes are inherited by a group of offspring flowers.

This is the factual occurrence in different species of petunias.

Genes responsible for color, scent, and size differentiate one species of petunia from another and are inherited as a group.

It would be logical if beardtongues were responsible for that.

They are not.

Indeed, they are flexing those regulations to the verge of breaking.

In 2023, researchers examined the genetic makeup of these bell-shaped organisms and discovered that there were approximately 21 loci, or specific positions on 8 chromosomes, that were consistently inherited as a group.

In this episode, there is an unexpected call for more individuals to pursue PhDs in plant genetics. The paper's language is filled with cautious statements from the field of molecular biology, as the function of each genetic loci has not been definitively established. Therefore, we are unable to accurately determine their specific roles.

Nevertheless, it appears that the genes present in these locations play a crucial role in determining the specific characteristics of both the bird and bee associated with each flower.

However, the issue lies in the fact that instead of these genes being located in close proximity to one another on a certain chromosome, they are dispersed throughout the entire genome.

Furthermore, the DNA located in the middle was not moving collectively.

Consider the peculiarity of this situation.

Consider a scenario where you are driving on the interstate and there is a significant number of automobiles, namely 21, all following the same path and consistently arriving at the same destination, although not originally intending to travel to the same place.

It appears that there is no force or factor causing them to adhere or remain together.

The phrase "So that..." is requesting a clarification or an elucidation.

The researchers hypothesize that the reason for this phenomenon is the presence of significant selective pressure to maintain the gene clusters responsible for the production of flowers that are pollinated by hummingbirds and bees.

These items will be inherited and remain together for generations, even if it requires deviating from the typical rules of inheritance.

Hummingbird flowers remain as such for a valid purpose, just as bee flowers retain their identity as bee flowers.

Hybrid blooms, by comparison, appear to be exceedingly scarce.

Therefore, it is possible to have a hybrid offspring with a purple coloration in the form of a baby flower.

Furthermore, the aforementioned flower has the ability to reproduce with another hybrid, resulting in the continuous production of intermediate purple blossoms.

However, it will not.

Both birds and bees will perceive the bloom and exhibit indifference, as they do not possess a significant interest in it, subsequently proceeding to a flower that aligns with their preferences.

Proceed to the next task.

Consequently, the hybrids have a higher probability of engaging in backcrossing with one of the parent species.

In a short amount of time, the descendants of the hybrids will inherit either all blue flower characteristics or all red flower characteristics once again. This is due to the fact that the pollinators will only pollinate flowers with the same qualities.

However, hybridization did occur, resulting in the exchange of genes between the reds and the blues.

These 21 cars are intentionally compelled to remain in close proximity, even though they are not physically linked, yet allowing for movement between them.

It appears that the reds and blues are violating the principle of independent assortment, as these 21 unconnected loci are remaining together.

However, natural selection prevails over all other factors and compels the persistence of such features within a population.

The primary inquiry that remains unresolved is the extent to which the shared genetic material between reds and blues is attributable to the recent divergence of the flowers into distinct species, as opposed to subsequent genetic exchange.

Deciphering this could not only elucidate the phenomenon occurring in Beardtongues, but also aid geneticists' comprehension of the initial phases of speciation.

These blooms have the potential to aid in the discovery of how organisms rapidly develop new characteristics to adjust to environmental changes, such as those resulting from the climate crisis.

Instead of being considered an anomaly, Beardtongues could potentially serve as the next model organism, unveiling novel insights into genetics.

Greetings, ladies and gentlemen. This is Reid speaking.

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